[FFmpeg-user] Question about conversion (Transcoding)

[Kieran O Leary]

On Wed, 19 Sep 2018, 17:36 JD, <jd1008 at gmail.com> wrote:

>
>
> On 09/18/2018 12:53 PM, Carl Eugen Hoyos wrote:
> > 2018-09-18 18:50 GMT+02:00, JD <jd1008 at gmail.com>:
> >> I have an mpeg2 file which I am trying to convert to a dvd iso.
> >>
> >> I am using dvdauthor to do it.
> >> dvdauthor says the file is not mpeg2 video compatible.
> >>
> >> When I run ffprobe on the file, I get this
> >>
> >> ffprobe /usr/tmp/title_3-09h31m23s.mpg
> >> ffprobe version N-51556-ge278500 Copyright (c) 2007-2013 the FFmpeg
> >> developers
> >>     built on Apr  4 2013 05:11:43 with gcc 4.6 (Debian 4.6.3-1)
> >>     configuration: --prefix=/root/ffmpeg-static/32bit --arch=x86_32
> >> --extra-cflags='-m32 -I/root/ffmpeg-static/32bit/include -static'
> >> --extra-ldflags='-m32 -L/root/ffmpeg-static/32bit/lib -static'
> >> --extra-libs='-lxml2 -lexpat -lfreetype' --enable-static
> >> --disable-shared --disable-ffserver --disable-doc --enable-bzlib
> >> --enable-zlib --enable-postproc --enable-runtime-cpudetect
> >> --enable-libx264 --enable-gpl --enable-libtheora --enable-libvorbis
> >> --enable-libmp3lame --enable-gray --enable-libass --enable-libfreetype
> >> --enable-libopenjpeg --enable-libspeex --enable-libvo-aacenc
> >> --enable-libvo-amrwbenc --enable-version3 --enable-libvpx
> >>     libavutil      52. 24.100 / 52. 24.100
> >>     libavcodec     55.  2.100 / 55.  2.100
> >>     libavformat    55.  1.100 / 55.  1.100
> >>     libavdevice    55.  0.100 / 55.  0.100
> >>     libavfilter     3. 49.100 /  3. 49.100
> >>     libswscale      2.  2.100 /  2.  2.100
> >>     libswresample   0. 17.102 /  0. 17.102
> >>     libpostproc    52.  2.100 / 52.  2.100
> >> [mpeg @ 0xab1d7c0] max_analyze_duration 5000000 reached at 5024000
> >> microseconds
> >> [mpeg @ 0xab1d7c0] Could not find codec parameters for stream 1 (Audio:
> >> ac3, 0 channels): unspecified sample format
> >> Consider increasing the value for the 'analyzeduration' and 'probesize'
> >> options
> >> [NULL @ 0xab1e760] start time is not set in estimate_timings_from_pts
> >> Input #0, mpeg, from '/usr/tmp/title_3-09h31m23s.mpg':
> >>     Duration: 02:10:42.11, start: 45337.301611, bitrate: 5391 kb/s
> >>       Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p, 720x480
> [SAR
> >> 32:27 DAR 16:9], 29.97 fps, 59.92 tbr, 90k tbn, 59.94 tbc
> >>       Stream #0:1[0x20]: Audio: ac3, 0 channels
> >>       Stream #0:2[0x80]: Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s
> >>
> >> So, how do I convert this file to a DVD compatible mpeg2 file?
> > Please try the following:
> > $ ffmpeg -i title_3-09h31m23s.mpg -target ntsc-dvd -acodec copy out.mpg
> >
> > If it does not work, you can try to remove "-acodec copy".
> >
> > Note that all dvd players I have seen also play the resulting
> > mpg file if I simply put it on a dvd (without using dvdauthor).
> >
> > You could also test with "-acodec copy -vcodec copy" to
> > maximize quality.
> >
> > Carl Eugen
> > _______________________________________________
> Hi Carl,
> Since it is a huge file (6GB), it is still transcoding
> per your ffmpeg incantation.
> I can only continue the operation for about 2 to 4 hours
> per day, on an old and slow laptop.
> So, before I suspend to disk, I "Control-Z" the program.
> So far it has processed about 2.5GB.
> But I WILL get back to you about how it turned out.


You can just add in -t 60 to Carl's command if you want to just process the
first minute and test if dvdauthor likes it or not?
ffmpeg -i title_3-09h31m23s.mpg -target ntsc-dvd -acodec copy -t 60
60sectest.mpg