[MPlayer-DOCS] Interested in contributing case studies

[Guillaume POIRIER]

Hi,

On 10/26/06, Mark Pilgrim <pilgrim at gmail.com> wrote:
> On 10/23/06, Guillaume Poirier <gpoirier at mplayerhq.hu> wrote:
> > I'm a bit surprised. I'm quite confident that Quicktime supports
> > anamorphic videos in some way. If it doesn't support SAR, maybe it
> > supports Pixel Aspect Ratio or Display Aspect Ration?
>
> I made a 30-second sample video using my mencoder recipe in draft 3,
> but omitting the scale filter.
>
> http://diveintomark.org/tmp/foo.mp4
>
> Here's a screenshot of two video players interpreting the file.  VLC
> is on the top, and QuickTime Player on the bottom.  I have QuickTime
> 7.1.3 installed.
>
> http://diveintomark.org/public/2006/10/quicktime-vs-vlc.jpg
>
> For the benefit of those who don't wish to download the sample movie,
> or if the screenshot disappears in the future, VLC is playing the
> video at the correct aspect ratio, having scaled it to 854x352.
> QuickTime Player is playing it at 720x352, and the QuickTime Player
> "movie info" dialog confirms that QuickTime sees nothing wrong with
> that.

At least, it's good to see that QuickTime does not refuse to play the
file if you set an aspect ratio that VLC understands.


> > The doc here:
> > http://developer.apple.com/documentation/QuickTime/Conceptual/
> > QT7-1_Update_Guide/Content/2NewFeaturesChangesa.html
>
> I'm sorry, those docs are way over my head.  Is it describing some
> QuickTime-specific way of embedding the correct aspect ratio?

Maybe, but I'm no expert on that field. To put it in a nutshell:
- The doc does seem to say that QT supports aspect ratio
- There are just too many different kinds of aspect ratio out there,
so I wouldn't be surprised that QT only supports one of them.

I hope what what I'm saying make some sense.

I'm gonna google around and hopefully find the missing information we need.


>  If so,
> perhaps it would be possible to automate that with MP4Box or some
> other tool that can manipulate raw atoms.

Yeah, I guess so.


> > Also, like I said, I don't quite like "too personal" style, so I'd
> > prefer smth along the lines of:
>
> I'm happy to make the other stylistic changes after we come to a
> consensus on the aspect ratio problem.

Ok, great!

Guillaume
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