[FFmpeg-devel] libavcodec/mpeg12.c Problem showed up in SVN-r18959

[Greg McCrory]

Index: libavcodec/mpeg12.c
===================================================================
--- libavcodec/mpeg12.c (revision 18958)
+++ libavcodec/mpeg12.c (revision 18959)
@@ -2226,7 +2226,7 @@
                  }
              }
              if(s && state == PICTURE_START_CODE){
-                ff_fetch_timestamp(s, i-4, 1);
+                ff_fetch_timestamp(s, i-3, 1);
              }
          }
      }


I don't know enough about what's happening here to know why i-4 was 
changed to i-3, but I do know that when the change was made, my ntsc dvd 
decodes started to exhibit jerky playback.

I have always used the following command line to encode for my iphone:

     nice -n 15 ffmpeg -v 1 -t 15 -i "$filename" -threads 1 -vcodec 
libx264 \
     -b 1200k -maxrate 1500k -refs 6 -subq 5 -r 23.976 \
     -me_method epzs -me_range 64 \
     -bf 0 -level 30 -g 300 -keyint_min 24 -sc_threshold 40 \
     -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.8 -qmax 51 -qdiff 4 -i_qfactor 
0.71428572 \
     -bufsize 2000k -cmp 1 -s 640x320 -f mp4 -dts_delta_threshold 1 
-async 800 \
     -acodec libfaac -ab 192k -ar 48000 -ac 2 \
     -y $outfilename.mp4

The above command line has always produced beautiful results, but with  
SVN-r18959 smooth playback is gone.  I changed i-3 to i-4 and 
recompiled--playback is once again smooth.

GMc