logitech c920 fps drop in recording
A simple v4l2 full-featured video grabber
Brought to you by:
assisp
Menu
▾
▴
Hello,
I recently bought Logictech c920, with guvcview, (in h264 mode) I can view 720p (or even 1080p) at 30fps without issues. But when in record mode frame rate drops drammatically down to even 3fps. With cheese, although it feels less advanced than guvcview, it does not display fps, I can record at 720p and get a decent video, judging by the way this looks when i make fast movements, clap hands quickly, etc.
Is there a workaround/solution for guvcview? I truly appreciate its capabilities especially pulse-audio jack interface introduced in last version.
Thank you
Hi,
If you don't plan to use any video effects, just set the video codec to
raw.
This will save the camera output directly (without re-encoding), with this
setup you should be able to save a h264 video stream at even 60 fps in a
raspberry pi ;D
If you choose any other codec you will need not only to decode the camera
output but also to encode it with the selected codec, and apparently this
is a bit to stressing to your cpu.
Cheese, AFAIK, doesn't have h264 support so, probably is just setting your
camera output to MJPG.
It's important that you don't select any video filters, if you do so, then
frames must be encoded and you can't save the camera output directly.
Regards,
Paulo
2017-03-06 6:54 GMT+00:00 Achilleus Mantzios panixgr@users.sf.net:
Thank you Paulo, I'll check right away. I don't think that c920 supports 60fps, at least my attempts with gst-launch-1.0 failed to increase fps beyond 30 in either 720p or 1080p.
Just checked, works like a charm! Thanks. However there is a small problem, which I reproduced in both my boxes running ubuntu 16.10, with guvcview 2.0.4 and with two different web cams . After I hit "Stop Video" the message
"
AUDIO: (portaudio) Aborting audio stream
AUDIO: Closing audio stream...
"
is shown, there is an increase in CPU activity, disk activity (IMO correctly) stops, and the stop button does not listen the click(s). Sending Ctrl-C (SIGINT=2) is caught but does nothing, Sending Ctrl-\ (SIGQUIT=3) causes the program to core dump.
Hi,
Can you try the latest version (2.0.5) ?
You can get ubuntu binaries from my ppa:
stable: https://launchpad.net/~pj-assis/+archive/ubuntu/ppa
or
testing (daily git builds):
https://launchpad.net/~pj-assis/+archive/ubuntu/testing
Regards,
Paulo
2017-03-06 20:22 GMT+00:00 Achilleus Mantzios panixgr@users.sf.net:
I see some related changes in 2.0.5 in ChangeLog. Will try that ASAP. Thank you so much for your great help!
Hello, tried that, but saw no difference. It behaves exactly the same way. Also I tried deinstall libguvcview as well and then re-install both packages (from the new source) and somehow I lost /dev/video0 (the default built-in webcam in my sony vaio). I could not bring this back no matter how many kernels I tried : 4.8.0-41-generic down to 3.5 . I don't know what caused this. Booting with windows the builtin camera works fine. I haven't checked with my other linux or the new logitech c920.
lsmod | grep -i uvc
shows nothing, I can't load the module. I don't know what is wrong here.
Last edit: Achilleus Mantzios 2017-03-08
I attach dpkg.log and apt history log just in case you might see anything from those.
apt log
lsmod | grep -i uvc
showed nothing, so I tried to
modprobe uvcvideo
the module was loaded but still no /dev/video0
Maybe I pressed some Fn-Key without knowing? From windows I can use the web eye cam. I am stuck, it seems.
Last edit: Achilleus Mantzios 2017-03-08
Hi,
This is strange, but I can assure you that user space apps like guvcview,
can't affect kernel space like that.
Some times however, if the camera doesn't disconnect properly, the video
node doesn't get deleted automatically, so next time you reboot, since
video node creation is incremental, udev will use the next available video
node, video1 for instance, and the old node, video0, although it can be
listed with 'ls', it just won't work.
In this cases you can just remove it manually with 'rm'.
As for the crash in guvcview you reported, I really can't reproduce it with
2.0.5, if you could post a backtrace it would be very helpful.
Regards,
Paulo
2017-03-08 8:32 GMT+00:00 Achilleus Mantzios panixgr@users.sf.net:
Hi, this isn't really a crash. The control window freezes. By Ctrl-C the camera monitor window dies but the control window does not, and also does not listen to "Stop" or "Quit".
As far as the camera goes, there is nothing in /dev/video* no device at all.
It seems the hardware itself is disabled. Maybe somehow I pressed the wrong buttons and somehow linux has a memory persistent across boots? In windows it is detected and working good. I am puzzled.
The important thing is to get the camera back somehow.
Thank you for any ideas. This is a SONY VAIO laptop circa 2012. The integrated eye webcam worked great till yesterday.
Hi,
2017-03-08 10:23 GMT+00:00 Achilleus Mantzios panixgr@users.sf.net:
No, I don't think so, if it's disabled in hardware it shouldn't work in
windows either.
Try rebooting and check dmesg for related messages.
Note: after a little bit of googling I found this post:
https://forums.linuxmint.com/viewtopic.php?t=91266
It looks like some vaio models need some firmware to be uploaded to set the
camera fully uvc compatible, not sure if its your case, but it may be worth
checking it out.
Regards,
Paulo
Hello Paulo,
I got home from work, my son had worked on the laptop and I just saw that the ..... built-in motion eye camera was .... working again .... !!!
Fact is I always got messages of the type : "usb 1-1.2: new high-speed USB device number ..." with numbers recycling from 1->127, which means that smth was/is generally broken with this cam. I rebooted and the camera was lost again, then after some hours I just tried moving the lid up down a little bit, even tapping it a little , and voila, the annoying dmesg were gone, and lsusb showed the camera again. Cheese/Guvcview apparently worked.
This is the cam :
Bus 001 Device 005: ID 0c45:6409 Microdia Webcam
I installed the firmware package but didn't actually upload it yet. I don't know if this firmware really applies.
I also installed the newest guvcview and it works, (even with the motion eye cam).
Thank you Paulo, I'll keep you posted with my adventures. I'll try to use pulse audio and doing concurrent videos along with ardour (guitar recordings ).
I may bother you again soon it seems, THANX!!!
Last edit: Achilleus Mantzios 2017-03-08
Here is a vid I made with guvcview, using the pulse audio, realtime along with the recording.
https://www.youtube.com/watch?v=sbJDNJyUHtM
I made and uploaded this vid in less that 12 mins, playing the song included!! This is just great!
This is fantastic! I can finally record video and audio using my Logitech c920 in Ubuntu Studio.
Thank you for your efforts!
-sid