[MEncoder-users] mencoder output

[Corey Hickey]

Marco wrote:
> Is mencoder scaling the input? What do messages (1) and (2) mean?
> 
> Thanks,
> Marco
> 
> 
> success: format: 0  data: 0x0 - 0x140b800
> MPEG-PS file format detected.
> VIDEO:  MPEG2  720x576  (aspect 2)  25.000 fps  9800.0 kbps (1225.0 kbyte/s)
> [V] filefmt:2  fourcc:0x10000002  size:720x576  fps:25.00  ftime:=0.0400
> ==========================================================================
> Opening audio decoder: [liba52] AC3 decoding with liba52
> AC3: 5.1 (3f+2r+lfe)  48000 Hz  384.0 kbit/s
> AUDIO: 48000 Hz, 2 ch, s16le, 384.0 kbit/25.00% (ratio: 48000->192000)
> Selected audio codec: [a52] afm:liba52 (AC3-liba52)
> ==========================================================================
> xvid: using library version 1.1.0 (build xvid-1.1.0)
> Opening video filter: [expand osd=1]
> Expand: -1 x -1, -1 ; -1  (-1=autodetect) osd: 1
> Opening video filter: [crop w=704 h=576 x=2 y=0]
> Crop: 704 x 576, 2 ; 0
> ==========================================================================
> Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
> VDec: vo config request - 720 x 576 (preferred csp: Mpeg PES)
> (1) >>> Could not find matching colorspace - retrying with -vf scale...
>       >>> Opening video filter: [scale]
>       >>> VDecoder init failed :(

That's just mencoder trying to use a hardware MPEG decoder and failing.
You can see, below, that it tries libmpeg2 and succeeds. You can prevent
mencoder from trying mpegpes, if you want, by adding the following line
to a mencoder config file (/etc/mplayer/mencoder.conf or
~/.mplayer/mencoder):

vc=-mpegpes,

Don't forget the '-' and the ','.

> Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder libmpeg2-v0.4.0b
> Selected video codec: [mpeg12] vfm:libmpeg2 (MPEG-1 or 2 (libmpeg2))
> ==========================================================================
> audiocodec: framecopy (format=2000 chans=2 rate=48000 bits=16
> bps=48000 sample-1)
> Writing AVI header...
> ODML: Aspect information not (yet?) available or unspecified, not
> writing vprp header.
> (2) >>> VDec: vo config request - 720 x 576 (preferred csp: Planar YV12)
>      >>> VDec: using Planar YV12 as output csp (no 0)
>      >>> Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.

Right here mencoder is specifying that the video should be scaled to
match the original 1.33:1 aspect ratio. The video doesn't actually get
encoded that way (see below) but will be scaled on playback. If you
don't want that to happen you can either:

- rescale manually with the scale video filter
- prevent the aspect ratio from being used with the -noaspect option
- set the aspect manually with the dsize video filter

There are probably other ways, but I always use the first option so I
don't pay attention to the others.

> videocodec: XviD (704x576 fourcc=44495658 [XVID])
> xvid: par=0/0 (vga11), displayed=750x576, sampled=704x576
> xvid: 2Pass Rate Control -- 2nd pass -- bitrate=1500kbit/s

-Corey