[gst-devel] MPEG video format

[Dan Taylor]

Looks like I need to add pixel-aspect-ratio caps handling to fbdevsink.

Thanks. 

> -----Original Message-----
> From: Edward Hervey [mailto:bilboed at gmail.com] 
> Sent: Tuesday, March 24, 2009 1:17 AM
> To: Discussion of the development of GStreamer
> Subject: Re: [gst-devel] MPEG video format
> 
> On Mon, 2009-03-23 at 20:57 -0700, Dan Taylor wrote:
> > I am having a problem with the output video aspect ratio 
> from mpeg2dec.
> > 
> > A sample that illustrates the problem is available at
> > http://www.w6rz.net/parkrun1280_18mbps.ts.,
> > although it also happens on live DVB streams.
> > 
> > The video is supposed to be 1920x1080, but during caps 
> negotiation, it
> > is offered as 1280x1080.
> > The header appears to have 1280x1080, but aspect code 3, 
> which is 16:9.
> > 
> > The result is that after scaling the picture appears 
> roughly 5:4, rather
> > than 16:9.
> 
>    Here I see the following caps: video/x-raw-yuv, 
> format=(fourcc)I420,
> width=(int)1280, height=(int)1080, pixel-aspect-ratio=(fraction)3/2,
> framerate=(fraction)30000/1001
> 
>   Which is:
>   pixel_width: 1280
>   pixel_height: 1080
>   Framerate: 30000/10001
>   Pixel aspect ratio (PAR) : 3/2
> 
>   The relationship between display-aspect-ratio (DAR) and PAR is as
> follows:
>   pixel_width / pixel_height * PAR = DAR
> 
>   We therefore have DAR = 1280 / 1080 * (3/2) = 16/9
> 
>   Everything is correct (a Display Aspect Ratio of 16:9)
> 
>      Edward
> 
> > 
> > Should the mpeg decoder be putting out the 1920x1080 caps, 
> or should the
> > other elements of the
> > stream be looking at some other caps?
> > 
> > 
> > 
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