/* decavcodec.c

   Copyright (c) 2003-2020 HandBrake Team
   Copyright 2022 NVIDIA Corporation
   This file is part of the HandBrake source code
   Homepage: <http://handbrake.fr/>.
   It may be used under the terms of the GNU General Public License v2.
   For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html
 */

/* This module is Handbrake's interface to the ffmpeg decoder library
   (libavcodec & small parts of libavformat). It contains four Handbrake
   "work objects":

    decavcodeca connects HB to an ffmpeg audio decoder
    decavcodecv connects HB to an ffmpeg video decoder

        (Two different routines are needed because the ffmpeg library
        has different decoder calling conventions for audio & video.
        These work objects are self-contained & follow all
        of HB's conventions for a decoder module. They can be used like
        any other HB decoder

    These decoders handle 2 kinds of input.  Streams that are demuxed
    by HandBrake and streams that are demuxed by libavformat.  In the
    case of streams that are demuxed by HandBrake, there is an extra
    parse step required that happens in decodeVideo and decavcodecaWork.
    In the case of streams that are demuxed by libavformat, there is context
    information that we need from the libavformat.  This information is
    propagated from hb_stream_open to these decoders through title->opaque_priv.

    A consequence of the above is that the streams that are demuxed by HandBrake
    *can't* use information from the AVStream because there isn't one - they
    get their data from either the dvd reader or the mpeg reader, not the ffmpeg
    stream reader. That means that they have to make up for deficiencies in the
    AVCodecContext info by using stuff kept in the HB "title" struct. It
    also means that ffmpeg codecs that randomly scatter state needed by
    the decoder across both the AVCodecContext & the AVStream (e.g., the
    VC1 decoder) can't easily be used by the HB mpeg stream reader.
 */

#include "handbrake/handbrake.h"
#include "handbrake/hbffmpeg.h"
#include "handbrake/hbavfilter.h"
#include "libavcodec/bsf.h"
#include "libavfilter/avfilter.h"
#include "libavfilter/buffersrc.h"
#include "libavfilter/buffersink.h"
#include "libavutil/hwcontext.h"
#include "handbrake/lang.h"
#include "handbrake/audio_resample.h"

#if HB_PROJECT_FEATURE_QSV
#include "libavutil/hwcontext_qsv.h"
#include "handbrake/qsv_common.h"
#include "handbrake/qsv_libav.h"
#endif

#if HB_PROJECT_FEATURE_NVENC
#include "handbrake/nvenc_common.h"
#endif

static void compute_frame_duration( hb_work_private_t *pv );
static int  decavcodecaInit( hb_work_object_t *, hb_job_t * );
static int  decavcodecaWork( hb_work_object_t *, hb_buffer_t **, hb_buffer_t ** );
static void decavcodecClose( hb_work_object_t * );
static int decavcodecaInfo( hb_work_object_t *, hb_work_info_t * );
static int decavcodecaBSInfo( hb_work_object_t *, const hb_buffer_t *, hb_work_info_t * );

hb_work_object_t hb_decavcodeca =
{
    .id = WORK_DECAVCODEC,
    .name = "Audio decoder (libavcodec)",
    .init = decavcodecaInit,
    .work = decavcodecaWork,
    .close = decavcodecClose,
    .info = decavcodecaInfo,
    .bsinfo = decavcodecaBSInfo
};

typedef struct
{
    uint8_t              * data;
    int                    size;
    int64_t                pts;
    int64_t                dts;
    int                    frametype;
    int                    scr_sequence;
    int                    new_chap;
    int                    discard;
} packet_info_t;

typedef struct reordered_data_s reordered_data_t;

struct reordered_data_s
{
    int64_t                sequence;
    int64_t                pts;
    int                    scr_sequence;
    int                    new_chap;
};

#define REORDERED_HASH_SZ   (2 << 7)
#define REORDERED_HASH_MASK (REORDERED_HASH_SZ - 1)

struct video_filters_s
{
    hb_avfilter_graph_t * graph;

    int                   width;
    int                   height;
    int                   color_range;
    int                   pix_fmt;
};

struct hb_work_private_s
{
    hb_job_t             * job;
    hb_title_t           * title;
    const AVCodec        * codec;
    AVCodecContext       * context;
    AVCodecParserContext * parser;
    AVFrame              * frame;
    AVPacket             * pkt;
    hb_buffer_t          * palette;
    int                    threads;
    int                    video_codec_opened;
    hb_buffer_list_t       list;
    double                 duration;        // frame duration (for video)
    double                 field_duration;  // field duration (for video)
    int64_t                chap_time;       // time of next chap mark
    int                    chap_scr;
    int                    new_chap;        // output chapter mark pending
    int64_t                last_pts;
    double                 next_pts;
    uint32_t               nframes;
    uint32_t               decode_errors;
    packet_info_t          packet_info;
    uint8_t                unfinished;
    reordered_data_t     * reordered_hash[REORDERED_HASH_SZ];
    int64_t                sequence;
    int                    last_scr_sequence;
    int                    last_chapter;
    struct video_filters_s video_filters;

    hb_audio_t           * audio;
    hb_audio_resample_t  * resample;
    int                    drop_samples;

#if HB_PROJECT_FEATURE_QSV
    // QSV-specific settings
    struct
    {
        int                decode;
        hb_qsv_config      config;
        const char       * codec_name;
    } qsv;
#endif

    hb_list_t            * list_subtitle;
};

static void decodeAudio( hb_work_private_t *pv, packet_info_t * packet_info );

/***********************************************************************
 * hb_work_decavcodec_init
 ***********************************************************************
 *
 **********************************************************************/
static int decavcodecaInit( hb_work_object_t * w, hb_job_t * job )
{
    const AVCodec *codec;

    hb_work_private_t * pv = calloc( 1, sizeof( hb_work_private_t ) );
    w->private_data = pv;

    pv->job          = job;
    pv->audio        = w->audio;
    pv->drop_samples = w->audio->config.in.encoder_delay;
    pv->next_pts     = (int64_t)AV_NOPTS_VALUE;
    if (job)
        pv->title    = job->title;
    else
        pv->title    = w->title;
    hb_buffer_list_clear(&pv->list);

    codec       = avcodec_find_decoder(w->codec_param);
    pv->context = avcodec_alloc_context3(codec);

    if (pv->title->opaque_priv != NULL)
    {
        AVFormatContext *ic = (AVFormatContext*)pv->title->opaque_priv;
        avcodec_parameters_to_context(pv->context,
                                      ic->streams[w->audio->id]->codecpar);
        // libav's eac3 parser toggles the codec_id in the context as
        // it reads eac3 data between AV_CODEC_ID_AC3 and AV_CODEC_ID_EAC3.
        // It detects an AC3 sync pattern sometimes in ac3_sync() which
        // causes it to eventually set avctx->codec_id to AV_CODEC_ID_AC3
        // in ff_aac_ac3_parse(). Since we are parsing some data before
        // we get here, the codec_id may have flipped.  This will cause an
        // error in hb_avcodec_open().  So flip it back!
        pv->context->codec_id = w->codec_param;
    }
    else
    {
        pv->parser = av_parser_init(w->codec_param);
    }
    hb_ff_set_sample_fmt(pv->context, codec, AV_SAMPLE_FMT_FLT);

    // Set decoder opts...
    AVDictionary *av_opts = NULL;

    /* Downmixing & sample_fmt conversion */
    if (!(w->audio->config.out.codec & HB_ACODEC_PASS_FLAG))
    {
        // Currently, samplerate conversion is performed in sync.c
        // So set output samplerate to input samplerate
        // This should someday get reworked to be part of an audio
        // filter pipeline.
        pv->resample =
            hb_audio_resample_init(AV_SAMPLE_FMT_FLT,
                                   w->audio->config.in.samplerate,
                                   w->audio->config.out.mixdown,
                                   w->audio->config.out.normalize_mix_level);
        if (pv->resample == NULL)
        {
            hb_error("decavcodecaInit: hb_audio_resample_init() failed");
            return 1;
        }
        /*
         * Some audio decoders can downmix using embedded coefficients,
         * or dedicated audio substreams for a specific channel layout.
         *
         * But some will e.g. use normalized mix coefficients unconditionally,
         * so we need to make sure this matches what the user actually requested.
         */
        int avcodec_downmix = 0;
        switch (w->codec_param)
        {
            case AV_CODEC_ID_AC3:
            case AV_CODEC_ID_EAC3:
                avcodec_downmix = w->audio->config.out.normalize_mix_level == 0;
                break;
            case AV_CODEC_ID_DTS:
                avcodec_downmix = w->audio->config.out.normalize_mix_level == 0;
                break;
            case AV_CODEC_ID_TRUEHD:
                avcodec_downmix = (w->audio->config.out.normalize_mix_level == 0     ||
                                   w->audio->config.out.mixdown == HB_AMIXDOWN_MONO  ||
                                   w->audio->config.out.mixdown == HB_AMIXDOWN_DOLBY ||
                                   w->audio->config.out.mixdown == HB_AMIXDOWN_DOLBYPLII);
                break;
            default:
                break;
        }
        if (avcodec_downmix)
        {
            switch (w->audio->config.out.mixdown)
            {
                // request 5.1 before downmixing to dpl1/dpl2
                case HB_AMIXDOWN_DOLBY:
                case HB_AMIXDOWN_DOLBYPLII:
                {
                    av_dict_set(&av_opts, "downmix", "5.1(side)", 0);
                    break;
                }
                // request the layout corresponding to the selected mixdown
                default:
                {
                    char description[256];
                    AVChannelLayout ch_layout = {0};
                    av_channel_layout_from_mask(&ch_layout, hb_ff_mixdown_xlat(w->audio->config.out.mixdown, NULL));
                    av_channel_layout_describe(&ch_layout, description, sizeof(description));
                    av_channel_layout_uninit(&ch_layout);
                    av_dict_set(&av_opts, "downmix", description, 0);
                    break;
                }
            }
        }
    }

    // libavcodec can't decode TrueHD Mono (bug #356)
    // work around it by requesting Stereo and downmixing
    if (w->codec_param                     == AV_CODEC_ID_TRUEHD &&
        w->audio->config.in.channel_layout == AV_CH_LAYOUT_MONO)
    {
        av_dict_set(&av_opts, "downmix", "stereo", 0);
    }

    // Dynamic Range Compression
    if (w->audio->config.out.dynamic_range_compression >= 0.0f &&
        hb_audio_can_apply_drc(w->audio->config.in.codec,
                               w->audio->config.in.codec_param, 0))
    {
        float drc_scale_max = 1.0f;
        /*
         * avcodec_open will fail if the value for any of the options is out of
         * range, so assume a conservative maximum of 1 and try to determine the
         * option's actual upper limit.
         */
        if (codec != NULL && codec->priv_class != NULL)
        {
            const AVOption *opt;
            opt = av_opt_find2((void*)&codec->priv_class, "drc_scale", NULL,
                               AV_OPT_FLAG_DECODING_PARAM|AV_OPT_FLAG_AUDIO_PARAM,
                               AV_OPT_SEARCH_FAKE_OBJ, NULL);
            if (opt != NULL)
            {
                drc_scale_max = opt->max;
            }
        }
        if (w->audio->config.out.dynamic_range_compression > drc_scale_max)
        {
            hb_log("decavcodecaInit: track %d, sanitizing out-of-range DRC %.2f to %.2f",
                   w->audio->config.out.track,
                   w->audio->config.out.dynamic_range_compression, drc_scale_max);
            w->audio->config.out.dynamic_range_compression = drc_scale_max;
        }

        char drc_scale[5]; // "?.??\n"
        snprintf(drc_scale, sizeof(drc_scale), "%.2f",
                 w->audio->config.out.dynamic_range_compression);
        av_dict_set(&av_opts, "drc_scale", drc_scale, 0);
    }

    if (hb_avcodec_open(pv->context, codec, &av_opts, 0))
    {
        av_dict_free( &av_opts );
        hb_log("decavcodecaInit: avcodec_open failed");
        return 1;
    }
    pv->context->pkt_timebase.num = pv->audio->config.in.timebase.num;
    pv->context->pkt_timebase.den = pv->audio->config.in.timebase.den;

    // libavcodec can't decode TrueHD Mono (bug #356)
    // work around it by requesting Stereo and downmixing
    if (w->codec_param                     == AV_CODEC_ID_TRUEHD &&
        w->audio->config.in.channel_layout == AV_CH_LAYOUT_MONO)
    {
        pv->context->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
    }

    // avcodec_open populates av_opts with the things it didn't recognize.
    AVDictionaryEntry *t = NULL;
    while ((t = av_dict_get(av_opts, "", t, AV_DICT_IGNORE_SUFFIX)) != NULL)
    {
            hb_log("decavcodecaInit: unknown option '%s'", t->key);
    }
    av_dict_free( &av_opts );

    pv->frame = av_frame_alloc();
    if (pv->frame == NULL)
    {
        hb_log("decavcodecaInit: av_frame_alloc failed");
        return 1;
    }

    pv->pkt = av_packet_alloc();
    if (pv->pkt == NULL)
    {
        hb_log("decavcodecaInit: av_packet_alloc failed");
        return 1;
    }

    return 0;
}

/***********************************************************************
 * Close
 ***********************************************************************
 *
 **********************************************************************/
static void close_video_filters(hb_work_private_t *pv)
{
    hb_avfilter_graph_close(&pv->video_filters.graph);
}

static void closePrivData( hb_work_private_t ** ppv )
{
    hb_work_private_t * pv = *ppv;

    if ( pv )
    {
        hb_buffer_list_close(&pv->list);

        if ( pv->job && pv->context && pv->context->codec )
        {
            hb_log( "%s-decoder done: %u frames, %u decoder errors",
                    pv->context->codec->name, pv->nframes, pv->decode_errors);
        }
        av_frame_free(&pv->frame);
        close_video_filters(pv);
        if ( pv->parser )
        {
            av_parser_close(pv->parser);
        }
        if ( pv->context && pv->context->codec )
        {
#if HB_PROJECT_FEATURE_QSV
            /*
             * FIXME: knowingly leaked.
             *
             * If we're using our FFmpeg QSV wrapper, qsv_decode_end() will call
             * MFXClose() on the QSV session. Even if decoding is complete, we
             * still need that session for QSV filtering and/or encoding, so we
             * we can't close the context here until we implement a proper fix.
             *
             * Interestingly, this may cause crashes even when QSV-accelerated
             * decoding and encoding sessions are independent (e.g. decoding via
             * libavcodec, but encoding using libhb, without us requesting any
             * form of communication between the two libmfx sessions).
             */
            //if (!(pv->qsv.decode && pv->job != NULL && (pv->job->vcodec & HB_VCODEC_QSV_MASK)))
            hb_qsv_uninit_dec(pv->context);
#endif
            {
                hb_avcodec_free_context(&pv->context);
            }
        }
        if ( pv->context )
        {
            hb_avcodec_free_context(&pv->context);
        }
        av_packet_free(&pv->pkt);
        hb_audio_resample_free(pv->resample);

        int ii;
        for (ii = 0; ii < REORDERED_HASH_SZ; ii++)
        {
            free(pv->reordered_hash[ii]);
        }
        free(pv);
    }
    *ppv = NULL;
}

static void decavcodecClose( hb_work_object_t * w )
{
    hb_work_private_t * pv = w->private_data;

    if ( pv )
    {
        closePrivData( &pv );
        w->private_data = NULL;
    }
}

static void audioParserFlush(hb_work_object_t * w)
{
    hb_work_private_t * pv = w->private_data;
    uint8_t * pout = NULL;
    int       pout_len = 0;
    int64_t   parser_pts = AV_NOPTS_VALUE;

    do
    {
        if (pv->parser)
        {
            av_parser_parse2(pv->parser, pv->context, &pout, &pout_len,
                                   NULL, 0,
                                   AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0 );
            parser_pts = pv->parser->pts;
        }

        if (pout != NULL && pout_len > 0)
        {
            pv->packet_info.data         = pout;
            pv->packet_info.size         = pout_len;
            pv->packet_info.pts          = parser_pts;

            decodeAudio(pv, &pv->packet_info);
        }
    } while (pout != NULL && pout_len > 0);
}

/***********************************************************************
 * Work
 ***********************************************************************
 *
 **********************************************************************/
static int decavcodecaWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
                            hb_buffer_t ** buf_out )
{
    hb_work_private_t * pv = w->private_data;
    hb_buffer_t * in = *buf_in;

    // libavcodec/mpeg12dec.c requires buffers to be zero padded.
    // If not zero padded, it can get stuck in an infinite loop.
    // It's likely there are other decoders that expect the same.
    if (in->data != NULL)
    {
        memset(in->data + in->size, 0, in->alloc - in->size);
    }

    if (in->s.flags & HB_BUF_FLAG_EOF)
    {
        /* EOF on input stream - send it downstream & say that we're done */
        audioParserFlush(w);
        decodeAudio(pv, NULL);
        hb_buffer_list_append(&pv->list, in);
        *buf_in = NULL;
        *buf_out = hb_buffer_list_clear(&pv->list);
        return HB_WORK_DONE;
    }

    *buf_out = NULL;

    int     pos, len;
    int64_t pts = in->s.start;

    // There are a 3 scenarios that can happen here.
    // 1. The buffer contains exactly one frame of data
    // 2. The buffer contains multiple frames of data
    // 3. The buffer contains a partial frame of data
    //
    // In scenario 2, we want to be sure that the timestamps are only
    // applied to the first frame in the buffer.  Additional frames
    // in the buffer will have their timestamps computed in sync.
    //
    // In scenario 3, we need to save the ancillary buffer info of an
    // unfinished frame so it can be applied when we receive the last
    // buffer of that frame.
    if (!pv->unfinished)
    {
        // New packet, and no previous data pending
        pv->packet_info.scr_sequence = in->s.scr_sequence;
        pv->packet_info.new_chap     = in->s.new_chap;
        pv->packet_info.frametype    = in->s.frametype;
        pv->packet_info.discard      = !!(in->s.flags & HB_FLAG_DISCARD);
    }
    for (pos = 0; pos < in->size; pos += len)
    {
        uint8_t * pout = NULL;
        int       pout_len = 0;
        int64_t   parser_pts;

        if ( pv->parser != NULL )
        {
            len = av_parser_parse2(pv->parser, pv->context, &pout, &pout_len,
                                   in->data + pos, in->size - pos,
                                   pts, pts, 0 );
            parser_pts = pv->parser->pts;
            pts = AV_NOPTS_VALUE;
        }
        else
        {
            pout = in->data;
            len = pout_len = in->size;
            parser_pts = in->s.start;
        }
        if (pout != NULL && pout_len > 0)
        {
            pv->packet_info.data         = pout;
            pv->packet_info.size         = pout_len;
            pv->packet_info.pts          = parser_pts;

            decodeAudio(pv, &pv->packet_info);

            // There could have been an unfinished packet when we entered
            // decodeAudio that is now finished.  The next packet is associated
            // with the input buffer, so set it's chapter and scr info.
            pv->packet_info.scr_sequence = in->s.scr_sequence;
            pv->packet_info.discard      = !!(in->s.flags & HB_FLAG_DISCARD);
            pv->unfinished               = 0;
        }
        if (len > 0 && pout_len <= 0)
        {
            pv->unfinished               = 1;
        }
    }
    *buf_out = hb_buffer_list_clear(&pv->list);
    return HB_WORK_OK;
}

static int decavcodecaInfo( hb_work_object_t *w, hb_work_info_t *info )
{
    hb_work_private_t *pv = w->private_data;

    memset( info, 0, sizeof(*info) );

    if ( pv && pv->context )
    {
        AVCodecContext *context = pv->context;
        info->bitrate = context->bit_rate;
        info->rate.num = context->time_base.num;
        info->rate.den = context->time_base.den;
        info->profile = context->profile;
        info->level = context->level;
        return 1;
    }
    return 0;
}

static int parse_adts_extradata( hb_audio_t * audio, AVCodecContext * context,
                                 AVPacket * pkt )
{
    const AVBitStreamFilter * bsf;
    AVBSFContext            * ctx = NULL;
    int                       ret;

    bsf = av_bsf_get_by_name("aac_adtstoasc");
    ret = av_bsf_alloc(bsf, &ctx);
    if (ret < 0)
    {
        hb_error("decavcodec: bitstream filter alloc failure");
        return ret;
    }
    ctx->time_base_in.num = 1;
    ctx->time_base_in.den = audio->config.out.samplerate;
    avcodec_parameters_from_context(ctx->par_in, context);
    ret = av_bsf_init(ctx);
    if (ret < 0)
    {
        hb_error("decavcodec: bitstream filter init failure");
        av_bsf_free(&ctx);
        return ret;
    }

    ret = av_bsf_send_packet(ctx, pkt);
    if (ret < 0)
    {
        hb_error("decavcodec: av_bsf_send_packet failure");
        av_bsf_free(&ctx);
        return ret;
    }

    ret = av_bsf_receive_packet(ctx, pkt);
    av_bsf_free(&ctx);
    if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
    {
        return 0;
    }
    else if (ret < 0)
    {
        if (ret != AVERROR_INVALIDDATA)
        {
            hb_error("decavcodec: av_bsf_receive_packet failure %x", -ret);
        }
        return ret;
    }

    if (audio->priv.config.extradata.length == 0)
    {
        const uint8_t * extradata;
        size_t          size;

        extradata = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
                                            &size);
        if (extradata != NULL && size > 0)
        {
            int len;
            len = MIN(size, HB_CONFIG_MAX_SIZE);
            memcpy(audio->priv.config.extradata.bytes, extradata, len);
            audio->priv.config.extradata.length = len;
        }
    }

    return 0;
}

static int decavcodecaBSInfo( hb_work_object_t *w, const hb_buffer_t *buf,
                             hb_work_info_t *info )
{
    hb_work_private_t *pv = w->private_data;
    int result = 0, done = 0;
    hb_audio_t *audio = w->audio;

    memset( info, 0, sizeof(*info) );

    if ( pv && pv->context )
    {
        return decavcodecaInfo( w, info );
    }

    const AVCodec *codec = avcodec_find_decoder( w->codec_param );
    if ( ! codec )
    {
        // there's no ffmpeg codec for this audio type - give up
        return -1;
    }

    static char codec_name[64];
    info->name =  strncpy( codec_name, codec->name, sizeof(codec_name)-1 );

    AVCodecContext *context      = avcodec_alloc_context3(codec);
    AVCodecParserContext *parser = NULL;

    if (w->title && w->title->opaque_priv != NULL)
    {
        AVFormatContext *ic = (AVFormatContext*)w->title->opaque_priv;
        avcodec_parameters_to_context(context,
                                      ic->streams[audio->id]->codecpar);
        // libav's eac3 parser toggles the codec_id in the context as
        // it reads eac3 data between AV_CODEC_ID_AC3 and AV_CODEC_ID_EAC3.
        // It detects an AC3 sync pattern sometimes in ac3_sync() which
        // causes it to eventually set avctx->codec_id to AV_CODEC_ID_AC3
        // in ff_aac_ac3_parse(). Since we are parsing some data before
        // we get here, the codec_id may have flipped.  This will cause an
        // error in hb_avcodec_open().  So flip it back!
        context->codec_id = w->codec_param;
    }
    else
    {
        parser = av_parser_init(codec->id);
    }

    hb_ff_set_sample_fmt( context, codec, AV_SAMPLE_FMT_FLT );

    AVDictionary * av_opts = NULL;
    av_dict_set( &av_opts, "err_detect", "crccheck+explode", 0 );
    if ( hb_avcodec_open( context, codec, &av_opts, 0 ) )
    {
        av_dict_free( &av_opts );
        return -1;
    }
    if (audio != NULL)
    {
        context->pkt_timebase.num = audio->config.in.timebase.num;
        context->pkt_timebase.den = audio->config.in.timebase.den;
    }

    av_dict_free( &av_opts );
    unsigned char *parse_buffer;
    int parse_pos, parse_buffer_size;

    while (buf != NULL && !done)
    {
        parse_pos = 0;
        while (parse_pos < buf->size && !done)
        {
            int parse_len, truehd_mono = 0, ret;

            if (parser != NULL)
            {
                parse_len = av_parser_parse2(parser, context,
                                &parse_buffer, &parse_buffer_size,
                                buf->data + parse_pos, buf->size - parse_pos,
                                buf->s.start, buf->s.start, 0);
            }
            else
            {
                parse_buffer = buf->data + parse_pos;
                parse_len = parse_buffer_size = buf->size - parse_pos;
            }

            if (parse_buffer_size == 0)
            {
                parse_pos += parse_len;
                continue;
            }

            // libavcodec can't decode TrueHD Mono (bug #356)
            // work around it by requesting Stereo before decoding
            if (context->codec_id == AV_CODEC_ID_TRUEHD &&
                context->ch_layout.u.mask == AV_CH_LAYOUT_MONO)
            {
                truehd_mono                     = 1;
                AVChannelLayout ch_layout = AV_CHANNEL_LAYOUT_STEREO;
                av_opt_set_chlayout(context, "downmix", &ch_layout, AV_OPT_SEARCH_CHILDREN);
                context->ch_layout = ch_layout;
            }

            AVPacket *avp = av_packet_alloc();
            avp->data = parse_buffer;
            avp->size = parse_buffer_size;

            ret = avcodec_send_packet(context, avp);
            if (ret < 0 && ret != AVERROR_EOF)
            {
                parse_pos += parse_len;
                av_packet_free(&avp);
                continue;
            }

            AVFrame *frame = NULL;
            do
            {
                if (frame == NULL)
                {
                    frame = av_frame_alloc();
                }
                ret = avcodec_receive_frame(context, frame);
                if (ret >= 0)
                {
                    // libavcoded doesn't consistently set frame->sample_rate
                    if (frame->sample_rate != 0)
                    {
                        info->rate.num = frame->sample_rate;
                    }
                    else
                    {
                        info->rate.num = context->sample_rate;
                        hb_log("decavcodecaBSInfo: warning: invalid frame sample_rate! Using context sample_rate.");
                    }
                    info->rate.den          = 1;
                    info->samples_per_frame = frame->nb_samples;
                    info->sample_bit_depth  = context->bits_per_raw_sample;

                    int bps = av_get_bits_per_sample(context->codec_id);
                    int channels = frame->ch_layout.nb_channels;

                    info->bitrate = bps * channels * info->rate.num;
                    if (info->bitrate <= 0)
                    {
                        if (context->bit_rate > 0)
                        {
                            info->bitrate = context->bit_rate;
                        }
                        else
                        {
                            info->bitrate = 1;
                        }
                    }

                    if (truehd_mono)
                    {
                        info->channel_layout = AV_CH_LAYOUT_MONO;
                        info->matrix_encoding = AV_MATRIX_ENCODING_NONE;
                    }
                    else
                    {
                        AVFrameSideData *side_data;
                        if ((side_data =
                             av_frame_get_side_data(frame,
                                                    AV_FRAME_DATA_MATRIXENCODING)) != NULL)
                        {
                            info->matrix_encoding = *side_data->data;
                        }
                        else
                        {
                            info->matrix_encoding = AV_MATRIX_ENCODING_NONE;
                        }
                        if (info->matrix_encoding == AV_MATRIX_ENCODING_DOLBY ||
                            info->matrix_encoding == AV_MATRIX_ENCODING_DPLII)
                        {
                            info->channel_layout = AV_CH_LAYOUT_STEREO_DOWNMIX;
                        }
                        else
                        {
                            info->channel_layout = frame->ch_layout.u.mask;
                        }
                    }
                    if (info->channel_layout == 0)
                    {
                        // Channel layout was not set.  Guess a layout based
                        // on number of channels.
                        AVChannelLayout channel_layout;
                        av_channel_layout_default(&channel_layout, frame->ch_layout.nb_channels);
                        info->channel_layout = channel_layout.u.mask;
                        av_channel_layout_uninit(&channel_layout);
                    }
                    if (context->codec_id == AV_CODEC_ID_AC3 ||
                        context->codec_id == AV_CODEC_ID_EAC3)
                    {
                        if (context->audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE)
                        {
                            info->mode = 7;
                        }
                        else
                        {
                            info->mode = context->audio_service_type;
                        }
                    }
                    else if (context->codec_id == AV_CODEC_ID_AAC &&
                             context->extradata_size == 0)
                    {
                        // Parse ADTS AAC streams for AudioSpecificConfig.
                        // This data is required in order to write
                        // proper headers in MP4, WebM, and MKV files.
                        parse_adts_extradata(audio, context, avp);
                    }

                    result = 1;
                    done = 1;
                    av_frame_unref(frame);
                    break;
                }
            } while (ret >= 0);
            av_packet_free(&avp);
            av_frame_free(&frame);
            parse_pos += parse_len;
        }
        buf = buf->next;
    }

    info->profile = context->profile;
    info->level = context->level;
    info->channel_map = &hb_libav_chan_map;

    if ( parser != NULL )
        av_parser_close( parser );
    hb_avcodec_free_context(&context);
    return result;
}

reordered_data_t *
reordered_hash_rem(hb_work_private_t * pv, int64_t sequence)
{
    reordered_data_t * reordered;
    int                slot = sequence & REORDERED_HASH_MASK;

    reordered = pv->reordered_hash[slot];
    if (reordered == NULL)
    {
        // This shouldn't happen...
        // But, this happens sometimes when libav outputs exactly the same
        // frame twice for some reason.
        hb_deep_log(3, "decavcodec: missing sequence %"PRId64"", sequence);
    }
    pv->reordered_hash[slot] = NULL;
    return reordered;
}

void
reordered_hash_add(hb_work_private_t * pv, reordered_data_t * reordered)
{
    int slot = reordered->sequence & REORDERED_HASH_MASK;

    // Free any unused previous entries.
    // This can happen due to libav parser feeding partial
    // frames data to the decoder.
    // It can also happen due to decoding errors.
    free(pv->reordered_hash[slot]);
    pv->reordered_hash[slot] = reordered;
}

/* -------------------------------------------------------------
 * General purpose video decoder using libavcodec
 */

// send cc_buf to the CC decoder(s)
static void cc_send_to_decoder(hb_work_private_t *pv, hb_buffer_t *buf)
{
    if (buf == NULL)
        return;

    // if there's more than one decoder for the captions send a copy
    // of the buffer to all.
    hb_subtitle_t *subtitle;
    int ii = 0, n = hb_list_count(pv->list_subtitle);
    while (--n > 0)
    {
        // make a copy of the buf then forward it to the decoder
        hb_buffer_t *cpy = hb_buffer_dup(buf);

        subtitle = hb_list_item(pv->list_subtitle, ii++);
        hb_fifo_push(subtitle->fifo_in, cpy);
    }
    subtitle = hb_list_item(pv->list_subtitle, ii);
    hb_fifo_push( subtitle->fifo_in, buf );
}

static hb_buffer_t * cc_fill_buffer(hb_work_private_t *pv, uint8_t *cc, int size)
{
    hb_buffer_t * buf = hb_buffer_init(size);

    memcpy(buf->data, cc, size);
    return buf;
}

// copy one video frame into an HB buf. If the frame isn't in our color space
// or at least one of its dimensions is odd, use sws_scale to convert/rescale it.
// Otherwise just copy the bits.
static hb_buffer_t *copy_frame( hb_work_private_t *pv )
{
    reordered_data_t * reordered = NULL;
    hb_buffer_t      * out;

#if HB_PROJECT_FEATURE_QSV
    // no need to copy the frame data when decoding with QSV to opaque memory
    if (pv->qsv.decode &&
        pv->qsv.config.io_pattern == MFX_IOPATTERN_OUT_VIDEO_MEMORY)
    {
        out = hb_qsv_copy_avframe_to_video_buffer(pv->job, pv->frame, 0);
    }
    else
#endif
    {
        out = hb_avframe_to_video_buffer(pv->frame, (AVRational){1,1});
    }

    // Make sure every frame is tagged.
    if (out->f.color_prim == HB_COLR_PRI_UNDEF || out->f.color_transfer == HB_COLR_TRA_UNDEF || out->f.color_matrix == HB_COLR_MAT_UNDEF)
    {
        out->f.color_prim = pv->title->color_prim;
        out->f.color_transfer = pv->title->color_transfer;
        out->f.color_matrix = pv->title->color_matrix;
    }

    if (pv->frame->pts != AV_NOPTS_VALUE)
    {
        reordered = reordered_hash_rem(pv, pv->frame->pts);
    }
    if (reordered != NULL)
    {
        out->s.scr_sequence   = reordered->scr_sequence;
        out->s.start          = reordered->pts;
        out->s.new_chap       = reordered->new_chap;
        pv->last_scr_sequence = reordered->scr_sequence;
        pv->last_chapter      = reordered->new_chap;
        free(reordered);
    }
    else
    {
        out->s.scr_sequence   = pv->last_scr_sequence;
        out->s.start          = AV_NOPTS_VALUE;
    }

    double  frame_dur = pv->duration;
    if (pv->frame->repeat_pict)
    {
        frame_dur += pv->frame->repeat_pict * pv->field_duration;
    }
    if (out->s.start == AV_NOPTS_VALUE)
    {
        out->s.start = pv->next_pts;
    }
    else
    {
        pv->next_pts = out->s.start;
    }
    if (pv->next_pts != (int64_t)AV_NOPTS_VALUE)
    {
        pv->next_pts += frame_dur;
        out->s.stop   = pv->next_pts;
    }
    out->s.duration  = frame_dur;

    if (out->s.new_chap > 0 && out->s.new_chap == pv->new_chap)
    {
        pv->new_chap = 0;
    }
    // It is possible that the buffer with new_chap gets dropped
    // by the decoder.  So also check if the output buffer is after
    // the new_chap in the timeline.
    if (pv->new_chap > 0 &&
        (out->s.scr_sequence > pv->chap_scr ||
         (out->s.scr_sequence == pv->chap_scr && out->s.start > pv->chap_time)))
    {
        out->s.new_chap = pv->new_chap;
        pv->new_chap    = 0;
    }

    // Check for CC data
    AVFrameSideData *sd;
    sd = av_frame_get_side_data(pv->frame, AV_FRAME_DATA_A53_CC);
    if (sd != NULL)
    {
        if (!pv->job && pv->title && sd->size > 0)
        {
            hb_subtitle_t *subtitle;
            int i = 0;

            while ((subtitle = hb_list_item(pv->title->list_subtitle, i++)))
            {
                /*
                 * Let's call them 608 subs for now even if they aren't,
                 * since they are the only types we grok.
                 */
                if (subtitle->source == CC608SUB)
                {
                    break;
                }
            }
            if (subtitle == NULL)
            {
                iso639_lang_t * lang;
                hb_audio_t    * audio;

                subtitle        = calloc(sizeof( hb_subtitle_t ), 1);
                subtitle->track = hb_list_count(pv->title->list_subtitle);
                subtitle->id           = HB_SUBTITLE_EMBEDDED_CC_TAG;
                subtitle->format       = TEXTSUB;
                subtitle->source       = CC608SUB;
                subtitle->config.dest  = PASSTHRUSUB;
                subtitle->codec        = WORK_DECAVSUB;
                subtitle->codec_param  = AV_CODEC_ID_EIA_608;
                subtitle->attributes   = HB_SUBTITLE_ATTR_CC;
                subtitle->timebase.num = 1;
                subtitle->timebase.den = 90000;

                /*
                 * The language of the subtitles will be the same as the
                 * first audio track, i.e. the same as the video.
                 */
                audio = hb_list_item(pv->title->list_audio, 0);
                if (audio != NULL)
                {
                    lang = lang_for_code2( audio->config.lang.iso639_2 );
                } else {
                    lang = lang_for_code2( "und" );
                }
                snprintf(subtitle->lang, sizeof(subtitle->lang),
                         "%s, Closed Caption [%s]",
                         strlen(lang->native_name) ? lang->native_name :
                                                     lang->eng_name,
                         hb_subsource_name(subtitle->source));
                snprintf(subtitle->iso639_2, sizeof(subtitle->iso639_2),
                         "%s", lang->iso639_2);

                hb_list_add(pv->title->list_subtitle, subtitle);
            }
        }
        if (pv->list_subtitle != NULL && sd->size > 0)
        {
            hb_buffer_t *cc_buf;
            cc_buf = cc_fill_buffer(pv, sd->data, sd->size);
            if (cc_buf != NULL)
            {
                cc_buf->s.start        = out->s.start;
                cc_buf->s.duration     = (int64_t)AV_NOPTS_VALUE;
                cc_buf->s.scr_sequence = out->s.scr_sequence;
            }
            cc_send_to_decoder(pv, cc_buf);
        }
    }

    // Check for HDR mastering data
    sd = av_frame_get_side_data(pv->frame, AV_FRAME_DATA_MASTERING_DISPLAY_METADATA);
    if (sd != NULL)
    {
        if (!pv->job && pv->title && sd->size > 0)
        {
            AVMasteringDisplayMetadata *mastering = (AVMasteringDisplayMetadata *)sd->data;
            pv->title->mastering = hb_mastering_ff_to_hb(*mastering);
        }
    }

    // Check for HDR content light level data
    sd = av_frame_get_side_data(pv->frame, AV_FRAME_DATA_CONTENT_LIGHT_LEVEL);
    if (sd != NULL)
    {
        if (!pv->job && pv->title && sd->size > 0)
        {
            AVContentLightMetadata *coll = (AVContentLightMetadata *)sd->data;
            pv->title->coll.max_cll = coll->MaxCLL;
            pv->title->coll.max_fall = coll->MaxFALL;
        }
    }

    return out;
}

static const char * get_range_name(int color_range)
{
    switch (color_range)
    {
        case AVCOL_RANGE_UNSPECIFIED:
        case AVCOL_RANGE_MPEG:
            return "limited";
        case AVCOL_RANGE_JPEG:
            return "full";
    }
    return "limited";
}

int reinit_video_filters(hb_work_private_t * pv)
{
    int                orig_width;
    int                orig_height;
    hb_value_array_t * filters;
    hb_dict_t        * settings;
    hb_filter_init_t   filter_init;
    enum AVPixelFormat pix_fmt;
    enum AVColorRange  color_range;

    memset((void*)&filter_init, 0, sizeof(filter_init));

#if HB_PROJECT_FEATURE_QSV
    if (pv->qsv.decode &&
        pv->qsv.config.io_pattern == MFX_IOPATTERN_OUT_VIDEO_MEMORY)
    {
        // Can't use software filters when decoding with QSV opaque memory
        return 0;
    }
#endif
    if (!pv->job)
    {
        // HandBrake's video pipeline uses yuv420 color.  This means all
        // dimensions must be even.  So we must adjust the dimensions
        // of incoming video if not even.
        orig_width = pv->context->width & ~1;
        orig_height = pv->context->height & ~1;
        pix_fmt = AV_PIX_FMT_YUV420P;
        color_range = AVCOL_RANGE_MPEG;
    }
    else
    {
        if (pv->title->rotation == HB_ROTATION_90 ||
            pv->title->rotation == HB_ROTATION_270)
        {
            orig_width = pv->job->title->geometry.height;
            orig_height = pv->job->title->geometry.width;
        }
        else
        {
            orig_width = pv->job->title->geometry.width;
            orig_height = pv->job->title->geometry.height;
        }
        pix_fmt = pv->job->input_pix_fmt;
        color_range = pv->job->color_range;
    }

    if (pix_fmt            == pv->frame->format  &&
        orig_width         == pv->frame->width   &&
        orig_height        == pv->frame->height  &&
        color_range        == pv->frame->color_range &&
        HB_ROTATION_0      == pv->title->rotation)
    {
        // No filtering required.
        close_video_filters(pv);
        return 0;
    }

    if (pv->video_filters.graph       != NULL              &&
        pv->video_filters.width       == pv->frame->width  &&
        pv->video_filters.height      == pv->frame->height &&
        pv->video_filters.color_range == pv->frame->color_range &&
        pv->video_filters.pix_fmt     == pv->frame->format)
    {
        // Current filter settings are good
        return 0;
    }

    pv->video_filters.width       = pv->frame->width;
    pv->video_filters.height      = pv->frame->height;
    pv->video_filters.color_range = pv->frame->color_range;
    pv->video_filters.pix_fmt     = pv->frame->format;

    // New filter required, create filter graph
    close_video_filters(pv);

    int clock_min, clock_max, clock;
    hb_rational_t vrate;

    hb_video_framerate_get_limits(&clock_min, &clock_max, &clock);
    vrate.num = clock;
    vrate.den = pv->duration * (clock / 90000.);

    filters = hb_value_array_init();
    if (pix_fmt            != pv->frame->format ||
        orig_width         != pv->frame->width  ||
        orig_height        != pv->frame->height ||
        color_range        != pv->frame->color_range)
    {
        settings = hb_dict_init();
#if HB_PROJECT_FEATURE_QSV && (defined( _WIN32 ) || defined( __MINGW32__ ))
        if (hb_qsv_hw_filters_are_enabled(pv->job))
        {
            hb_dict_set(settings, "w", hb_value_int(orig_width));
            hb_dict_set(settings, "h", hb_value_int(orig_height));
            hb_avfilter_append_dict(filters, "vpp_qsv", settings);
        }
        else
#endif
#if HB_PROJECT_FEATURE_NVENC
        if (pv->frame->hw_frames_ctx)
        {
            hb_dict_set(settings, "w", hb_value_int(orig_width));
            hb_dict_set(settings, "h", hb_value_int(orig_height));
            hb_dict_set(settings, "interp_algo", hb_value_string("lanczos"));
            hb_dict_set(settings, "format", hb_value_string(av_get_pix_fmt_name(pix_fmt)));
            hb_avfilter_append_dict(filters, "scale_cuda", settings);
            filter_init.nv_hw_ctx.hw_frames_ctx = pv->frame->hw_frames_ctx;
        }
        else
#endif
        {
            hb_dict_set(settings, "pix_fmts", hb_value_string(av_get_pix_fmt_name(pix_fmt)));
            hb_avfilter_append_dict(filters, "format", settings);
            settings = hb_dict_init();

            hb_dict_set(settings, "w", hb_value_int(orig_width));
            hb_dict_set(settings, "h", hb_value_int(orig_height));
            hb_dict_set_string(settings, "filter", "lanczos");
            hb_dict_set_string(settings, "range", get_range_name(color_range));
            hb_avfilter_append_dict(filters, "zscale", settings);
        }
    }
    if (pv->title->rotation != HB_ROTATION_0)
    {
        switch (pv->title->rotation)
        {
            case HB_ROTATION_90:
                settings = hb_dict_init();
                hb_dict_set(settings, "dir", hb_value_string("cclock"));
                hb_avfilter_append_dict(filters, "transpose", settings);
                hb_log("Auto-Rotating video 90 degrees");
                break;
            case HB_ROTATION_180:
                hb_avfilter_append_dict(filters, "hflip", hb_value_null());
                hb_avfilter_append_dict(filters, "vflip", hb_value_null());
                hb_log("Auto-Rotating video 180 degrees");
                break;
            case HB_ROTATION_270:
                settings = hb_dict_init();
                hb_dict_set(settings, "dir", hb_value_string("clock"));
                hb_avfilter_append_dict(filters, "transpose", settings);
                hb_log("Auto-Rotating video 270 degrees");
                break;
            default:
                hb_log("reinit_video_filters: Unknown rotation, failed");
        }
    }

    filter_init.job               = pv->job;
    filter_init.pix_fmt           = pv->frame->format;
    filter_init.geometry.width    = pv->frame->width;
    filter_init.geometry.height   = pv->frame->height;
    filter_init.geometry.par.num  = pv->frame->sample_aspect_ratio.num;
    filter_init.geometry.par.den  = pv->frame->sample_aspect_ratio.den;
    filter_init.time_base.num     = 1;
    filter_init.time_base.den     = 1;
    filter_init.vrate.num         = vrate.num;
    filter_init.vrate.den         = vrate.den;

    pv->video_filters.graph = hb_avfilter_graph_init(filters, &filter_init);
    hb_value_free(&filters);
    if (pv->video_filters.graph == NULL)
    {
        hb_error("reinit_video_filters: failed to create filter graph");
        goto fail;
    }

    return 0;

fail:
    close_video_filters(pv);

    return 1;
}

static void filter_video(hb_work_private_t *pv)
{
    reinit_video_filters(pv);
    if (pv->video_filters.graph != NULL)
    {
        int result;

        hb_avfilter_add_frame(pv->video_filters.graph, pv->frame);
        result = hb_avfilter_get_frame(pv->video_filters.graph, pv->frame);
        while (result >= 0)
        {
            hb_buffer_t * buf = copy_frame(pv);
            hb_buffer_list_append(&pv->list, buf);
            av_frame_unref(pv->frame);
            ++pv->nframes;
            result = hb_avfilter_get_frame(pv->video_filters.graph, pv->frame);
        }
    }
    else
    {
        hb_buffer_t * buf = copy_frame(pv);
        hb_buffer_list_append(&pv->list, buf);
        av_frame_unref(pv->frame);
        ++pv->nframes;
    }
}

/*
 * Decodes a video frame from the specified raw packet data
 *      ('data', 'size').
 * The output of this function is stored in 'pv->list', which contains a list
 * of zero or more decoded packets.
 */
static int decodeFrame( hb_work_private_t * pv, packet_info_t * packet_info )
{
    int got_picture = 0, oldlevel = 0, ret;
    AVPacket *avp = pv->pkt;
    reordered_data_t * reordered;

    if ( global_verbosity_level <= 1 )
    {
        oldlevel = av_log_get_level();
        av_log_set_level( AV_LOG_QUIET );
    }

    if (packet_info != NULL)
    {
        avp->data = packet_info->data;
        avp->size = packet_info->size;
        avp->pts  = pv->sequence;
        avp->dts  = pv->sequence;
        reordered = malloc(sizeof(*reordered));
        if (reordered != NULL)
        {
            reordered->sequence     = pv->sequence++;
            reordered->pts          = packet_info->pts;
            reordered->scr_sequence = packet_info->scr_sequence;
            reordered->new_chap     = packet_info->new_chap;
            reordered_hash_add(pv, reordered);
        }

        // libav avcodec video decoder needs AVPacket flagged with
        // AV_PKT_FLAG_KEY for some codecs. For example, sequence of
        // PNG in a mov container.
        if (packet_info->frametype & HB_FRAME_MASK_KEY)
        {
            avp->flags |= AV_PKT_FLAG_KEY;
        }
        avp->flags  |= packet_info->discard * AV_PKT_FLAG_DISCARD;
    }
    else
    {
        avp->data = NULL;
        avp->size = 0;
    }

    if (pv->palette != NULL)
    {
        uint8_t * palette;
        int size;
        palette = av_packet_new_side_data(avp, AV_PKT_DATA_PALETTE,
                                          AVPALETTE_SIZE);
        size = MIN(pv->palette->size, AVPALETTE_SIZE);
        memcpy(palette, pv->palette->data, size);
        hb_buffer_close(&pv->palette);
    }

    ret = avcodec_send_packet(pv->context, avp);
    av_packet_unref(avp);
    if (ret < 0 && ret != AVERROR_EOF)
    {
        ++pv->decode_errors;
        return 0;
    }

    do
    {
        ret = avcodec_receive_frame(pv->context, pv->frame);
        if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
        {
            ++pv->decode_errors;
        }
        if (ret < 0)
        {
            break;
        }
        got_picture = 1;

        // recompute the frame/field duration, because sometimes it changes
        compute_frame_duration( pv );
        filter_video(pv);
    } while (ret >= 0);

    if ( global_verbosity_level <= 1 )
    {
        av_log_set_level( oldlevel );
    }

    return got_picture;
}


static int decavcodecvInit( hb_work_object_t * w, hb_job_t * job )
{

    hb_work_private_t *pv = calloc( 1, sizeof( hb_work_private_t ) );

    w->private_data = pv;
    pv->job         = job;
    pv->next_pts    = (int64_t)AV_NOPTS_VALUE;
    if ( job )
        pv->title = job->title;
    else
        pv->title = w->title;
    if (pv->title->flags & HBTF_RAW_VIDEO)
        pv->next_pts = 0;
    hb_buffer_list_clear(&pv->list);

#if HB_PROJECT_FEATURE_QSV
    if ((pv->qsv.decode = hb_qsv_decode_is_enabled(job)))
    {
        pv->qsv.codec_name = hb_qsv_decode_get_codec_name(w->codec_param);
        pv->qsv.config.io_pattern = MFX_IOPATTERN_OUT_SYSTEM_MEMORY;
        if(hb_qsv_full_path_is_enabled(job))
        {
            hb_qsv_info_t *info = hb_qsv_encoder_info_get(hb_qsv_get_adapter_index(), job->vcodec);
            if (info != NULL)
            {
                // setup the QSV configuration
                pv->qsv.config.io_pattern         = MFX_IOPATTERN_OUT_VIDEO_MEMORY;
                pv->qsv.config.impl_requested     = info->implementation;
                pv->qsv.config.async_depth        = job->qsv.async_depth;
                pv->qsv.config.sync_need          =  0;
                pv->qsv.config.usage_threaded     =  1;
                pv->qsv.config.additional_buffers = 64; // FIFO_LARGE
                if (info->capabilities & HB_QSV_CAP_RATECONTROL_LA)
                {
                    // more surfaces may be needed for the lookahead
                    pv->qsv.config.additional_buffers = 160;
                }
                if (!pv->job->qsv.ctx)
                {
                    hb_error( "decavcodecvInit: no context" );
                    return 1;
                }
                pv->job->qsv.ctx->full_path_is_enabled = 1;
                if (!pv->job->qsv.ctx->hb_dec_qsv_frames_ctx)
                {
                    pv->job->qsv.ctx->hb_dec_qsv_frames_ctx = av_mallocz(sizeof(HBQSVFramesContext));
                    if(!pv->job->qsv.ctx->hb_dec_qsv_frames_ctx)
                    {
                        hb_error( "decavcodecvInit: HBQSVFramesContext dec alloc failed" );
                        return 1;
                    }
                }
                if (!pv->job->qsv.ctx->dec_space)
                {
                    pv->job->qsv.ctx->dec_space = av_mallocz(sizeof(hb_qsv_space));
                    if(!pv->job->qsv.ctx->dec_space)
                    {
                        hb_error( "decavcodecvInit: dec_space alloc failed" );
                        return 1;
                    }
                    pv->job->qsv.ctx->dec_space->is_init_done = 1;
                }
            }
        }
    }
#endif

    if( pv->job && pv->job->title && !pv->job->title->has_resolution_change )
    {
        pv->threads = HB_FFMPEG_THREADS_AUTO;
    }

#if HB_PROJECT_FEATURE_QSV
    if (pv->qsv.decode)
    {
        pv->codec = avcodec_find_decoder_by_name(pv->qsv.codec_name);
    }
    else
#endif
    {
        pv->codec = avcodec_find_decoder(w->codec_param);
    }
    if ( pv->codec == NULL )
    {
        hb_log( "decavcodecvInit: failed to find codec for id (%d)", w->codec_param );
        return 1;
    }

#if HB_PROJECT_FEATURE_NVENC
    int use_hw_dec = 0;
    if (hb_nvdec_is_enabled(job))
    {
        use_hw_dec = 1;
    }
#endif

    pv->context = avcodec_alloc_context3( pv->codec );
    pv->context->workaround_bugs = FF_BUG_AUTODETECT;
    pv->context->err_recognition = AV_EF_CRCCHECK;
    pv->context->error_concealment = FF_EC_GUESS_MVS|FF_EC_DEBLOCK;

#if HB_PROJECT_FEATURE_NVENC
    if (use_hw_dec)
    {
        hb_nvdec_hw_ctx_init(pv->context, pv->job);
    }
#endif

    if ( pv->title->opaque_priv )
    {
        AVFormatContext *ic = (AVFormatContext*)pv->title->opaque_priv;

        avcodec_parameters_to_context(pv->context,
                                  ic->streams[pv->title->video_id]->codecpar);

#if HB_PROJECT_FEATURE_QSV
        if (pv->qsv.decode &&
            pv->qsv.config.io_pattern == MFX_IOPATTERN_OUT_VIDEO_MEMORY)
        {
            // assign callbacks and job to have access to qsv context from ffmpeg
            pv->context->get_format      = hb_qsv_get_format;
            pv->context->get_buffer2     = hb_qsv_get_buffer;
            pv->context->opaque          = pv->job;
            pv->context->hwaccel_context = 0;
        }
#endif

        // Set decoder opts
        AVDictionary * av_opts = NULL;
        if (pv->title->flags & HBTF_NO_IDR)
        {
            av_dict_set( &av_opts, "flags", "output_corrupt", 0 );
        }

#if HB_PROJECT_FEATURE_QSV
        if (pv->qsv.decode)
        {
            if (pv->context->codec_id == AV_CODEC_ID_HEVC)
                av_dict_set( &av_opts, "load_plugin", "hevc_hw", 0 );
#if defined(_WIN32) || defined(__MINGW32__)
            if (!hb_qsv_full_path_is_enabled(job))
            {
                hb_qsv_device_init(job);
                pv->context->hw_device_ctx = av_buffer_ref(job->qsv.ctx->hb_hw_device_ctx);
                pv->context->get_format = hb_qsv_get_format;
                pv->context->opaque = pv->job;
            }
#endif
        }
#endif

        if ( hb_avcodec_open( pv->context, pv->codec, &av_opts, pv->threads ) )
        {
            av_dict_free( &av_opts );
            hb_log( "decavcodecvInit: avcodec_open failed" );
            return 1;
        }
        pv->context->pkt_timebase.num = pv->title->video_timebase.num;
        pv->context->pkt_timebase.den = pv->title->video_timebase.den;
        av_dict_free( &av_opts );

        pv->video_codec_opened = 1;
    }
    else
    {
        pv->parser = av_parser_init( w->codec_param );
    }

    pv->frame = av_frame_alloc();
    if (pv->frame == NULL)
    {
        hb_log("decavcodecvInit: av_frame_alloc failed");
        return 1;
    }

    pv->pkt = av_packet_alloc();
    if (pv->pkt == NULL)
    {
        hb_log("decavcodecvInit: av_packet_alloc failed");
        return 1;
    }

    /*
     * If not scanning, then are we supposed to extract Closed Captions
     * and send them to the decoder?
     */
    if (job != NULL && hb_list_count(job->list_subtitle) > 0)
    {
        hb_subtitle_t *subtitle;
        int i = 0;

        while ((subtitle = hb_list_item(job->list_subtitle, i++)) != NULL)
        {
            if (subtitle->source == CC608SUB &&
                subtitle->id == HB_SUBTITLE_EMBEDDED_CC_TAG)
            {
                if (pv->list_subtitle == NULL)
                {
                    pv->list_subtitle = hb_list_init();
                }
                hb_list_add(pv->list_subtitle, subtitle);
            }
        }
    }
    return 0;
}

static int setup_extradata( hb_work_private_t * pv, AVCodecContext * context )
{
    const AVBitStreamFilter * bsf;
    AVBSFContext            * ctx = NULL;
    int                       ii, ret;
    AVPacket                * avp = pv->pkt;
    const enum AVCodecID    * ids;

    if (context->extradata != NULL)
    {
        return 0;
    }
    bsf = av_bsf_get_by_name("extract_extradata");
    if (bsf == NULL)
    {
        hb_error("setup_extradata: bitstream filter lookup failure");
        return 0;
    }
    if (bsf->codec_ids == NULL)
    {
        hb_error("setup_extradata: extract_extradata missing codec_ids");
        return 0;
    }
    for (ids = bsf->codec_ids; *ids != AV_CODEC_ID_NONE; ids++)
    {
        if (*ids == context->codec_id)
        {
            break;
        }
    }
    if (*ids == AV_CODEC_ID_NONE)
    {
        // Codec not supported by extract_extradata BSF
        return 0;
    }
    ret = av_bsf_alloc(bsf, &ctx);
    if (ret < 0)
    {
        hb_error("setup_extradata: bitstream filter alloc failure");
        return 0;
    }
    avcodec_parameters_from_context(ctx->par_in, context);
    ret = av_bsf_init(ctx);
    if (ret < 0)
    {
        hb_error("setup_extradata: bitstream filter init failure");
        av_bsf_free(&ctx);
        return 0;
    }

    avp->data = pv->packet_info.data;
    avp->size = pv->packet_info.size;
    avp->pts  = pv->sequence;
    avp->dts  = pv->sequence;
    ret = av_bsf_send_packet(ctx, avp);
    if (ret < 0)
    {
        hb_error("setup_extradata: av_bsf_send_packet failure");
        av_bsf_free(&ctx);
        return 0;
    }

    ret = av_bsf_receive_packet(ctx, avp);
    av_bsf_free(&ctx);
    if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
    {
        return 1;
    }
    else if (ret < 0)
    {
        if (ret != AVERROR_INVALIDDATA)
        {
            hb_error("setup_extradata: av_bsf_receive_packet failure %x", -ret);
        }
        return ret;
    }
    for (ii = 0; ii < avp->side_data_elems; ii++)
    {
        if (avp->side_data[ii].type == AV_PKT_DATA_NEW_EXTRADATA)
        {
            context->extradata_size = avp->side_data[ii].size;
            context->extradata = av_malloc(context->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);

            if (context->extradata != NULL)
            {
                memcpy(context->extradata, avp->side_data[ii].data, context->extradata_size);
                av_packet_unref(avp);
                return 0;
            }
        }
    }
    av_packet_unref(avp);

    return 1;
}

static int decodePacket( hb_work_object_t * w )
{
    hb_work_private_t * pv     = w->private_data;

    // if this is the first frame open the codec (we have to wait for the
    // first frame because of M$ VC1 braindamage).
    if ( !pv->video_codec_opened )
    {
        AVCodecContext * context = avcodec_alloc_context3(pv->codec);
        if (setup_extradata(pv, context))
        {
            // we didn't find the headers needed to set up extradata.
            // the codec will abort if we open it so just free the buf
            // and hope we eventually get the info we need.
            return HB_WORK_OK;
        }

#if HB_PROJECT_FEATURE_NVENC
        AVBufferRef *hw_device_ctx = NULL;
        if (pv->context->hw_device_ctx)
        {
            int ret = av_buffer_replace(&hw_device_ctx, pv->context->hw_device_ctx);
            if (ret < 0)
            {
                return HB_WORK_ERROR;
            }
        }
#endif

        hb_avcodec_free_context(&pv->context);
        pv->context = context;

        pv->context->workaround_bugs   = FF_BUG_AUTODETECT;
        pv->context->err_recognition   = AV_EF_CRCCHECK;
        pv->context->error_concealment = FF_EC_GUESS_MVS|FF_EC_DEBLOCK;

#if HB_PROJECT_FEATURE_NVENC
        if (hw_device_ctx)
        {
            int ret = av_buffer_replace(&pv->context->hw_device_ctx, hw_device_ctx);
            av_buffer_unref(&hw_device_ctx);
            if (ret < 0)
            {
                return HB_WORK_ERROR;
            }
        }
#endif

#if HB_PROJECT_FEATURE_QSV
        if (pv->qsv.decode &&
            pv->qsv.config.io_pattern == MFX_IOPATTERN_OUT_VIDEO_MEMORY)
        {
            // set the QSV configuration before opening the decoder
            pv->context->hwaccel_context = &pv->qsv.config;
        }
#endif

        AVDictionary * av_opts = NULL;
        if (pv->title->flags & HBTF_NO_IDR)
        {
            av_dict_set( &av_opts, "flags", "output_corrupt", 0 );
        }

        // disable threaded decoding for scan, can cause crashes
        if ( hb_avcodec_open( pv->context, pv->codec, &av_opts, pv->threads ) )
        {
            av_dict_free( &av_opts );
            hb_log( "decavcodecvWork: avcodec_open failed" );
            // avcodec_open can fail due to incorrectly parsed extradata
            // so try again when this fails
            av_freep( &pv->context->extradata );
            pv->context->extradata_size = 0;
            return HB_WORK_OK;
        }
        pv->context->pkt_timebase.num = pv->title->video_timebase.num;
        pv->context->pkt_timebase.den = pv->title->video_timebase.den;
        av_dict_free( &av_opts );
        pv->video_codec_opened = 1;
    }

    decodeFrame(pv, &pv->packet_info);

    return HB_WORK_OK;
}

static void videoParserFlush(hb_work_object_t * w)
{
    hb_work_private_t * pv = w->private_data;
    int       result;
    uint8_t * pout = NULL;
    int       pout_len = 0;
    int64_t   parser_pts = AV_NOPTS_VALUE;
    int64_t   parser_dts = AV_NOPTS_VALUE;

    do
    {
        if (pv->parser)
        {
            av_parser_parse2(pv->parser, pv->context, &pout, &pout_len,
                                   NULL, 0,
                                   AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0 );
            parser_pts = pv->parser->pts;
            parser_dts = pv->parser->dts;
        }

        if (pout != NULL && pout_len > 0)
        {
            pv->packet_info.data         = pout;
            pv->packet_info.size         = pout_len;
            pv->packet_info.pts          = parser_pts;
            pv->packet_info.dts          = parser_dts;

            result = decodePacket(w);
            if (result != HB_WORK_OK)
            {
                break;
            }
            w->frame_count++;
        }
    } while (pout != NULL && pout_len > 0);
}

static int decavcodecvWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
                            hb_buffer_t ** buf_out )
{
    hb_work_private_t * pv     = w->private_data;
    hb_buffer_t       * in     = *buf_in;
    int                 result = HB_WORK_OK;

    *buf_out = NULL;

    // libavcodec/mpeg12dec.c requires buffers to be zero padded.
    // If not zero padded, it can get stuck in an infinite loop.
    // It's likely there are other decoders that expect the same.
    if (in->data != NULL)
    {
        memset(in->data + in->size, 0, in->alloc - in->size);
    }
    if (in->palette != NULL)
    {
        pv->palette = in->palette;
        in->palette = NULL;
    }

    /* if we got an empty buffer signaling end-of-stream send it downstream */
    if (in->s.flags & HB_BUF_FLAG_EOF)
    {
        if (pv->context != NULL && pv->context->codec != NULL)
        {
            videoParserFlush(w);
            while (decodeFrame(pv, NULL))
            {
                continue;
            }
        }
        hb_buffer_list_append(&pv->list, hb_buffer_dup(in));
        *buf_out = hb_buffer_list_clear(&pv->list);
        return HB_WORK_DONE;
    }

    /*
     * The following loop is a do..while because we need to handle both
     * data & the flush at the end (signaled by size=0). At the end there's
     * generally a frame in the parser & one or more frames in the decoder
     * (depending on the bframes setting).
     */
    int      pos, len;
    int64_t  pts = in->s.start;
    int64_t  dts = in->s.renderOffset;

    if (in->s.new_chap > 0)
    {
        pv->new_chap = in->s.new_chap;
        pv->chap_scr = in->s.scr_sequence;
        if (in->s.start != AV_NOPTS_VALUE)
        {
            pv->chap_time = in->s.start;
        }
        else
        {
            pv->chap_time = pv->last_pts + 1;
        }
    }
    if (in->s.start != AV_NOPTS_VALUE)
    {
        pv->last_pts = in->s.start;
    }

    // There are a 3 scenarios that can happen here.
    // 1. The buffer contains exactly one frame of data
    // 2. The buffer contains multiple frames of data
    // 3. The buffer contains a partial frame of data
    //
    // In scenario 2, we want to be sure that the timestamps are only
    // applied to the first frame in the buffer.  Additional frames
    // in the buffer will have their timestamps computed in sync.
    //
    // In scenario 3, we need to save the ancillary buffer info of an
    // unfinished frame so it can be applied when we receive the last
    // buffer of that frame.
    if (!pv->unfinished)
    {
        // New packet, and no previous data pending
        pv->packet_info.scr_sequence = in->s.scr_sequence;
        pv->packet_info.new_chap     = in->s.new_chap;
        pv->packet_info.frametype    = in->s.frametype;
        pv->packet_info.discard      = !!(in->s.flags & HB_FLAG_DISCARD);
    }
    for (pos = 0; pos < in->size; pos += len)
    {
        uint8_t * pout = NULL;
        int       pout_len = 0;
        int64_t   parser_pts, parser_dts;

        if (pv->parser)
        {
            int codec_id = pv->context->codec_id;
            len = av_parser_parse2(pv->parser, pv->context, &pout, &pout_len,
                                   in->data + pos, in->size - pos,
                                   pts, dts, 0 );
            parser_pts = pv->parser->pts;
            parser_dts = pv->parser->dts;
            pts = AV_NOPTS_VALUE;
            dts = AV_NOPTS_VALUE;

            if (codec_id != pv->context->codec_id)
            {
                // The parser has decided to change the decoder underneath
                // us.  Update our context to match.  This can happen
                // for MPEG-1/2 video, perhaps others
                pv->codec = avcodec_find_decoder(pv->context->codec_id);
            }
        }
        else
        {
            pout = in->data;
            len = pout_len = in->size;
            parser_pts = pts;
            parser_dts = dts;
        }

        if (pout != NULL && pout_len > 0)
        {
            pv->packet_info.data         = pout;
            pv->packet_info.size         = pout_len;
            pv->packet_info.pts          = parser_pts;
            pv->packet_info.dts          = parser_dts;

            result = decodePacket(w);
            if (result != HB_WORK_OK)
            {
                break;
            }
            w->frame_count++;

            // There could have been an unfinished packet that is now finished.
            // The next packet is associated with the input buffer, so set
            // it's chapter and scr info.
            pv->packet_info.scr_sequence = in->s.scr_sequence;
            pv->packet_info.new_chap     = in->s.new_chap;
            pv->packet_info.frametype    = in->s.frametype;
            pv->packet_info.discard      = !!(in->s.flags & HB_FLAG_DISCARD);
            pv->unfinished               = 0;
        }
        if (len > 0 && pout_len <= 0)
        {
            pv->unfinished = 1;
        }
    }
    *buf_out = hb_buffer_list_clear(&pv->list);

    return result;
}


static void compute_frame_duration( hb_work_private_t *pv )
{
    double duration = 0.;
    int64_t max_fps = 64LL;

    // context->time_base may be in fields, so set the max *fields* per second
    if ( pv->context->ticks_per_frame > 1 )
        max_fps *= pv->context->ticks_per_frame;

    if ( pv->title->opaque_priv )
    {
        // If ffmpeg is demuxing for us, it collects some additional
        // information about framerates that is often more accurate
        // than context->time_base.
        AVFormatContext *ic = (AVFormatContext*)pv->title->opaque_priv;
        AVStream *st = ic->streams[pv->title->video_id];
        if ( st->nb_frames && st->duration )
        {
            // compute the average frame duration from the total number
            // of frames & the total duration.
            duration = ( (double)st->duration * (double)st->time_base.num ) /
                       ( (double)st->nb_frames * (double)st->time_base.den );
        }
        // Raw demuxers set a default fps of 25 and do not parse
        // a value from the container.  So use the codec time_base
        // for raw demuxers.
        else if (ic->iformat->raw_codec_id == AV_CODEC_ID_NONE)
        {
            // XXX We don't have a frame count or duration so try to use the
            // far less reliable time base info in the stream.
            // Because the time bases are so screwed up, we only take values
            // in the range 8fps - 64fps.
            AVRational *tb = NULL;
            if ( st->avg_frame_rate.den * 64LL > st->avg_frame_rate.num &&
                 st->avg_frame_rate.num > st->avg_frame_rate.den * 8LL )
            {
                tb = &(st->avg_frame_rate);
                duration =  (double)tb->den / (double)tb->num;
            }
            else if ( st->time_base.num * 64LL > st->time_base.den &&
                      st->time_base.den > st->time_base.num * 8LL )
            {
                tb = &(st->time_base);
                duration =  (double)tb->num / (double)tb->den;
            }
        }
        if ( !duration &&
             pv->context->time_base.num * max_fps > pv->context->time_base.den &&
             pv->context->time_base.den > pv->context->time_base.num * 8LL )
        {
            duration =  (double)pv->context->time_base.num /
                        (double)pv->context->time_base.den;
            if ( pv->context->ticks_per_frame > 1 )
            {
                // for ffmpeg 0.5 & later, the H.264 & MPEG-2 time base is
                // field rate rather than frame rate so convert back to frames.
                duration *= pv->context->ticks_per_frame;
            }
        }
    }
    else
    {
        if ( pv->context->time_base.num * max_fps > pv->context->time_base.den &&
             pv->context->time_base.den > pv->context->time_base.num * 8LL )
        {
            duration =  (double)pv->context->time_base.num /
                            (double)pv->context->time_base.den;
            if ( pv->context->ticks_per_frame > 1 )
            {
                // for ffmpeg 0.5 & later, the H.264 & MPEG-2 time base is
                // field rate rather than frame rate so convert back to frames.
                duration *= pv->context->ticks_per_frame;
            }
        }
    }
    if ( duration == 0 )
    {
        // No valid timing info found in the stream, so pick some value
        duration = 1001. / 24000.;
    }
    pv->duration = duration * 90000.;
    pv->field_duration = pv->duration;
    if ( pv->context->ticks_per_frame > 1 )
    {
        pv->field_duration /= pv->context->ticks_per_frame;
    }
}

static int decavcodecvInfo( hb_work_object_t *w, hb_work_info_t *info )
{
    hb_work_private_t *pv = w->private_data;

    int clock_min, clock_max, clock;
    hb_video_framerate_get_limits(&clock_min, &clock_max, &clock);

    memset( info, 0, sizeof(*info) );

    if (pv->context == NULL || pv->context->codec == NULL)
        return 0;

    info->bitrate = pv->context->bit_rate;
    if (w->title->rotation == HB_ROTATION_90 ||
        w->title->rotation == HB_ROTATION_270)
    {
        // HandBrake's video pipeline uses yuv420 color.  This means all
        // dimensions must be even.  So we must adjust the dimensions
        // of incoming video if not even.
        info->geometry.width = pv->context->height & ~1;
        info->geometry.height = pv->context->width & ~1;

        info->geometry.par.num = pv->context->sample_aspect_ratio.den;
        info->geometry.par.den = pv->context->sample_aspect_ratio.num;
    }
    else
    {
        // HandBrake's video pipeline uses yuv420 color.  This means all
        // dimensions must be even.  So we must adjust the dimensions
        // of incoming video if not even.
        info->geometry.width = pv->context->width & ~1;
        info->geometry.height = pv->context->height & ~1;

        info->geometry.par.num = pv->context->sample_aspect_ratio.num;
        info->geometry.par.den = pv->context->sample_aspect_ratio.den;
    }

    compute_frame_duration( pv );
    info->rate.num = clock;
    info->rate.den = pv->duration * (clock / 90000.);

    info->profile = pv->context->profile;
    info->level = pv->context->level;
    info->name = pv->context->codec->name;

    info->pix_fmt        = pv->context->pix_fmt;
    info->color_prim     = pv->context->color_primaries;
    info->color_transfer = pv->context->color_trc;
    info->color_matrix   = pv->context->colorspace;
    info->color_range     = pv->context->color_range;
    info->chroma_location = pv->context->chroma_sample_location;

    info->video_decode_support = HB_DECODE_SUPPORT_SW;

#if HB_PROJECT_FEATURE_QSV
    if (hb_qsv_available())
    {
        if (hb_qsv_decode_is_codec_supported(hb_qsv_get_adapter_index(), pv->context->codec_id, pv->context->pix_fmt, pv->context->width, pv->context->height))
        {
            info->video_decode_support |= HB_DECODE_SUPPORT_QSV;
        }
    }
#endif

#if HB_PROJECT_FEATURE_NVENC
    if (hb_check_nvenc_available() && hb_nvdec_available(w->title->video_codec_param)){
        info->video_decode_support |= HB_DECODE_SUPPORT_NVDEC;
    }
#endif

    return 1;
}

static int decavcodecvBSInfo( hb_work_object_t *w, const hb_buffer_t *buf,
                              hb_work_info_t *info )
{
    return 0;
}

static void decavcodecvFlush( hb_work_object_t *w )
{
    hb_work_private_t *pv = w->private_data;

    if (pv->context != NULL && pv->context->codec != NULL)
    {
        hb_buffer_list_close(&pv->list);
        if ( pv->title->opaque_priv == NULL )
        {
            pv->video_codec_opened = 0;
            hb_avcodec_free_context(&pv->context);
            if ( pv->parser )
            {
                av_parser_close(pv->parser);
            }
            pv->parser = av_parser_init( w->codec_param );
            pv->context = avcodec_alloc_context3( pv->codec );
        }
        else
        {
            avcodec_flush_buffers( pv->context );
        }
    }
}

hb_work_object_t hb_decavcodecv =
{
    .id = WORK_DECAVCODECV,
    .name = "Video decoder (libavcodec)",
    .init = decavcodecvInit,
    .work = decavcodecvWork,
    .close = decavcodecClose,
    .flush = decavcodecvFlush,
    .info = decavcodecvInfo,
    .bsinfo = decavcodecvBSInfo
};

static void decodeAudio(hb_work_private_t *pv, packet_info_t * packet_info)
{
    AVCodecContext * context = pv->context;
    AVPacket       * avp = pv->pkt;
    int              ret;

    // libav does not supply timestamps for wmapro audio (possibly others)
    // if there is an input timestamp, initialize next_pts
    if (pv->next_pts     == (int64_t)AV_NOPTS_VALUE &&
        packet_info      != NULL &&
        packet_info->pts != AV_NOPTS_VALUE)
    {
        pv->next_pts = packet_info->pts;
    }
    if (packet_info != NULL)
    {
        avp->data = packet_info->data;
        avp->size = packet_info->size;
        avp->pts  = packet_info->pts;
        avp->dts  = AV_NOPTS_VALUE;
        avp->flags |= packet_info->discard * AV_PKT_FLAG_DISCARD;
    }
    else
    {
        avp->data = NULL;
        avp->size = 0;
    }

    ret = avcodec_send_packet(context, avp);
    if (ret < 0 && ret != AVERROR_EOF)
    {
        av_packet_unref(avp);
        return;
    }

    do
    {
        ret = avcodec_receive_frame(context, pv->frame);
        if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
        {
            ++pv->decode_errors;
        }
        if (ret < 0)
        {
            break;
        }

        hb_buffer_t * out;
        int           samplerate;

        // libavcoded doesn't yet consistently set frame->sample_rate
        if (pv->frame->sample_rate != 0)
        {
            samplerate = pv->frame->sample_rate;
        }
        else
        {
            samplerate = context->sample_rate;
        }
        pv->duration = (90000. * pv->frame->nb_samples / samplerate);

        int64_t pts = pv->frame->pts;
        double  duration = pv->duration;

        if (pv->audio->config.out.codec & HB_ACODEC_PASS_FLAG)
        {
            // Note that even though we are doing passthru, we had to decode
            // so that we know the stop time and the pts of the next audio
            // packet.
            out = hb_buffer_init(avp->size);
            memcpy(out->data, avp->data, avp->size);
        }
        else
        {
            AVFrameSideData *side_data;
            AVChannelLayout  channel_layout;
            if ((side_data =
                 av_frame_get_side_data(pv->frame,
                                AV_FRAME_DATA_DOWNMIX_INFO)) != NULL)
            {
                double          surround_mix_level, center_mix_level;
                AVDownmixInfo * downmix_info;

                downmix_info = (AVDownmixInfo*)side_data->data;
                if (pv->audio->config.out.mixdown == HB_AMIXDOWN_DOLBY ||
                    pv->audio->config.out.mixdown == HB_AMIXDOWN_DOLBYPLII)
                {
                    surround_mix_level = downmix_info->surround_mix_level_ltrt;
                    center_mix_level   = downmix_info->center_mix_level_ltrt;
                }
                else
                {
                    surround_mix_level = downmix_info->surround_mix_level;
                    center_mix_level   = downmix_info->center_mix_level;
                }
                hb_audio_resample_set_mix_levels(pv->resample,
                                                 surround_mix_level,
                                                 center_mix_level,
                                                 downmix_info->lfe_mix_level);
            }
            channel_layout = pv->frame->ch_layout;
            if (channel_layout.order != AV_CHANNEL_ORDER_NATIVE || channel_layout.u.mask == 0)
            {
                AVChannelLayout default_ch_layout;
                av_channel_layout_default(&default_ch_layout, pv->frame->ch_layout.nb_channels);
                channel_layout = default_ch_layout;
            }
            hb_audio_resample_set_channel_layout(pv->resample, channel_layout.u.mask);
            hb_audio_resample_set_sample_fmt(pv->resample,
                                             pv->frame->format);
            hb_audio_resample_set_sample_rate(pv->resample,
                                             pv->frame->sample_rate);
            if (hb_audio_resample_update(pv->resample))
            {
                hb_log("decavcodec: hb_audio_resample_update() failed");
                av_frame_unref(pv->frame);
                av_packet_unref(avp);
                return;
            }
            out = hb_audio_resample(pv->resample,
                                    (const uint8_t **)pv->frame->extended_data,
                                    pv->frame->nb_samples);
            if (out != NULL && pv->drop_samples > 0)
            {
                /* drop audio samples that are part of the encoder delay */
                int channels = hb_mixdown_get_discrete_channel_count(
                                                pv->audio->config.out.mixdown);
                int sample_size = channels * sizeof(float);
                int samples = out->size / sample_size;
                if (samples <= pv->drop_samples)
                {
                    hb_buffer_close(&out);
                    pv->drop_samples -= samples;
                }
                else
                {
                    int size = pv->drop_samples * sample_size;
                    double drop_duration = pv->drop_samples * 90000L /
                                           pv->audio->config.out.samplerate;
                    memmove(out->data, out->data + size, out->size - size);
                    out->size -= size;
                    pts += drop_duration;
                    duration -= drop_duration;
                    pv->drop_samples = 0;
                }
            }
        }

        if (out != NULL)
        {
            if (packet_info != NULL)
            {
                out->s.scr_sequence = packet_info->scr_sequence;
            }
            out->s.start        = pts;
            out->s.duration     = duration;
            if (out->s.start == AV_NOPTS_VALUE)
            {
                out->s.start = pv->next_pts;
            }
            else
            {
                pv->next_pts = out->s.start;
            }
            if (pv->next_pts != (int64_t)AV_NOPTS_VALUE)
            {
                pv->next_pts += pv->duration;
                out->s.stop  = pv->next_pts;
            }
            hb_buffer_list_append(&pv->list, out);
        }
        av_frame_unref(pv->frame);
        ++pv->nframes;
    } while (ret >= 0);
    av_packet_unref(avp);
}
