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[tjobbins]

Edited:  Edited the title to indicate the problem as I've now diagnosed it:  with my configuration, ffdshow is being included twice in the output chain, which uses slightly more resources and makes the ffdshow OSD output inaccurate.

Hi all

I am trying to use ffdshow to upscale my DVDs using the Resize filter.

The issue I am having is that it appears that MC itself is already resizing the DVD content before it reaches ffdshow, meaning that I can't use ffdshow to resize and therefore can't tweak any resize settings.

My config:

Windows XP SP3
NVidia 7800GT with latest WHQL drivers
MC 13.0.101 (also used .95)
Latest version of CCCP, installed with media players (Zoom player and Media Player Classic)
No other codecs / playback software installed

MC DVD playback settings:

Video Decoder:  MPC - MPEG-2 Video Decoder (Gabest)
Use FFDShow video decoder for post-processing = Ticked

Video Renderer:  Haali renderer

Audio Decoder:  ffdshow Audio Decoder

Symptoms of problem:

• Set ffdshow On Screen Display to ON, showing input size and output size
• Start a DVD playing in MC
• ffdshow OSD shows Input Size: 1360x768 Output Size: 1360x768
• i.e. it has not done any resizing, the input source was already resized to my desktop resolution.
• By comparsion:  A DVD played in Media Player Classic - Homecinema will show Input Size: 720x576 Output Size: 1360x768
• i.e. in that media player, ffdshow is being fed the original DVD image and is upscaling it itself, as expected and desired.

I haven't found any options to alter this.  I can't set ffdshow as the Video Decoder, it says that's incompatible; and of course if I untick ffdshow as post-processor, ffdshow is not used at all (confirmed as no OSD then appears.)

I am presuming that it is MC itself that is scaling the content before it is sent to ffdshow, so I think I need a way to tell it not to do that.


Thanks


Tom

[tjobbins]

One more piece of info that may be relevant:

CPU usage is noticably higher in MC when playing DVDs versus Media Player Classic.

On my AMD X2 4800 (dual core, 2.4ghz) system,  overall CPU usage in MC averages around 50% when playing DVDs with settings as above.

In Media Player Classic, it's around 35%

I wonder if this is because of one of the following:
a) Both MC and ffdshow are resizing (though I would be surprised that ffdshow would attempt to resize an input size that was identical to the set output size)
b) The MC resizer is less efficient than the ffdshow resizer.
c) MC seems to be including ffdshow twice, whereas MPC only invokes it once

Regarding point C -  I notice that Media Center appears to call ffdshow twice for video; perhaps this explains the extra CPU usage?

Media Center - DVD Playback Settings - List of filters

• Default DirectSound Device
• Haali's Video Renderer
• ffdshow raw video filter  <-- this one is not included by MPC
• ffdshow Audio Decoder
• ffdshow Video Decoder
• MPC - MPEG-2 Video Decoder (Gabest)
• DVD Navigator

Media Player Classic - List of filters during DVD playback

• Default DirectSound Device
• Haali's Video Renderer
• Audio Switcher
• ffdshow Video Decoder
• ffdshow Audio Decoder
• MPC - MPEG-2 Video Decoder (Gabest)
• DVD Navigator

[tjobbins]

Ah, I think I've got it!   

Actually, MC is not resizing at all.  But because ffdshow is being included twice, the OSD I am seeing is from the second inclusion of ffdshow, by which time ffdshow (the first inclusion) has already resized:

That is: 

• the first time ffdshow is invoked, it resizes from DVD res to desktop res. It displays an OSD showing this.
• the second time it gets invoked, the res is already desktop res, and the OSD displayed overlays the first OSD, thus showing an input at desktop size, not DVD size.

I think I have confirmed this - if I look very closely at the OSD, I notice that the text on the Input Size appears blurry, like there is a value overlaying another value!

Here's a screencap of that; notice how the Input Size looks like 1360x768 was written over the top of something else:



So the question is now - is there a way to stop MC including ffdshow twice in the output chain for DVD playback?

[JimH]

Did you find the DVD topic in our Wiki?  It's here: http://wiki.jrmediacenter.com/index.php/DVD_Playback

This doesn't look right:

Use FFDShow video decoder for post-processing = Ticked

[tjobbins]

Thanks Jim, I hadn't read the DVD article fully.

So, the situation now summarises as follows:

When using the MPC Gabest decoder (ffdshow not set to decode DVD)
ffdshow post-processing must be ticked in MC, else ffdshow is not invoked at all and no resizing occurs.
With this done, ffdshow is invoked twice - as described in earlier posts - which wastes some CPU resources.

When using ffdshow to decode DVD (MPEG2 set to libavcodec or libmpeg2, DVD Decoding ticked in ffdshow
ffdshow post-processing is not ticked in MC.
ffdshow is invoked once only, and resizing occurs OK.

So:  with my configuration, if I want to use ffdshow for resizing, I must also use ffdshow for decoding.  If I want to use another decoder (e.g. MPC Gabest), then adding ffdshow for resizing will cause ffdshow to execute twice.

According to the DVD wiki you sent me, the Gabest decoders are still the recommended ones; and CCCP uses that by default.  I've not looked at other DVD decoders yet, and I don't know if other DVD decoders would show the same duplicate-ffdshow-inclusion issue as the MPC Gabest one does.

I'll experiment with MPC Gabest vs ffdshow decoding, and also try some other decoders. 

Thanks for your help.


Tom