Guide: Stereo to 5.1 upmix using DPLII (2nd Ed.)

[joshbm]

Chainmax:

Yes I will write with more then just BeSweet and ffdshow in mind , but I believe that you will have to first output to wave. Then from there take the wave and input it into something like Surcode. Unless someone has devised a DirectShow filter to implement Surcode's AC3 Encoding.

ahgc:

Yes, AC3Filter works very nicely. This guide was written with AC3Filter in mind at the very first revision. It was shortly changed thereafter, due to channel swapping complications as well as lack of program revision. The only real difference that I would see a need to use ffdshow over AC3Filter is: the LFE sounds much better with ffdshow as well as ffdshow carries a multitude of different options-- such as: Resampling the audio to 48000 Khz on the fly and again if Channel Swapping was a necessity (as noted before, AC3Filter swaps channels improperly if an LFE is desired).

Regards,
Josh

[ahgc]

Ok.. still struggling .. Here's the situation:

-> 2 Channel WAV - 135m41s - 1.33GB
Running it through this process (either with ac3filter or ffdshow) I get
-> 6 Channel WAV - 135m15s - 3.99GB -> that's 26 sec missing!
But.. If I replace "WavDest+Filewriter" with "Dump" filter I get a 4.01GB file (not readable by player of course but most likely is complete with those 26 missing seconds)
My question is if the "WavDest+Filewriter" filter combination has any filesize limits. Thx
Regds,

Antonio

[ahgc]

Well after some testing here are my conclusions:

1. There is in fact some limitating factor concerning file size (destination). I believe it has to do either with WavDest filter or File Writer filter.
1.1. My solution was to split the source WAV into 2 and run them through graphedit separately. Then join them back toghether. Worked perfectly.

2. The resultant 6ch wav, when I run it through besweet to create the AC3, channels get swapped in some manner. But if I use the same besweet to separate the 6ch wav into 6 mono wav files, they come out correctly (filenames that is - C, LR, LF etc).
2.2 My solution is to use the tool on this thread by Amnon82, to use those six wav in the correct order, to mux them and create the new ac3!

Hope my experiences help someone. If there are simpler solutions please feel free to post
Regards,

Antonio

BTW: Found this great 6ch (wav and wma) on MS's site to test channels. It might be useful to most of us!

[joshbm]

Thanks for the post! I have a question, why not use ffdshow to channel swap? What channels are getting "mixed up"?

PS- I was also thinking that I'm glad ffdshow will soon support direct real-time AC3 encoding to a file-- because then you will not have to worry about the size of the file (you will also not have to use WavDest).

Regards,
Josh

[ahgc]

Yes, I am also anxiously waiting fot that feature!
About using ffdshow to do the channel swapping. It still didn't sound quite right on the output to me. But that was most likely due to some mistake I made.
I believe the channels that came out swapped were FR<->C , SR<->LFE and SL seamed to disappear. But I didn't do very extensive testing on this, so I am not quite sure on the accuracy of what I just said.

Regds

Antonio

[joshbm]

Guide updated with channel swapping . Thanks ahgc, Sakuya, and Sycho for pointing that out!

Regards,
Josh

[ahgc]

Thank you for putting out the correct channel swapping for ffdshow. Worked 5* here. Now only thing missing is really AC3 encoding
Regds,

Antonio

[ursamtl]

Originally posted by joshbm
Of course you can modify ffdshow settings to your liking as well as upmixing methods with Dolby Prologic II in InterVideo Audio Processor Fx such as Movie Mode and Music Mode. Sometimes I like to check "Sample Rate" and change the samplerate from 44100 Khz to 48000 Khz.

For those of you upmixing music, you might want to switch to Music mode because the default DPLII Movie mode is optimized (especially in terms of its steering logic) for movie soundtracks with centered dialog. According to Dolby documentation, this may inadvertently center vocals that are intentionally off-center, etc. The other settings such as Panorama, Dimension, Center width control, Autobalance, etc.

For more information on these settings, you can check out Dolby Surround Pro Logic II Decoder Principles of Operation. The Dolby Technical Library has several other informative articles.

Regards,
Steve.

[joshbm]

Thanks ursamtl, do you mind if I add that to the guide (of course with credit given )?

Regards,
Josh

[ursamtl]

Originally posted by joshbm
Thanks ursamtl, do you mind if I add that to the guide (of course with credit given )?

Regards,
Josh

Not at all! No need to credit me, it's just a link to the Dolby docs. Nice work on your guide, by the way. I'm glad to see you're updating it as the info and suggestions comes in.

Steve.

[joshbm]

Guide updated.

[ahgc]

Well I was looking for other upmix filters since both I've tried have these problems known to most of us:
- Cyberlink PowerDVD's filter only allows DPL I upmix (rear channels come out the same);
- Intervideo WinDVD's filter chops off one second or two at the beggining of the stream;
Any other filter that allows DPLII upmix?

Regds

Antonio

[joshbm]

Why don't you add a second before in your stereo source?

Regards,
Josh

[ahgc]

[editet - it was an unreadable mess]

Thx for the reply josh. So here's the problem after I looked into this closely.
The filter doesn't appear to actually "shorten" source's duration, but it "mutes" first second and a half (?) of it on the output.
So to perform what you suggested I would have to know that exact "mute" time, and then on the output 6ch wav remove the exact same time from the beggining. Of course experiments are always an option but very time consuming

Regds

Antonio

[joshbm]

Did some testing and came out somewhat confused.

Here is the results I received:

Input: 30.00 second, stereo wav (1000 Khz Sine pitch)
Output: 29.7525 second, 6-channel wav (1000 Khz Sine pitch), 1.5 seconds *almost exactly* (I am unsure if it is, breifly looked at it) at beginning was muted. Then a fade in was present (kinda weird).

I saved the stereo.wav file I used as well as the Center output channel. I can post my results, I'll get back to you with more information.

More testing to come.

Regards,
Josh

[joshbm]

I've done some other tests...

Test 1
Tones: 1

Input Length: 30.00 seconds
Input Channels: 2

Output Length: 29.7525 seconds
Output Channels: 6

Difference: 0.2475 seconds clipped off (where?)
Muted: ~1.5 seconds
___________________________

Test 2
Tones: 2

Input Length: 60 seconds
Input Channels: 2

Output Length: 59.7550 seconds
Output Channels: 6

Difference: 0.245 seconds clipped off
Muted: ~1.5 seconds

You can easily see the mute and the fade in as well as the delay.
___________________________


Regards,
Josh

[rca29]

I couldn't get this method to work with the Intervideo files provided here. I'm running XP Sp2 just for the record.
The problem is that i cannot select the prologic II (nor even prologic I mode) in the Intervideo Filter properties tab (following all the procedures) as they stay grey.
So i tried to use the (already) installed "Cyberlink Audio Effect" filter from Cyberlink's PowerDvd 5.0 .
All the steps remained the same as in this guide (including channel swap), with exception made to final ac3 encode made with SoftEncode (a personal taste here).

The results were great, so i thought sharing my experience.

Thanks a lot for this guide and good encodings

[joshbm]

Make sure you double click register.bat when you download the InterVideo files. Also be sure not to delete the files or move them once you have registered them. If that does not work, download and install the trial version of InterVideo.

About CyberLink Audio Effect, it only upmixes to Dolby Prologic I, even though you have selected DPLII. The rear channels are exactly the same.

PS- I am glad you have found this guide useful .

Regards,
Josh

[Sycho]

Originally posted by ahgc
- Cyberlink PowerDVD's filter only allows DPL I upmix (rear channels come out the same);

okay to clear up the hole cyberlink thing. The filter used by Power DVD is a Dolby Surround Pro Logic II decoder, but it only has Dolby Surround Pro Logic enabled, no Pro Logic II, just Pro Logic

[Sakuya]

This is kind of off topic but I got 20040828 of FFDSHOW and I cannot find Channel Swap on the list in FFDSHOW Audio Decorder properties. Version 20041012 won't work for me because after I installed that, whenever I open an AVI in Vdub or VdubMOD, I get an error like this:

Couldn't locate decompressor for format 'XVID'(unknown).
Virtualdub requires a Video for Windows (VFW) compatible codec to
decompress video. DirectShow codecs, such as those used by Windows Media Player, are not suitable. Only 'Direct Stream Copy' is available for this video.

And yes, all my videos play fine in every other player. When installing FFDSHOW, I did check all the filters related to Virtualdub. The only thing I unchecked not to install was the documents. Version 20040828 makes AVI files work in Vdub but it does not have Channel Swap.

For Versoin 20041012, I'm pretty sure it worked until I installed InterVideo DVD 6. I'm really sure of it! Right after I installed that, it wouldn't work in Vdub no more. Since you uploaded that ZIP file of filters, I uninstalled InterVideo. But it still won't work in Vdub. So I went to install a previous version and it worked. Any help is appreciated.