patched ffmpeg nov 2

source/patched-ffmpeg-mt/libavcodec/pthread.c

 /*
  * Copyright (c) 2004 Roman Shaposhnik
  * Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)
  *
  * Many thanks to Steven M. Schultz for providing clever ideas and
  * to Michael Niedermayer <michaelni@gmx.at> for writing initial
  * implementation.
  *
  * This file is part of FFmpeg.
  *
@@ skipping 760 matching lines @@
         avctx->active_thread_type = FF_THREAD_SLICE;
 }
 
 int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
 {
     if (avctx->thread_opaque) {
         av_log(avctx, AV_LOG_ERROR, "avcodec_thread_init called after avcodec_open, this does nothing in ffmpeg-mt\n");
         return -1;
     }
 
-    avctx->thread_count = thread_count;
+    avctx->thread_count = FFMAX(1, thread_count);
 
     if (avctx->codec) {
         validate_thread_parameters(avctx);
 
         if (avctx->active_thread_type&FF_THREAD_SLICE)
             return thread_init(avctx);
         else if (avctx->active_thread_type&FF_THREAD_FRAME)
             return frame_thread_init(avctx);
     }
 
     return 0;
 }
 
 void avcodec_thread_free(AVCodecContext *avctx)
 {
     if (avctx->active_thread_type&FF_THREAD_FRAME)
         frame_thread_free(avctx, avctx->thread_count);
     else
         thread_free(avctx);
 }