AVC vs. H.264

[agressiv]

Everything I've read says these are the same, yet tools such as http://mediainfo.sourceforge.net definitely show some files as being AVC (x264) and some being H.264 (Nero)

Is this purely cosmetic? Just a curiosity.

agressiv

[Sagittaire]

Everything I've read says these are the same, yet tools such as http://mediainfo.sourceforge.net definitely show some files as being AVC (x264) and some being H.264 (Nero)

Is this purely cosmetic? Just a curiosity.

agressiv

H264 is the name for ITU
MPEG4 AVC is the name for MPEG

[bond]

h.264 and avc are identical

[DarkZell666]

To sum up, it's the dern same standard which has been named 2 different ways.

But, you will see either "AVC1" or "H264" or "X264" or even "VSSH" as a fourCC in avi files, which will all refer to the same video format.

It's just like having "XviD", "DivX", "MP42", "DIV3", etc. => MPEG4 ASP :)

[akupenguin]

MP42 and DIV3 are not quite mpeg4asp. They can be losslessly converted, but a standards-complaint mpeg4 codec won't decode them as-is.

[bond]

a standard compliant decoder "as is" also wont decode packed bitstream avi files as created by xvid and divx.

[DarkZell666]

I like the "not quite" bit in this story :p

Everything is always not quite what it should be, and doesn't quite do what it should be doing :D

This gives us users quite a headache, knowing what does what, and juggling with tool X and tool Y to achieve what we want (which sometimes isn't that much complicated).

You need to become a full-time encoder to know all this nowadays ;)

Just my .02€ retrospective on the matter.

[Zenitram]

Everything I've read says these are the same, yet tools such as http://mediainfo.sourceforge.net definitely show some files as being AVC (x264) and some being H.264 (Nero)

Is this purely cosmetic? Just a curiosity.

agressiv

This is what there is in the container. And yes, this is cosmetic.

I am working on having a common name for different codecs code, but all is not yet done.
And for example I tried to rename DivX to MPEG-4 Video (the "real" codec name), but too many people wrote me to say I am wrong, that the codec is DivX and not the strange name I put, that DivX and Xvid are different etc...

There is another problem : a codec can decode "AVC1" fourCC, but not "H264", even if the video stream is the same. Only because the fourCC was not registered in Windows fourCC database. So user need to know the exact FourCC.

So I am working to show directly the codec name in the container (AVC or H264 or x264 or...), and after the name the family (MPEG-4 Video for DivX/Xvid/DX50/MP42..., H264 for AVC /x264/AVC1...).

Work is in progress :)

Zen, developer of MediaInfo

[CruNcher]

Commercial Video standards are allways a two sided sword, everyone who works (research) on them has is own plans either "stabing" everyone in the back @ the end by useing their own not released research and the research from the others Microsoft and Real for example or modifing the Devices in the end so they aren't interoperable with the "competitors" (research partners) files anymore that easily (Apple,Sony,Nero) by useing different parser stuff or own containers or whatever else (they are very inovative in developing interoperability killers) :P. Fourcc is still existant and used for forceing this also in the new container generation called MP4 http://www.ftyps.com/ in the end they sitting in a room or @ a conferenece and everyone of them (except maybe the non comercial researchers) are lieng to each other ;)

[Brother John]

(MPEG-4 Video for DivX/Xvid/DX50/MP42.
Just as a sidenote:
MPEG-4 Part 2, or ASP as we most often say, is officially labeled "MPEG-4 Visual". "MPEG-4 Video" doesn't exist.

[Zenitram]

Just as a sidenote:
MPEG-4 Part 2, or ASP as we most often say, is officially labeled "MPEG-4 Visual". "MPEG-4 Video" doesn't exist.
Yes, you're right.
But I must do with users (newbees), they often don't understand "Visual".
I don't really know how to do for giving the best information without have a lot of "spam" from people who does'nt understand :)
I hope that "MPEG-4 Video" is a good way between MPEG-4 Visual (the real name) and DivX (the common known name)! With this text, I don't have anymore strange mails :)

[Brother John]

Imo the best solution would be to split things up into two fields: "Video format" (or similar) showing the name of the format/standard and "Video codec" derived from FourCC/User data showing the name of the codec used for encoding. That way you'd provide the newbies with the information they understand, you'd keep being accurate and provide an additional piece of information.

"MPEG-4 Video" is really unclear on first glance. It's extremely inviting to mistake it for a generic term for all MPEG-4 video formats: Visual and AVC. You might exchange the strange newbiew mails with strange mails from confused experienced users.

[bond]

Fourcc is still existant and used for forceing this also in the new container generation called MP4 http://www.ftyps.com/it is not possible to have private fourccs for signalling the codec in mp4 as it has been done and described by you for avi

[PuzZLeR]

Just to add:

H.264 is synonymous with AVC. Both are the exact same thing, just named differently by the two groups in the joint effort. This is an extension of the MPEG, and MPEG-4 standard - MPEG4 Part 10 to be exact.

Nero Digitial (or Ateme) and x264 are implementations based on H.264/AVC.

Keep in mind, that although similar, H.263(+) is NOT synonymous with ASP, the formats based on the older MPEG, and MPEG-4 standard - MPEG-4 Part 2 to be exact.

DivX, Xvid, RealVideo and even WMV (before VC-1) are implementations based on this H.263(+)/ASP type of technology.

AVI, MP4, MOV, MKV and WMV/ASF are containers for these codecs only. Some can handle all the standards/codecs/implementations, and some can’t.

So endeth the lesson. :)

[Stux]

a standard compliant decoder "as is" also wont decode packed bitstream avi files as created by xvid and divx.

MS-MPEG4v2/v3 and DivX 3, share a very similar block/macroblock layer with MPEG-4 ASP, but the picture and stream framing is completely different.

Actually, I looked into the lossless covnersion of DivX 3 to MPEG-4, and found that you could do it, as long as the QPs in the stream didn't go above a certain level, once you went above that level (say >= QP12), then you couldn't losslessly convert them.

[Stux]

it is not possible to have private fourccs for signalling the codec in mp4 as it has been done and described by you for avi

But a lot of MPEG-4 codecs do signal the encoder in the stream userdata

[bond]

Actually, I looked into the lossless covnersion of DivX 3 to MPEG-4, and found that you could do it, as long as the QPs in the stream didn't go above a certain level, once you went above that level (say >= QP12), then you couldn't losslessly convert them.there is already a tool being able to do that :search:

But a lot of MPEG-4 codecs do signal the encoder in the stream userdatanothing wrong with that :)