Hi Hans,
thank you for the comments!
Am Montag, den 12.01.2015, 16:03 +0100 schrieb Hans Verkuil:
> On 12/22/2014 05:00 PM, Philipp Zabel wrote:
> > The encoder needs to know the nominal framerate for the constant bitrate
> > control mechanism to work. Currently the only way to set the framerate is
> > by using VIDIOC_S_PARM on the output queue.
> >
> > Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> > ---
> > drivers/media/platform/coda/coda-common.c | 29 +++++++++++++++++++++++++++++
> > 1 file changed, 29 insertions(+)
> >
> > diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c
> > index 39330a7..63eb510 100644
> > --- a/drivers/media/platform/coda/coda-common.c
> > +++ b/drivers/media/platform/coda/coda-common.c
> > @@ -803,6 +803,32 @@ static int coda_decoder_cmd(struct file *file, void *fh,
> > return 0;
> > }
> >
> > +static int coda_g_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
> > +{
> > + struct coda_ctx *ctx = fh_to_ctx(fh);
> > +
>
> If a->type != V4L2_BUF_TYPE_VIDEO_OUTPUT, then return -EINVAL.
If the decoder can retrieve the framerate from the stream, wouldn't it
make sense to allow G_PARM for a->type == V4L2_BUF_TYPE_VIDEO_CAPTURE ?
> Ditto for s_parm.
Will do.
> > + a->parm.output.timeperframe.denominator = 1;
> > + a->parm.output.timeperframe.numerator = ctx->params.framerate;
> > +
> > + return 0;
> > +}
> > +
> > +static int coda_s_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
> > +{
> > + struct coda_ctx *ctx = fh_to_ctx(fh);
> > +
> > + if (a->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
> > + a->parm.output.timeperframe.numerator != 0) {
> > + ctx->params.framerate = a->parm.output.timeperframe.denominator
> > + / a->parm.output.timeperframe.numerator;
>
> Hmm, what happens if the denominator is 1 and the numerator is 2?
> You probably want to clamp ctx->params.framerate to the range of allowed framerates.
> And at least ensure a framerate > 0.
>
> Also check with v4l2_compliance! You'd have caught at least the missing a->type check.
Oh dear, I need to improve my v4l-utils update habits. I'll fix this
patch and resend it.
regards
Philipp
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