From 79c6ff93c74e793ccceb464ee3698478c812ce79 Mon Sep 17 00:00:00 2001
From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Date: Fri, 27 Aug 2010 13:41:44 -0300
Subject: V4L/DVB: V4L2: add a generic function to find the nearest discrete
format to the required one
Many video drivers implement a fixed 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@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
drivers/media/video/v4l2-common.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
(limited to 'drivers/media/video/v4l2-common.c')
diff --git a/drivers/media/video/v4l2-common.c b/drivers/media/video/v4l2-common.c
index 8ee1179be926..31ae1a138613 100644
--- a/drivers/media/video/v4l2-common.c
+++ b/drivers/media/video/v4l2-common.c
@@ -676,3 +676,27 @@ 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 = UINT_MAX;
+ struct v4l2_frmsize_discrete *size, *best = NULL;
+
+ if (!probe)
+ return best;
+
+ for (i = 0, size = probe->sizes; i < probe->num_sizes; i++, size++) {
+ 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);
--
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