From: Ville Syrjälä ville.syrjala@linux.intel.com
These functions return the chroma subsampling factors for the specified pixel format.
Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/drm_crtc_helper.c | 67 +++++++++++++++++++++++++++++++++++++ include/drm/drm_crtc_helper.h | 2 + 2 files changed, 69 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 7c5c516..1528068 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -1087,3 +1087,70 @@ int drm_format_plane_cpp(uint32_t format, int plane) } } EXPORT_SYMBOL(drm_format_plane_cpp); + +/** + * drm_format_horz_chroma_subsampling - get the horizontal chroma subsampling factor + * @format: pixel format (V4L2_PIX_FMT_*) + * + * See linux/videodev2.h for valid values of @format. + * + * RETURNS: + * The horizontal chroma subsampling factor for the + * specified pixel format. + */ +int drm_format_horz_chroma_subsampling(uint32_t format) +{ + /* FIXME add all subsampled formats. */ + + switch (format) { + case V4L2_PIX_FMT_Y41P: + case V4L2_PIX_FMT_YUV411P: + case V4L2_PIX_FMT_YUV410: + case V4L2_PIX_FMT_YVU410: + return 4; + case V4L2_PIX_FMT_YUYV: + case V4L2_PIX_FMT_YVYU: + case V4L2_PIX_FMT_UYVY: + case V4L2_PIX_FMT_VYUY: + case V4L2_PIX_FMT_YUV422P: + case V4L2_PIX_FMT_YUV420: + case V4L2_PIX_FMT_YVU420: + case V4L2_PIX_FMT_NV12: + case V4L2_PIX_FMT_NV21: + case V4L2_PIX_FMT_NV16: + case V4L2_PIX_FMT_NV61: + return 2; + default: + return 1; + } +} +EXPORT_SYMBOL(drm_format_horz_chroma_subsampling); + +/** + * drm_format_vert_chroma_subsampling - get the vertical chroma subsampling factor + * @format: pixel format (V4L2_PIX_FMT_*) + * + * See linux/videodev2.h for valid values of @format. + * + * RETURNS: + * The vertical chroma subsampling factor for the + * specified pixel format. + */ +int drm_format_vert_chroma_subsampling(uint32_t format) +{ + /* FIXME add all subsampled formats. */ + + switch (format) { + case V4L2_PIX_FMT_YUV410: + case V4L2_PIX_FMT_YVU410: + return 4; + case V4L2_PIX_FMT_YUV420: + case V4L2_PIX_FMT_YVU420: + case V4L2_PIX_FMT_NV12: + case V4L2_PIX_FMT_NV21: + return 2; + default: + return 1; + } +} +EXPORT_SYMBOL(drm_format_vert_chroma_subsampling); diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h index 9996643..25d46b8 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -149,5 +149,7 @@ extern void drm_kms_helper_poll_enable(struct drm_device *dev);
extern int drm_format_num_planes(uint32_t format); extern int drm_format_plane_cpp(uint32_t format, int plane); +extern int drm_format_horz_chroma_subsampling(uint32_t format); +extern int drm_format_vert_chroma_subsampling(uint32_t format);
#endif