[FFmpeg-user] How can I use the fieldmatch filter to detelecine?

[L. Lee]

On 4/19/13 3:19 AM, "Carl Eugen Hoyos" <cehoyos at ag.or.at> wrote:

>L. Lee <llee040 <at> sbcglobal.net> writes:
>
>> https://dl.dropboxusercontent.com/u/42718751/Blockyclip_mpg.zip
>
>Could you test if the mpdecimate filter works better
>for this sample?
>$ ffmpeg -i sample -vf mpdecimate -r 24000/1001 -qscale 2 out.avi
>The fieldmatch filter does not help because your sample
>does not contain any interlaced frames, so there are no
>fields to match...
>In the future, the decimate filter will hopefully
>support dropping three of five frames.


Thanks. Well, that's interesting! I get a crash. Seems to be mpdecimate:

ffmpeg -i /sample.mpg -vf mpdecimate -r 24000/1001 -qscale 2 /sample.avi
ffmpeg version N-37959-g20e99a9 Copyright (c) 2000-2013 the FFmpeg
developers
  built on Apr 16 2013 13:28:23 with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
  configuration: --enable-filter=fieldmatch --enable-libmp3lame
--enable-gpl --enable-libfaac --enable-pthreads --enable-ffplay
--enable-nonfree --enable-libx264
  libavutil      52. 26.100 / 52. 26.100
  libavcodec     55.  2.100 / 55.  2.100
  libavformat    55.  2.100 / 55.  2.100
  libavdevice    55.  0.100 / 55.  0.100
  libavfilter     3. 56.101 /  3. 56.101
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  3.100 / 52.  3.100
[h264 @ 0x7fcd92021a00] mmco: unref short failure
    Last message repeated 1 times
Input #0, mpegts, from 'sample.mpg':
  Duration: 00:02:00.69, start: 1.404767, bitrate: 11454 kb/s
  Program 1 
    Stream #0:0[0x1011]: Video: h264 (Main) (HDMV / 0x564D4448), yuv420p,
1280x720 [SAR 1:1 DAR 16:9], 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc
    Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz,
5.1(side), fltp, 384 kb/s
Please use -q:a or -q:v, -qscale is ambiguous
Output #0, avi, to 'sample.avi':
  Metadata:
    ISFT            : Lavf55.2.100
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 1280x720 [SAR
1:1 DAR 16:9], q=2-31, 200 kb/s, 23.98 tbn, 23.98 tbc
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, fltp
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> mpeg4)
  Stream #0:1 -> #0:1 (ac3 -> libmp3lame)
Press [q] to stop, [?] for help
[h264 @ 0x7fcd928d2000] mmco: unref short failure
[h264 @ 0x7fcd928d3800] mmco: unref short failure
Segmentation fault: 11




>
>As an alternative, you could try to interlace your video
>to get the telecine pattern back (it appears your video
>was de-interlaced after telecine was used) and feed the
>result to fieldmatch. I am not saying that is the best
>option, but you could test:
>-vf interlace,fieldmatch...

This strategy gave me good results, and it didn't seem to take
significantly longer. Thanks!

Laine Lee