[MEncoder-users] Cannot go above 640x480 with v4l2 webcam capture

[Kovacs Peter Tamas]

Dear All,

I'm trying to capture a video stream from a Logitech Quickcam Pro for
Notebooks webcam.
I'm using the latest uvcvideo kernel module (from SVN), latest libwebcam
(from SVN), and mencoder (from SVN).

If I try to capture a video stream with resolution 640x480 or below,
everything is working fine, eg:
mencoder tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0
-nosound -ovc lavc -o capture.avi

However, when I try to go further, it always gives me a 640x480 stream, like:
--------------------------------------
pc05 ~# mencoder tv:// -tv
driver=v4l2:width=800:height=600:device=/dev/video0 -nosound -ovc lavc -o
capture.avi
MEncoder SVN-r27899 (C) 2000-2008 MPlayer Team
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 6400+ (Family: 15, Model:
67, Stepping: 3)
3DNow supported but disabled
3DNowExt supported but disabled
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

success: format: 9  data: 0x0 - 0x0
TV file format detected.
Selected driver: v4l2
 name: Video 4 Linux 2 input
 author: Martin Olschewski <olschewski at zpr.uni-koeln.de>
 comment: first try, more to come ;-)
v4l2: your device driver does not support VIDIOC_G_STD ioctl,
VIDIOC_G_PARM was used instead.
Selected device: UVC Camera (046d:0991)
 Capabilites:  video capture  streaming
 supported norms:
 inputs: 0 = Camera 1;
 Current input: 0
 Current format: YUYV
v4l2: ioctl set format failed: Invalid argument
v4l2: ioctl set format failed: Invalid argument
v4l2: ioctl set format failed: Invalid argument
tv.c: norm_from_string(pal): Bogus norm parameter, setting default.
v4l2: ioctl enum norm failed: Invalid argument
Error: Cannot set norm!
Selected input hasn't got a tuner!
v4l2: ioctl set mute failed: Invalid argument
v4l2: ioctl query control failed: Invalid argument
[V] filefmt:9  fourcc:0x32595559  size:640x480  fps:15.000  ftime:=0.0667
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: Packed YUY2)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
VDec: using Packed YUY2 as output csp (no 0)
Movie-Aspect is undefined - no prescaling applied.
SwScaler: reducing / aligning filtersize 1 -> 4
SwScaler: reducing / aligning filtersize 1 -> 4
SwScaler: reducing / aligning filtersize 1 -> 1
SwScaler: reducing / aligning filtersize 9 -> 8
[swscaler @ 0x1104800]BICUBIC scaler, from yuyv422 to yuv420p using MMX2
[swscaler @ 0x1104800]using 4-tap MMX scaler for horizontal luminance scaling
[swscaler @ 0x1104800]using 4-tap MMX scaler for horizontal chrominance
scaling
[swscaler @ 0x1104800]using 1-tap MMX "scaler" for vertical scaling (YV12
like)
[swscaler @ 0x1104800]640x480 -> 640x480
videocodec: libavcodec (640x480 fourcc=34504d46 [FMP4])
Selected video codec: [rawyuy2] vfm: raw (RAW YUY2)
==========================================================================
Forcing audio preload to 0, max pts correction to 0.
New_Face failed. Maybe the font path is wrong.
Please supply the text font file (~/.mplayer/subfont.ttf).
subtitle font: load_sub_face failed.
New_Face failed. Maybe the font path is wrong.
Please supply the text font file (~/.mplayer/subfont.ttf).
subtitle font: load_sub_face failed.
Writing header...
ODML: Aspect information not (yet?) available or unspecified, not writing
vprp header.
Writing header...
ODML: Aspect information not (yet?) available or unspecified, not writing
vprp header.
Pos:   2.3s     35f ( 0%) 13.01fps Trem:   0min   0mb  A-V:0.000 [543:0]
Flushing video frames.
Writing index...
Writing header...
ODML: Aspect information not (yet?) available or unspecified, not writing
vprp header.

Video stream:  543.651 kbit/s  (67956 B/s)  size: 158565 bytes  2.333 secs
 35 frames
v4l2: ioctl set mute failed: Invalid argument
v4l2: 37 frames successfully processed, -36 frames dropped.
--------------------------------------------

>From this log, it doesn't look like it tried to go for 800x600.

However, when I insert the uvcvideo kernel module, it can be seen that it
supports this resolution (in YUV and MJPEG too):
--------------------------------------------------------
Nov 20 01:08:11 pc05 kernel: uvcvideo: UVC device initialized.
Nov 20 01:08:11 pc05 kernel: uvcvideo: Probing generic UVC device 4
Nov 20 01:08:11 pc05 kernel: uvcvideo: Found format MJPEG.
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 160x120 (30.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 176x144 (30.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 320x240 (15.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 352x288 (15.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 640x480 (15.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 800x600 (15.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 960x720 (10.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: Found format YUV 4:2:2 (YUYV).
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 160x120 (30.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 176x144 (30.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 320x240 (15.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 352x288 (15.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 640x480 (15.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 800x600 (15.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 960x720 (10.0 fps)
Nov 20 01:08:11 pc05 kernel: uvcvideo: - 1600x1200 (5.0 fps)
---------------------------------------------

I've also tried using outfmt:mjpeg, and it works, but still cannot get a
higher resolution video stream.
Using guvcview, I can use the camera in 800x600 and even 960x720, both in
YUV and MJPEG.

I'm running a stripped down Fedora 8 on x86_64 with 2.6.24 kernel:
pc05 ~# uname -a
Linux pc05 2.6.24.5-fedora #7 SMP Fri Nov 7 13:42:49 CET 2008 x86_64
x86_64 x86_64 GNU/Linux

Do you have an idea what could be the reason for this behaviour?

Thank you very much for your kind help in advance,
Peter