[FFmpeg-user] trim silent mp4 to rounded second?

[Carl Eugen Hoyos]

2016-11-29 13:03 GMT+01:00 Moritz Barsnick <barsnick at gmx.net>:
> On Mon, Nov 28, 2016 at 14:22:28 -0500, Erik Blankinship wrote:
>> For example, I want to trim a video to exactly 12 seconds (from 00:00:00.00
>> to 12 seconds).
>
> That may be a challenge...
>
>>     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 407 kb/s, 29.86 fps, 29.97 tbr, 90k tbn, 59.94 tbc (default)
>
> If the actual frame rate is 29.86 fps

His input video was created with libavformat (which cannot produce
valid vfr mov files) so if we assume a valid input file, the timebase
implies 30000/1001 fps.
The file may be invalid though.

Carl Eugen