diff options
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-common.c | 30 | ||||
| -rw-r--r-- | include/media/v4l2-common.h | 34 |
2 files changed, 64 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c index 96c1b31de9e3..9b65529dfaf6 100644 --- a/drivers/media/v4l2-core/v4l2-common.c +++ b/drivers/media/v4l2-core/v4l2-common.c @@ -383,6 +383,36 @@ v4l2_find_nearest_format(const struct v4l2_frmsize_discrete *sizes, } EXPORT_SYMBOL_GPL(v4l2_find_nearest_format); +const void * +__v4l2_find_nearest_size(const void *array, size_t array_size, + size_t entry_size, size_t width_offset, + size_t height_offset, s32 width, s32 height) +{ + u32 error, min_error = U32_MAX; + const void *best = NULL; + unsigned int i; + + if (!array) + return NULL; + + for (i = 0; i < array_size; i++, array += entry_size) { + const u32 *entry_width = array + width_offset; + const u32 *entry_height = array + height_offset; + + error = abs(*entry_width - width) + abs(*entry_height - height); + if (error > min_error) + continue; + + min_error = error; + best = array; + if (!error) + break; + } + + return best; +} +EXPORT_SYMBOL_GPL(__v4l2_find_nearest_size); + void v4l2_get_timestamp(struct timeval *tv) { struct timespec ts; diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h index f3aa1d728c0b..38947dc42ab6 100644 --- a/include/media/v4l2-common.h +++ b/include/media/v4l2-common.h @@ -333,6 +333,40 @@ v4l2_find_nearest_format(const struct v4l2_frmsize_discrete *sizes, s32 width, s32 height); /** + * v4l2_find_nearest_size - Find the nearest size among a discrete + * set of resolutions contained in an array of a driver specific struct. + * + * @array: a driver specific array of image sizes + * @array_size: the length of the driver specific array of image sizes + * @width_field: the name of the width field in the driver specific struct + * @height_field: the name of the height field in the driver specific struct + * @width: desired width. + * @height: desired height. + * + * Finds the closest resolution to minimize the width and height differences + * between what requested and the supported resolutions. The size of the width + * and height fields in the driver specific must equal to that of u32, i.e. four + * bytes. + * + * Returns the best match or NULL if the length of the array is zero. + */ +#define v4l2_find_nearest_size(array, array_size, width_field, height_field, \ + width, height) \ + ({ \ + BUILD_BUG_ON(sizeof((array)->width_field) != sizeof(u32) || \ + sizeof((array)->height_field) != sizeof(u32)); \ + (typeof(&(*(array))))__v4l2_find_nearest_size( \ + (array), array_size, sizeof(*(array)), \ + offsetof(typeof(*(array)), width_field), \ + offsetof(typeof(*(array)), height_field), \ + width, height); \ + }) +const void * +__v4l2_find_nearest_size(const void *array, size_t array_size, + size_t entry_size, size_t width_offset, + size_t height_offset, s32 width, s32 height); + +/** * v4l2_get_timestamp - helper routine to get a timestamp to be used when * filling streaming metadata. Internally, it uses ktime_get_ts(), * which is the recommended way to get it. |