bttv 2.6.26 problem

Error: Could not set image size to 352x288 for color format I420 (15) (VIDIOCMCAPTURE: buffer 0)

Quoted 1 line · Linos

Error: Could not set image size to 352x288 for color format I420 (15) (VIDIOCMCAPTURE: buffer 0)

The problem is that the v4l1-compat code for VIDIOCMCAPTURE calls VIDIOC_S_FMT. At the beginning of bttv_s_fmt_vid_cap the call to bttv_switch_type fails because the buffers have already been mmap'ed by the application. I'd say this is a bug in bttv.

In which case does the videobuf_queue_is_busy test prevent bad things from happening?

A workaround is to set the resolution and image format before the buffers are mapped, f.ex. with this small program:
--------------
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <linux/videodev.h>

void main()
{
struct video_mmap vmm;
vmm.height=352;
vmm.width=288; vmm.format=VIDEO_PALETTE_YUV420P; vmm.frame=0; ioctl(open("/dev/video",O_RDWR),VIDIOCMCAPTURE,&vmm);
}
--------------

Daniel

Quoted 34 lines · Daniel Glöckner

Quoted 3 lines · Linos

Error: Could not set image size to 352x288 for color format I420 (15) (VIDIOCMCAPTURE: buffer 0)

The problem is that the v4l1-compat code for VIDIOCMCAPTURE calls VIDIOC_S_FMT. At the beginning of bttv_s_fmt_vid_cap the call to bttv_switch_type fails because the buffers have already been mmap'ed by the application. I'd say this is a bug in bttv.

In which case does the videobuf_queue_is_busy test prevent bad things from happening?

A workaround is to set the resolution and image format before the buffers are mapped, f.ex. with this small program:
--------------
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <linux/videodev.h>

void main()
{
struct video_mmap vmm;
vmm.height=352;
vmm.width=288; vmm.format=VIDEO_PALETTE_YUV420P; vmm.frame=0; ioctl(open("/dev/video",O_RDWR),VIDIOCMCAPTURE,&vmm);
}
--------------

Quoted 2 lines

Daniel

Hi Daniel,
thanks for help, i have tried the code you have posted, but it does
not works or i have not understand you correctly, i have compiled the code, i have tried directly with /dev/video (like your example) or changing it with /dev/video0 (the video dev i am using), after compile it and execute it i launch the helix producer but still the same error.

webcontrol:~# gcc -o test_video test_video.c
test_video.c: In function 'main':
test_video.c:7: warning: return type of 'main' is not 'int'
webcontrol:~# ./test_video
webcontrol:~# producer -vc /dev/video0 -ad 128k -vp "0" -dt -vm sharp -o
/tmp/test.rm
Helix DNA(TM) Producer 11.0 Build number: 11.0.0.2013
Info: Starting encode
Error: Could not set image size to 352x288 for color format I420 (15)
(VIDIOCMCAPTURE: buffer 0)
Warning: Capture Buffer is empty at 455505251ms for last 61 times

do i am doing anything wrong?

Regards,
Miguel Angel.

Quoted 3 lines · Linos

Quoted 2 lines · Daniel Glöckner

vmm.height=352;
vmm.width=288;

I believe the changes Daniel suggested would have to be applied to the source of helix producer in order to work.

None the less, the proper
fix would be to fix the associated bug in the driver which is the real cause of the problem.

Quoted 4 lines · David Ellingsworth

Quoted 3 lines · Linos

Quoted 2 lines · Daniel Glöckner

vmm.height=352;
vmm.width=288;

D'oh!
I swapped width and height..

Quoted 2 lines

I believe the changes Daniel suggested would have to be applied to the source of helix producer in order to work.

I didn't test helix producer, but with my simple test app and correct width and height it works.

Quoted 3 lines

None the less, the proper
fix would be to fix the associated bug in the driver which is the real cause of the problem.

Agreed

Daniel