TMPGEnc MP2 Stereo formats

[geohei]

Hi.

When encoding video/audio with TMPGEnc, it offers 3 possibilities for stereo MP2:

1. Stereo
2. Joint-Stereo
3. Dual channel

- What is the optimum (quality wise), when space is not an issue?
- What are the differences.

Many thanks.

[bunyip]

I've wondered about that too - so I went searching the web and found this explanantion.

Stereo has 2 seperate channels, but the bitrate allocation between those two channels changes accordingly to the amount of information there is in each channel.

Joint stereo has 2 channels, but takes advantage of what is common between the channels, so the compression gain is higher.
Two of the most used joint stereo modes are IS (intensity stereo) and M/S (Mid/Side). M/S matrixing computes the sum and the difference of the two audio channels and stores these as two channels. This method is very efficient and is a lossless process, which means the two original channels can be extracted exactly as they were.
Intensity stereo replaces the left and right channels with a single signal plus directional information. This method is lossy and destroys DPL information. This method is only recommended at low bitrates.
Many encoders can use a combination of full stereo and either or both of these methods, deciding which to use on a per-frame basis.

Dual channel has 2 mono-channels, meaning each channel is encoded with half the bitrate of the overall bitrate.

It would seem from this that plain 'Stereo' is the best option to use.

[geohei]

... seems to be.

Thanks a lot for the investigation