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View Full Version : Question to the experts. DivX 3.11 to MPEG4 Conversion


mikemikez
8th July 2002, 04:22
Hi,

Just some crazy idea I had;
Would there be any possibily for creating a true MPEG4 compliant codec that's made in such a way that converting from DivX 3.11 to it would not give much loss in quality? I was just thinking that maybe some of the same algorythms could be implemented in the MPEG4 codec thereby making conversion more like a translation process than a complete reencoding....

Would sure be handy because the upcomming new DVD/mediaplayers will mosst certainly not support divx3.11 but will support MPEG4 and many people have many gigabytes of divx3.11 video they want to keep using.

Anyone?

Thanks,

Mike

Nic
8th July 2002, 08:48
Rumour has it, that that very thing is possible (with no loss)
Rumour also has it, that -h will work on that project soon (when he eventually gets some time :) )

But thats just all rumour ( :D )

-Nic

mikemikez
8th July 2002, 12:13
No kidding!?

Wow, that would make a lot of poeple including myself mucho mucho happy! :)

You got any more details on this project? Is there some other topic in which this is discussed?


Regards,


Mike

Nic
8th July 2002, 12:48
:D Its all up to -h, never been discussed anywhere else really (when I mentioned it before in another thread, people didnt believe it. Im not sure if I did, but if -h says its possible then I believe him)

Basically it would mean looking thru ffmpeg, seeing how it reads the DivX3 files & then re-writing the bit stream

An extract of a PM from -h to me:
"I'll probably start with the MSMPEG->MPEG4 conversion prog actually, since it can start just with ffmpeg code (hijack the decoder right before the MSMPEG quantized coeffs are sent to dequant/idct, and send them to the MPEG4 coeff coding stuff instead), then whittle away at the source until it's compact and readable."

But please dont bother -h with this. He'll do it in his own time. Best to forget about it for now, because it will only come, when it comes :)

Cheers,
-Nic

mikemikez
8th July 2002, 13:07
But it would involve "making" a new MPEG4 compliant codec like XviD, right? Just one that uses the same kind of algorythms used in MSMpeg4 DivX 3.11, right?

Well, I won't bother anyone with it but I would like to stress that this project is of huge relevance to many people. There's probably like petabytes of divx 3.11 encoded stuff in peoples drawers just waiting to be playable on some set-top machine!
Keeping that in mind, this thing is more urgently needed than any other MPEG4 implementation like XviD or DivX 4/5. People want to secure their old stuff before they move on to a new codec.


Mike

Nic
8th July 2002, 13:14
No,

It will just be a little prog that takes out the MS-MPEG4v3 bitstream, re-writes at as a compatible MPEG4 bitstream, so you can then play it with whatever MPEG-4 filter you want...No need for another codec.

Keeping that in mind, this thing is more urgently needed than any other MPEG4 implementation like XviD or DivX 4/5.

I dont quite agree with that, but I understand where your coming from :)

-Nic

mikemikez
8th July 2002, 13:25
Hey, I got some home movies too in divx 3.11!! :)