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Pale Blue Ego
2007-03-23, 12:38
I realize this is a specialized question perhaps better suited for another forum, but I thought I would post here first in hopes one of my fellow Squeezebox mates could point me in the right direction.

I'm archiving 3-hour internet radio shows (talk radio, not music) for my own personal use and would like to find a way to get rid of the ads. I have looked for specialized software to do this, and have not found anything useful. I do have software that does a great job of flagging ads in HDTV recordings for removal, but I'm having a hard time finding a solution to do this on an archived podcast or captured mp3 stream.

I can think of a couple methods that would possibly automate the process, the first being software that locates blocks of silence or perhaps some standard tone which is inserted by the broadcaster to signal a commercial.

Another method would be pattern-matching, where I could point the software to a directory of known ad recordings, and let it scan for matches in the full broadcast. I think this could be done with standard *nix tools and scripting, but I'm not yet skilled enough to do it myself.

One other possibility would be to mux the audio with a 3-hour video file and see if my HDTV software could find the ads. I'll explore that next if I don't get any leads to an audio-only solution, but I don't think it will work as I believe that software looks for a special video block to identify ads.

Thanks for reading this far and any help is appreciated.

matthijskoopmans
2007-03-24, 03:13
I believe the density in the sound during TV ads is higher than in regular TV broadcasts, resulting in a perceived higher volume (in some countries there are regulations on volume of advertisements, set by the broadcaster or the broadcasting authority. Increasing the density, and therefore the perceived volume, has the same attention grabbing effect). This is how your TV/HDrecorder can distinguish between advertisement and general content.

If same principle would apply on internet radio, theoretically the same trick could be applied.

notanatheist
2007-03-24, 23:02
More likely find something that will just do track splits at gaps greater than a certain length. Then manually remove the offensive material and re-encode.

Audacity (audacity.sourceforge.net) won't do it automatically but at least you can see a timeline on the audio and cut what you want out. It can import most audio formats and output depends upon encoders available.

hickinbottoms
2007-03-25, 01:20
I've also had some success with mp3splt, which does do this automatically:
http://mp3splt.sourceforge.net/mp3splt_page/home.php

I've not tried the GUI version, but the command-line version works fine
for me on Linux. You can tune the volume that constitutes silence and
the length of silence that is needed for a gap. With a little
experimentation I've managed to split programmes up quite well with the
options "-s -p th=-40".

Stuart


notanatheist wrote:
> More likely find something that will just do track splits at gaps
> greater than a certain length. Then manually remove the offensive
> material and re-encode.
>
> Audacity (audacity.sourceforge.net) won't do it automatically but at
> least you can see a timeline on the audio and cut what you want out. It
> can import most audio formats and output depends upon encoders
> available.
>
>
>