Function mux_task_start

fftools/ffmpeg_sched.c:1115–1175

}

static int mux_task_start(SchMux *mux)
{
    int ret = 0;

    ret = task_start(&mux->task);
    if (ret < 0)
        return ret;

    /* flush the pre-muxing queues */
    while (1) {
        int       min_stream = -1;
        Timestamp min_ts     = { .ts = AV_NOPTS_VALUE };

        AVPacket *pkt;

        // find the stream with the earliest dts or EOF in pre-muxing queue
        for (unsigned i = 0; i < mux->nb_streams; i++) {
            SchMuxStream *ms = &mux->streams[i];

            if (av_fifo_peek(ms->pre_mux_queue.fifo, &pkt, 1, 0) < 0)
                continue;

            if (!pkt || pkt->dts == AV_NOPTS_VALUE) {
                min_stream = i;
                break;
            }

            if (min_ts.ts == AV_NOPTS_VALUE ||
                av_compare_ts(min_ts.ts, min_ts.tb, pkt->dts, pkt->time_base) > 0) {
                min_stream = i;
                min_ts     = (Timestamp){ .ts = pkt->dts, .tb = pkt->time_base };
            }
        }

        if (min_stream >= 0) {
            SchMuxStream *ms = &mux->streams[min_stream];

            ret = av_fifo_read(ms->pre_mux_queue.fifo, &pkt, 1);
            av_assert0(ret >= 0);

            if (pkt) {
                if (!ms->init_eof)
                    ret = tq_send(mux->queue, min_stream, pkt);
                av_packet_free(&pkt);
                if (ret == AVERROR_EOF)
                    ms->init_eof = 1;
                else if (ret < 0)
                    return ret;
            } else
                tq_send_finish(mux->queue, min_stream);

            continue;
        }

        break;
    }

    atomic_store(&mux->mux_started, 1);