AV codecs: VFW or libraries ?

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Carlo Bramix
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Location: Italy

Post by Carlo Bramix » Tue May 29, 2007 10:28 am

Sorry, but I didn't understand why you think that the usual approach with media filters is bad.
In my opinion, the idea is good.
Long time ago there were VGA adapters without any kind of acceleration, then video card with overlay capabilities and automatic YUV to RGB colorspace converters arrived, and later with some quantization and motion estimation processing handled directly by hardware...
We need something that makes these features available to the coders/decoders without making mortal jumps.
And perhaps this "something" could be DirectShow.
In some ways, the "shared libraries" method is easier to implement, but I don't think that rewriting every time the same code is a good idea.
Re-using the code is usually better and it has better debugging (becasue it's more used).
I don't see the problems of performances and stability.
Probably, we must see how these problematic codecs have been written, or what you decided to install for playing a specific file format.
And I don't have a ninja-PC, just an old (old...) Pentium.

Sincerely,

Carlo Bramini.

Haos
Test Team
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Post by Haos » Tue May 29, 2007 4:49 pm

Carlo: This should be passed to GreatLord:)

forart
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Post by forart » Wed May 30, 2007 11:05 am

Carlo Bramix wrote:Sorry, but I didn't understand why you think that the usual approach with media filters is bad.
OK, to understand what i mean, install ALL codec packs (so you should be sure to have any existing codec installed) from this -italian- page: SEZIONE CODEC PACK.

...and forget to install these:

QuickTime Alternative
Real Alternative

Then try avi/dvd playing and encoding by VirtualDub: share your experiences.

:?
»Forward Agency NPO
In progress we (always) trust.

loki1985
Posts: 82
Joined: Tue Dec 07, 2004 1:39 pm

Post by loki1985 » Thu Jun 07, 2007 11:04 am

@forart: sorry, but the way i understand you it means an API should not be implemented only because some folks made some bloated buggy codec compilation installers? this is like saying: do not implement a DirectX API, because there are some really crappy games that use directx...

i think a native implementation of directshow is very important for lots of games and multimedia applications. also a lot of older applications use VfW, which should also be implemented because of this.

billyswong
Posts: 55
Joined: Tue Nov 29, 2005 7:20 pm
Location: Hong Kong, China

Post by billyswong » Sun Jun 10, 2007 4:55 pm

I don't think the codec problem is due to the api, it's more of the frontend part. I believe it will be gracefully solved if there is an entry in the control panel which let the user to view and manipulate those video/audio codecs.

GreatLord
Developer
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Location: Sweden

Post by GreatLord » Sun Jun 10, 2007 11:29 pm

DirectShow is very complex how it works.
codecc is lest problem.

what we need before even start plan for dsshow implementions is

1. ks.sys
2. wdm
3. ddraw.dll DD, DDSURF, DDCliper, D3D, MC and VP COM interface

frist then we can start plan dshow,

dshow controll the video and audio card direcly and pass down the info and back. about yuv to rgb it is handler complete by the hardware drv
noting what I need think of.

Some basic facts for VBE driver
Then we got a special mode we can swtich the whole graphice card into yuv mode with vbe drv, yes it is posible adding native yuv support to or vbe drv in fullscreen.

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