[FFmpeg-user] Aspect ratio preservation in WMV

[Robert Krüger]

On Sep 27, 2011, at 04:51 , Andrew Wason wrote:

> On Sun, Sep 25, 2011 at 7:23 PM, Rodney Baker <rodney.baker at iinet.net.au> wrote:
>> On Mon, 26 Sep 2011 02:18:34 Paul-Antoine Arras wrote:
>>> Output #0, asf, to 'output.wmv':
>>>    Metadata:
>>>      WM/EncodingSettings: Lavf52.64.2
>>>      Stream #0.0: Video: WMV3 / 0x33564D57, yuv420p, 720x576 [PAR 64:45
>>> DAR 16:9], q=2-31, 1k tbn, 1k tbc
>> ^^^^^^^^^^^^
>> 
>> ffmpeg is writing the stream out with an aspect ratio of 16:9
>> (Display Aspect Ratio)
> 
> 
> ASF supports a couple of different mechanisms for storing aspect ratio
> information, looking in ffmpeg libavformat/asfenc.c it doesn't seem to
> use any of them. So I think this is a missing feature.
> 
> I think in asfenc.c:asf_write_header1() you would need to write
> AspectRatioX and AspectRatioY into the ff_asf_extended_content_header
> section.  See the spec:
> http://msdn.microsoft.com/en-us/library/bb643323.aspx
> 

Paul-Antoine, could you take the time and file this as an issue in the tracker, if possible with a reproducible test case and include the information Andrew provided, so it does not get lost if you don't intend to fix it yourself or it isn't fixed immediately by anyone else? This normally increases your chances of getting your problem solved, you get notified when something happens and it helps the project.