[MPlayer-users] recording video from a webcam

[Keith Lawson]

On Thu, 23 Oct 2008, wt at teksavvy.com wrote:

>
> I'm trying to use mencoder to make a video recording from a webcam.
>
> The following command was used and the resulting console output is shown below. Could someone tell me if I missed a library when I compiled the latest source from svn? Is this problem a result of a misconfiguration.  I should note that I had no difficulties running the below command with MPlayer v1.0rc2.
>
>
> $ mencoder -v tv:// -tv driver=v4l:device=/dev/video0:width=640:height=480 -ovc lavc -lavcopts vcodec=mpeg4:acodec=libmp3lame:aspect=4/3 -ffourcc DX50 -oac mp3lame -lameopts preset=standard -o test.avi
>
>
> MEncoder dev-SVN-r27808-4.2.1 (C) 2000-2008 MPlayer Team
> CPU: Mobile Intel(R) Pentium(R) 4 - M CPU 1.80GHz (Family: 15, Model: 2, Stepping: 7)
> CPUflags: Type: 15 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
> Compiled for x86 CPU with extensions: MMX MMX2 SSE SSE2
>
> Configuration: --enable-gui
> init_freetype
> get_path('font/font.desc') -> '/home/wt/.mplayer/font/font.desc'
> font: can't open file: /home/wt/.mplayer/font/font.desc
> font: can't open file: /usr/local/share/mplayer/font/font.desc
> Using MMX (with tiny bit MMX2) Optimized OnScreenDisplay
> STREAM: [tv] tv://
> STREAM: Description: TV Input
> STREAM: Author: Benjamin Zores, Albeu
> STREAM: Comment:
> success: format: 9  data: 0x0 - 0x0
> TV file format detected.
> Selected driver: v4l
> name: Video 4 Linux input
> author: Alex Beregszaszi
> comment: under development
> Selected device: Creative Nx Pro
> Capabilites: capture
> Device type: 1
> Supported sizes: 176x144 => 640x480
> Inputs: 1
>  0: ZC301-2:  (tuner:0, norm:pal)
> Using input 'ZC301-2'
> tv.c: norm_from_string(pal): Bogus norm parameter, setting default.
> Selected norm : pal
> Unknown norm!
> Error: Cannot set norm!

Did you try manually specifying the norm on the command line? Something 
like:

-tv driver=v4l:device=/dev/video0:width=640:height=480:norm=NTSC

> Requested width: 640
> Requested height: 480
> Selected input hasn't got a tuner!
> ==> Found video stream: 0
> Output format: Planar YV12
> Picture values:
> Depth: 12, Palette: yuv420p (Format: Planar YV12)
> Brightness: 32768, Hue: 0, Colour: 0, Contrast: 32768
> mbuf: size=2457616, frames=2
> Using a ring buffer for maximum 861 frames, 378 MB total size.
> [V] filefmt:9  fourcc:0x32315659  size:640x480  fps:0.000  ftime:=   inf
> [file] File size is 0 bytes
> STREAM: [file] test.avi
> STREAM: Description: File
> STREAM: Author: Albeu
> STREAM: Comment: based on the code from ??? (probably Arpi)
> Opening video filter: [expand osd=1]
> Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
> ==========================================================================
> Opening video decoder: [raw] RAW Uncompressed Video
> VDec: vo config request - 640 x 480 (preferred colorspace: Planar YV12)
> Trying filter chain: expand lavc
> VDec: using Planar YV12 as output csp (no 0)
> Movie-Aspect is undefined - no prescaling applied.
> VO Config (640x480->640x480,flags=0,'MPlayer',0x32315659)
> REQ: flags=0x401  req=0x0
> videocodec: libavcodec (640x480 fourcc=34504d46 [FMP4])
> [mpeg4 @ 0x8b58340]bitrate tolerance too small for bitrate
> Could not open codec.
> FATAL: Cannot initialize video driver.
> VDecoder init failed :(
> Cannot find codec matching selected -vo and video format 0x32315659.
> Read DOCS/HTML/en/codecs.html!

I would take mplayer's suggestion and read DOCS/HTML/en/codecs.html to see 
if you can figure out this error.

> ==========================================================================
>
> Exiting...
>
>
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