[FFmpeg-devel] Regression: r20954-5 broke threads auto in libx264

[Måns Rullgård]

Jason Garrett-Glaser <darkshikari at gmail.com> writes:

> -threads 0 now no longer works to specify auto threads in libx264.  We
> have received a ton of complaints from users already about ffmpeg
> performance going down massively in the past few weeks.
>
> This is a serious regression.
>
> If nobody can come up with a reasonable fix for this in the next day
> or two, I will disconnect the threads option in libx264.c, forcing it
> to auto in all cases.

Something like this perhaps?

diff --git a/ffmpeg.c b/ffmpeg.c
index 4b956ba..5ab7f7c 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -2931,7 +2931,6 @@ static void opt_input_file(const char *filename)
     for(i=0;i<ic->nb_streams;i++) {
         AVStream *st = ic->streams[i];
         AVCodecContext *enc = st->codec;
-        if(thread_count>1)
             avcodec_thread_init(enc, thread_count);
         switch(enc->codec_type) {
         case CODEC_TYPE_AUDIO:
@@ -3066,7 +3065,6 @@ static void new_video_stream(AVFormatContext *oc)
     bitstream_filters[nb_output_files][oc->nb_streams - 1]= video_bitstream_filters;
     video_bitstream_filters= NULL;
 
-    if(thread_count>1)
         avcodec_thread_init(st->codec, thread_count);
 
     video_enc = st->codec;
@@ -3212,7 +3210,6 @@ static void new_audio_stream(AVFormatContext *oc)
     bitstream_filters[nb_output_files][oc->nb_streams - 1]= audio_bitstream_filters;
     audio_bitstream_filters= NULL;
 
-    if(thread_count>1)
         avcodec_thread_init(st->codec, thread_count);
 
     audio_enc = st->codec;
diff --git a/libavcodec/pthread.c b/libavcodec/pthread.c
index 556e546..60c82cd 100644
--- a/libavcodec/pthread.c
+++ b/libavcodec/pthread.c
@@ -145,6 +145,11 @@ int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
     int i;
     ThreadContext *c;
 
+    avctx->thread_count = thread_count;
+
+    if (thread_count <= 1)
+        return 0;
+
     c = av_mallocz(sizeof(ThreadContext));
     if (!c)
         return -1;
@@ -156,7 +161,6 @@ int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
     }
 
     avctx->thread_opaque = c;
-    avctx->thread_count = thread_count;
     c->current_job = 0;
     c->job_count = 0;
     c->job_size = 0;


-- 
M?ns Rullg?rd
mans at mansr.com