SVQ3: Allow decoding if thread_count is > 1

svq3 still doesn't support multithreading, but it's simpler for clients if
they can enable threading for all codecs by default.

Originally committed as revision 26015 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -979,7 +979,7 @@ int ff_h264_frame_start(H264Context *h){
     /* can't be in alloc_tables because linesize isn't known there.
      * FIXME: redo bipred weight to not require extra buffer? */
     for(i = 0; i < s->avctx->thread_count; i++)
-        if(!h->thread_context[i]->s.obmc_scratchpad)
+        if(h->thread_context[i] && !h->thread_context[i]->s.obmc_scratchpad)
             h->thread_context[i]->s.obmc_scratchpad = av_malloc(16*2*s->linesize + 8*2*s->uvlinesize);
 
     /* some macroblocks can be accessed before they're available in case of lost slices, mbaff or threading*/

libavcodec/svq3.c

@@ -796,11 +796,6 @@ static av_cold int svq3_decode_init(AVCodecContext *avctx)
     unsigned char *extradata;
     unsigned int size;
 
-    if(avctx->thread_count > 1){
-        av_log(avctx, AV_LOG_ERROR, "SVQ3 does not support multithreaded decoding, patch welcome! (check latest SVN too)\n");
-        return -1;
-    }
-
     if (ff_h264_decode_init(avctx) < 0)
         return -1;