hi ~~ Dongsoo, Nathaniel ~
I am sorry for disturbing you, and not descripe the question clear ~
Thanks very much for your help ~~
I know that I must stop preview with streamoff and re-configure with
s_fmt ~~ I have asked to you before ~!~
The "full frame" means a complete frame ~Because I just need to get the
frame data and post it to multimedia framework, so I want to consult to
you that if I can get a complete frame with memcpy ~~
I want to know that can I get a complete frame from buf.start to the
end , and the memory-lenth is buf.byteused ~
buf.byteused
|-----------------------------|
buf.start end
在 2009-06-08一的 20:40 +0900，Dongsoo, Nathaniel Kim写道：
> Hi,
>
> Sorry I'm not an expert, you can expect expertise from maintainers not from me.
> But before answering your question about capturing, I'm not sure about
> what the "full frame" means. I just assume that you meant to say the
> biggest resolution of image frame, right?
>
> So, when you are to capture a full resolution data while preview is
> working, you need to stop preview with streamoff, re-configure
> resolution with s_fmt to external camera module and start capturing
> issuing streamon with re-configured resolution. I think you are
> well-aware with this, aren't you? And in my opinion, memcpy may be
> cool for that. What else are you expecting to use? and for what?
> Anyway, I wish you luck.
> Cheers,
>
> Nate
>
>
> On Mon, Jun 8, 2009 at 5:02 PM, xie<yili.xie@xxxxxxxxx> wrote:
> > Hi Dongsoo, Nathaniel ~
> > You must be expert on V4l2 ~ Thanks very much for your help and advice
> > ~!~
> > I used the MXC camera interface driver from Fressscale ,I readed the
> > driver interface just now ,and have fouded that the driver not modified
> > the buf.lenth but buf.byteused . You are very right , I will use the
> > buf.byteused instead of buf.length ~
> >
> > There is also a problem I want to consult to you ~ Can i get a full
> > frame with the below method if the driver have no problem ?
> >
> > memcpy((mCameraProwave->getPreviewHeap())->base(),
> > v4l2Buffer[buf.index].start, buf.byteused) ;
> >
> > Because I just need to implement a hal for getting the frame data and
> > post it to top layer , so I used the memcpy simply . Am I right ~ ? Or
> > what about your advice ?
> >
> > Thanks a lot ~~
> >
> >
> >
> > 在 2009-06-08一的 15:56 +0900，Dongsoo, Nathaniel Kim写道：
> >> Hello Xie,
> >>
> >> I'm not sure which camera interface driver you are using, but it seems
> >> to be camera interface driver's problem. Let me guess, are you using
> >> pxa camera interface driver from Marvell?(proprietary but not in up
> >> stream kernel)
> >> It just looks like that camera interface driver is not returning
> >> proper data in dqbuf.
> >>
> >> And one more thing. I prefer to use byteused rather than length in
> >> buf. because as far as I know the size of preview data from camera is
> >> in byte unit which we need to copy to memory. But it should be
> >> possible to use length, I guess..
> >> Cheers,
> >>
> >> Nate
> >>
> >> On Mon, Jun 8, 2009 at 11:05 AM, xie<yili.xie@xxxxxxxxx> wrote:
> >> > Dear all ~~
> >> >
> >> > I have met a issue when I used the mmap method for previewing . I just
> >> > used the standard code as spec to get the image data :
> >> > status_t CameraHardwareProwave::V4l2Camera::v4l2CaptureMainloop()
> >> > {
> >> > LOG_FUNCTION_NAME
> >> > int rt ;
> >> > unsigned int i ;
> >> > fd_set fds ;
> >> > struct timeval tv ;
> >> > struct v4l2_buffer buf ;
> >> >
> >> > for(;;){
> >> > FD_ZERO(&fds) ;
> >> > FD_SET(v4l2Fd, &fds) ;
> >> > //now the time is long ,just for debug
> >> > tv.tv_sec = 2 ;
> >> > tv.tv_usec = 0 ;
> >> >
> >> > rt = select(v4l2Fd + 1, &fds, NULL, NULL, &tv) ;
> >> > LOGD("The value of select return : %d\n", rt) ;
> >> >
> >> > /********** for debug
> >> > if(V4L2_NOERROR != v4l2ReadFrame()){
> >> > LOGE("READ ERROR") ;
> >> > }
> >> > ***********/
> >> >
> >> > if(-1 == rt){
> >> > LOGE("there is something wrong in select function(select)") ;
> >> > //no defined error manage
> >> > return V4L2_IOCTL_ERROR ;
> >> > }
> >> > if(0 == rt){
> >> > LOGE("wait for data timeout in select") ;
> >> > return V4L2_TIMEOUT ;
> >> > }
> >> >
> >> > memset(&buf, 0, sizeof(buf)) ;
> >> > buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE ;
> >> > buf.memory = V4L2_MEMORY_MMAP ;
> >> > if(-1 == ioctl(v4l2Fd, VIDIOC_DQBUF, &buf)){
> >> > LOGE("there is something wrong in dequeue buffer(VIDIOC_DQBUF)") ;
> >> > return V4L2_IOCTL_ERROR ;
> >> > }
> >> >
> >> > assert(i < n_buf) ;
> >> > LOGE("buf.index 0buf.length = %d %d \n", buf.index , buf.length) ;
> >> > memcpy((mCameraProwave->getPreviewHeap())->base(),
> >> > v4l2Buffer[buf.index].start, buf.length) ;
> >> > if(-1 == ioctl(v4l2Fd, VIDIOC_QBUF, &buf)){
> >> > LOGE("there is something wrong in enqueue buffer(VIDIOC_QBUF)") ;
> >> > return V4L2_IOCTL_ERROR ;
> >> > }
> >> > //break ; //i don't know whether the break is needed ;
> >> >
> >> > }
> >> > return V4L2_NOERROR ;
> >> > }
> >> >
> >> > when executed the VIDIOC_DQBUF IOCTL,the return value was right, but the
> >> > value of buf.length would always be zero. Then I used the read()
> >> > function to read raw data in the file handle for debug, and I can get
> >> > the raw data. Anybody have met this issue before ? Who can give me some
> >> > advices or tell me what is wrong , thanks a lot ~
> >> >
> >> >
> >>
> >>
> >>
> >
> >
>
>
>
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