[MPlayer-users] [Question]Changing aspect ratio when playing a video file

[Nico Sabbi]

On Friday 12 September 2008 11:50:03 Kan-I Jyo wrote:
> Dear list,
>
> For I am new to this list, what I am posting might be some kind of
> cliche to most of you, but I would like to know the basic routine
> when playing a video file.
>
> It is my understanding that when we open a file in a video player,
> such as (s)mplayer(one of my favorite), the flow would generally
> goes like:
>
> Open a file -> Check file header for some format information ->
> looking for a appropriate decoding codec -> decoding the data and
> send them back to video player -> show the strem on screen.
>
> If the above to be correct, at which stage(s), would the "changing
> aspect ratio" opearation would be taken?


"decode the video" data, unless there's some aspect ratio change
signalled in the demuxer or stream layer (dvds, at the stream layer,
sometimes report a different A/R than the one in the video stream,
but only at the beginning of a title,  not mid-stream)


>
> At the same time, which part of the above is going to be in charge
> of doing this "changing aspect ratio" work?

libmpcodecs/vd_*.c

>
> As I am not an expert on this area, my question may not be precise
> enough. Please give me some comment/direction on how the above is
> going to work