Replacing windows audio decoder for TV - is it possible?

[fobos8]

Hi

I'm running windows 7 64 bit and I'd like to replace the audio codecs so I can tweak the settings for live TV. I'd like to know if anyone has successfully done this before I open up a hornets nest of installing and using different codecs.

I'm in the UK and SD TV has mpeg audio with mpeg2 video, and HD TV has dolby audio with H264 video.

Is it possible to JUST replace the audio codecs or do I have to do video aswell?

Kind regards, Andrew

[holidayboy]

Out of interest, how do you want to tweak the audio?

You might be aware already, you can use MCDU once you have some alternative codecs installed - such as ffdshow etc.

http://www.hack7mc.com/2009/04/media-ce ... ows-7.html


I did try a long (long, long) time ago to use third party video codecs but soon went back to the MS ones as I always had issues with either the SD or HD channels depending on what I was using.

[fobos8]

Hi Rob

I'd like to put a slight delay on the audio. I output my video via HDMI to plasma and audio to DAC and speakers via spdif from my soundcard.

This means I get audio slightly before the video.

With MCDU it looks like you disable the windows codec container and then specify your choice of audio AND video codecs. I'd really just like to do audio only as I've not read about many positive experiences of people using non windows media foundation codecs for live TV.

Any suggestions on how to introduce a delay? Unfortunately, there is no delay feature on my soundcard.

Cheers, Andrew

[Dan]

I tried this and broke my install so bad I had to roll back to an earlier image. I recommend you take a drive image before messing with the Microsoft decoders.

[barnabas1969]

I agree that you should make a system image before you mess with this. I assume that your audio system does not have a "lipsync" setting to adjust the delay? There was a previous thread where the poster had this issue with a set of speakers that simply takes a digital input, converts it to analog, amplifies it, and plays through some speakers. His system had no delay. He installed Haley Media Splitter and used the delay setting in the settings program for that software to adjust the delay. That's much safer than using a codec pack.

[holidayboy]

Was the other thread related to live tv, or video file playback?

MCDU just swaps the registry entries for the tv/dvd codec after taking ownership.
I've never had any issues with MCDU itself.

Codec packs are a different story.....

I'd still +1 the suggestion to create a system image / backup before you start though.

[holidayboy]

Hi Rob


With MCDU it looks like you disable the windows codec container and then specify your choice of audio AND video codecs. I'd really just like to do audio only as I've not read about many positive experiences of people using non windows media foundation codecs for live TV.

You can definitely use a non MS audio codec with the standard MS video codec using MCDU.

The tool does two things:

1. It takes ownership of the registry keys that tell Media Center which codecs to use for TV and DVD playback.

2. It sets the registry keys to use whatever you specify in the two boxes.

You can set the codecs back to default whenever you want.

Another codec to try might be AC3Filter

[fobos8]

You can definitely use a non MS audio codec with the standard MS video codec using MCDU.

Great - I'll try again when I get a spare hour.

Any idea where in the registry it renames the codecs? It would be useful to verify and see what is being used and changed.

Cheers, Andrew

[holidayboy]

The audio and video codecs for TV and DVD are here (ignore the MPEG2 part - they do the MPEG4/h.264 channels too, which is why swapping the video codec caused me issues):

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Decoder

I used DSFM from softella.com to find the correct CLSID to enter manually when I tried doing this during the TVPack2008 days - using MCDU is a lot easier!

[fobos8]

Well - almost there !

Installed AC3 Filter and used MCDU tool to replace the Microsoft Audio decoder with AC3.

TV works great and I can now get control of audio delay which is what I wanted - I now have it synchronized with video.

However......

I now can't play my downloaded films (.avi), home videos (.mp4) and some music files (.m4a).

However if I install Media Player Codec pack aswell I can play my home vids and all music files. Still I can't play the .avi files.

Any suggestions?

I tried using LAV audio which took over from the microsoft audio decoder for live TV but with this installed I couldn't play home vids (.mp4) or (.avi). Installing Media Player Codec pack aswell makes no difference.

Cheers, Andrew

[holidayboy]

You can try playing around with Win7DSFilterTweaker in order to use different codecs for various formats.

http://codecguide.com/windows7_preferre ... weaker.htm

This is where you definitely need a good backup/restore plan as using it can easily break stuff if you're not careful.

I suggest just changing one thing at a time and then test the system thoroughly before changing anything else!

[fobos8]

Okay thanks Rob

so to recap where I am now....... I have the AC3 filter set up as my preferred audio decoder for live TV and DVDs. I should leave this as it is and use Win7DSFilterTweaker to find some other codecs to decode the formats which now don't work, i.e. avi, mp4 and m4a.

is that what you mean?

Regards, Andrew

[holidayboy]

[fobos8]

Unfortunately I'm not getting anywhere with this. Have spend about 5 hours use the Tweaker tool and various codecs but haven't had any joy.

I don't understand why setting the WMC preferred audio decoder to be AC3 Filter can stop avi and mp4 files from working. Is it because these containers use a audio format not supported by AC3?

I seem to be groping around in the dark blindly trying different things to get this working . Can anyone explain to me what might be going on? This might help me find a solution.

Cheers, Andrew

[holidayboy]

Have you tried the disable media foundation options?

It's been a while since I used the tweaker, I'll try and test a few settings tomorrow.

[fobos8]

yes - I tried that, installed ffdshow 64 bit and set this as the preferred decoder for all the formats I could.

Good luck with your tests

[fobos8]

Rob - Is there any way to "see" which decoders media centre is trying to use for various formats? Might help to find out what is going wrong.

Can graph studio be set up to diagnose this?

[holidayboy]

OK, I've managed to set LAV for the TV audio codec and maintain playback of my mkv, avi, mpg and mp4 files. I don't have ffdshow installed right now to test.

http://code.google.com/p/lavfilters/downloads/list

This works on my HTPC and also a laptop but obviously we could well have different codecs installed etc so if this doesn't work right away, don't give up!

This is a bit weird but following these steps should work, let us know! (Make sure that Media Center is closed after each step):

1. Reset everything to defaults (both in the filter tweaker and MCDU).

2. Make sure playback of files and TV are OK. Close MC.

3. Set up any third party codecs for filetypes in the filter tweaker tool (I have mine all at default).

4. In the filter tweaker media foundation tab, disable media foundation for everything.

5. Make sure playback of files and TV are OK. Close MC.

6. Launch MCDU, click through the popups as usual and set the Audio codec to LAV and apply, click through the popups and then keep MCDU open.

7. Make sure TV playback is OK, run MC in windowed mode to confirm that LAV is decoding audio. You should find that file playback is now broken. Close MC.

8. On the MCDU window, untick the take ownership box, then set the codec back to the MS one and apply, click through popups.

9. Make sure that TV playback is OK (run MC in windowed mode and you should see that LAV is still decoding TV audio). See if file playback is OK...

[barnabas1969]

Can graph studio be set up to diagnose this?

Yes, it's a great little program.

[holidayboy]

I've used graphstudio in the past when a few of us were messing with the dump.ax filter to turn h.264 .wtv files into .ts files.

It's worth a look. You could run it a few times with various options set in the two utilities to see what shows up.