MJPEG V4L2_PIX_FMT_MJPEG - Error capturing first image

Question

Hi again,

This is continue question for "Unable to find a compatible palette format with Logitech Sphere." case Support Question 2007x 01x 14x 033716

Camera is (Bus 001 Device 002: ID 046d:08c2 Logitech, Inc.). Logitech Sphere.

Motion will now start nicely without errors, but then stops in few seconds with error: "[1] Error capturing first image"

[0] Processing thread 0 - config file /usr/local/etc/motion.conf
[0] Motion running in setup mode.
[0] Thread 1 is from /usr/local/etc/motion.conf
[0] Thread 1 is device: /dev/video1 input 8
[0] Waiting for threads to finish, pid: 10952
[1] Thread started
[1] cap.driver: "uvcvideo"
[1] cap.card: "USB Video Class device"
[1] cap.bus_info: "0000:00:07.2"
[1] cap.capabilities=0x04000001
[1] - VIDEO_CAPTURE
[1] - STREAMING
[1] v4l2_select_input: name = "Camera", type 0x00000002, status 00000000
[1] - CAMERA
[1] Device doesn't support VIDIOC_G_STD
[1] Supported palettes:
[1] 0: MJPG (MJPEG)
[0] motion-httpd/3.2.8 running, accepting connections
[0] motion-httpd: waiting for data on port TCP 8080
[1] Using palette MJPG (320x240)
[1] found control 0x00980900, "Brightness", range 0,255
[1]     "Brightness", default 127, current 127
[1] found control 0x00980901, "Contrast", range 0,255
[1]     "Contrast", default 32, current 32
[1] found control 0x00980902, "Saturation", range 0,255
[1]     "Saturation", default 39, current 39
[1] found control 0x00980913, "Gain", range 0,255
[1]     "Gain", default 0, current 16
[1] found control 0x08000000, "Backlight Compensation", range 0,2
[1]     "Backlight Compensation", default 1, current 1
[1] found control 0x08000001, "Power Line Frequency", range 0,2
[1]     "Power Line Frequency", default 2, current 2
[1] mmap information:
[1] frames=4
[1] 0 length=42666
[1] 1 length=42666
[1] 2 length=42666
[1] 3 length=42666
[1] Using V4L2
[1] Error capturing first image
[1] Thread finishing...

Environment

Motion version:	3.2.8 svn revision 163
ffmpeg version:
Libraries:	ffmpeg
Server OS:	Ubuntu 6.10 (Edgy Eft)

-- PeterBowle - 24 Jan 2007

Follow up

I think that you build motion with ffmpeg support , because it's mandatory to work with MJPEG .

Anyway Did you see any other message in log files ( /var/log/messages or /var/log/syslog ) ?

Because i don't see above what was the error in vid_next().

-- AngelCarpintero - 24 Jan 2007

Question

Ok, after compiling with ffmpeg support: (ffmpeg version information):

FFmpeg version SVN-rUNKNOWN, Copyright (c) 2000-2004 Fabrice Bellard
  configuration:  --enable-gpl --enable-pp --enable-pthreads --enable-vorbis --enable-libogg --enable-a52 --enable-dts --enable-libgsm --enable-dc1394 --disable-debug --enable-shared --prefix=/usr
  libavutil version: 0d.49.0.0
  libavcodec version: 0d.51.11.0
  libavformat version: 0d.50.5.0
  built on Sep 20 2006 00:26:15, gcc: 4.1.2 20060906 (prerelease) (Ubuntu 4.1.1-13ubuntu2)

I get more detailed error message from motion:

[1] Using V4L2
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] outbuf size mismatch. pic_size 153600  bufsize: 230400: Invalid argument
[1] Error capturing first image
[1] Thread finishing...

Follow up

I'm trying to fix that problem , but i have no any webcam with MJPEG palette support so it's not easy to fix it in "blind" way.

-- AngelCarpintero - 26 Jan 2007

Question

With revision 166 error message is:

[1] Using V4L2
[1] Not a JPEG file: starts with 0x4b 0x47
[1] Not a JPEG file: starts with 0x4f 0x4b
[1] Not a JPEG file: starts with 0x4e 0x4d
[1] Not a JPEG file: starts with 0x4d 0x4b
[1] Not a JPEG file: starts with 0x4e 0x4c
[1] Not a JPEG file: starts with 0x4c 0x4a
[1] Not a JPEG file: starts with 0x4c 0x49
[1] Not a JPEG file: starts with 0x4e 0x4a
[1] Not a JPEG file: starts with 0x4d 0x48
[1] Not a JPEG file: starts with 0x41 0x39
[1] Error capturing first image
[1] Thread finishing...

Follow Up

Well i fixed the previous issue with the buffer size , but seems that still there's a bug around. The logs messages you posted are from the decompress process , so i guess the problem is that MJPEG is not well parsed or the huffman table are not added correctly. Let me see ...

-- AngelCarpintero - 31 Jan 2007

Answer

I've fixed MJPEG issues in motion svn -r167.

Give a try ... some imagen distorsion may happen. I'll try to see where is the problem maybe libavcodec decompression/conversion .

-- AngelCarpintero - 31 Jan 2007

Comment

Ok problem solved! Colors needs some tuning, but it works pretty well.