[Motion-user] My whack at v4l2

[Andrew H. <ham...@mc...>]

Hello once again.  I thought I'd try out the v4l2 patch, but I had a few 
problems.  At first I was getting:
Unable to map buffer (22)

and motion would fall back on v4l (I think).

Eventually I got around this by changing this line from:
vd->buffers[i] = mmap(0 /* start anywhere */ ,
                       vd->buf.length, PROT_READ,
                       MAP_SHARED, vd->fd, vd->buf.m.offset);
to:
vd->buffers[i] = mmap(0 /* start anywhere */ ,
                       vd->buf.length, PROT_READ | PROT_WRITE,
                       MAP_SHARED, vd->fd, vd->buf.m.offset);

Then I started getting:
motion: video.c:445: v4l2_next: Assertion `vd->buf.bytesused == 
vd->framesizeIn' failed.
Aborted

I then commented out:
assert(vd->buf.bytesused == vd->framesizeIn);

and motion seems to start up with v4l2. I don't have a camera hooked up 
to the computer at the moment but I can see a blue screen with motion 
timestamps on the motion web port I have listening. Here is what happens 
when I start it now:

[0] Thread 1 is from motion.conf
[1] Thread started
Opening /dev/video0 as a V4L2 device...length: 155648 offset: 0
Buffer mapped at address 0xb6b51000.
length: 155648 offset: 155648
Buffer mapped at address 0xb6b2b000.
length: 155648 offset: 311296
Buffer mapped at address 0xb6b05000.
length: 155648 offset: 466944
Buffer mapped at address 0xb6adf000.
v4l2_init: allocating framebuffer of size: 155648
V4L2 init successful, returning 0xb6ab8008
v4l2_video_enable: beginning...
v4l2_video_enable: succesful
[0] motion-httpd/3.2.7 running, accepting connections
[0] motion-httpd: waiting for data on port TCP 8080
[1] Started stream webcam server in port 8081

I have no idea if what I did is correct or sane, but I thought I would 
share it with the rest of you.

Sincerely,
Andrew Hamilton