do not reset duration_error for all streams, only reset current stream, fix wrong_fps.gxf

Originally committed as revision 12353 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/utils.c

@@ -1932,7 +1932,7 @@ int av_find_stream_info(AVFormatContext *ic)
 //                if(st->codec->codec_type == CODEC_TYPE_VIDEO)
 //                    av_log(NULL, AV_LOG_ERROR, "%f\n", dur);
                 if(duration_count[index] < 2)
-                    memset(duration_error, 0, MAX_STREAMS * sizeof(*duration_error));
+                    memset(duration_error[index], 0, sizeof(*duration_error));
                 for(i=1; i<MAX_STD_TIMEBASES; i++){
                     int framerate= get_std_framerate(i);
                     int ticks= lrintf(dur*framerate/(1001*12));