Hi Guennadi,
On Thursday 05 August 2010 20:03:46 Guennadi Liakhovetski wrote:
> Many video drivers implement a discrete set of frame formats and thus face
> a task of finding the best match for a user-requested format. Implementing
> this in a generic function has also an advantage, that different drivers
> with similar supported format sets will select the same format for the
> user, which improves consistency across drivers.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
> ---
>
> I'm currently away from my hardware, so, this is only compile tested and
> run-time tested with a test application. In any case, reviews and
> suggestions welcome.
>
> drivers/media/video/v4l2-common.c | 26 ++++++++++++++++++++++++++
> include/linux/videodev2.h | 10 ++++++++++
> 2 files changed, 36 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/media/video/v4l2-common.c
> b/drivers/media/video/v4l2-common.c index 4e53b0b..90727e6 100644
> --- a/drivers/media/video/v4l2-common.c
> +++ b/drivers/media/video/v4l2-common.c
> @@ -1144,3 +1144,29 @@ int v4l_fill_dv_preset_info(u32 preset, struct
> v4l2_dv_enum_preset *info) return 0;
> }
> EXPORT_SYMBOL_GPL(v4l_fill_dv_preset_info);
> +
> +struct v4l2_frmsize_discrete *v4l2_find_nearest_format(struct
> v4l2_discrete_probe *probe, + s32 width, s32 height)
> +{
> + int i;
> + u32 error, min_error = ~0;
> + struct v4l2_frmsize_discrete *size, *best = NULL;
> +
> + if (!probe)
> + return best;
> +
> + for (i = 0, size = probe->sizes; i < probe->num_sizes; i++, size++) {
> + if (probe->probe && !probe->probe(probe))
What's this call for ?
> + continue;
> + error = abs(size->width - width) + abs(size->height - height);
> + if (error < min_error) {
> + min_error = error;
> + best = size;
> + }
> + if (!error)
> + break;
> + }
> +
> + return best;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_find_nearest_format);
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index 047f7e6..f622bba 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -394,6 +394,16 @@ struct v4l2_frmsize_discrete {
> __u32 height; /* Frame height [pixel] */
> };
>
> +struct v4l2_discrete_probe {
> + struct v4l2_frmsize_discrete *sizes;
> + int num_sizes;
> + void *priv;
> + bool (*probe)(struct v4l2_discrete_probe *);
> +};
> +
> +struct v4l2_frmsize_discrete *v4l2_find_nearest_format(struct
> v4l2_discrete_probe *probe, + s32 width, s32 height);
> +
> struct v4l2_frmsize_stepwise {
> __u32 min_width; /* Minimum frame width [pixel] */
> __u32 max_width; /* Maximum frame width [pixel] */
--
Regards,
Laurent Pinchart
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