[Ffmpeg-devel] question: wmv3 codec image "drifts"

[Ryan Martell]

On Dec 1, 2006, at 12:00 AM, Kostya wrote:
> On Wed, Nov 29, 2006 at 05:12:44PM -0600, Ryan Martell wrote:
>>
> [...]
>>
>> I have provided a sample at:
>>
>> /MPlayer/incoming/DriftingWMV9
>>
>> The audio doesn't sync, but that's a different issue I'm sure.
>>
>> I don't think this is my mms problem, because mplayer has the same
>> problem (using a different mms library).
>>
>> Any thoughts?
>
> Your sample is encoded with WMV3 Simple Profile and VC-1 standard
> says maximum picture size for SP is 320x240, your file has a bit
> greater dimensions. When I hack extradata to treat file as Main  
> Profile
> reference decoder does decode it but also not without glitches.
> I'll see what can be done and what's wrong with motion compensation.

Thanks Kostya.

Here are the settings for Windows Media Encoder for that stream:

Compression Tab
Audio encoding mode: CBR
Video encoding mode: CBR

Audience: 299.96Kbps
Audio codec: Windows Media Audio 9.1
Audio format: 32kbps, 44kHz, stereo, CBR
Video codec: Windows Media Video 9
Video bit rate: 259 Kbps
Video size: 448 x 336
Frame rate: 29.97 fps
Key frame: 10 s
Image quality: 99
Buffer size: 5 s

Video Size Tab:
Output: 448 x 336
Aspect Ratio
Output: 1.33: 1
Alignment:
Width: 2
Height: 2

Again, it IS being encoded by the standard Windows Media Encoder, but  
of course, a M$ stream that doesn't conform to the specification  
doesn't surprise me. ;-)

Let me know if there's anything I can do to help,

Thanks,
-Ryan