[FFmpeg-user] Starting to copy takes long

Cecil Westerhof Cecil at decebal.nl
Wed Mar 29 05:17:00 EEST 2017


On Wednesday 29 Mar 2017 02:32 CEST, James Darnley wrote:

> On 2017-03-29 02:04, Cley Faye wrote:
>> 2017-03-29 1:54 GMT+02:00 Cecil Westerhof <Cecil at decebal.nl>:
>>
>>> I want to copy a little bit of a video. I do this with:
>>> ffmpeg -i input.mov -ss 16:28 -t 5 output.mov
>>>
>>> But it takes about 2:20 before the copying starts. Is this normal?
>>>
>>
>> ‚ÄčTry moving the -ss part before your input. -ss before an input use
>> forward (if possible fast forward) on your source, while before an
>> output it means processing everything before, then start using the
>> output after the given time.
>
> Furthermore ffmpeg is not copying anything there.  You did not tell
> ffmpeg to copy.  It is encoding with (probably rubbish) defaults.

You are right. But it was only a temporary hack, because what I really
wanted was:
    ffmpeg -ss 16:28 -t 5 -i input.mov output%03d.jpg

But because I had the -ss and -t on the wrong place it took very long.
So I cut the piece I wanted to get the images from. (But in the wrong
way.)

Next time I should be more carefull.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


More information about the ffmpeg-user mailing list