Function mpeg_decode_frame

libavcodec/mpeg12dec.c:2556–2621

}

static int mpeg_decode_frame(AVCodecContext *avctx, AVFrame *picture,
                             int *got_output, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int ret;
    int buf_size = avpkt->size;
    Mpeg1Context *s = avctx->priv_data;
    MPVContext *const s2 = &s->slice.c;

    if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
        /* special case for last picture */
        if (s2->low_delay == 0 && s2->next_pic.ptr) {
            int ret = av_frame_ref(picture, s2->next_pic.ptr->f);
            if (ret < 0)
                return ret;

            ff_mpv_unref_picture(&s2->next_pic);

            *got_output = 1;
        }
        return buf_size;
    }

    if (!s2->context_initialized &&
        (s2->codec_tag == AV_RL32("VCR2") || s2->codec_tag == AV_RL32("BW10")))
        vcr2_init_sequence(avctx);

    s->slice_count = 0;

    if (avctx->extradata && !s->extradata_decoded) {
        ret = decode_chunks(avctx, picture, got_output,
                            avctx->extradata, avctx->extradata_size);
        if (*got_output) {
            av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
            av_frame_unref(picture);
            *got_output = 0;
        }
        s->extradata_decoded = 1;
        if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
            ff_mpv_unref_picture(&s2->cur_pic);
            return ret;
        }
    }

    ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
    if (ret<0 || *got_output) {
        ff_mpv_unref_picture(&s2->cur_pic);

        if (s->timecode_frame_start != -1 && *got_output) {
            char tcbuf[AV_TIMECODE_STR_SIZE];
            AVFrameSideData *tcside = av_frame_new_side_data(picture,
                                                             AV_FRAME_DATA_GOP_TIMECODE,
                                                             sizeof(int64_t));
            if (!tcside)
                return AVERROR(ENOMEM);
            memcpy(tcside->data, &s->timecode_frame_start, sizeof(int64_t));

            av_timecode_make_mpeg_tc_string(tcbuf, s->timecode_frame_start);