[FFmpeg-devel] evaluating the experimental status of ffv1 version 3

[Peter B.]

I've now repeated the HD-and-beyond tests with the current git-head and
it seems that there actually are some problems with 2160p files (not
just "crowd_run").

When selecting 30 slices, the file can't be transcoded to FFv1, because
ffmpeg is segfaulting.

Here's commandline and uncut console output:

==============================
./ffmpeg -i "input/xiph-derf/ab_HD/crowd_run_2160p50.y4m" -an -vcodec
ffv1 -level 3 -context 0 -coder 0 -g 1 -threads 4 -strict experimental
-slices 30 -slicecrc 0
"/home/pb/Videos/ffv1-HD-probs/video/crowd_run_2160p50/crowd_run_2160p50-3l_0cn_0c_001g_04t_30s_0crc.avi"
-----------------------------

ffmpeg version N-44860-g74bd0cf Copyright (c) 2000-2012 the FFmpeg
developers
  built on Sep 29 2012 11:30:46 with gcc 4.6.1 (Ubuntu/Linaro
4.6.1-9ubuntu3)
  configuration: --prefix=/usr/local --enable-gpl --enable-nonfree
--enable-version3 --enable-postproc --enable-swscale --enable-avfilter
--enable-pthreads --enable-bzlib --enable-libmp3lame --enable-libvorbis
--enable-libxvid --enable-zlib --enable-libopenjpeg --enable-decoder=png
--enable-encoder=png --enable-libfreetype --enable-libschroedinger
  libavutil      51. 73.101 / 51. 73.101
  libavcodec     54. 61.100 / 54. 61.100
  libavformat    54. 29.105 / 54. 29.105
  libavdevice    54.  3.100 / 54.  3.100
  libavfilter     3. 18.100 /  3. 18.100
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 16.100 /  0. 16.100
  libpostproc    52.  1.100 / 52.  1.100
[yuv4mpegpipe @ 0x1939240] Stream #0: not enough frames to estimate
rate; consider increasing probesize
[yuv4mpegpipe @ 0x1939240] Estimating duration from bitrate, this may be
inaccurate
Input #0, yuv4mpegpipe, from 'input/xiph-derf/ab_HD/crowd_run_2160p50.y4m':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p,
3840x2160, SAR 1:1 DAR 16:9, 50 tbr, 50 tbn, 50 tbc
Output #0, avi, to
'/home/pb/Videos/ffv1-HD-probs/video/crowd_run_2160p50/crowd_run_2160p50-3l_0cn_0c_001g_04t_30s_0crc.avi':
  Metadata:
    ISFT            : Lavf54.29.105
    Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv420p, 3840x2160
[SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 50 tbn, 50 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> ffv1)
Press [q] to stop, [?] for help
./test_ffv1.sh: line 176: 17918 Segmentation fault      ./ffmpeg -i
"input/xiph-derf/ab_HD/crowd_run_2160p50.y4m" -an -vcodec ffv1 -level 3
-context 0 -coder 0 -g 1 -threads 4 -strict experimental -slices 30
-slicecrc 0
"/home/pb/Videos/ffv1-HD-probs/video/crowd_run_2160p50/crowd_run_2160p50-3l_0cn_0c_001g_04t_30s_0crc.avi"
Execution return value: 139
======================

With different values for "slices" (4 6 9 12 16 24), this does not
happen and the FFv1 file can be generated properly. Framemd5-checked.

Thanks,
Pb