[FFmpeg-user] Unable to trim certain MTS files unless I start from 0:00:00

[Simon Daniels]

Thanks Audrey. And apologies to ffmpeg-user as I think my message was sent
a few times :-(

I'm not seeing the * on my end so I believe that's an email formatting
issue.

I tried moving the -i to the first argument but I got the same results on
the latest GIT HEAD. It only trims correctly if starting from 0. Again,
it's only unique to these MTS files off my Panasonic Lumix camera. I've
trimmed other MTS files without issues.

Users-MacBook-Pro:ffmpeg-HEAD-a4a88fd user$ ./ffmpeg -i 00004.MTS -ss
00:00:01 -t 00:00:25 -threads 3 -acodec copy -vcodec copy "output.MTS"
ffmpeg version 0.10.2.git-a4a88fd Copyright (c) 2000-2012 the FFmpeg
developers
  built on Apr 19 2012 09:13:53 with llvm_gcc 4.2.1 (Based on Apple Inc.
build 5658) (LLVM build 2336.1.00)
  configuration: --enable-static --disable-shared --disable-outdev=sdl
--enable-runtime-cpudetect --disable-bzlib --disable-libfreetype
--disable-libopenjpeg --enable-zlib --arch=x86_64
--sysroot=/Developer/SDKs/MacOSX10.7.sdk --extra-cflags='-isysroot
/Developer/SDKs/MacOSX10.7.sdk'
  libavutil      51. 46.100 / 51. 46.100
  libavcodec     54. 14.101 / 54. 14.101
  libavformat    54.  3.100 / 54.  3.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 70.100 /  2. 70.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 11.100 /  0. 11.100
Input #0, mpegts, from '00004.MTS':
  Duration: 00:01:24.57, start: 0.632622, bitrate: 15063 kb/s
  Program 1
    Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p,
1280x720 [SAR 1:1 DAR 16:9], 29.97 fps, 29.97 tbr, 90k tbn, 119.88 tbc
    Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo,
s16, 192 kb/s
    Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] /
0x0090)
File 'output.MTS' already exists. Overwrite ? [y/N] y
muxrate VBR, pcr every 5 pkts, sdt every 200, pat/pmt every 40 pkts
Output #0, mpegts, to 'output.MTS':
  Metadata:
    encoder         : Lavf54.3.100
    Stream #0:0: Video: h264 (HDMV / 0x564D4448), yuv420p, 1280x720 [SAR
1:1 DAR 16:9], q=2-31, 29.97 fps, 90k tbn, 59.94 tbc
    Stream #0:1: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, 192 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame=    0 fps=0.0 q=-1.0 Lsize=     656kB time=00:00:00.00 bitrate=
0.0kbits/s
video:0kB audio:586kB global headers:0kB muxing overhead 11.958493%



On Thu, Apr 19, 2012 at 1:05 AM, Andrey Utkin <
andrey.krieger.utkin at gmail.com> wrote:

> 2012/4/19 Simon Daniels <simondaniels23 at gmail.com>:
> > Hi guys,
> >
> > I have a set of .MTS files that I'm trying to trim. If I start at
> 0:00:00,
> > the output video works fine. But if I start trimmingany time after
> 0:00:00,
> > the output video is empty. I've used the exact same command line with
> other
> > .MTS files and had no problem. It seems like something specific to this
> > Panasonic Lumix camera. MP4 and MOV files work fine too.
> >
> > This repros in FFmpeg HEAD-8dfb13e, 0.10.2, and 0.8.3.
> >
> > Any ideas? Thanks!
> >
> > Users-MacBook-Pro:ffmpeg-0.10.2 user$ *./ffmpeg -ss 00:00:01 -t 00:00:25
> -i
> > 00004.MTS -threads 3 -acodec copy -vcodec copy "output.MTS"*
>
> What do the * signs mean in cmdline?
>
> AFAIR, -ss, -t args position matters. Placing them before -i makes
> them work without transcoding, and after - with transcoding. Try
> second way, it will be more time expensive, but should generally work
> better.
> If my idea is right, and if you need to avoid transcoding, then
> probably your case requires writing tailored application.
>
> --
> Andrey Utkin
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>