[Ffmpeg-devel] cutting a file and getting still images
Víctor Paesa
wzrlpy
Sat Nov 4 00:21:25 CET 2006
Hi,
> Cyrus A wrote:
>> Cyrus A wrote:
>>> V?ctor Paesa wrote:
>>>>> Hi,
>>>>>
>>>>>> Cyrus A wrote:
>>>>>>
>>>>>>> I'm trying to crop a 30-minute or hour-long segment of video down
>>>>>>> to 1
>>>>>>> minute and then immediately generate 60 still frames (one for each
>>>>>>> second) from the resulting chopped video.
>>>>>>>
>>>>>>> Here are the commands I used:
>>>>>>>
>>>>>>> long input file generated with:
>>>>>>> ffmpeg -v 0 -i /dev/video0 -async 1 -y -vcodec mpeg4 -acodec mp3 -t
>>>>>>> 1780 -b 1750k -ab 192 -s 480x384 -r ntsc -vtag DX50
>>>>>>> 'long_input_file.avi'
>>>>>>>
>>>>>>> "cut" command:
>>>>>>> ffmpeg -ss 180 -t 60 -y -vcodec copy -acodec copy -i
>>>>>>> long_input_file.avi short_output_file.avi
>>>>>>>
>>>>>>> still frames generation:
>>>>>>> ffmpeg -i short_output_file.avi -r 1 -f image2 frame%03d.jpg
>>>>>>>
>>>>>>>
>>>>>>> Console output for second command:
>>>>>>>
>>>>>>> FFmpeg version SVN-r6849, Copyright (c) 2000-2006 Fabrice
>>>>>>> Bellard, et
>>>>>>> al.
>>>>>>> configuration: --enable-mp3lame
>>>>>>> libavutil version: 49.0.2
>>>>>>> libavcodec version: 51.23.0
>>>>>>> libavformat version: 50.6.0
>>>>>>> built on Oct 31 2006 12:55:14, gcc: 4.1.1 20060525 (Red Hat
>>>>>>> 4.1.1-1)
>>>>>>>
>>>>>>> Seems that stream 0 comes from film source: 30000.00 (30000/1) ->
>>>>>>> 29.97 (30000/1001)
>>>>>>> Input #0, avi, from 'short_output_file.avi':
>>>>>>> Duration: 00:01:00.3, start: 0.000000, bitrate: 1972 kb/s
>>>>>>> Stream #0.0: Video: mpeg4, yuv420p, 480x384, 29.97 fps(r)
>>>>>>> Stream #0.1: Audio: mp3, 48000 Hz, stereo, 192 kb/s
>>>>>>> Output #0, image2, to 'frame%03d.jpg':
>>>>>>> Stream #0.0: Video: mjpeg, yuvj420p, 480x384, q=2-31, 200 kb/s,
>>>>>>> 1.00
>>>>>>> fps(c)
>>>>>>> Stream mapping:
>>>>>>> Stream #0.0 -> #0.0
>>>>>>> Press [q] to stop encoding
>>>>>>> frame= 1 q=5.9 Lsize= 0kB time=1.0 bitrate= 0.0kbits/s
>>>>>>> video:22kB audio:0kB global headers:0kB muxing overhead
>>>>>>> -100.000000%
>>>>>>>
>>>>>>> Result:
>>>>>>>
>>>>>>> Only the first image (frame001.jpg) is created.
>>>>>>>
>>>>>>> Observations:
>>>>>>>
>>>>>>> The ffmpeg long file generation command works well. The file
>>>>>>> looks and
>>>>>>> sounds good. Similarly,the "cutting" command above seems to work
>>>>>>> well.
>>>>>>> I can get any size video from any part of the longer video with
>>>>>>> ease.
>>>>>>> The videos play normally in mplayer as well as DivX and WMP on
>>>>>>> windows. However, it's the stills frame generation that seems
>>>>>>> broken.
>>>>>>> Two caveats:
>>>>>>>
>>>>>>> First, if the stills generation command is run on a file that was
>>>>>>> "cut" using "-ss 0 -t 60" (no seek), the stills are generated
>>>>>>> correctly. Anything other than "-ss 0" causes problems.
>>>>>>>
>>>>>>> Second, videos recorded by an old version of ffmpeg (0.4.8 --
>>>>>>> probably
>>>>>>> early 2005 or late 2004) seem to be "cut" and "stills extracted"
>>>>>>> correctly by the series of commands above.
>>>>>>>
>>>>>>> file command output for avi recorded with "old" ffmpeg and chopped
>>>>>>> with rev6849: RIFF (little-endian) data, AVI, 480 x 384, ~30 fps,
>>>>>>> video: DivX 4, audio: MPEG-1 Layer 3 (mono, 44100 Hz)
>>>>>>>
>>>>>>> file command output for avi recorded and chopped with rev6849: RIFF
>>>>>>> (little-endian) data, AVI, 480 x 384, ~30 fps, video: DivX 5,
>>>>>>> audio:
>>>>>>> MPEG-1 Layer 3 (stereo, 48000 Hz)
>>>>>>>
>>>>>>> I don't think the recording rate nor the DivX 4 vs DivX5
>>>>>>> differences
>>>>>>> have anything to do with my problem, but I could be wrong.
>>>>>>>
>>>>>>> FILES:
>>>>>>>
>>>>>>> A file recorded with "old" ffmpeg and chopped on rev 6849 can be
>>>>>>> found
>>>>>>> here:
>>>>>>>
>>>>>>> http://wkyt.dynalias.com/rec_with_old_chopped_with_6849.avi
>>>>>>>
>>>>>>> A file recorded with rev 6849 and chopped with rev 6849 can be
>>>>>>> found
>>>>>>> here:
>>>>>>>
>>>>>>> http://wkyt.dynalias.com/rec_with_6849_and_chopped_with_6849.avi
>>>>>>>
>>>>>>> Please let me know what you think of this problem. It is the very
>>>>>>> final step in a system I've been working on sporadically for about
>>>>>>> 9
>>>>>>> months. I might just take the rest of the week off if I can get
>>>>>>> this
>>>>>>> to work. Thanks again for your help.
>>>>>>>
>>>>>>> Cyrus
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> ffmpeg-devel mailing list
>>>>>>> ffmpeg-devel at mplayerhq.hu
>>>>>>> http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
>>>>>>>
>>>>>> Ok, apparently my last message was too long because nobody has
>>>>>> responded
>>>>>> yet. Just do this:
>>>>>>
>>>>>> Download this file:
>>>>>>
>>>>>> http://wkyt.dynalias.com/rec_with_6849_and_chopped_with_6849.avi
>>>>>>
>>>>>> and run the following command to get 1 still frame for each second
>>>>>> of
>>>>>> video:
>>>>>>
>>>>>> fmpeg -i rec_with_6849_and_chopped_with_6849.avi -r 1 -f image2
>>>>>> frame%03d.jpg
>>>>>>
>>>>>> Then tell me if it works.
>>>>>>
>>>>>>
>>>>> No, it's not long, it is a good description (and I appreciate it).
>>>>>
>>>>>
>>>> [snip]
>>>>
>>>>> I'll rebase to your SVN-6849, configure with --enable-mp3lame, and
>>>>> I'll tell you how it goes.
>>>>>
>>>>>
>>>>
>>>> Bad news, I'm not able to reproduce your problem, SVN-r6849 also
>>>> generates 62 frames:
>>>>
>>>> $ ./ffmpeg -i /cygdrive/n/rec_with_6849_and_chopped_with_6849.avi -r
>>>> 1 -f
>>>> image2 frame%03d.jpg
>>>> FFmpeg version SVN-r6849, Copyright (c) 2000-2006 Fabrice Bellard,
>>>> et al.
>>>> configuration: --enable-mp3lame --disable-shared
>>>> libavutil version: 49.0.2
>>>> libavcodec version: 51.23.0
>>>> libavformat version: 50.6.0
>>>> built on Nov 3 2006 21:46:54, gcc: 3.4.4 (cygming special) (gdc
>>>> 0.12,
>>>> using dmd 0.125)
>>>>
>>>> Seems that stream 0 comes from film source: 30000.00 (30000/1) ->
>>>> 29.97
>>>> (30000/1001)
>>>> Input #0, avi, from
>>>> '/cygdrive/n/rec_with_6849_and_chopped_with_6849.avi':
>>>> Duration: 00:01:00.0, start: 0.000000, bitrate: 1979 kb/s
>>>> Stream #0.0: Video: mpeg4, yuv420p, 480x384, 29.97 fps(r)
>>>> Stream #0.1: Audio: mp3, 48000 Hz, stereo, 192 kb/s
>>>> Output #0, image2, to 'frame%03d.jpg':
>>>> Stream #0.0: Video: mjpeg, yuvj420p, 480x384, q=2-31, 200 kb/s,
>>>> 1.00
>>>> fps(c)
>>>> Stream mapping:
>>>> Stream #0.0 -> #0.0
>>>> Press [q] to stop encoding
>>>> frame= 62 q=5.5 Lsize= 0kB time=62.0 bitrate= 0.0kbits/s
>>>> video:1705kB audio:0kB global headers:0kB muxing overhead -100.000000%
>>>>
>>>>
>>>> I'm afraid your problem is platform related. If you can, try to
>>>> build on
>>>> a different one (try "make distclean" before, just in case).
>>>>
>>>> Regards,
>>>> V?ctor
>>>> _______________________________________________
>>>> ffmpeg-devel mailing list
>>>> ffmpeg-devel at mplayerhq.hu
>>>> http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
>>>>
>>> This experiement was on FC5 x86_64 Athlong X2 with the latest 2.6.17
>>> RPM kernel. What kernel were you using?
>>> _______________________________________________
>>> ffmpeg-devel mailing list
>>> ffmpeg-devel at mplayerhq.hu
>>> http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
>> DOH! I must have made a mistake with the file I posted because it just
>> worked for me on that file, too.
>>
>> Try this file instead:
>>
>> http://wkyt.dynalias.com/rec_with_6849_and_chopped_with_6849_2.avi
>>
>> That file - just this minute - failed for me. Hopefully it'll fail for
>> you too.
>>
>> As I said in my long post, using -ss 0 to cut files seems to be ok. I
>> must have done that with the first file. Sorry.
>>
>> Cyrus
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at mplayerhq.hu
>> http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
> Here is the console output of the failure:
>
> [cyrus at wkyt ROOT]$ /home/cyrus/ffmpeg_6849/ffmpeg -i
> rec_with_6849_and_chopped_with_6849_2.avi -r 1 -f image2 frame%03d.jpg
> FFmpeg version SVN-r6849, Copyright (c) 2000-2006 Fabrice Bellard, et al.
> configuration: --enable-mp3lame
> libavutil version: 49.0.2
> libavcodec version: 51.23.0
> libavformat version: 50.6.0
> built on Oct 31 2006 12:55:14, gcc: 4.1.1 20060525 (Red Hat 4.1.1-1)
>
> Seems that stream 0 comes from film source: 30000.00 (30000/1) -> 29.97
> (30000/1001)
> Input #0, avi, from 'rec_with_6849_and_chopped_with_6849_2.avi':
> Duration: 00:01:00.2, start: 0.000000, bitrate: 1948 kb/s
> Stream #0.0: Video: mpeg4, yuv420p, 480x384, 29.97 fps(r)
> Stream #0.1: Audio: mp3, 44100 Hz, stereo, 192 kb/s
> Output #0, image2, to 'frame%03d.jpg':
> Stream #0.0: Video: mjpeg, yuvj420p, 480x384, q=2-31, 200 kb/s, 1.00
> fps(c)
> Stream mapping:
> Stream #0.0 -> #0.0
> Press [q] to stop encoding
> frame= 1 q=5.4 Lsize= 0kB time=1.0 bitrate= 0.0kbits/s
> video:22kB audio:0kB global headers:0kB muxing overhead -100.000000%
>
Reproduced with your rec_with_6849_and_chopped_with_6849_2.avi,
it must be a bug.
I'm not a real developer, and I don't know how to fix it, but
I have found that piping the file is a valid workaround, try it:
$ cat rec_with_6849_and_chopped_with_6849_2.avi |./ffmpeg -i - -r 1 -f
image2 frame%03d.jpg
FFmpeg version SVN-r6849, Copyright (c) 2000-2006 Fabrice Bellard, et al.
configuration: --enable-mp3lame --disable-shared
libavutil version: 49.0.2
libavcodec version: 51.23.0
libavformat version: 50.6.0
built on Nov 4 2006 00:08:02, gcc: 3.4.4 (cygming special) (gdc 0.12,
using dmd 0.125)
Seems that stream 0 comes from film source: 30000.00 (30000/1) -> 29.97
(30000/1001)
Input #0, avi, from 'pipe:':
Duration: 00:01:00.2, start: 0.000000, bitrate: N/A
Stream #0.0: Video: mpeg4, yuv420p, 480x384, 29.97 fps(r)
Stream #0.1: Audio: mp3, 44100 Hz, stereo, 192 kb/s
Output #0, image2, to 'frame%03d.jpg':
Stream #0.0: Video: mjpeg, yuvj420p, 480x384, q=2-31, 200 kb/s, 1.00
fps(c)
Stream mapping:
Stream #0.0 -> #0.0
frame= 62 q=5.4 Lsize= 0kB time=62.0 bitrate= 0.0kbits/s
video:1684kB audio:0kB global headers:0kB muxing overhead -100.000000%
Regards,
V?ctor
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