Playing raw video with mplayer on Ubuntu 10.04

william.l.metcalf · 07-06-2011, 10:18 AM

I am in the process of writing a program that reads in video frames from a capture card. For now, I am taking those raw video frames and writing them to a file. I am trying to play those files with mplayer and I am running into issues. The video that plays is slowly and continuously scrolling vertically. The video seems to be playing correctly, i.e. I don't see any big loss of frames or anything like that other than the video scrolling vertically.

To play the video I am using the following command:

wmetcalf@wmetcalf-desktop:~/Desktop/Linux/Samples/bin/i386$ mplayer /home/wmetcalf/Desktop/video.raw -demuxer rawvideo -rawvideo ntsc:uyvy

The following is output before the video plays:

MPlayer SVN-r1.0~rc3+svn20090426-4.4.3 (C) 2000-2009 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing /home/wmetcalf/Desktop/video.raw.
rawvideo file format detected.
open: No such file or directory
[MGA] Couldn't open: /dev/mga_vid
open: No such file or directory
[MGA] Couldn't open: /dev/mga_vid
[VO_TDFXFB] Can't open /dev/fb0: Permission denied.
[VO_3DFX] Unable to open /dev/3dfx.
==========================================================================
Opening video decoder: [raw] RAW Uncompressed Video
VDec: vo config request - 720 x 480 (preferred colorspace: Packed UYVY)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
VDec: using Packed UYVY as output csp (no 0)
Movie-Aspect is undefined - no prescaling applied.
SwScaler: reducing / aligning filtersize 1 -> 4
Last message repeated 1 times
SwScaler: reducing / aligning filtersize 1 -> 1
SwScaler: reducing / aligning filtersize 9 -> 8
[swscaler @ 0x92f5bf0]BICUBIC scaler, from uyvy422 to yuv420p using MMX2
[swscaler @ 0x92f5bf0]using 4-tap MMX scaler for horizontal luminance scaling
[swscaler @ 0x92f5bf0]using 4-tap MMX scaler for horizontal chrominance scaling
[swscaler @ 0x92f5bf0]using 1-tap MMX "scaler" for vertical scaling (YV12 like)
[swscaler @ 0x92f5bf0]720x480 -> 720x480
VO: [xv] 720x480 => 720x480 Planar YV12
Selected video codec: [rawuyvy] vfm: raw (RAW UYVY)
==========================================================================
Audio: no sound
Starting playback...
V: 4.8 121/121 0% 8% 0.0% 0 0
Exiting... (Quit)

I am thinking that maybe I have some kind of colorspace parameter wrong or something like that, but I am not exactly sure how to figure out what colorspace I need to use. I am pretty new to messing with RAW video so any help you can provide would be very appreciated!

-William

teckk · 07-07-2011, 12:24 PM

Here is what the man page says on it if it helps.

Code:

 -rawvideo <option1:option2:...>
              This option lets you play raw video files.  You have to use -de-
              muxer rawvideo as well.

              Available options are:

                 fps=<value>
                      rate in frames per second (default: 25.0)
                 sqcif|qcif|cif|4cif|pal|ntsc
                      set standard image size
                 w=<value>
                      image width in pixels
                 h=<value>
                      image height in pixels
                 i420|yv12|yuy2|y8
                      set colorspace
                 format=<value>
                      colorspace  (fourcc)  in  hex  or  string constant.  Use
                      -rawvideo format=help for a list of possible strings.
                 size=<value>
                      frame size in Bytes

              EXAMPLE:
                 mplayer foreman.qcif -demuxer rawvideo -rawvideo qcif
                      Play the famous "foreman" sample video.
                 mplayer  sample-720x576.yuv   -demuxer   rawvideo   -rawvideo
                 w=720:h=576
                      Play a raw YUV sample.