airmax / v4l2loopback Goto Github PK

i noticed that v42loopback currently only supports a single loopback device.

it would be great, if this could be expanded to a user-defineable number.

e.g. the "vloopback" driver (v4l1-loopback) has a parm:
pipes: Nr of pipes to create (each pipe uses two video devices) (int)

luckily with v4l2loopback, we only need a single device per pipe :-)

but i currently have to juggle with both v4l1- and v4l2-loopback drivers to get 
barely enough devices (gstreamer can only use v4l2-loopback; but my other apps 
can use v4l1-loopbacks as well)

to make stream format signal source driven it is necessary to find out
which opener calls ioctl.

Hi,
I try to use gstreamer to use the internal cam of my n900 as a webcam, this is 
my setup:
* on the n900 I'm running:
  gst-launch v4l2src device=/dev/video0 ! videoscale ! video/x-raw-yuv,width=320,height=240 ! ffmpegcolorspace ! smokeenc ! \
  udpsink host=$DESKTOP_HOST port=$PORT

* on my desktop:
  gst-launch udpsrc port=$PORT ! smokedec ! v4l2sink device=/dev/video0

/dev/video0 is the v4l2loopback device.

I'm using the v4l2loopback 0.3.1-1 package from ubuntu natty.

% LANG=C gst-launch -vvvv udpsrc port=$PORT ! smokedec ! v4l2sink 
device=/dev/video0
Setting pipeline to PAUSED ...
libv4l2: error getting pixformat: Invalid argument
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
/GstPipeline:pipeline0/GstSmokeDec:smokedec0.GstPad:src: caps = 
video/x-raw-yuv, format=(fourcc)I420, width=(int)320, height=(int)240, 
framerate=(fraction)2993/100

** (gst-launch-0.10:4842): CRITICAL **: gst_v4l2sink_sync_overlay_fields: 
assertion `v4l2_ioctl (fd, VIDIOC_G_FMT, &format) >= 0' failed
/GstPipeline:pipeline0/GstV4l2Sink:v4l2sink0.GstPad:sink: caps = 
video/x-raw-yuv, format=(fourcc)I420, width=(int)320, height=(int)240, 
framerate=(fraction)2993/100


And when using mplayer on /dev/video0 I get:

% mplayer -fps 15 tv:// -tv  driver=v4l2:device=/dev/video0
MPlayer 1.0rc4-4.4.5 (C) 2000-2010 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing tv://.
TV file format detected.
Selected driver: v4l2
 name: Video 4 Linux 2 input
 author: Martin Olschewski <[email protected]>
 comment: first try, more to come ;-)
Selected device: Dummy video device
 Capabilites:  video capture  video output  read/write  streaming
 supported norms: 0 = NTSC; 1 = NTSC-M; 2 = NTSC-M-JP; 3 = NTSC-M-KR; 4 = NTSC-443; 5 = PAL; 6 = PAL-BG; 7 = PAL-H; 8 = PAL-I; 9 = PAL-DK; 10 = PAL-M; 11 = PAL-N; 12 = PAL-Nc; 13 = PAL-60; 14 = SECAM; 15 = SECAM-B; 16 = SECAM-G; 17 = SECAM-H; 18 = SECAM-DK; 19 = SECAM-L; 20 = SECAM-Lc;
 inputs: 0 = loopback;
 Current input: 0
 Current format: YUV420
v4l2: ioctl set format failed: Invalid argument
Selected input hasn't got a tuner!
v4l2: ioctl set mute failed: Invalid argument
v4l2: ioctl query control failed: Invalid argument
v4l2: ioctl query control failed: Invalid argument
v4l2: ioctl query control failed: Invalid argument
v4l2: ioctl query control failed: Invalid argument
open: No such file or directory
[MGA] Couldn't open: /dev/mga_vid
open: No such file or directory
[MGA] Couldn't open: /dev/mga_vid
[VO_TDFXFB] Can't open /dev/fb0: No such file or directory.
[VO_3DFX] Unable to open /dev/3dfx.
==========================================================================
Opening video decoder: [raw] RAW Uncompressed Video
Movie-Aspect is undefined - no prescaling applied.
VO: [vdpau] 320x240 => 320x240 Planar I420 
Selected video codec: [rawi420] vfm: raw (RAW I420)
==========================================================================
Audio: no sound
FPS forced to be 15.000  (ftime: 0.067).
Starting playback...
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?
Frame too small! (76800<115200) Wrong format?


MPlayer interrupted by signal 2 in module: sleep_timer
V:   0.0  39/ 39  0%  0%  0.0% 0 0 

MPlayer interrupted by signal 2 in module: free_demuxer

I'm not sure where exactly the problem is, but for me it looks like the looback 
device is not working with the v4l2sink.

I'm more than happy to help debuggingthis furth.
Thanks for your help.

permanent task until driver is included to kernel.

if program trying to capture from loopback without input, where should it fail?

on open, or requesting formats, or somewhere else?

fix frame queue.

The attached patch contains 2 small changes:
 Removed empty line in middle of description from control file.
 Modified debian/rules to not try and copy non-existant header.

it is great to see video capture device which can give data to as many
users, as system can handle.

why do all the webcam drivers allow only one opener?

What kernel version do you use?
2.6.36

diff -r 6cdbe4e4e3d0 test.c
--- a/test.c    Wed Jun 16 06:19:59 2010 -0400
+++ b/test.c    Tue Nov 02 20:51:27 2010 +0000
@@ -17,6 +17,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <assert.h>
+#include <linux/slab.h>

 #define VIDEO_DEVICE "/dev/video1"
 #define FRAME_WIDTH  640
diff -r 6cdbe4e4e3d0 v4l2loopback.c
--- a/v4l2loopback.c    Wed Jun 16 06:19:59 2010 -0400
+++ b/v4l2loopback.c    Tue Nov 02 20:51:27 2010 +0000
@@ -11,6 +11,7 @@
  *
  */
 #include <linux/version.h>
+#include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
 #include <linux/time.h>
@@ -605,14 +606,14 @@
        init_buffers(dev->buffer_size);
        dev->ready_for_capture = 1;
    }
-   dprintkrw("v4l2_loopback_write() trying to write %d bytes\n", count);
+   dprintkrw("v4l2_loopback_write() trying to write %ld bytes\n", count);
    if (count > dev->buffer_size)
        count = dev->buffer_size;
    if (copy_from_user(
           (void *) (dev->image + dev->buffers[write_index].m.offset),
           (void *) buf, count)) {
        printk(KERN_ERR "v4l2-loopback: "
-          "failed copy_from_user() in write buf, could not write %d\n",
+          "failed copy_from_user() in write buf, could not write %ld\n",
           count);
        return -EFAULT;
    }

What steps will reproduce the problem?
1. Run Make from extracted tars location where source is located. 

The first error I receive is 'struct video_device' has no member named
'vidioc_querycap'

There are a bunch of others that are not members.

this maybe wrong place for question , but i cant find anywhere else to contact

How do i use the input from a file?

i want to make a jpeg,avi or mpeg available as a V4L2? video device.

for some reason such a construction fails to work normally, so using memcpy
instead
if (copy_from_user((void*)image, (void*)buf, count)) {
    printk (KERN_INFO "failed copy_from_user() in write \n");
    return -EFAULT;
}

I have to find what is the right way to copy data to(from) userspace

What kernel version do you use?
2.6.29
What steps will reproduce the problem?
1. svn checkout tree
2. make

What is the expected output? What do you see instead?
expected: v4l2loopback.ko
see:
$ make
Building vloopback driver...
make -C /lib/modules/`uname -r`/build
M=/home/paul/Archlinux/work/v4l2loopback modules
make[1]: entrant dans le répertoire « /usr/src/linux-2.6.29-ARCH »
  CC [M]  /home/paul/Archlinux/work/v4l2loopback/v4l2loopback.o
/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.c: In function
‘v4l_loopback_write’:
/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.c:552: attention :
format ‘%d’ expects type ‘int’, but argument 2 has type ‘size_t’
/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.c:562: attention :
format ‘%d’ expects type ‘int’, but argument 2 has type ‘size_t’
/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.c: In function 
‘init_vdev’:
/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.c:606: attention :
assignment from incompatible pointer type
/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.c: Hors de toute fonction :
/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.c:661: attention :
initialization from incompatible pointer type
/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.c:662: erreur:
‘v4l_compat_ioctl32’ undeclared here (not in a function)
make[2]: *** [/home/paul/Archlinux/work/v4l2loopback/v4l2loopback.o] Erreur 1
make[1]: *** [_module_/home/paul/Archlinux/work/v4l2loopback] Erreur 2
make[1]: quittant le répertoire « /usr/src/linux-2.6.29-ARCH »
make: *** [v4l2loopback] Erreur 2


What version of the product are you using? On what operating system?
r67
Archlinux

Please provide any additional information below.
Was ok with kernel 2.6.28

hi
sorry for abusing the issue tracker, but i would like to announce a fork of 
v4l2loopback i did a while ago

the reason for the fork was that i had the impression of v4l2loopback not being 
very actively maintained any more (though i'm wondering where i got that idea 
from)
the other reason is, that i don't like googlecode and prefer git :-)


anyhow, the source code can be found at
 https://github.com/umlaeute/v4l2loopback

this code has also been packaged for debian and is now part of debian(>squeeze) 
and ubuntu(>=natty): http://packages.debian.org/v4l2loopback

features include:
 - variable number of loopback devices
 - mostly working with gstreamer's v4l2sink (no more v4l2looback gst-element needed)
 - v4l2 compliance
 - known to work with 2.6.35 (and afaict from looking at the patch in issue22 for 2.6.36 as well)


i guess merging the 2 lines again would be a good idea.
sorry for the noise

What kernel version do you use?

2.28.10

What steps will reproduce the problem?

1. setup source from deb
2. setup module with m-a
3. modprob v4l2loopback
4. v4lsink

What is the expected output? What do you see instead?

I have error:
ERROR:gst-v4lsink-loopback.c:103:v4l2_sink_loopback_constructor: assertion
failed: (self->priv->output_fd >= 0)
Aborted

now only streaming capture and basic IO output is tested.

On start of reading video frames are lost, several seconds later all ok.

driver already works with luvcview and mplayer, need to find out what skype
wants from me.

make basic read write work correct.

What kernel version do you use?

3.0.0-12-generic (Ubuntu 11.10)

What steps will reproduce the problem?
1. gst-launch -v filesrc location=KillerElite2011.avi ! v4l2sink 
device=/dev/video0

What is the expected output? What do you see instead?

Setting pipeline to PAUSED ...
libv4l2: pixformat getting error: Invalid argument
The pipeline is Preparing ...
The pipeline was prepared ...
Setting pipeline to PLAYING ...

New clock: GstSystemClock

(gst-launch-0.10:3204): GStreamer-CRITICAL **: gst_caps_get_structure: 
assertion `GST_IS_CAPS (caps)' failed

(gst-launch-0.10:3204): GStreamer-CRITICAL **: gst_structure_get_name: 
assertion `structure != NULL' failed
Caught SIGSEGV accessing address (nil)
Spinning.  Please run 'gdb gst-launch 3204' to continue debugging, Ctrl-C to 
quit, or Ctrl-\ to dump core.

What version of the product are you using? On what operating system?
Ubuntu Desktop 11.10

Please provide any additional information below.

When i use:

gst-launch -v filesrc location=sample.mp4 ! decodebin ! ffmpegcolorspace ! 
v4l2sink device=/dev/video0

The video output nas tv resolution and no sound. How can i fix that?

Also, how must i send mp4 files via rtp/usp?

Thanks, 

Diego Silva

allmost all work is done by v4l2 infrastructure, but mmap should be done by
hands.

What kernel version do you use? 2.6.27-7-generic intrepid

What steps will reproduce the problem?
1. sudo modprobe v4l2loopback
2. sudo v4lsink 'v4l2src device=/dev/video0 ! ffmpegcolorspace !
V4l2SinkLoopback' 
3. start skype as normal user, into options, only original device listed.
similar in amsn (also v4l2)

What is the expected output? What do you see instead?
I expected "Dummy video device" to be in list of webcams, instead see nothing.

When executed as sudo, device appears, but clicking "Test" causes skype to
simply crash.

What version of the product are you using? On what operating system?
v4l2loopback-source 0.1.0-1 intrepid, from deb

Please provide any additional information below.
mplayer tv:// -tv device=/dev/video1 works fine but only as root (sudo),
devices have permissions as follows : 
ls -l /dev/video*
crw-rw----+ 1 root video 81, 0 2009-04-15 19:56 /dev/video0
crw-rw----  1 root video 81, 1 2009-04-15 19:59 /dev/video1

What kernel version do you use?
3.8-trunk-amd64 #1 SMP Debian 3.8-1~experimental.1 x86_64

What steps will reproduce the problem?
1. make install
make[1]: Leaving directory `/usr/src/linux-headers-3.8-trunk-amd64'
depmod -ae
WARNING: -e needs -E or --F
2. modprobe v4l2loopback
Error: could not insert module 
/lib/modules/3.8-trunk-amd64/extra/v4l2loopback.ko: Invalid parameters


What version of the product are you using? On what operating system?
git head. Debian sid

What kernel version do you use?
3.6.6
What steps will reproduce the problem?
1. make
2.
3.

What is the expected output? What do you see instead?
[root@node140 v4l2loopback]# make
Building vloopback driver...
make -C /lib/modules/`uname -r`/build M=/home/src/v4l2loopback modules
make[1]: Entering directory `/usr/src/kernels/3.6.6-1.fc17.x86_64'
  CC [M]  /home/src/v4l2loopback/v4l2loopback.o
/home/src/v4l2loopback/v4l2loopback.c: In function âv4l_loopback_openâ:
/home/src/v4l2loopback/v4l2loopback.c:540:2: error: implicit declaration of 
func                                                                            
                                  tion âkzallocâ 
[-Werror=implicit-function-declaration]
/home/src/v4l2loopback/v4l2loopback.c:540:9: warning: assignment makes pointer 
f                                                                               
                               rom integer without a cast [enabled by default]
/home/src/v4l2loopback/v4l2loopback.c: In function âv4l_loopback_closeâ:
/home/src/v4l2loopback/v4l2loopback.c:562:2: error: implicit declaration of 
func                                                                            
                                  tion âkfreeâ 
[-Werror=implicit-function-declaration]
/home/src/v4l2loopback/v4l2loopback.c: In function âv4l_loopback_writeâ:
/home/src/v4l2loopback/v4l2loopback.c:608:2: warning: format â%dâ expects 
argume                                                                          
                                    nt of type âintâ, but argument 2 has type 
âsize_tâ [-Wformat]
/home/src/v4l2loopback/v4l2loopback.c:616:6: warning: format â%dâ expects 
argume                                                                          
                                    nt of type âintâ, but argument 2 has type 
âsize_tâ [-Wformat]
/home/src/v4l2loopback/v4l2loopback.c: In function âinit_buffersâ:
/home/src/v4l2loopback/v4l2loopback.c:651:18: error: âstruct v4l2_bufferâ has 
no                                                                              
                                 member named âinputâ
/home/src/v4l2loopback/v4l2loopback.c: In function âv4l2_loopback_initâ:
/home/src/v4l2loopback/v4l2loopback.c:702:15: warning: assignment makes pointer 

                              from integer without a cast [enabled by default]
/home/src/v4l2loopback/v4l2loopback.c: In function âinit_moduleâ:
/home/src/v4l2loopback/v4l2loopback.c:754:6: warning: assignment makes pointer 
f                                                                               
                               rom integer without a cast [enabled by default]
cc1: some warnings being treated as errors
make[2]: *** [/home/src/v4l2loopback/v4l2loopback.o] Error 1
make[1]: *** [_module_/home/src/v4l2loopback] Error 2
make[1]: Leaving directory `/usr/src/kernels/3.6.6-1.fc17.x86_64'
make: *** [v4l2loopback] Error 2


What version of the product are you using? On what operating system?
hg clone

Please provide any additional information below.

What kernel version do you use?

Linux Febria 2.6.32-22-generic #33-Ubuntu SMP Wed Apr 28 13:28:05 UTC 2010
x86_64 GNU/Linux

What steps will reproduce the problem?
1. Download SVN source
2. Try sudo make, or as root, `make`

What is the expected output? What do you see instead?
Completed compilation. Instead, I observe:


ryty@Febria:/usr/src/v4l2loopback-read-only$ sudo make
Building vloopback driver...
make -C /lib/modules/`uname -r`/build M=/usr/src/v4l2loopback-read-only modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.32-22-generic'
  CC [M]  /usr/src/v4l2loopback-read-only/v4l2loopback.o
/usr/src/v4l2loopback-read-only/v4l2loopback.c: In function ‘vidioc_qbuf’:
/usr/src/v4l2loopback-read-only/v4l2loopback.c:360: error: ‘TASK_NORMAL’
undeclared (first use in this function)
/usr/src/v4l2loopback-read-only/v4l2loopback.c:360: error: (Each undeclared
identifier is reported only once
/usr/src/v4l2loopback-read-only/v4l2loopback.c:360: error: for each
function it appears in.)
/usr/src/v4l2loopback-read-only/v4l2loopback.c: In function ‘vidioc_dqbuf’:
/usr/src/v4l2loopback-read-only/v4l2loopback.c:379: error:
‘TASK_INTERRUPTIBLE’ undeclared (first use in this function)
/usr/src/v4l2loopback-read-only/v4l2loopback.c:379: error: implicit
declaration of function ‘signal_pending’
/usr/src/v4l2loopback-read-only/v4l2loopback.c:379: error: implicit
declaration of function ‘schedule’
/usr/src/v4l2loopback-read-only/v4l2loopback.c: In function
‘v4l_loopback_read’:
/usr/src/v4l2loopback-read-only/v4l2loopback.c:572: error:
‘TASK_INTERRUPTIBLE’ undeclared (first use in this function)
/usr/src/v4l2loopback-read-only/v4l2loopback.c: In function
‘v4l_loopback_write’:
/usr/src/v4l2loopback-read-only/v4l2loopback.c:604: warning: format ‘%d’
expects type ‘int’, but argument 2 has type ‘size_t’
/usr/src/v4l2loopback-read-only/v4l2loopback.c:612: warning: format ‘%d’
expects type ‘int’, but argument 2 has type ‘size_t’
/usr/src/v4l2loopback-read-only/v4l2loopback.c:617: error: ‘TASK_NORMAL’
undeclared (first use in this function)
make[2]: *** [/usr/src/v4l2loopback-read-only/v4l2loopback.o] Error 1
make[1]: *** [_module_/usr/src/v4l2loopback-read-only] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-2.6.32-22-generic'
make: *** [v4l2loopback] Error 2
ryty@Febria:/usr/src/v4l2loopback-read-only$

What version of the product are you using? On what operating system?

Latest from SVN, although the latest .deb also shows the same issue. Ubuntu
10.04 x86_64.

Please provide any additional information below.

I have been able to resolve some of the issues by adding:

#include <linux/sched.h>

On line 11 of v4l2loopback.h. Still trying to figure out the other issue.

Ryan

What kernel version do you use?
2.6.31

ahm where is the source code? I cannot check out, seems to be empty.....

***I have posted this problem on the v4lsink projects issues section and was 
advised the 
problem is likely with v4l2loopback, apologies if that is not the case.***

run v4lsink with a video test source

$sudo v4lsink 'videotestsrc ! V4l2SinkLoopback'

When viewed in mplayer by connecting to the loopback device (/dev/video1) 
everything
looks normal (see mplayer-test-signal.png)

When captured using Abode flashplayer 10 the image is very distorted (see
flashplayer-test-signal.png)

I have included an swf for testing, you will need the Adobe Standalone Flash 
Player, run

$ flashplayer webcam.swf

When flash connects directly to the built it web cam on /dev/video0 the
picture is OK, when running /dev/video0 though v4lsink and then accessing
the virtual device (/dev/video1) in flashplayer the same distortions are
apparent, so this is not isolated to the videotestsrc. 

I am running Ubuntu Jaunty with default 2.6.28 kernel

I have also tried the same on a system with a bttv card and the same issue 
occurs so it does not 
appear to be a quirk with the web cam.