QuickTime HD and WMV HD audio channels are mixed up.

[heffeque]

QuickTime HD and WMV HD audio channels are mixed up.

How did I get to that conclusion? Well... I noticed that when playing QuickTime High Definition (h.264) trailers and WMV HD videos... when played with VLC... people talked in the back left channel instead in the front center one!

At first I though "that's odd..." and checked to see if that happened in their respective players (QuickTime and Windows Media Player 10) and in both of them all the talking was in the front center speaker. I tried BSPlayer and Media Player Classic and both of them have the 5.1 channels possitioned correctly too.

After that I checked other DivX, Xvid, DVD, etc videos that had 5.1 on VLC (0.8.4a) and the channels were working correctly so... that means that VLC is not working correctly only with those two types of HD formats.

I hope this info was of use.

Oh, and I have the "Force Dolby Surround" in Auto.

[heffeque]

From the other post:

I have looked for Multi Channel HD Trailers on QT's web site, haven't been able to find any. Run QT and check info, always says 2 channel.
Tried playing H.264 with AAC multi channel audio in QT and it doesn't work, plays video only. Web site says QT pro supports 20 some odd channels of sound, but I have not got it to play 5.1 in several tries with different files that should be compatible. Oddly enough these same files are being played and reported correctly in other programs. So this does seem to be a QT problem.

As for your problem! It sounds like you may have an up mixer that isn't preforming correctly.

This is kinda like WinDVD 7 that says it can play H.264 but crashes every time you try or gives you audio with a blue screen and then crashes. Seems that H.264 with AAC audio still has some compatibility problems between vendors. If the vendors are honest they will admit that it is a work in progress.

The "Poseidon" 720p Trailer is in 5.1 and so says QuickTime player. VLC says that it has 6 channels but when you go to the audio settings it only let's you select mono, stereo and "2 front 2 rear". This last one isn't selectable with 2 channel videos so it IS detecting something, but not correctly. It's in stereo by default and I put it in 2+2 and that's when the channels get mixed up and the center goes to another channel, in quick time format the center goes to front left speaker, in wmvhd it goes to the back left and DOES let you select 5.1, unlike the 2+2 of the qt format.

And if you check the trailer "Imagine me and you", it's coded in 5.1 but they only use the left and right channels (now that's dumb). Well VLC makes the left channel go to the back left speaker, if that's any help for you, VLC devs

[DJ]

In another post here today I learned that AAC is considered broken in VLC and has been placed on the to do list. I have experienced that the down mix from 5.1 to 2 channels is not correct, gain goes up more than 6db and is distorted. From your complaint however, I would still look at the up mix or 2 channel to surround as a possible problem. Files can be coded to be something they are not. Even had a DVD once that claimed it was 2 channel DTS (in more than 1 program) and was really 5.1 DTS. All I'm saying is everything is not always what it seems.

[heffeque]

A 2 channel DTS that's actually 5.1 is an existing format.
ratDVD actually does that, and with very good results.

[DJ]

A 2 channel DTS that's actually 5.1 is an existing format.
ratDVD actually does that, and with very good results.

All I'm saying is that I have seen these problems in commercial product and that it can effect how a player functions. In my opinion flags in a digital stream should never be miss set in any decent coder program.

[heffeque]

No need to be rude here! I read just fine thank you! Perhaps you are not understanding what has been said! In other posts here it has been explained that AAC is broken in VLC and to the best of my knowledge QT doesn't play wmv or at least it doesn't for me. What does it do in WMP 9 or 10?? Do DVDs ac3 files play correctly in both VLC and WMP 9 or 10??

Well... I didn't mean to be rude, just sarcastic. Oh, well.

I saw the AAC problem already, thanks anyway

Wmp 10 doesn't play qt-hd, or at least not in my computer.

As for ac3 it plays ok in vlc, wmp, bsplayer, mpc, etc.

[DJ]

No need to be rude here! I read just fine thank you! Perhaps you are not understanding what has been said! In other posts here it has been explained that AAC is broken in VLC and to the best of my knowledge QT doesn't play wmv or at least it doesn't for me. What does it do in WMP 9 or 10?? Do DVDs ac3 files play correctly in both VLC and WMP 9 or 10??

Well... I didn't mean to be rude, just sarcastic. Oh, well.

I saw the AAC problem already, thanks anyway

Wmp 10 doesn't play qt-hd, or at least not in my computer.

As for ac3 it plays ok in vlc, wmp, bsplayer, mpc, etc.

Then like the rest of us here, you are going to have to start monitoring the nightly builds until this is resolved.

[heffeque]

glad to know that it's a problem that's being worked on