Bug 316931

Summary: v4l2src plugin regression with uvcvideo: uses read() rather than mmap()
Product: [Fedora] Fedora Reporter: Michel Lind <michel>
Component: gstreamer-plugins-goodAssignee: Adam Jackson <ajax>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: anmar, cebbert, ivazqueznet, tjb
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: 0.10.6-7 Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2008-01-16 16:28:16 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
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Description Flags
Patch to fix V4L2 buffer issue none

Description Michel Lind 2007-10-03 14:43:44 UTC 
Description of problem:
The v4l2 plugin in 0.10.6 uses read() exclusively; right now the linux-uvc
project only supports mmap() as it performs better.

Version-Release number of selected component (if applicable):
gstreamer-plugins-good-0.10.6-5.fc8

How reproducible:
Always

Steps to Reproduce:
1. Install linux-uvc and plug in a UVC webcam (Logitech, Thinkpad)
2. gstreamer-properties, set device to v4l2, test

Actual results:
Failure -- could not get buffers from /dev/video0

Expected results:
Should work (Ekiga works)


Additional info:
Fixed in CVS -- could the patch be applied?
Comment 1 Michel Lind 2007-11-12 00:24:52 UTC 
Still a problem with the latest version of linux-uvc -- ping?
Comment 2 Ignacio Vazquez-Abrams 2007-12-08 19:18:01 UTC 
Looks like a single change will fix this, although __tim in #gstreamer says that
it should be set to GST_V4L2_MIN_BUFFERS instead of 2.

http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/sys/v4l2/gstv4l2src.c?r1=1.83&r2=1.84
Comment 3 Ignacio Vazquez-Abrams 2007-12-08 20:31:30 UTC 
Created attachment 282101 [details]
Patch to fix V4L2 buffer issue

The attached patch fixes the issue for F8/x86_64.
Comment 4 Thomas J. Baker 2007-12-11 18:36:11 UTC 
The include patch works for me and makes the webcam on my M1210 work with cheese...
Comment 5 Chuck Ebbert 2008-01-11 22:48:39 UTC 
Where are you getting linux-uvc from?
Comment 6 Michel Lind 2008-01-11 23:12:57 UTC 
Compiled from SVN sources. I have a package for it, but it depends on DKMS, and
I'm not sure Fedora currently accepts DKMS-packaged kernel modules.
Comment 7 Fedora Update System 2008-01-15 23:10:26 UTC 
gstreamer-plugins-good-0.10.6-7.fc8 has been pushed to the Fedora 8 stable repository.  If problems still persist, please make note of it in this bug report.