[PATCH] v4l2-ctrl: add control for thumnails

From: Stanimir Varbanov
Date: Tue May 26 2020 - 04:55:02 EST


Add v4l2 control for decoder thumbnail.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
---
Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 7 +++++++
drivers/media/v4l2-core/v4l2-ctrls.c | 2 ++
include/uapi/linux/v4l2-controls.h | 2 ++
3 files changed, 11 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
index d0d506a444b1..e838e410651b 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
@@ -3726,6 +3726,13 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
disables generating SPS and PPS at every IDR. Setting it to one enables
generating SPS and PPS at every IDR.

+``V4L2_CID_MPEG_VIDEO_DECODER_THUMBNAIL (button)``
+ Instructs the decoder to produce immediate output. The decoder should
+ consume first input buffer for progressive stream (or first two buffers
+ for interlace). Decoder should not allocate more output buffers that it
+ is required to consume one input frame. Usually the decoder input
+ buffers will contain only I/IDR frames but it is not mandatory.
+
.. _v4l2-mpeg-hevc:

``V4L2_CID_MPEG_VIDEO_HEVC_SPS (struct)``
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index b188577db40f..cb2554404c63 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -991,6 +991,7 @@ const char *v4l2_ctrl_get_name(u32 id)
case V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS: return "HEVC Slice Parameters";
case V4L2_CID_MPEG_VIDEO_HEVC_DECODE_MODE: return "HEVC Decode Mode";
case V4L2_CID_MPEG_VIDEO_HEVC_START_CODE: return "HEVC Start Code";
+ case V4L2_CID_MPEG_VIDEO_DECODER_THUMBNAIL: return "Thumbnail generation";

/* CAMERA controls */
/* Keep the order of the 'case's the same as in v4l2-controls.h! */
@@ -1234,6 +1235,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
case V4L2_CID_AUTO_FOCUS_START:
case V4L2_CID_AUTO_FOCUS_STOP:
case V4L2_CID_DO_WHITE_BALANCE:
+ case V4L2_CID_MPEG_VIDEO_DECODER_THUMBNAIL:
*type = V4L2_CTRL_TYPE_BUTTON;
*flags |= V4L2_CTRL_FLAG_WRITE_ONLY |
V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 62271418c1be..7e44a2779863 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -743,6 +743,8 @@ enum v4l2_cid_mpeg_video_hevc_size_of_length_field {
#define V4L2_CID_MPEG_VIDEO_REF_NUMBER_FOR_PFRAMES (V4L2_CID_MPEG_BASE + 643)
#define V4L2_CID_MPEG_VIDEO_PREPEND_SPSPPS_TO_IDR (V4L2_CID_MPEG_BASE + 644)

+#define V4L2_CID_MPEG_VIDEO_DECODER_THUMBNAIL (V4L2_CID_MPEG_BASE + 645)
+
/* MPEG-class control IDs specific to the CX2341x driver as defined by V4L2 */
#define V4L2_CID_MPEG_CX2341X_BASE (V4L2_CTRL_CLASS_MPEG | 0x1000)
#define V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE (V4L2_CID_MPEG_CX2341X_BASE+0)
--
2.17.1