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bond
26th July 2006, 18:30
i recently stumbled over some issues with wmv9 seeming to be incompatible to vc-1 in some cases:

1) wmv9 offers a "complex profile" which vc-1 doesnt know and which seems to set the profile flag to "2" in the vc-1 header. according to the vc-1 specs its forbidden to set it to "2" (reserved value). i assume this makes all complex profile encodes vc-1 incompatible?

is there any way to make them vc-1 compatible without quality loss? are there other things that make complex profile encodes vc-1 incompliant except the profile flag? if yes, what?

2) lots of wmv9 encoded clips i have, have a thingie called "RTM Flag" set to 0. the vc-1 specs define this reserved flag to always be set to 1. i assume this makes all those wmv9 clips vc-1 incompliant?

what is this flag about?

3) for completeness: old WMVA advanced profile of wmv9 is not vc-1 compliant
Sulik
26th July 2006, 19:23
The Complex profile was pretty much never used by MS or anybody else anyways.
It was very impractical, especially due to the 4:1:1 chroma format for interlaced content and the inability to be carried over a transport stream (no startcodes).
bond
26th July 2006, 19:25
complex profile supports interlacing for sure (i thought wmv9 supports this only since advanced profile)? 4:1:1???
benwaggoner
27th July 2006, 01:59
complex profile supports interlacing for sure (i thought wmv9 supports this only since advanced profile)? 4:1:1???
Yep. We got better :).
bond
27th July 2006, 08:28
benwaggoner , what about my other questions?
zambelli
2nd August 2006, 04:07
1) It has come to my attention recently as well that Complex Profile doesn't seem to be covered by the VC-1 spec and therefore isn't fully supported anymore. The old 4:1:1 interlaced mode is definitely not supported as it's been replaced by a proper 4:2:0 interlaced mode in Advanced Profile.

2) Don't know, but I can ask. Can you PM me your email address?

3) Correct.
bond
3rd August 2006, 19:44
it seems those files with the RTM flag set to 0 have incompliant p-frames

any idea on how they differ from the specs?
zambelli
17th August 2006, 03:32
Our VC-1 spec guru :) is having trouble finding the string "RTM" in any of the SMPTE VC-1 specs. Can you point us to the exact page?
Sulik
17th August 2006, 09:38
Our VC-1 spec guru is having trouble finding the string "RTM" in any of the SMPTE VC-1 specs. Can you point us to the exact page?

I think he meant that this RTM flag is part of the WMV9 spec (not VC-1), but was subsequently removed from the VC-1 spec, ie it appears as a 'reserved' bit in VC-1 header (Simple/Main).
bond
17th August 2006, 19:22
I think he meant that this RTM flag is part of the WMV9 spec (not VC-1), but was subsequently removed from the VC-1 spec, ie it appears as a 'reserved' bit in VC-1 header (Simple/Main).exactly

it has been called that way in some first draft of vc-1, still running under the name vc-9

i kinda wonder why m$ doesnt know its own format/the specification process :D
zambelli
17th August 2006, 21:32
it has been called that way in some first draft of vc-1, still running under the name vc-9
Ah, you didn't mention that part.
i kinda wonder why m$ doesnt know its own format/the specification process :D
Nice way to jump to conclusions. :sly: You didn't say which revision of the spec you were looking at, so how were we supposed to know?

Anyway... I'll get back to you with info on the RTM string.
bond
17th August 2006, 21:40
Nice way to jump to conclusions. :sly: You didn't say which revision of the spec you were looking at, so how were we supposed to know?

Anyway... I'll get back to you with info on the RTM string.thx :)

i assumed that those names actually come from microsoft
zambelli
19th August 2006, 03:57
OK, here's the scoop on the Reserved_RTM flag.

RTM stands for Release To Manufacturing, which is what Microsoft calls final release (non-beta) versions of its products. During the beta phase of WMV9 codec development there were changes made to the bitstream which in turn required changes in the decoder. In order to differentiate those beta bitstreams from the final bitstreams, the RTM flag was created and was required to be set to 1.
When VC-1 spec was submitted to SMPTE, the flag was referred to as Reserved_RTM in early versions of the spec, beginning with Working Draft 2 and up to Committe Draft 1R2. Starting with CD1R3, the name of the flag was changed to Reserved5.

Bottom line: any bitstream with Reserved_RTM/Reserved5 flag set to 0 was produced by a beta WMV9 encoder. Anybody encoding with final versions of the WMV9 codec (as shipped with WMP9, WMP10 or WMP11beta) will never run into this flag.
bond
19th August 2006, 15:30
i expected something like that, thx

do you know the technical differences to the vc-1 specs?
zambelli
20th August 2006, 23:27
do you know the technical differences to the vc-1 specs?
No, I haven't really done much comparing. What kind of technical differences did you have in mind?
bond
21st August 2006, 19:36
No, I haven't really done much comparing. What kind of technical differences did you have in mind?no idea really, i think it has something to do with p-frames being different, but i dunno the details
daniel.aam
20th October 2006, 15:46
Apologies for the naive question. When one talks about complex profile, I take they are talking about WM AP? If not what exactly is the WMV9 complex profile? Obviously with the new dmo you have SP, MP and AP [which is effcetvly WVC1 fourcc] how does Complex profile fit into this how do you avoid it?

Just to add to this what reg settings can be config with MP@ML???

Thanks In Advance.
foxyshadis
20th October 2006, 20:16
Complex profile is an unsupported WMP9 (and 10?) codec, that is removed from the current WMP11/VC-1 codec. The only way to do anything with it now is basically to transcode.
zambelli
20th October 2006, 23:55
Apologies for the naive question. When one talks about complex profile, I take they are talking about WM AP? If not what exactly is the WMV9 complex profile? Obviously with the new dmo you have SP, MP and AP [which is effcetvly WVC1 fourcc] how does Complex profile fit into this how do you avoid it?
Unless the complex profile video is interlaced (using 4:1:1 interlacing mode), a VC-1 decoder still might be able to handle it. It's not supported in the spec though.

Just to add to this what reg settings can be config with MP@ML???
See http://forum.doom9.org/showthread.php?t=112634.
bond
21st October 2006, 13:22
to make it short: wmv9 complex profile is not vc-1 compatible