[FFmpeg-user] how to drop an input stream

[Francois Visagie]

> -----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.