Function imf_read_packet

libavformat/imfdec.c:767–889

}

static int imf_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    IMFVirtualTrackResourcePlaybackCtx *resource = NULL;
    int ret = 0;
    IMFVirtualTrackPlaybackCtx *track;
    int64_t delta_ts;
    AVStream *st;
    AVRational next_timestamp;

    track = get_next_track_with_minimum_timestamp(s);

    if (!track) {
        av_log(s, AV_LOG_ERROR, "No track found for playback\n");
        return AVERROR_INVALIDDATA;
    }

    av_log(s, AV_LOG_DEBUG, "Found track %d to read at timestamp %lf\n",
           track->index, av_q2d(track->current_timestamp));

    ret = get_resource_context_for_timestamp(s, track, &resource);
    if (ret)
        return ret;

    ret = av_read_frame(resource->ctx, pkt);
    if (ret)
        return ret;

    av_log(s, AV_LOG_DEBUG, "Got packet: pts=%" PRId64 ", dts=%" PRId64
            ", duration=%" PRId64 ", stream_index=%d, pos=%" PRId64
            ", time_base=" AVRATIONAL_FORMAT "\n", pkt->pts, pkt->dts, pkt->duration,
            pkt->stream_index, pkt->pos, AVRATIONAL_ARG(pkt->time_base));

    /* IMF resources contain only one stream */

    if (pkt->stream_index != 0)
        return AVERROR_INVALIDDATA;
    st = resource->ctx->streams[0];

    pkt->stream_index = track->index;

    /* adjust the packet PTS and DTS based on the temporal position of the resource within the timeline */

    ret = imf_time_to_ts(&delta_ts, resource->ts_offset, st->time_base);

    if (!ret) {
        if (pkt->pts != AV_NOPTS_VALUE)
            pkt->pts += delta_ts;
        if (pkt->dts != AV_NOPTS_VALUE)
            pkt->dts += delta_ts;
    } else {
        av_log(s, AV_LOG_WARNING, "Incoherent time stamp " AVRATIONAL_FORMAT
               " for time base " AVRATIONAL_FORMAT,
               AVRATIONAL_ARG(resource->ts_offset),
               AVRATIONAL_ARG(pkt->time_base));
    }

    /* advance the track timestamp by the packet duration */