[mythtv-users] OT? Timestretch playback of radio recordings

[John Pilkington]

John Pilkington wrote:
> Recordings from UK DVB-T radio stations come with a blank video stream, 
> and can be played within MythTV with timestretch.  I usually strip out 
> the mp2 sound to a smaller file and play this with RealPlayer, but 
> AFAICT this doesn't offer timestretch, and much Googling hasn't produced 
> clear suggestions.
> 
> Can anyone please recommend an mp2 player that offers speed control? 
> SoX, the soundtouch library and Audacity all apparently have some 
> capability but I'd like a user-friendly player as an rpm for FC5.
> 
I got no hits from this post, but found a reference by Mike Dean to
timestretch in (some versions of) xine:

> http://threebit.net/mail-archive/mythtv-users/msg48923.html

I mailed him off list and got these instructions.  They work for me -
although the stretch factor increments offered by the UI seem 
unnecessarily large.

Thanks, Mike.

> To allow you to verify you don't have it (since the UI isn't the most intuitive), here are some more specific instructions for enabling it:  first, right-click in the video window, select Audio|Postprocess|Chain Reaction...  Then select "stretch" for the filter.  Next, change "preserve_pitch" to "factor" and, finally, set the factor to the desired value (i.e. 0.8 or 0.75 or whatever--the default is 0.8, which is 1.25x).

John P