[FFmpeg-user] -t option in output parameter

Carl Eugen Hoyos ceffmpeg at gmail.com
Fri Aug 24 13:15:52 EEST 2018

2018-08-24 8:07 GMT+02:00, Axit Soni <aksprince2111 at gmail.com>:

> Whenever I am passing -t option in Output Parameter like,
> *ffmpeg -r 30 -i <input_fifo> -c copy -t 10 output.mp4*

Complete, uncut console output missing.

> I am expecting that my output.mp4 should have
> "30 FPS * 10 Seconds = exact 300 Frames". but output.mp4 file
> have frames between "270 frames to 300 frames".

I believe the input option -r is not completely reliable but
that is not necessarily the issue you have (see above).

> Any one knows this behavior than please let me know reason
> behind it.
> I also get information from another forum like, "-c copy option
> seeks thru IFrames only"... Is this information is correct.

How would this be related?

> How can I make sure that My output.mp4 file with exact
> 300 frames.

The -vframes option cames to mind...

Carl Eugen

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