[FFmpeg-user] how to drop an input stream

gheine at mathnmaps.com gheine at mathnmaps.com
Mon Sep 2 21:11:28 CEST 2013


Thanks for your assistance.

Tried

$ ffmpeg -i EE.mpg -map 0:1 -map 0:2  -target ntsc-dvd EEout.mpg

Output video, as you indicated, dropped the source data stream 0:0.
However, feeding EEout.mpg into dvdauthor generated exactly the same 
synchronization errors.

Next I tried writing the audio and video to separate files, changing
the format of the audio, and recombining:

$ ffmpeg -i EE.mpg -map 0:1    EEaud.wav
$ ffmpeg -i EE.mpg -map 0:2    EEvid.mpg
$ ffmpeg -i EEaud.wav -i EEvid.mpg  -target ntsc-dvd EEout.mpg

This worked (no warnings or errors from dvdauthor).

<<<<<<<<<<<<<<<< >>>>>>>>>>>>>>>>>

On 2013-09-02 01:52, Francois Visagie wrote:
>> -----Original Message-----
>> From: ffmpeg-user-bounces at ffmpeg.org [mailto:ffmpeg-user-
>> bounces at ffmpeg.org] On Behalf Of gheine at mathnmaps.com
>> Sent: 02 September 2013 00:28
>> To: ffmpeg-user at ffmpeg.org
>> Subject: [FFmpeg-user] how to drop an input stream
>> 
>> Have a short video clip ripped from a DVD (probably using mplayer -
>> dumpstream).
>> Here is what ffprobe says about the clip:
>> 
>> <CODE>
>> ffprobe version git-2013-08-25-626739e Copyright (c) 2007-2013 the 
>> FFmpeg
>> developers
>>    built on Aug 24 2013 20:38:02 with gcc 4.6 (Ubuntu/Linaro
>> 4.6.3-1ubuntu5)
>>    configuration: --prefix=/home/gheine/ffmpeg_build
>> --extra-cflags=-I/home/gheine/ffmpeg_build/include
>> --extra-ldflags=-L/home/gheine/ffmpeg_build/lib
>> --bindir=/home/gheine/bin --extra-libs=-ldl --enable-gpl 
>> --enable-libass
> --
>> enable-libfdk-aac --enable-libmp3lame --enable-libopus 
>> --enable-libtheora
> --
>> enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree
> --enable-
>> x11grab
>>    libavutil      52. 42.100 / 52. 42.100
>>    libavcodec     55. 29.100 / 55. 29.100
>>    libavformat    55. 14.102 / 55. 14.102
>>    libavdevice    55.  3.100 / 55.  3.100
>>    libavfilter     3. 82.102 /  3. 82.102
>>    libswscale      2.  5.100 /  2.  5.100
>>    libswresample   0. 17.103 /  0. 17.103
>>    libpostproc    52.  3.100 / 52.  3.100
>> [NULL @ 0xafe11e0] start time is not set in estimate_timings_from_pts
> Input
>> #0, mpeg, from 'EE.mpg':
>>    Duration: 00:00:36.45, start: 0.514689, bitrate: 6504 kb/s
>>      Stream #0:0[0x1bf]: Data: dvd_nav_packet
>>      Stream #0:1[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 448 kb/s
>>      Stream #0:2[0x1e0]: Video: mpeg2video (Main), yuv420p, 720x480 
>> [SAR
>> 8:9 DAR 4:3], max. 9000 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
>> Unsupported codec with id 1145979222 for input stream 0k </CODE>
>> 
>> What's the best way to get rid of that unwanted data stream 0:0 ?
> 
> Unless you explicitly include it with '-map', ffmpeg will automatically
> exclude the data stream. See the section on stream selection:
> http://www.ffmpeg.org/ffmpeg-all.html#Stream-selection.
> 
>> Followup question:  ultimate goal is to rewrite this clip onto another
> dvd.
>> Here is the result using dvdauthor:
>> <CODE>
>> $ dvdauthor  -o ../Test/ -t EE.mpg --video=ntsc DVDAuthor::dvdauthor,
>> version 0.7.0.
>> Build options: gnugetopt imagemagick iconv freetype fribidi fontconfig
> Send
>> bug reports to <dvdauthor-users at lists.sourceforge.net>
>> 
>> INFO: no default video format, must explicitly specify NTSC or PAL
>> INFO: dvdauthor creating VTS
>> STAT: Picking VTS 07
>> 
>> STAT: Processing EE.mpg...
>> WARN: Audio pts for channel 0 moves backwards by 2879; please 
>> remultiplex
>> input.
>> WARN: Previous sector: 0.500 - 0.564
>> WARN: Current sector: 0.532 - 0.564
>> WARN: Audio pts for channel 0 moves backwards by 1; please remultiplex
>> input.
>> WARN: Previous sector: 0.532 - 0.564
>> WARN: Current sector: 0.564 - 0.596
>> WARN: Audio pts for channel 0 moves backwards by 2; please remultiplex
>> input.
>> WARN: Previous sector: 0.948 - 0.980
>> WARN: Current sector: 0.979 - 1.011
>> ERR:  Cannot infer pts for VOBU if there is no audio or video and it 
>> is
> the
>> ERR:  first VOBU.`
>> </CODE>
>> Will getting rid of stream 0:0 fix this problem?
> 
> I doubt it (in the sense that the data stream doesn't look to be the 
> cause
> of the problems), but remultiplexing as suggested should help with the
> timestamp problems and will implicitly get rid of the data stream 
> anyway as
> above.
> 
> For remultiplexing, specify a target file type with '-target 
> {pal|ntsc}-dvd'
> as appropriate.
> 
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> ffmpeg-user at ffmpeg.org
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