Function ff_frame_thread_encoder_init

libavcodec/frame_thread_encoder.c:120–273

}

av_cold int ff_frame_thread_encoder_init(AVCodecContext *avctx)
{
    int i=0;
    ThreadContext *c;
    AVCodecContext *thread_avctx = NULL;
    AVCodecParameters *par = NULL;
    int ret;

    if(   !(avctx->thread_type & FF_THREAD_FRAME)
       || !(avctx->codec->capabilities & AV_CODEC_CAP_FRAME_THREADS))
        return 0;

    if(   !avctx->thread_count
       && avctx->codec_id == AV_CODEC_ID_MJPEG
       && !(avctx->flags & AV_CODEC_FLAG_QSCALE)) {
        av_log(avctx, AV_LOG_DEBUG,
               "Forcing thread count to 1 for MJPEG encoding, use -thread_type slice "
               "or a constant quantizer if you want to use multiple cpu cores\n");
        avctx->thread_count = 1;
    }
    if(   avctx->thread_count > 1
       && avctx->codec_id == AV_CODEC_ID_MJPEG
       && !(avctx->flags & AV_CODEC_FLAG_QSCALE))
        av_log(avctx, AV_LOG_WARNING,
               "MJPEG CBR encoding works badly with frame multi-threading, consider "
               "using -threads 1, -thread_type slice or a constant quantizer.\n");

    if (avctx->codec_id == AV_CODEC_ID_HUFFYUV ||
        avctx->codec_id == AV_CODEC_ID_FFVHUFF) {
        int warn = 0;
        int64_t tmp;

        if (avctx->flags & AV_CODEC_FLAG_PASS1)
            warn = 1;
        else if (av_opt_get_int(avctx->priv_data, "context", 0, &tmp) >= 0 &&
                 tmp > 0) {
            warn = av_opt_get_int(avctx->priv_data, "non_deterministic", 0, &tmp) < 0
                   || !tmp;
        }
        // huffyuv does not support these with multiple frame threads currently
        if (warn) {
            av_log(avctx, AV_LOG_WARNING,
               "Forcing thread count to 1 for huffyuv encoding with first pass or context 1\n");
            avctx->thread_count = 1;
        }
    }

    if(!avctx->thread_count) {
        avctx->thread_count = av_cpu_count();
        avctx->thread_count = FFMIN(avctx->thread_count, MAX_THREADS);
    }

    if(avctx->thread_count <= 1)
        return 0;

    if(avctx->thread_count > MAX_THREADS)
        return AVERROR(EINVAL);