LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware
User Name
Password
Linux - Hardware This forum is for Hardware issues.
Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?

Notices


Reply
  Search this Thread
Old 01-14-2011, 11:40 PM   #1
Dafydd
Member
 
Registered: Oct 2008
Posts: 344

Rep: Reputation: 29
Need UVC webcam to produce 30 fps


Logitech 9000 pro.

I need 30 fps so I can splice into existing video.
I am using this script.
Code:
#!/bin/bash
##Turn on webcam and save video and audio output to file.

# check if there is no command line argument
if [ $# -eq 0 ]
then
echo "You forgot to name the output file!"
echo "Usage :: webcam-capture name of output file"
exit
fi

name=$1;


mencoder -tv fps=30:driver=v4l2:buffersize=256:norm=NTSC:input=0:volume=40:amode=1:quality=100:width=640:height=480:device=/dev/video0:adevice=/dev/dsp1:audiorate=44100:immediatemode=0:forceaudio tv:// -o "$name".avi -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=490:keyint=18 -ofps 30 -vf lavcdeint -oac mp3lame -lameopts cbr:br=96:mode=0 -noskip


echo "Recording. Ctrl-C or close window to stop"
Even though I have set 'fps' to 30, I only get between 14 and 16. Several thread on the internet tell me that UVC in only capable of 15 fps in 640x480 mode.

Is there some way to make the camera (ID 046d:0809 Logitech, Inc.) work as something OTHER than a UVC type camera? Is there a code snippet to work with?

I have no problems with getting the camera to work with any of the apps in the Ubuntu reposit. The script above records video and audio great, just not 30 fps.

TIA
Dave

PS
The video I will be splicing into will be shot with a video recorder and windows software. If it is a USB hookup, will it have the same constraints of UVC at 15 fps. IIRC, it is the USB that has the compression problem that limit it to 15 fps.
 
Old 01-17-2011, 08:56 PM   #2
Dafydd
Member
 
Registered: Oct 2008
Posts: 344

Original Poster
Rep: Reputation: 29
Further search and read has led me to the reason for the low FPS on the webcam. Everything states that the UVC is capible of 30 fps. What it doesn't tell you is that the fps speed is determined by the exposure.

The less light the longer it takes the camera to correct and compress the image. The solution is to turn off automatic exposure. That can drastically affect image quality, but it does speed up fps.

Lets mark this solved for a while.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
turn off auto exposure on a uvc webcam zoran119 Slackware 7 10-22-2009 07:27 AM
[SOLVED] Streaming UVC webcam Koppie Linux - Software 1 09-05-2009 04:32 PM
ASUS netbook--third-party UVC webcam craig61107 Linux - Laptop and Netbook 1 04-17-2009 02:21 PM
Chicony UVC webcam not working in Slackware 12.2 Ryuu Linux - Laptop and Netbook 1 02-14-2009 07:33 AM
UVC Webcam Ubuntu j0eh4x Linux - Hardware 5 01-05-2009 10:33 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware

All times are GMT -5. The time now is 03:07 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration