julguribye
Registered
What's the difference between Normal Stereo and Joint Stereo in the Mp3 encoder in iTunes?
Joint Stereo?
- Thread starter julguribye
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kenny
Registered
Normal Stereo is just what it says... Normal. That is, both channels are encoded independently at half the configured bitrate. For instance, if you specify 128kb MP3's, each of the channels will be encoded at 64kb. The advantage here is that stereo separation and imaging is more faithfully maintained, but because the actual bitrate of each stream is lower, the general quality suffers.
Joint Stereo attempts to encode the similarities for both channels as a single stream and the differences between the channels separately. I'm a little hazy on the technical details here, but the result is supposed to be that you use more of the effective bitrate for all of the music by encoding more efficiently. I've found that for general usage it sounds fine, but in A-B testing, the stereo image is flattened significantly.
Personally, I encode all my music as normal stereo at VBR with a minimum of 192kb. The files end up being nearly 50% larger, but the sure do sound a lot better than, say, 160kb joint. As always, your mileage may vary.
Joint Stereo attempts to encode the similarities for both channels as a single stream and the differences between the channels separately. I'm a little hazy on the technical details here, but the result is supposed to be that you use more of the effective bitrate for all of the music by encoding more efficiently. I've found that for general usage it sounds fine, but in A-B testing, the stereo image is flattened significantly.
Personally, I encode all my music as normal stereo at VBR with a minimum of 192kb. The files end up being nearly 50% larger, but the sure do sound a lot better than, say, 160kb joint. As always, your mileage may vary.
GadgetLover
Senior Member & Tech Guru
Originally posted by kenny
Personally, I encode all my music as normal stereo at VBR with a minimum of 192kb. The files end up being nearly 50% larger, but the sure do sound a lot better than, say, 160kb joint. As always, your mileage may vary.
But isn't VBR problematic in that many mp3-CD/DVD players and software players have problems with it (or can't decode it at all)?
julguribye
Registered
iPod can
kenny
Registered
I've not found anything that had fatal problems with VBR files. In fact, the only thing I've found that had any serious problems at all was mpg123 (a CLI player) on Linux. It'll sometimes report garbage in the header and refuse to play, but there's a switch (I think it's '-y', but I could be wrong - the machine is not on line @ the moment, but I can research if you need) that will essentially tell it to ignore the problem and continue, and it plays fine.
The other common issue is that the elapsed time indicator will not always show an accurate count of remaining time or even elapsed time while otherwise playing the file fine. I've seen this happen with XMMS (again, *nix) and an older hardware player I have, but it doesn't affect the playback other than showing the wrong times. It's more of a visual oddity than anything else.
Of course, more modern players don't have a problem at all. iTunes, Audion, WinAmp, SoundJam (how we miss thee
), et al. are fine with VBRs. And, as julguribye pointed out, iPod is quite happy with VBRs.