ffdshow tryouts project: Discussion & Development

[rica]

Or another option is MPC-HC Audio Renderer with the contribution of albain:

http://forum.doom9.org/showthread.ph...73#post1331573

[rica]

BTW, MSDN document:

http://msdn.microsoft.com/en-us/libr...8VS.85%29.aspx


_ _ _ _ _ _ _

[Gerbrand]

Hello,

I do not know if this is the right place to post this, but I posted this issue over at avs and did not get an answer.

My issue is the following:

When playing a Blu-ray with LPCM (e.g. Casino Royale, Pirates of the Caribbean) through the following graph

MPC-HC internal splitter -> ffdshow audio -> reclock (encode to AC3) -> SPDIF

I am not getting sound from one of the two surround channels (somethings left and sometimes right).

I have narrowed the problem down to ffdshow audio (I am using build 3069): e.g. if I use MPC-HC's internal LPCM decoder it works fine. Also, if I use ffdshow audio's "swap channel" function I can swap the mute channel from left to right surround.

Ffdshow, reclock and my receiver all report 6 channels present.

Any idea what could be causing this? If I select the Dolby Digital track all works fine, DTS-HD also works (although I only get the core).

Thanks for helping out (or directing me to the right thread),

Gerbrand

[rica]

Sorry if i misunderstood:
You get LPCM (decoded as is via ffdshow) over what?
You get ac3 (pass-through) over SPDIF, it is fine?
And what are you trying to do: re-encode LPCM to ac3 and sent it to receiver?

[Gerbrand]

Sorry if I have not been clear enough.

What I try to do is the following: decode the LPCM using FFDshow, then reencode to AC3 using Reclock and output over SPDIF.

I only get this issue when I use ffdshow to decode the LPCM. If I use another decoder, it works fine. Also if I use another format (e.g. DTS) it works. I have tried it without Reclock (use FFDshow for the reencode) and I still get the same issue. So to me it seems it must definitely be ffdshow.

Any ideas?

Gerbrand

[rica]

Have no idea but i keep going not to understand why you are trying to downsample an LPCM of a Blu?
You don't have analog outputs or an HDMI output (like 4*** series has)?

Anyway, give it a go with this:

Originally Posted by albain

FFDShow TrueHD bitstream outputs Reclock IEEE Float mediatype

[rica]

Originally Posted by rica

BTW, MSDN document:

http://msdn.microsoft.com/en-us/libr...8VS.85%29.aspx

Seems MS only agreed with Dolby Laboratories.
DTS-HD support seems to be missing in WAVEFORMATEXTENSIBLE_IEC61937 as far as i understood?

[SamuriHL]

Um, what the? That seems rather ungood.

[whurlston]

Originally Posted by rica

Seems MS only agreed with Dolby Laboratories.
DTS_HD support is missing in WAVEFORMATEXTENSIBLE_IEC61937 as far as i understand.

It's not missing from the WAVEFORMATEXTENSIBLE_IEC61937, as mentioned in that document.

Support for DTS-HD compressed streams is missing from the Windows 7 HD Audio class driver: http://msdn.microsoft.com/en-us/library/dd567920.aspx

[rica]

Correct, thanks.

Note Not all the available formats are supported by the Windows 7 HD audio class driver. The formats supported by Windows 7 are indicated in the tables with an asterisk (*).

No asterisk on DTS-HD?

[Gerbrand]

Originally Posted by rica

Have no idea but i keep going not to understand why you are trying to downsample an LPCM of a Blu?
You don't have analog outputs or an HDMI output (like 4*** series has)?

My receiver does not have HDMI in and the analogue outs of my motherboard are not so good. I try to use the downsampled LPCM, because sometimes a different mix (more dynamics) is used for the HD audio formats than for the regular dolby digital tracks.

Anyway, I will give the link a try.

Gerbrand

[albain]

Originally Posted by Gerbrand

Sorry if I have not been clear enough.

What I try to do is the following: decode the LPCM using FFDshow, then reencode to AC3 using Reclock and output over SPDIF.

I only get this issue when I use ffdshow to decode the LPCM. If I use another decoder, it works fine. Also if I use another format (e.g. DTS) it works. I have tried it without Reclock (use FFDshow for the reencode) and I still get the same issue. So to me it seems it must definitely be ffdshow.

Any ideas?

Gerbrand

FFDShow has the ability to encode to AC3 : just check the AC3 box in the output section and see if it solves the problem

Also, provide the information about what is outputted by ffdshow : sample rate (48khz or more), number of channels, sample size (16 bits, 24 bits, ...)
And compare this information when you don't use ffdshow.


To bitstream testers : status summary
Everything you can see from the output of ffdshow is fully on our control. I can provide AC3,PCM mediatype or anyone else, use the windows 7 IEC structure or not...
So far I have tried several combinations with no success :

• AC3 SPDIF structure as for DD/DTS (beta 8, but IEC implementation was not correct, maybe a new test should be done) => Link to new build with AC3 media type
  Settings : IEC unchecked, use with Reclock. And in Reclock settings, uncheck "Enable audio timestretching" to avoid that reclock messes up with the data
• PCM output but with the right description of the compressed data (beta 9)
• PCM output with the new IEC structure (for windows 7) (not compatible with reclock, to be used on windows 7 and a compatible audio driver) (beta 9 + IEC checked)
• Same IEC structure but with the real compressed media type instead (beta 10 + IEC checked)
• The real compressed media type without IEC structure (beta 10)

Next steps :

• Work with MPC-HC team to bring the necessary modifications to the audio renderer (wasapi)
• Get some answers from Microsoft about the IEC implementation, from AMD about the bitstream implementation

About DTS-HD, this is the next step, the media type is there, there is just a lack of details but this is doable

[Inventive Software]

Originally Posted by clsid

If ffdshow doesn't load then it doesn't support the format.

And before you ask. If you want it to get added follow the following steps:
1) Open a feature request at the SourceForge project page
2) Include a sample file
3) Wait*

* This step may take forever. Certainly if it is a wma3 variant that is not yet supported by FFmpeg.

WMA Pro support recently got added to FFmpeg. I posted this twice already but it seems to have gotten buried in the bitstreaming discussion.

[THX-UltraII]

Originally Posted by Inventive Software

WMA Pro support recently got added to FFmpeg. I posted this twice already but it seems to have gotten buried in the bitstreaming discussion.

thanks for your reply.

But why is it then that ffdshow does not load (and of course not decode) the audio? I ve selected all the codecs to be sure but it just does not work.

[clsid]

@Inventive Software
I already knew that as I read the FFmpeg SVN log almost daily. It changes nothing, as there currently does not seem to be anyone with the time and willingness to add it to ffdshow. There are simply too few developers working on ffdshow at this moment.

@THX-UltraII
ffdshow does not include everything that FFmpeg does, only a subset.

[THX-UltraII]

Originally Posted by clsid

@Inventive Software
I already knew that as I read the FFmpeg SVN log almost daily. It changes nothing, as there currently does not seem to be anyone with the time and willingness to add it to ffdshow. There are simply too few developers working on ffdshow at this moment.

@THX-UltraII
ffdshow does not include everything that FFmpeg does, only a subset.

So for my 1400gb .mwv material ffdshow is just not usable?!

[albain]

Originally Posted by clsid

There are simply too few developers working on ffdshow at this moment.

Yes, this is annoying

[Inventive Software]

Originally Posted by clsid

@Inventive Software
I already knew that as I read the FFmpeg SVN log almost daily. It changes nothing, as there currently does not seem to be anyone with the time and willingness to add it to ffdshow. There are simply too few developers working on ffdshow at this moment.

What's required to get it working? I thought it was a case of plugging in the code, changing certain links to it, and compiling and away ya go. Yes I know in real life it's never as simple as that.

[albain]

Originally Posted by Inventive Software

What's required to get it working? I thought it was a case of plugging in the code, changing certain links to it, and compiling and away ya go. Yes I know in real life it's never as simple as that.

No, you must :
1/ declare a new decoder in FFDShow and add it to the interface (ffdshow.rc) in the codec section
2/ detect the input format according to the media type and assign the new decoder

[SamuriHL]

Originally Posted by albain;1331689
[B

To bitstream testers : status summary[/B]
Everything you can see from the output of ffdshow is fully on our control. I can provide AC3,PCM mediatype or anyone else, use the windows 7 IEC structure or not...
So far I have tried several combinations with no success :

• AC3 SPDIF structure as for DD/DTS (beta 8, but IEC implementation was not correct, maybe a new test should be done) => Link to new build with AC3 media type
  Settings : IEC unchecked, use with Reclock. And in Reclock settings, uncheck "Enable audio timestretching" to avoid that reclock messes up with the data
• PCM output but with the right description of the compressed data (beta 9)
• PCM output with the new IEC structure (for windows 7) (not compatible with reclock, to be used on windows 7 and a compatible audio driver) (beta 9 + IEC checked)
• Same IEC structure but with the real compressed media type instead (beta 10 + IEC checked)
• The real compressed media type without IEC structure (beta 10)

"The renderer accepted the change of media type but failed with reconnection"

That's with ReClock enabled, IEC unchecked, with the new AC3 build.