Play a OGG/OGM DS2

[fiorettoe]

How can I play a OGG/OGM file with surround2 tecnology?

another little question:
When I try to play a OGM file with Windows Media Player 6.4, the video is slow and the audio is trouble.

I have installed OoggDS 0.991

Thank You

[LigH]

Originally posted by fiorettoe
How can I play a OGG/OGM file with surround2 technology?

Because this is in general a stereo file (it contains only 2 channels), you may just play it with whatever equipment you have. If you just have stereo speakers or headphones attached, you will be able to listen to stereo sound, maybe with some kind of reverb-like sound.

If you give the audio from your soundcard to an A/V receiver which is able to decode Dolby Surround - ProLogic, then you can also enjoy some front/rear 3D effects if you have at least 4 speakers attached well. If you have more than 1 rear speaker, they may have the same volume, though - the original DS-DPL decoder only separates left/right and front/rear.

If your A/V receiver is even able to decode Dolby Surround - ProLogic II (or similar technologies with other names), and at least 5 speakers are attached well, then you may even be able to get different output on the left and right surround speaker.

You see: It all depends on the capabilities of your surround decoding engine; the surround information is matrix-encoded in a 2-channel audio so that listening with a lower-technology equipment shall not sound bad, but with a higher-technology equipment gives you even a little more surround impression.


The only kind of Ogg Vorbis audio file which could only be played with a multi-channel audio device (e.g. a true 6ch surround soundcard or studio sampling card) is a 6-channel Ogg file. But here I don't have any experience...

[kxy]

3 questions.

Let say the A/V receiver is able to decode Dolby Surround - ProLogic II, now would there be a distinct difference if the vorbis is encoded with lossly channel coupling or lossless channel coupling?

It was known that bitrate allocation gives a long jump from -q 4.99 to -q5. Does the lossy channel coupling degradating the quality too much, and not becoming progressively less lossy and seamlessly lossless?

Theory aside, can we hear a difference? I did some test, I notices that the rear speakers produce a echoing and warbling sound with lossly and a slight better (less warbling) with lossless. Of course it is not abx or anything so I might just being biased.

[frank]

fiorettoe,
for your OGG problem you should ask the OGG developers. The reason for trouble is the OGG DirectSound filter.
As I mentioned OGG is NOT a standard.
wav, mp3, mp2 are working well, take one of that formats and you are done!

[fiorettoe]

Thank you Frank!!!

I hope OGG will be a standard, cause it is IMHO very very good.

bye

[LigH]

@fiorettoe:

Did you try other players? ZoomPlayer or BSplayer may be a bit better for this task... May you have a slower PC (<400 MHz)? Ogg Vorbis decoding may take a bit more time than MP3.

[fiorettoe]

NO, the problem isn't the player or processore, but the "Audio renderer device" that the player use in the Graphedit Graph.

If I use "Defaul WaveOut Device" the sound is trouble, while with "Default Directsound Device" is all OK.

The cause is in OGGDS directshow filter.

Could be a bug.
bye

[kxy]

Anyone care to answer my 3 questions?

[LigH]

Originally posted by kxy
Anyone care to answer my 3 questions?

"Praxis is the only criterion of truth." -- With such a high quality, it shall hardly be noticeable. But as long as one doesn't try a very time-consuming listening test along with difference measuring, he won't be able to tell for sure.

In my opinion, it's quite useless to follow this question so far. When you are in the middle of watching an interesting movie, do you really care about hardly measurable differences? The loss of quality by downmixing from discrete channels to a surround matrix will be much more noticeable, I'd guess.

And finally: Isn't it possible with HeadAC3he to fix the lossiness of the stereo location encoding regardless of the chosen quality? And I remember that a special build of OggEnc is available (probably at the "Rare Warez" page) which always uses lossless stereo location encoding... -- Happy testing to everyone who insists in spending that much effort.

[ChristianHJW]

Originally posted by kxy
Let say the A/V receiver is able to decode Dolby Surround - ProLogic II, now would there be a distinct difference if the vorbis is encoded with lossly channel coupling or lossless channel coupling?

1. Didnt test it, but i assume it would as i noticed problems with rear channels ( but very very small, almost unhearable ) with Lame for bitrates < 130 kbps if 'joint Stereo' was used.
2. If 1. is correct, this will of course be fully depending on the bitrate you go for. At 160 kbps for sure not, at 64 kbps i bet it would, but 64 kbps Stereo with 'lossless' coupling is probably not a good idea either. It doesnt help much if your rear channels are properly decoded but the overall sound quality is shit.

Just out of my instinct i would say that you should be fine with bitrates > 100 kbps and lossless coupling.

It was known that bitrate allocation gives a long jump from -q 4.99 to -q5. Does the lossy channel coupling degradating the quality too much, and not becoming progressively less lossy and seamlessly lossless?

If lossy mode would degrade sound it wouldnt exist. In fact, for lower bitrates generally the opposite is the fact, means general audio quality gets better. Stereo imaging may be degraded a bit, while pre-echo, high frequency response and compression artefacts are much improved.
The problem with DPL is that a degraded channel separation can have noticeable effects on the rear channels ( artefacts like zirping sound ), that are being decoded from L and R by using a Matrix on them.

Theory aside, can we hear a difference? I did some test, I notices that the rear speakers produce a echoing and warbling sound with lossly and a slight better (less warbling) with lossless. Of course it is not abx or anything so I might just being biased.

I never had effects like this, but had my only experience here with lame MP3 tracks, not Vorbis tracks, and my laptop connected to my dads SONY TV with built in DPL decoder. I didnt hear echoing but we had clearly distortions, like the zirping sound i mentioned above. Maybe also a question of the quality of the DPL decoder, namely how good it can compensate phase shifts or similar ( dont know exactly ) between L/R.

I was playing with the lossy and non-lossy oggenc.exe when doing my world famous trial to prove that there is common sound information between soundtracks of different languages, in order to find out how much smaller filesize would be with full coupling compared to no coupling : http://forum.doom9.org/showthread.php?s=&threadid=22283&highlight=funtime

Worked like a charm, simply use OggdropXP on the WAV and rename the oggencNL.exe to oggenc.exe and you're done.