'Cropping' a recorded radio programme

[dinkypumpkin]

On 11/06/2012 17:22, Mark Fraser wrote:
> On Monday 11 Jun 2012 16:12:58 Shevek wrote:
>> TL;DR - Use latest build of mp3DirectCut http://mpesch3.de1.cc/mp3dc.html
>
> What about for Linux users?

One low-tech alternative: If you can determine cut points with your 
media player, Audacity, etc., you can try using ffmpeg to crop your MP4 
audio files.  For example, the command below would skip 30 seconds at 
the beginning of the file (-ss parameter), copy the next 30 minutes of 
audio (-t parameter) to output and skip the remainder of the file:

ffmpeg -i input.m4a -ss 00:00:30 -t 00:30:00 -vn -acodec copy -y output.m4a

You can use sub-second time/duration values if you have that level of 
precision.  See the ffmpeg man page or online documentation.  This 
should also work on Debian/Ubuntu distros with libav-based ffmpeg or 
avconv.

This method has the tiny benefit of copying the metadata tags as well 
(but not artwork).  No fades around the cuts or anything like that, though.