Re: [mp3encoder] Encode or decode single frame

2003-11-26 Thread Branimir Amidzic
Gabriel Bouvigne wrote:
My suggestion would be the following:
*Decode the whole bitstream to pcm
*correct the offsets if needed in the pcm stream
*encode it again in full stereo
*do your cooking/mixing between the original mp3 and the new frames that 
you can grab from the new mp3.
OK, thanks for advices. But I need few more. :-)
Should I reencode VBR files with exact bitrates for every frame and with same 
order as in original file, or should I reencode with one average bitrate?

What about repeating previous frame, instead of reencoding?

Thanks again.

___
mp3encoder mailing list
[EMAIL PROTECTED]
http://minnie.tuhs.org/mailman/listinfo/mp3encoder


Re: [mp3encoder] Encode or decode single frame

2003-11-26 Thread Gabriel Bouvigne
Branimir Amidzic wrote:

Is it possible to decode one single frame of MP3 data (all of main data 
from
previous frame(s) concatenated) to 1152 samples of PCM, and then encode 
it to
just one MP3 frame with LAME?
Well, it is quite problematic because mp3 is using mdct, and this is an 
overlapping transform.

I'm developing an application that would reencode only those frames that 
don't
have coupled blocks in L & R channel (problem with HW players), but I have
noticed that LAME has some ENC/DEC delays, and that worries me.
It will not be a single frame. In current Lame, this would be at least 3 
granules. Short blocks need transition blocks before and after, so you 
have (minimal case) the following succession of sizes: long - start - 
short - stop - long.
You need to change the whole start-short-stop sequence.

My suggestion would be the following:
*Decode the whole bitstream to pcm
*correct the offsets if needed in the pcm stream
*encode it again in full stereo
*do your cooking/mixing between the original mp3 and the new frames that 
you can grab from the new mp3.

Regards,

--

Gabriel Bouvigne
www.mp3-tech.org
personal page: http://gabriel.mp3-tech.org
___
mp3encoder mailing list
[EMAIL PROTECTED]
http://minnie.tuhs.org/mailman/listinfo/mp3encoder


[mp3encoder] Encode or decode single frame

2003-11-26 Thread Branimir Amidzic
Is it possible to decode one single frame of MP3 data (all of main data from
previous frame(s) concatenated) to 1152 samples of PCM, and then encode it to
just one MP3 frame with LAME?
I'm developing an application that would reencode only those frames that don't
have coupled blocks in L & R channel (problem with HW players), but I have
noticed that LAME has some ENC/DEC delays, and that worries me.
Thanks in advance.



___
mp3encoder mailing list
[EMAIL PROTECTED]
http://minnie.tuhs.org/mailman/listinfo/mp3encoder