"Default" versus "MPEG Standard" quantization matrices

[Katie Boundary]

In Tsunami, is there any particular rule of thumb that I should use when deciding which matrices to use for which types of content? I've already been informed that the "animation" matrix is only for content made exclusively of "solid blocks of color" and not for stuff like Gargoyles where all the backgrounds are matte paintings.

[pandy]

Quantization matrices are unique for every video (picture) - some of them can be more universal, some less.
They work like low pass filter.
There is lot quantization matrices already available or you can try to find best matrix for your content.
Animation (flat) quantization matrix is generally neutral and if you have sufficient bitrate probably best one - it works more like all pass filter.

To generate optimal (unique for image) quantization matrix you may use: http://vision.arc.nasa.gov/dctune/

HCEnc has large quantization matrices available so it may be used also.

You may read this http://forum.doom9.org/showthread.php?t=54147 .
This is not easy topic.

[Katie Boundary]

I just need to know when to use the "MPEG standard" matrix and when to use Tsunami's "Default" matrix. I have no interest in going out of my way to find custom oddball matrices that were designed for niche purposes.

[Sharc]

Use the default, it's optimized for movie content at medium bitrates (few Mbit/s). It's the same as Cinemacraft is using btw.
MPEG standard matrix had to be included probably because it's the "standard" compromise for all kind of footage. If they had it not included people would probably have asked for it .......

[Katie Boundary]

Use the default, it's optimized for movie content at medium bitrates (few Mbit/s).

What about live-action footage at 1150 kbps or less?

MPEG standard matrix had to be included probably because it's the "standard" compromise for all kind of footage.

Does that make it the matrix to use for animated footage against painted backgrounds, like anime?

[filler56789]

What about live-action footage at 1150 kbps or less?

Low-bitrate encoding is done better with low-bitrate matrices,
such as KVCD, Avamat, Bach1, etc.

FWIW — I stopped using low-bitrate matrices for MPEG-2 encoding several years ago... Storage space became less expensive, and a desktop is much more versatile than a standalone DVD /BD player :)

P.S.: for the curious:

http://forum.doom9.org/showthread.php?t=104679

http://forum.doom9.org/showthread.php?t=128618

http://forum.doom9.org/showthread.php?t=126446

[Katie Boundary]

Low-bitrate encoding is done better with low-bitrate matrices,
such as KVCD, Avamat, Bach1, etc.

FWIW — I stopped using low-bitrate matrices for MPEG-2 encoding several years ago... Storage space became less expensive, and a desktop is much more versatile than a standalone DVD /BD player :)

P.S.: for the curious:

http://forum.doom9.org/showthread.php?t=104679

http://forum.doom9.org/showthread.php?t=128618

http://forum.doom9.org/showthread.php?t=126446

That doesn't really answer my predicament: when is it appropriate to use the "Default" matrix, and when is it appropriate to use the "MPEG standard" matrix?

[Sharc]

I understand you are encoding VCD resolution, mpeg-1, 1150kbps constant bit rate.
- Make 2 sample encodes for every source, one with default and one with standard matrix
- Watch the result on the device which is normally intended for viewing (PC monitor, old CRT or new large TV ....)
- Keep the version which you like better (less macroblocks vs sharpness). This is the "more appropriate" one.
- If in doubt use Tsunami's default, because the most appropriate matrix depends also on the particular encoder.

[Katie Boundary]

I understand you are encoding VCD resolution, mpeg-1, 1150kbps constant bit rate.

That's one of the projects on my agenda... one of many.

[pandy]

That doesn't really answer my predicament: when is it appropriate to use the "Default" matrix, and when is it appropriate to use the "MPEG standard" matrix?

There is no answer for your question - at least answer is not simple.

Original MPEG matrices was designed in end 80's and beginning 90's - for sure there can be better universal matrices and for sure there can be lot of specialized matrices and at some point there can be unique best matrices for every GOP (unless GOP=1 then for every picture - this will be the most optimal and best).

btw DCTune produce optimal matrices from PSNR perspective - they may be suboptimal from perceived/subjective perspective.

[filler56789]

That doesn't really answer my predicament: when is it appropriate to use the "Default" matrix, and when is it appropriate to use the "MPEG standard" matrix?

That depends a lot on *who you are* and on *what you want* as well

(yes$S, I'm a shameless B-5 fangirl).

According to manono, none of those two matrices is good enough (or at all) if one wants high-quality (re-)encodes.

And as I said before, low-quality && constant bitrate VCD encodes look less horrible when one uses a low-bitrate quantization matrix.

"Case Else",

just try different QMs, and see what happens.

End Sub

P.S.: I forgot the "End Select" before "End Sub". I guess I'm getting too old... :p