Multichannel audio via wav

[Cheech]

I did a fair amount of searching for this and I am quite amazed on the lack of info on this, especially the .pk file.

So here is the story, I am trying to get my avisynth script into WME, and keep the multichannel audio. As far as I know, WME does not support AC3 and if it does, I can't find a AC3 x64 decoder. So to get around this, when I make my d2v project via DGIndex, I check convert to wav. I read the manual on DG's site, and saw that this method alone would only save stereo, and if I wanted multichannel I would have to check the downmix box. When I do this, a PK file around 7MB appears, but I have no idea what its for or how to use it.

I would also like to confirm that this is in fact outputting mulitchannel audio so I downloaded the trial of cooledit pro, but as far as I can tell, it says its stereo, but since im not using the pk file, im sure that's why.

Also, this audio is supposed to be DD 5.1 according to my TP player that came with the capture card, and DGIndex calls it DD 3/2 384. I understand what 5.1 means, 5 channels and 1 sub, but 3/2 doesnt really mean anything to me (I could guess and say 3 front, 2 back, but what about sub?). Does the sub count as a channel? So I should be encoding this audio as 6 channel right?

[check]

I don't have WME installed, but from memory it didn't like avs scripts in general. The best way to input a 5.1 stream would be to convert the original ac3 to a 5.1 wave file with a tool such as BeLite. This will produce a file in the ~3-4gb range for a normal movie.
As to your questions:
1. The filesize is a good indicator, a stereo wave takes 192kbytes/sec (1.536Mbits/sec), while a 5.1 takes three times as much (576).
2. No idea sorry, never done my downmixing with DGindex
3. As above XD
4. See my first para, easiest way to convert to WMA through WME would be to input a wave. Have you considered using Nic's WME encoder which will accept AVS files as input? It's avail. in the alternative codecs section.
If you need an ac3 decoder, ffdshow will do it for you.

[Cheech]

I don't have WME installed, but from memory it didn't like avs scripts in general. The best way to input a 5.1 stream would be to convert the original ac3 to a 5.1 wave file with a tool such as BeLite. This will produce a file in the ~3-4gb range for a normal movie.
As to your questions:
1. The filesize is a good indicator, a stereo wave takes 192kbytes/sec (1.536Mbits/sec), while a 5.1 takes three times as much (576).
2. No idea sorry, never done my downmixing with DGindex
3. As above XD
4. See my first para, easiest way to convert to WMA through WME would be to input a wave. Have you considered using Nic's WME encoder which will accept AVS files as input? It's avail. in the alternative codecs section.
If you need an ac3 decoder, ffdshow will do it for you.
There is a new update to WME because of the pending WMP11 and the the new program to replace WME (Studio something), and this update allows for avs file imports. As for your other suggestions, I will try them, they look like it would work ;)

And don't leave me hanging about the 3/2 5.1 mumbo jumbo, surely you know what they mean.

[Guest]

I read the manual on DG's site, and saw that this method alone would only save stereo, and if I wanted multichannel I would have to check the downmix box. The manual doesn't say that. Can you point me to what you are talking about?

When I do this, a PK file around 7MB appears, but I have no idea what its for or how to use it. DGIndex does not create any file(s) with that extension.

[Cheech]

The manual doesn't say that. Can you point me to what you are talking about?

DGIndex does not create any file(s) with that extension.
AC3 supports up to 6 channels but when decoding to WAV only 2 channels (left and right stereo) can be output, so a process of downmixing is applied.

DGIndex sure seemed like it created the file, its odd how it appears every time I run DGIndex with that dowmix box checked, it might be Cool Edit Pro, let me check.

Edit: Yea its cool edit :P

[Guest]

Regarding your question about 5.1 versus 3_2:

The AC3 specification gives downmixing of the LFE channel as optional. In practice, it is dangerous, because loudspeakers can be overdriven by the full scale low frequency content of the LFE channel (which is intended for a special speaker called a subwoofer). That's why downmixing of the LFE is almost never implemented. Encoding 5.1 such that it can be played properly on one or two speakers is an art that is seriously complicated by downmixing the LFE channel.

http://www.ambisonic.net/dvda.html#bass

[Cheech]

So 3_2 is 3 front 2 rear with LFE downmixed into it?

[Guest]

So 3_2 is 3 front 2 rear with LFE downmixed into it? No. It means 5.1 without the LFE (maybe 5.0 would be better terminology, but 3_2 is in common use). Since almost no application downmixes the LFE (including DGIndex), DGIndex labels the source as 3_2. The LFE is not downmixed because it is a) complex to implement (needs rolloff), and b) dangerous to downmix it, and c) the LFE is often avoided anyway by content providers. There are more details in the article at the link I gave you.

[Cheech]

Please read the article at the link I gave you.
You edited that in later :mad:

Edit: Gah, you added more info, I should make it a habit of waiting 15 min after you post to read it.

[Guest]

Edit: Gah, you added more info, I should make it a habit of waiting 15 min after you post to read it. You know me. :)

[Cheech]

After all this work, I found out that only the left/right front channels had any audio, so I wasn't loosing anything by doing it the old way. At least I know for the future :)

[Guest]

Nevertheless, this is good info to add to the DGIndex manual. I'll do that.

[Cheech]

Oh wait, one last angle to cover. Since I'm using AVISynth to do my trimming I want the audio to be trimmed as well respectively. But how do I load the 6 individual wavs in the similar manner of
audio=WAVSource("Conan 25 PID 044 T01 3_2ch 384Kbps DELAY -243ms.wav") for all six channels?

And also how will WME react to this? If I can get the first question resolved, I can test the second. In case it is as easy as putting a whole bunch of audio= lines in, I will try that now.

[Guest]

Oh wait, one last angle to cover. Since I'm using AVISynth to do my trimming I want the audio to be trimmed as well respectively. But how do I load the 6 individual wavs in the similar manner of
audio=WAVSource("Conan 25 PID 044 T01 3_2ch 384Kbps DELAY -243ms.wav") for all six channels?

And also how will WME react to this? If I can get the first question resolved, I can test the second. In case it is as easy as putting a whole bunch of audio= lines in, I will try that now. You said you have only 2 channels, so why are you asking this? Just import the WAV and dub it with the video, then trim as required.

The on-line DGIndex manual has been updated:

http://neuron2.net/dgmpgdec/DGIndexManual.html

[Cheech]

Well I wanted to know for when I do have a 6 channel clip, but now I really don't care anymore :) I have been trying to encode this damned show for over 3 weeks, and it feels like I'm the first person to ever attempt encoding video, ever.

PS: Nice update on the manual, glad my dumb questions can help those who would never bother to ask.

This is really off topic, but what language do you use to code DGIndex? I decided to learn my first programming language and I chose python because of its ease or learning and supposely its a powerful language, the books should be coming sometime next week. After school gets out within the next month, I would like to work on the GUI on DGIndex (snazz it up), if its even possible with python, I guess I'll find out once I read the books and get a clue on whats up.

[Guest]

This is really off topic, but what language do you use to code DGIndex? Microsoft Visual C++ and lots of assembly code. I'm not the only coder; please see the credits listing in the manual.

I decided to learn my first programming language and I chose python because of its ease or learning and supposely its a powerful language, the books should be coming sometime next week. After school gets out within the next month, I would like to work on the GUI on DGIndex (snazz it up), if its even possible with python, I guess I'll find out once I read the books and get a clue on whats up. Python is usually considered to put performance low on the priority list versus other things, while users of video processing applications tend to put it at the top. Porting DGMPGDec to Python would be a massive project, especially for a beginning programmer.

If you want to make a career of programming, you're much better off learning C/C++.

What kinds of improvements to the DGIndex GUI are you thinking of?

[Cheech]

I wasn't thinking of making this a career, just a hobby. Perhaps when I feel confident with Python I will pickup C++. With the GUI, I would have to see what my options were, but you know, more colors, better buttons, fonts, I dunno, I would have to fool around with it to see what I could do.