32000Hz instead of 48000Hz?

[Vanilla Coke]

When I open the File Information window in VirtualDub, it says that the audio stream is encoded at 32000Hz instead of 48000Hz. I did not downsample the AC3 audio on either DVD2AVI (to create the d2v project) or BeSweet (to create a 96kbps mp3). Why is this? All the movies I download from KaZaA always have a 48000Hz audio stream. I followed Doom9's DivX 5 GordianKnot guide and always chose the 5.1 channel audio track, rather than just 2 channels.

Also, I cannot tell any difference when I convert either a 5.1 channel AC3 or a 2 channel AC3 into a regular 2 channel mp3 using BeSweet. I did select the "LFE to LR Channels" option for the 5.1 channel. Is there supposed to be a significant difference in sound quality? Thanks for addressing my newbie questions.

[Fox Mulder]

Quotes from the Sticky: Audio FAQ
http://forum.doom9.org/showthread.php?s=&threadid=7633

23) Why is my MP3 destination file downsampled to 32kHz or lower?
In latter versions of LAME(3.9x), it will automatically downsample audio for low bitrates(<128kbps)

3) AC3->MP3. which AC3 stream should i decode ? 5.1 or 2.0 ?
the 2.0 stream has a better mix for 2 channels, than the 5.1 to 2.0 downmix features offered by AC3 decoding tools. therefore, it should be the best to work with the 2.0 stream.
Transcoding the 5.1 and downmixing it manually can only be useful for users who has a surround system that has Dolby ProLogic II decoder.
Some of the 2.0 tracks weren't downmixed for DPL2, so you must take the origianl 5.1 track and downmix it with a transcoder that capable of doing it.
more info on Dolby ProLogic & Dolby Surround can be found here ! (http://forum.doom9.org/showthread.php?s=&threadid=34828)

[Vanilla Coke]

Cool. Thanks a bunch. I guess I better use 128 kbps instead of 96 now.

[Vanilla Coke]

Does OggMachine do the same automatic downsample as Lame? If so, what is the threshold kbps to keep the ogg track at 48000Hz?

[DSPguru]

nope. it doesn't.