Why is MPC perceived to be the best?, (an off-topic audio encoding discussion) Options

[ScorLibran]

This is a question that has floated through my mind for most of a year, but only yesterday became more clear to me.

Actually, it's a two-part question...

... 1. Is MPC commonly accepted among the HA community as the best psychoacoustic encoding format? (i.e., the most efficient at achieving perceptual transparency.)

... 2. If so, why?

The first item I've heard stated quite frequently, but have never seen any results of "transparency threshold tests" that would reveal the superior efficiency of MPC. I've heard that MPC uses superior encoding technology, but I'm referring more to the end result of such development efforts...the perceived sound quality, as measured against other codecs at the point of perceptual transparency for a significant number of people.

These concerns on my part were born from a post I made here, where the points of MPC statistically tying other formats at 128kbps, but no other known test results existing, were brought up. The thread portion ended up in the recycle bin, but I'm taking the chance that my concerns about calling MPC "the best" weren't the reason it was put there.

Hence, I want to bring up this idea in a different context in the off-topic forum (in the hope that this will be the correct area for it).

What I'd like to see, for instance, for the education of myself and others, would be a results summary like the following (though this is a very simplistic example)...

Format............Perceptual Transparency Threshold (nominal bitrate across samples tested)
MPC.................nnn kbps
AAC.................nnn kbps
Vorbis..............nnn kbps

...and so forth

Granted, VBR is more efficient at mid-bitrates and up, and quality-based VBR modes aren't bitrate centric, but we need some means of measurement and comparison between codecs in this context, so if not calling it "nominal bitrate", then perhaps "average filesize per minute of audio across all samples"

Perceptual Transparency Threshold could have a fixed target, like >90% samples with 5.0 subjective ratings, and non-differentiable from reference with ABX testing.

This kind of test has been discussed before, and has been mostly viewed as having little "real-world value". And I agree. Roberto's tests are much more relevant for most music listeners, and for determining the best formats for useful purposes like streaming audio, portable players, etc.

Many of us (including me) have trouble testing even these bitrate ranges, so higher ones would be even more tedious, and would answer not as many pressing questions.

My point, though, is how can MPC be called "the best for achieving transparency" without a test such as this? (Because so far it's been shown to be only "among the best" at lower rates.)

[ScorLibran]

This "Really Big Codec Test" sounds exciting... did momentum for it die out?  It looks like a ton of work butit would be incredibly helpful for a lot of people if it were carried out... What happened?

As I said on the previous page, the timeframe will be May-June, but may be pushed a little farther out than that to take other scheduling issues into account (June-July?).

And it will be a great deal of work, especially luring enough people to participate to make the results statistically significant. But against popular belief, this won't necessarily be a "high-bitrate" test. People don't like testing high bitrates because they can't distinguish artifacts (or only with great difficulty). That means a lower bitrate range should be used anyway. Maybe a range like 96kbps to 192kbps (VBR wherever possible/available), so that most people will distinguish variances more easily in part of this range. They'll actually stop testing once they can't tell the test sample from the reference, as finding their transparency threshold for that sample and format will be the entire goal of the test.

I'll tentatively plan on starting the official discussion for this test soon after Roberto finishes his dial-up bitrate test.