Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. |
8th January 2007, 11:46 | #1 | Link |
Registered User
Join Date: Dec 2006
Location: Zagreb, Croatia
Posts: 4
|
Muxing VC-1 in ASF
I'm trying to write an ASF muxer for VC-1, and have some questions. What should be put into extradata space of BITMAPINFOHEADER structure for VC-1 (stream properties)? It seems to me that WM asf writer puts sequence header followed by entry point header there, but i can't find some useful info on that. Also, does WMP support annex b wrapper or is it mandatory to send stream info via extradata. Any other info or experiences, and information source would be greatly appreciated.
Thanks, Ivan. |
10th January 2007, 11:02 | #3 | Link |
Registered User
Join Date: Dec 2004
Location: Hamburg, Germany
Posts: 332
|
Hi zambelli,
I have a couple of question too First of all where can I get sample of VC1 with B frames contained within WMV file, provided by WindowsMediaEncoder. I'm interested in how MS puts -frames to WMV by themselves? |
11th January 2007, 04:34 | #4 | Link |
Doom9ing since 2001
Join Date: Oct 2001
Location: Seattle, WA, USA
Posts: 2,002
|
I can provide you samples of this, though if I'm understanding your request correctly, you're not asking for anything unusual - just regular Advanced Profile encoded video with B-frames, right?
|
11th January 2007, 04:36 | #5 | Link | |
Doom9ing since 2001
Join Date: Oct 2001
Location: Seattle, WA, USA
Posts: 2,002
|
Sharing the answer to Doksa's question publicly too:
Quote:
|
|
13th January 2007, 01:10 | #6 | Link |
Registered User
Join Date: Jan 2006
Posts: 39
|
"Entry header" is the first Entry Point header. Both Sequence header and Entry point header should contain the start codes as well.
Note on the Sequence header: if you have stream whith multiple sequence headers indicating different video sizes for example: seq1(720x480),seq2(1280x720),seq3(640x480) The Sequence header after BITMAPINFOHEADER should be the one indication the max video size (in this case 1280x720). Last edited by veffremov; 13th January 2007 at 06:43. |
7th February 2007, 10:23 | #7 | Link | |
Registered User
Join Date: Feb 2007
Location: Seoul, Korea
Posts: 7
|
Quote:
I'm also interesting about it. Can you share to me? Actually, Now I'm writing an ASF demuxer from scratch. ASF has to mux video samples with growing time stamps, but Video with B frames can't be that way. Is there someone who can explain "how MS can put B-Frames in to ASF container" to me ? Thanks in advance. Last edited by lovehis; 7th February 2007 at 10:26. Reason: correct typo |
|
7th February 2007, 11:48 | #8 | Link | |
Doom9ing since 2001
Join Date: Oct 2001
Location: Seattle, WA, USA
Posts: 2,002
|
Quote:
http://www.citizeninsomniac.com/video/MP_B_Frames.wmv http://www.citizeninsomniac.com/video/AP_B_Frames.wmv B-frame distance of 1 was used for both. |
|
7th February 2007, 16:47 | #9 | Link | |
Registered User
Join Date: Feb 2007
Location: Seoul, Korea
Posts: 7
|
Quote:
|
|
7th February 2007, 16:59 | #10 | Link | |
Registered User
Join Date: Dec 2006
Location: Zagreb, Croatia
Posts: 4
|
Quote:
I have another question, maybe someone will know - I have written ASF muxer for VC-1, and even though I have index object that looks ok, seeking doesn't work (at all - not that it works badly). Thanks, Ivan. |
|
7th February 2007, 17:26 | #11 | Link | |
Registered User
Join Date: Feb 2007
Location: Seoul, Korea
Posts: 7
|
Quote:
If you share your ASF files... I will check it out. |
|
11th February 2007, 18:58 | #14 | Link |
Registered User
Join Date: Aug 2004
Posts: 133
|
Looking at AP_B_Frames.wmv, we have:
Frame 0, pts 0:000, Keyframe, 10732 bytes Frame 1, pts 0:040, Delta frame, 6324 bytes Frame 2, pts 0:080, Delta frame, 1766 bytes Frame 3, pts 0:120, Delta frame, 5199 bytes Frame 4, pts 0:160, Delta frame, 1419 bytes Frame 5, pts 0:200, Delta frame, 5312 bytes Frame 6, pts 0:240, Delta frame, 1793 bytes We can assume that frames 2,4,6,... are B-frames. But their presentation times are not correct if one takes the needed reordering into account. Concluding from this, it seems ASF is not any better in terms of B-frame support then AVI (since decoder hacks are needed get get right association of timestamps). |
12th February 2007, 08:29 | #16 | Link | |
Registered User
Join Date: Aug 2004
Posts: 133
|
Quote:
|
|
18th March 2009, 15:22 | #18 | Link | |
Registered User
Join Date: Oct 2002
Posts: 160
|
Quote:
Even then it does not makes a good .wmv
__________________
VAIO VGX-XL3 4gig RAM, 4Tb HDD. MEDIA CENTER WINDOWS 7 simply the best!! |
|
|
|