[mythtv] resampling & mythtranscode

Geoffrey Hausheer ou401cru02 at sneakemail.com
Wed May 21 17:19:02 EDT 2003

On Wed, 21 May 2003 15:24:10 -0400, "Craig Longman craigl-at-begeek.com
|mythtv/1.0-Allow|" <sa9nhe32c40t at sneakemail.com> said:
> what i want is to convert it from the native pvr-250 format (mpeg1/2 i 
> think) into mpeg-4, and drop the bitrate down for some things i want to 
> archive.
I thought my original code could do this part.  However, not having a
pvr250, there was no way to test it.  but if you have it working, that's

  i had also wanted to resample the audio down from 48K to 32K, 
> in some cases.
Yeah, this is not really supported in my original code.
> btw, i'm trying to figure out a decent way of calculating the max size 
> of the audioframe i could receive.  the code in ReencodeFile() sets a 
> variable called audioframesize to 4096 * 4, but i've seen that not big 
> enough, some calls to audiolen() produce frame sizes of 18K+.  i had 
> thought that taking samplerate*samplebytes*samplechannels/fps, but there 
> are definitely audioframes larger than that.
> is there any 100% reliable way of calculating the maximum decoded audio 
> bytes per frame?
I can't help you here.  The audio-init code in ReencodeFile was basically
just ripped out of the NuppelRecorder initialization (or was it TV_rec?),
as I recall.  I never really understood how this was set initially, so
perhaps Isaac can be of more help here.

(I'm glad that someone other than me uses the transcoder :)

  Geoffrey Hausheer

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