audio bitrares encoding

[Delta2]

hi,

If I have a source with audio data rate of 121 kbps, or another with 150 kbps...or another with 340 kbps...etc...

What values must I select for the audio data rate within CCE in order to get best quality and audio sync ?

must I select that original data rates for each one or can I select only one data rate for all of them ? say..encoding all at 256 kbps

[Skelsgard]

The data rate doesn´t control the speed of the audio, therefore its syching with the video.
To get best quality for a stereo source if to be compressed to MP2 then use at least 224 kbps. Something lower might sound still OK but I don´t know how complex it is the sound u´re trying to encode. I hope u don´t have a source with 121 kbps (as MP3) cause its a low quality data rate if to be recompressed.

[Delta2]

yes, some of them has a lower bitrate, 121 kbps

Can I recompress this audio to MP2 at 224 kbps ?

thanks for your opinion

[Skelsgard]

Yes, of course. U can compress at any rate u want. I t wonpt alter the synching of the audio.

[Delta2]

Thanks,

But a audio with 121 kbps converted to MP2 at 224 kbps, does it affect the quality ? ie, things like fade or bass and all that parameters from audio ?

[Skelsgard]

the problem in this case is not the amount of bitrate asigned to compress bt the fact that the source is already a compressed one. That means that information was discarded to get the sound to use 121 kbps instead of 1536 kbps (wich is the BR for a Uncompressed PCM WAV at 48kHz 16 bits stereo).
When the bitrate is generous, let´s say 192 and up (for MP3), the file has a very good quality, u pretty much can´t tell apart the uncompressed and the compressed files. But when the bitrate is cheap, let´s say anything below 144 kbps, u CAN tell the difference .
And now u are gonna recompressed form a low quality source to another low quality format (MP2). U see where I´m going with this?
224 for MP2 is enough to get the final MP2 to sound like the source file.