Re: Direcshow problems with WMV9 Decoder for XP platform

Hi Alessandro,

setting the synchPoint worked thanks so much.

BUT ... it only displays one frame (the first one) for some reason. Is there
anything else I should be setting on the IMediaSample ?

Also on the encoder side, the first frame as a synchPoint set to FALSE and
the rest of the frames are all TRUE.

Thanks,
Kristine

"Kris" wrote:

Me again ...

Looking at the custom filter code I see that SetActualDataLength is about
the only thing that was set on the IMediaSample. This was done on the
FillBuffer() method.

Disregard the comment about how to access IMediaSample.

Thanks for your help,
Kristine

"Kris" wrote:

So one the encoder side ... use IMediaSample::IsSyncPoint() (this is just a
true/false flag).

Then when I get it on the receiver side use IMediaSample::SetSyncPoint
correct?

Also how to I access the IMediaSample?

Thanks for your help,
Kristine

"Alessandro Angeli" wrote:

From: "Kris"

How do I transmit the syncpoint flag? By using
IMediaSample::SetSyncPoint?? Will this modify the actual
encoded stream for the decoder to read?

Get the flag on the encoder side, transmit it to the decoder
side, set it on the sample before deliverying it. The sample
is metadata, it does not change the contents of the sample
buffer.

Note that this scenario was working with a DIVX
decoder/encoder (in that scenario a laptop was used and
not a mobile).

You've been lucky because the stream packing you had
included the required metadata in the stream itself and the
decoder you were using did not rely on the sample flags.

In the general case, you need to replicate the whole media
sample, not just its data buffer.

--
// Alessandro Angeli
// MVP :: DirectShow / MediaFoundation
// mvpnews at riseoftheants dot com
// http://www.riseoftheants.com/mmx/faq.htm






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