The encoder buffer can have a negative impact on the quality of the
encoded video.
Add a control to allow user space to disable the encoder buffer per
channel if the VCU supports the encoder buffer but the quality is not
sufficient.
Signed-off-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx>
---
.../media/platform/allegro-dvt/allegro-core.c | 32 +++++++++++++++++--
include/uapi/linux/v4l2-controls.h | 5 +++
2 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/drivers/media/platform/allegro-dvt/allegro-core.c b/drivers/media/platform/allegro-dvt/allegro-core.c
index cb42b6e3d85a..7ec85299d03e 100644
--- a/drivers/media/platform/allegro-dvt/allegro-core.c
+++ b/drivers/media/platform/allegro-dvt/allegro-core.c
@@ -105,6 +105,12 @@
#define BETA_OFFSET_DIV_2 -1
#define TC_OFFSET_DIV_2 -1
+/*
+ * This control allows applications to explicitly disable the encoder buffer.
+ * This value is Allegro specific.
+ */
+#define V4L2_CID_USER_ALLEGRO_ENCODER_BUFFER (V4L2_CID_USER_ALLEGRO_BASE + 0)
+
static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Debug level (0-2)");
@@ -275,6 +281,8 @@ struct allegro_channel {
struct v4l2_ctrl *mpeg_video_cpb_size;
struct v4l2_ctrl *mpeg_video_gop_size;
+ struct v4l2_ctrl *encoder_buffer;
+
/* user_id is used to identify the channel during CREATE_CHANNEL */
/* not sure, what to set here and if this is actually required */
int user_id;
@@ -1255,7 +1263,7 @@ static int fill_create_channel_param(struct allegro_channel *channel,
param->max_transfo_depth_intra = channel->max_transfo_depth_intra;
param->max_transfo_depth_inter = channel->max_transfo_depth_inter;
- param->encoder_buffer_enabled = channel->dev->has_encoder_buffer;
+ param->encoder_buffer_enabled = v4l2_ctrl_g_ctrl(channel->encoder_buffer);
param->encoder_buffer_offset = 0;
param->rate_control_mode = channel->frame_rc_enable ?
@@ -1381,7 +1389,7 @@ static int allegro_mcu_send_encode_frame(struct allegro_dev *dev,
u64 src_handle)
{
struct mcu_msg_encode_frame msg;
- bool use_encoder_buffer = channel->dev->has_encoder_buffer;
+ bool use_encoder_buffer = v4l2_ctrl_g_ctrl(channel->encoder_buffer);
memset(&msg, 0, sizeof(msg));
@@ -2466,6 +2474,8 @@ static void allegro_destroy_channel(struct allegro_channel *channel)
v4l2_ctrl_grab(channel->mpeg_video_cpb_size, false);
v4l2_ctrl_grab(channel->mpeg_video_gop_size, false);
+ v4l2_ctrl_grab(channel->encoder_buffer, false);
+
if (channel->user_id != -1) {
clear_bit(channel->user_id, &dev->channel_user_ids);
channel->user_id = -1;
@@ -2532,6 +2542,8 @@ static int allegro_create_channel(struct allegro_channel *channel)
v4l2_ctrl_grab(channel->mpeg_video_cpb_size, true);
v4l2_ctrl_grab(channel->mpeg_video_gop_size, true);
+ v4l2_ctrl_grab(channel->encoder_buffer, true);
+
reinit_completion(&channel->completion);
allegro_mcu_send_create_channel(dev, channel);
timeout = wait_for_completion_timeout(&channel->completion,
@@ -2915,6 +2927,10 @@ static int allegro_try_ctrl(struct v4l2_ctrl *ctrl)
case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
allegro_clamp_bitrate(channel, ctrl);
break;
+ case V4L2_CID_USER_ALLEGRO_ENCODER_BUFFER:
+ if (!channel->dev->has_encoder_buffer)
+ ctrl->val = 0;
+ break;
}
return 0;
@@ -2955,6 +2971,16 @@ static const struct v4l2_ctrl_ops allegro_ctrl_ops = {
.s_ctrl = allegro_s_ctrl,
};
+static const struct v4l2_ctrl_config allegro_encoder_buffer_ctrl_config = {
+ .id = V4L2_CID_USER_ALLEGRO_ENCODER_BUFFER,
+ .name = "Encoder Buffer Enable",
+ .type = V4L2_CTRL_TYPE_BOOLEAN,
+ .min = 0,
+ .max = 1,
+ .step = 1,
+ .def = 1,
+};
+
static int allegro_open(struct file *file)
{
struct video_device *vdev = video_devdata(file);
@@ -3106,6 +3132,8 @@ static int allegro_open(struct file *file)
V4L2_CID_MPEG_VIDEO_GOP_SIZE,
0, ALLEGRO_GOP_SIZE_MAX,
1, ALLEGRO_GOP_SIZE_DEFAULT);
+ channel->encoder_buffer = v4l2_ctrl_new_custom(handler,
+ &allegro_encoder_buffer_ctrl_config, NULL);
v4l2_ctrl_new_std(handler,
&allegro_ctrl_ops,
V4L2_CID_MIN_BUFFERS_FOR_OUTPUT,
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 5532b5f68493..8788cbfec28d 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -211,6 +211,11 @@ enum v4l2_colorfx {
* We reserve 128 controls for this driver.
*/
#define V4L2_CID_USER_CCS_BASE (V4L2_CID_USER_BASE + 0x10f0)
+/*
+ * The base for Allegro driver controls.
+ * We reserve 16 controls for this driver.
+ */
+#define V4L2_CID_USER_ALLEGRO_BASE (V4L2_CID_USER_BASE + 0x1170)
/* MPEG-class control IDs */
/* The MPEG controls are applicable to all codec controls
--
2.30.2
