[MPlayer-users] more newbie questions

[D Richard Felker III]

On Fri, Feb 14, 2003 at 11:01:02AM -0800, Brian Craft wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> What is the advantage of the RTC support? Is it more accurate? Or burn less
> cpu?
> 
> How can I tell what video format a file is in? I note this during mplayer
> start-up:
> 
>   VIDEO:  []  720x480  24bpp  29.97 fps  6456.6 kbps (788.2 kbyte/s)

No idea what this one is.

>   VIDEO:  MPEG2  720x480  (aspect 2)  29.97 fps  12250.0 kbps (1531.2 kbyte/s)
> 
> What's with the 29.97 fps? Is that really the frame rate of the source? What
> output devices run at 29.97 fps?

Yes, NTSC television (North America, Japan, etc.).

Well, actually the source material could be 24 fps movie, converted to
29.97 fps by so-called "telecine". Search the archives for details if
you're curious.

> What does the following mean?
> 
>   No accelerated IMDCT transform found

It means that your CPU doesn't have MMX/3dnow/etc., or that MPlayer
was not compiled with support for them.

> What's going on here, where it appears to be failing over to a different
> video codec? Does this mean I've failed to compile something correctly?
> 
>   Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
                                                    ^^^^^^^^^^^
>   VDec: vo config request - 720 x 480 (preferred csp: Mpeg PES)
>   Could not find matching colorspace - retrying with -vop scale...
>   Opening video filter: [scale]
>   The selected video_out device is incompatible with this codec.
>   VDecoder init failed :(

Unless you have a hardware mpeg decoder card, of course passthrough is
going to fail.

>   Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder v2.0
>   libmpeg2: Using MMX for IDCT transform
>   libmpeg2: Using MMX for motion compensation
>   VDec: vo config request - 720 x 480 (preferred csp: Planar YV12)
>   VDec: using Planar YV12 as output csp (no 0)
>   Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
>   VO: [xmga] 720x480 => 720x540 Planar YV12
>   [mga] Using 3 buffers.
>   Selected video codec: [mpeg12] vfm:libmpeg2 (MPEG 1 or 2 (libmpeg2))

Notice that mplayer falls back to the software decoder, which then
works fine.

Rich