[FFmpeg-user] To convert or not to convert

Rhodri James rhodri at kynesim.co.uk
Sun Dec 16 14:46:03 CET 2012

On Sat, 15 Dec 2012 20:21:54 -0000, Cecil Westerhof <Cecil at decebal.nl>  

> Op zaterdag 15 dec 2012 20:41 CET schreef Roger Pack:
>> On 12/15/12, Cecil Westerhof <Cecil at decebal.nl> wrote:


>>> I just bought a Canon SX240 HS. I made a short video for testing
>>> purposes. When looking at the input file with:
>>> ffmpeg -i MVI_0019.MOV
>>> I get:
>>> ffmpeg version 0.9.1, Copyright (c) 2000-2012 the FFmpeg developers
>>> built on Jan  6 2012 11:01:08 with gcc 4.6.2

A bit elderly, but I don't think this is your problem.


>>> I need to cut the start and the end from the video. That is not a
>>> problem. I was just wondering: should I do just a copy, or convert it
>>> to another format? I now have a warning,
>> Which warning are you referring to?
> The first line after showing all the used libraries:
>     Seems stream 0 codec frame rate differs from container frame rate:  
> 60000.00 (60000/1) -> 29.97 (30000/1001)

I think I've had this before.  IIRC, the camera codec fills in the .MOV  
file headers (the container) incorrectly.  Any sensible player will use  
the stream's frame rate anyway, so this isn't really a problem.

As to whether you should copy or convert, I recommend copying unless you  
have a pressing need to change the format.  Almost any conversion you do  
of video formats will reduce the quality of the video.

Rhodri James
Kynesim Ltd

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