Web lists-archives.com

Re: Set Frequency Problem

On 23/03/2010, Sanfelici Claudio <sanfelici@xxxxxxxxx> wrote:
> Hi !
> I was writing the C code for you and... I've solved the problem.
> In the Video for Linux two Api Specification, in the VIDIOC_G/S_INPUT
> section you can read:
> "It is ggod pratice to select an input before querying or negotiating any
> other parameters."
> So, if I call VIODIOC_S_INPUT everytime before call the VIDIOC_S_FREQUENCY
> it works!
> Has it sense?

Not for me. (N.B i'm no expert in v4l). Looking at xawtv sources (file
libng/plugins/drv0-v4l2.c) it does the following:

static void
v4l2_setfreq(void *handle, unsigned long freq)
    struct v4l2_handle *h = handle;
    struct v4l2_frequency f;

    if (ng_debug)
        fprintf(stderr,"v4l2: freq: %.3f\n",(float)freq/16);
    f.type = V4L2_TUNER_ANALOG_TV;
    f.frequency = freq;
    xioctl(h->fd, VIDIOC_S_FREQUENCY, &f, 0);

I think you are missing something or your driver is somehow broken,
but a lot of cheap (and not so) cards have an saa7130/7134 and work

> Thank you !

You are welcome just keep in mind that this list is deprecated, most
of the people is at linux-media@xxxxxxxxxxxxxxx

> P.S. about my second question? the way to start video overlay?

i have no clue. The best advice I can give you is to grab the sources
of some app (xawvt is a good starting point) and see how it works.
Isn't free software wonderful?


video4linux-list mailing list
Unsubscribe mailto:video4linux-list-request@xxxxxxxxxx?subject=unsubscribe