[FFmpeg-trac] #677(undetermined:new): Tell user when -t or -ss value exceeds input duration

FFmpeg trac at avcodec.org
Tue Nov 22 20:51:21 CET 2011


#677: Tell user when -t or -ss value exceeds input duration
-------------------------------------+-------------------------------------
               Reporter:  llogan     |                  Owner:
                   Type:             |                 Status:  new
  enhancement                        |              Component:
               Priority:  wish       |  undetermined
                Version:  git-       |               Keywords:
  master                             |               Blocking:
             Blocked By:             |  Analyzed by developer:  0
Reproduced by developer:  0          |
-------------------------------------+-------------------------------------
 Lately I've seen a few users on ffmpeg-user[1] and #ffmpeg[2] ask why
 their -t or -ss doesn't work, and in these cases it's because they are
 using a value that exceeds the input duration.

 Current behavior:
 {{{
 $ ffmpeg -ss 12 -i hop.mp4 -t 3 -y out.mpg
 ffmpeg version N-35078-g7831788, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Nov 22 2011 10:36:32 with gcc 4.6.2
   configuration: --prefix=/usr --enable-gpl
   libavutil    51. 26. 0 / 51. 26. 0
   libavcodec   53. 36. 0 / 53. 36. 0
   libavformat  53. 21. 0 / 53. 21. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 49. 0 /  2. 49. 0
   libswscale    2.  1. 0 /  2.  1. 0
   libpostproc  51.  2. 0 / 51.  2. 0
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'hop.mp4':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2avc1mp41
     creation_time   : 1970-01-01 00:00:00
     encoder         : Lavf52.32.0
   Duration: 00:00:10.13, start: 0.000000, bitrate: 563 kb/s
     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
 640x480, 559 kb/s, 30 fps, 30 tbr, 30 tbn, 60 tbc
     Metadata:
       creation_time   : 1970-01-01 00:00:00
       handler_name    :
 [buffer @ 0x17c1bc0] w:640 h:480 pixfmt:yuv420p tb:1/1000000 sar:0/1
 sws_param:
 [mpeg @ 0x17cb5e0] VBV buffer size not set, muxing may fail
 Output #0, mpeg, to 'out.mpg':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2avc1mp41
     creation_time   : 1970-01-01 00:00:00
     encoder         : Lavf53.21.0
     Stream #0:0(und): Video: mpeg1video, yuv420p, 640x480, q=2-31, 200
 kb/s, 90k tbn, 30 tbc
     Metadata:
       creation_time   : 1970-01-01 00:00:00
       handler_name    :
 Stream mapping:
   Stream #0:0 -> #0:0 (h264 -> mpeg1video)
 Press [q] to stop, [?] for help
 frame=    0 fps=  0 q=0.0 Lsize=       0kB time=00:00:00.00 bitrate=
 0.0kbits/s dup=0 drop=54
 video:0kB audio:0kB global headers:0kB muxing overhead -nan%
 }}}

 Output file is created, but with 0 bytes:
 {{{
 $ ls -lh out.mpg
 -rw-r--r-- 1 lou lou 0 Nov 22 10:42 out.mpg
 }}}

 The message could be something like: "Your -ss value exceeds the duration
 of your input. Aborting."

 I don't know if multiple inputs with different durations would complicate
 things.

 [1] http://ffmpeg.org/pipermail/ffmpeg-user/2011-November/003222.html
 [2] http://ffmpeg.org/pipermail/ffmpeg-devel-irc/2011-November/000309.html
 (21:45)

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/677>
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