XviD vs MPEG4

[Sohaib]

Hi there ...

Is it true that XviD is really just an encoder standard and XviD encoded streams can be played back without difficultly using an MPEG-4 ASP decoder? Does the decoder have to support GMC? WHich profile of the MPEG-4 ISO standard is needed to decode all XviD content?

Now, if the above is NOT true, how can someone go about writing their own XviD decoder? That is royalty free?

[dimzon]

Yes, since v1.0 it's 100% MPEG4 Part 2 ISO Compliant encoder
You need MPEG4 Advanced Profile to be able to decode any content created by XviD (including GMC/QPEL)

[Teegedeck]

Does the decoder have to support GMC? WHich profile of the MPEG-4 ISO standard is needed to decode all XviD content?
I think any Advanced Simple Profile decoder will do. On the other hand, the decoder doesn't even need to support GMC in order to decode an XviD file if the GMC option wasn't used when encoding that file with XviD.

[Hyper Shinchan]

I think any Advanced Simple Profile decoder will do. On the other hand, the decoder doesn't even need to support GMC if the GMC option wasn't used when encoding with XviD.
Yes, but a decoder to claim itself to be compatible with the ASP needs to have support for every feature used by the MPEG-4 ASP codec, including GMC and QPel, for this reason many hardware players are merely SP+B-frames+GMC (1 warpoint, generally). At least I think that ISO thinks so, an encoder can use also some part of the standard but it's still complaint, a decoder must use all the part of the standard that it claims to be compatible.

[dimzon]

an encoder can use also some part of the standard but it's still complaint, a decoder must use all the part of the standard that it claims to be compatible.
:goodpost:

[Sohaib]

Thanks a bunch for the help guys ... :-)

ummm... if possible, can someone help me with this querry too ... :-)
http://forum.doom9.org/showthread.php?t=112899

[Sohaib]

Also, since most people here seem to have quite intricate knowledge of these decoders, which additional features need to be added to the Simple Profile to make it ASP ...? .. B-frames, QPel, GMC (how many warp points?) and what else? Hmm... I should try and acquire the ISO spec ... <twiddles thumbs> ...

[bond]

xvid is not an encoder standard. xvid is an implementation of the mpeg-4 asp encoding standard

http://forum.doom9.org/showthread.php?t=73022

[shon3i]

xvid is not an encoder standard. xvid is an implementation of the mpeg-4 asp encoding standard

http://forum.doom9.org/showthread.php?t=73022
Yes, but will be came a standard like DivX, or Nero Digital (such a brand name)

[SeeMoreDigital]

Yes, but will be came a standard like DivX, or Nero Digital (such a brand name)Errm no!

As Bond says, DivX, XviD, NeroDigital, 3ivx etc should be considered as being nothing more than brand names and/or implementations of the MPEG-4 ISO/IEE 14496 standard.


Cheers