[FFmpeg-user] buffer underflow - processing VOB files

[Bob DeCarlo]

I located the fix for the core dump issue and create a patch:

$ git diff 91bb871376730a2394ed0ae1a3fd4295977002d3 0b86ea03d8415b5a3a6b07f3012a8097bca26ea5 >p.patch
Next, I applied this patch to commits and found this commit to be the one that causes by buffer under-run issue:  

$ git checkout ae9297097696f3d06417a6e8a5368d5f38a6edb4$ git apply p.patch # fixes core dump
... configure and make...
./ffmpeg -i ~/Videos/in.VOB -ss 50 -target ntsc-dvd -flags +cgop+ilme+ildct -alternate_scan 1 -top 1 -g 15 -sc_threshold 1000000000 -y out.VOB -v debug
The issue is reproduced and I believe  ae9297097696f3d06417a6e8a5368d5f38a6edb4 is where the issue was introduced, just after e5819fa62930966e6fb905cef21c985b91631d87.  I see from the code that some changes were made in ac3.

-Bob