Hi,

I am a DirectShow developper (from FFDShow dev. team actually) and I am
facing a problem that did not occur with windows media player 10.

The goal is the following : make WMP load a codec for decoding a given
format (for example H264), and load another filter that would perform
postprocessing upon the out uncompressed stream.
WMP 10 made this job : when it loads, it consults all the codecs for
decoding the input format, and then consults all the codecs that would be
able to receive uncompressed format eventually.
With WMP11, this no longer happens.
Can you tell me if something has changed, and if there is any option to set
or developments to be made ?

Thanks by advance

Regards,
Damien Bain-Thouverez

On Tue, 17 Jul 2007 13:32:04 -0700, Damien BT <Damien
BT@discussions.microsoft.com> wrote:

>Hi,
>
>I am a DirectShow developper (from FFDShow dev. team actually) and I am
>facing a problem that did not occur with windows media player 10.
>
>The goal is the following : make WMP load a codec for decoding a given
>format (for example H264), and load another filter that would perform
>postprocessing upon the out uncompressed stream.
>WMP 10 made this job : when it loads, it consults all the codecs for
>decoding the input format, and then consults all the codecs that would be
>able to receive uncompressed format eventually.
>With WMP11, this no longer happens.
>Can you tell me if something has changed, and if there is any option to set
>or developments to be made ?
>
>Thanks by advance
>
>Regards,
>Damien Bain-Thouverez


Hi Damien - I'm not sure I have the answer to your question, but I'll
try to push some ideas here. WMP operates in 2 modes : For many
non-native [post-install] codecs it will operate through DirectShow,
effectively it will create a Graph similar to the way GraphEdit works.

For natively installed codecs like WMA and WMV, there are shortcuts
which can be used which I understand use DMO (directX media objects)

Included in WMP is a tiny version of WM Encoder, wmpenc.exe which
manages transcoding, but it's very limited and is only supplied afaik
to convert audio file formats to MP3 or WMA, and to convert video
formats to those supported by portable devices like Creative Zen etc.


I think the step you are describing is the Graphedit path, where a
graph to connect input and output codecs is built. That is where IMO
you should concentrate your efforts to find out what is being created.

I know of 2 article stubs which may help here for WMP plugin dev :
http://msdn2.microsoft.com/en-us/library/bb249674.aspx
http://msdn2.microsoft.com/en-us/library/bb249677.aspx

In addition, Orban have made an AAC audio plugin for media player,
which also registers URL protocols : http://www.orban.com/plugin/

You might want to contact Greg Ogonowski from this page, to see if he
can provide any leads or help in your project based on their
development path : http://www.orban.com/contact/

HTH
Cheers - Neil
------------------------------------------------
Digital Media MVP : 2004-2007
http://mvp.support.microsoft.com/mvpfaqs

Hi Neil,

thanks for your reply.
I guess I understand what you're saying: windows media player 11 is now
built upon Media Foundation, but can still emulate graph building with
directshow, and maybe that the backward compatibility is not guaranteed at
100%

My issue concerns the graph building when using direct show : for decoding a
given format, a directshow media player would enumerate all the filters
basing on their merit and look for a compatible media type by calling their
"CheckMediaType" method. The issue is that CheckMediaType is called once
inside my filter with WMP11 whereas it was called twice with WMP 10 as
follows :

WMP10 steps to build the graph :
1/ CheckMediaType for decoding input format (H264 for example)
2/ CheckMediaType for "decoding" output decoded format (uncompressed format
YV12)
Result graph :
Source file -> Decoding filter -> Uncompressed post-processing filter ->
Video renderer

WMP11 steps to build the graph :
1/ CheckMediaType for decoding input format (H264 for example)
Result graph :
Source file -> Decoding filter -> DMO filter -> Video renderer

Therefore, it is no more possible to have postprocessing filters that would
plug between the decoder and the renderer to improve image picture, add
subtitles...

I think I should get in touch with the Windows Media Player development team
but I didn't find any contact or newsgroup to write in.

Thanks again for your time

Damien

"Neil Smith [MVP Digital Media]" wrote:

> On Tue, 17 Jul 2007 13:32:04 -0700, Damien BT <Damien
> BT@discussions.microsoft.com> wrote:
>
> >Hi,
> >
> >I am a DirectShow developper (from FFDShow dev. team actually) and I am
> >facing a problem that did not occur with windows media player 10.
> >
> >The goal is the following : make WMP load a codec for decoding a given
> >format (for example H264), and load another filter that would perform
> >postprocessing upon the out uncompressed stream.
> >WMP 10 made this job : when it loads, it consults all the codecs for
> >decoding the input format, and then consults all the codecs that would be
> >able to receive uncompressed format eventually.
> >With WMP11, this no longer happens.
> >Can you tell me if something has changed, and if there is any option to set
> >or developments to be made ?
> >
> >Thanks by advance
> >
> >Regards,
> >Damien Bain-Thouverez
>
>
> Hi Damien - I'm not sure I have the answer to your question, but I'll
> try to push some ideas here. WMP operates in 2 modes : For many
> non-native [post-install] codecs it will operate through DirectShow,
> effectively it will create a Graph similar to the way GraphEdit works.
>
> For natively installed codecs like WMA and WMV, there are shortcuts
> which can be used which I understand use DMO (directX media objects)
>
> Included in WMP is a tiny version of WM Encoder, wmpenc.exe which
> manages transcoding, but it's very limited and is only supplied afaik
> to convert audio file formats to MP3 or WMA, and to convert video
> formats to those supported by portable devices like Creative Zen etc.
>
>
> I think the step you are describing is the Graphedit path, where a
> graph to connect input and output codecs is built. That is where IMO
> you should concentrate your efforts to find out what is being created.
>
> I know of 2 article stubs which may help here for WMP plugin dev :
> http://msdn2.microsoft.com/en-us/library/bb249674.aspx
> http://msdn2.microsoft.com/en-us/library/bb249677.aspx
>
> In addition, Orban have made an AAC audio plugin for media player,
> which also registers URL protocols : http://www.orban.com/plugin/
>
> You might want to contact Greg Ogonowski from this page, to see if he
> can provide any leads or help in your project based on their
> development path : http://www.orban.com/contact/
>
> HTH
> Cheers - Neil
> ------------------------------------------------
> Digital Media MVP : 2004-2007
> http://mvp.support.microsoft.com/mvpfaqs
>

I think your best shot at this might be to hang out on the newsgroup
microsoft.public.windowsmedia.sdk

Alessandro and a few others may have some answers at a depth which I
don't go to - I'm principally a web developer with interest in
encoding and steaming, they are coming at this from the DS/DMO end and
probably have some insights which would be more helpful ;-)

Cheers - Neil

On Wed, 18 Jul 2007 05:32:01 -0700, Damien BT
<DamienBT@discussions.microsoft.com> wrote:

>Hi Neil,
>
>thanks for your reply.
>I guess I understand what you're saying: windows media player 11 is now
>built upon Media Foundation, but can still emulate graph building with
>directshow, and maybe that the backward compatibility is not guaranteed at
>100%
>
>My issue concerns the graph building when using direct show : for decoding a
>given format, a directshow media player would enumerate all the filters
>basing on their merit and look for a compatible media type by calling their
>"CheckMediaType" method. The issue is that CheckMediaType is called once
>inside my filter with WMP11 whereas it was called twice with WMP 10 as
>follows :
>
>WMP10 steps to build the graph :
>1/ CheckMediaType for decoding input format (H264 for example)
>2/ CheckMediaType for "decoding" output decoded format (uncompressed format
>YV12)
>Result graph :
>Source file -> Decoding filter -> Uncompressed post-processing filter ->
>Video renderer
>
>WMP11 steps to build the graph :
>1/ CheckMediaType for decoding input format (H264 for example)
>Result graph :
>Source file -> Decoding filter -> DMO filter -> Video renderer
>
>Therefore, it is no more possible to have postprocessing filters that would
>plug between the decoder and the renderer to improve image picture, add
>subtitles...
>
>I think I should get in touch with the Windows Media Player development team
>but I didn't find any contact or newsgroup to write in.
>
>Thanks again for your time
>
>Damien
>
>"Neil Smith [MVP Digital Media]" wrote:
>
>> On Tue, 17 Jul 2007 13:32:04 -0700, Damien BT <Damien
>> BT@discussions.microsoft.com> wrote:
>>
>> >Hi,
>> >
>> >I am a DirectShow developper (from FFDShow dev. team actually) and I am
>> >facing a problem that did not occur with windows media player 10.
>> >
>> >The goal is the following : make WMP load a codec for decoding a given
>> >format (for example H264), and load another filter that would perform
>> >postprocessing upon the out uncompressed stream.
>> >WMP 10 made this job : when it loads, it consults all the codecs for
>> >decoding the input format, and then consults all the codecs that would be
>> >able to receive uncompressed format eventually.
>> >With WMP11, this no longer happens.
>> >Can you tell me if something has changed, and if there is any option to set
>> >or developments to be made ?
>> >
>> >Thanks by advance
>> >
>> >Regards,
>> >Damien Bain-Thouverez
>>
>>
>> Hi Damien - I'm not sure I have the answer to your question, but I'll
>> try to push some ideas here. WMP operates in 2 modes : For many
>> non-native [post-install] codecs it will operate through DirectShow,
>> effectively it will create a Graph similar to the way GraphEdit works.
>>
>> For natively installed codecs like WMA and WMV, there are shortcuts
>> which can be used which I understand use DMO (directX media objects)
>>
>> Included in WMP is a tiny version of WM Encoder, wmpenc.exe which
>> manages transcoding, but it's very limited and is only supplied afaik
>> to convert audio file formats to MP3 or WMA, and to convert video
>> formats to those supported by portable devices like Creative Zen etc.
>>
>>
>> I think the step you are describing is the Graphedit path, where a
>> graph to connect input and output codecs is built. That is where IMO
>> you should concentrate your efforts to find out what is being created.
>>
>> I know of 2 article stubs which may help here for WMP plugin dev :
>> http://msdn2.microsoft.com/en-us/library/bb249674.aspx
>> http://msdn2.microsoft.com/en-us/library/bb249677.aspx
>>
>> In addition, Orban have made an AAC audio plugin for media player,
>> which also registers URL protocols : http://www.orban.com/plugin/
>>
>> You might want to contact Greg Ogonowski from this page, to see if he
>> can provide any leads or help in your project based on their
>> development path : http://www.orban.com/contact/
>>
>> HTH
>> Cheers - Neil
>> ------------------------------------------------
>> Digital Media MVP : 2004-2007
>> http://mvp.support.microsoft.com/mvpfaqs
>>
------------------------------------------------
Digital Media MVP : 2004-2007
http://mvp.support.microsoft.com/mvpfaqs

Thank you Neil, I'll try that

Regards,

Damien