| Message ID | 20240130112400.2636143-2-quic_sachinku@quicinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | add MBR type rate control for encoder | expand |
Hi Scahin, Le mardi 30 janvier 2024 à 16:53 +0530, Sachin Kumar Garg a écrit : > Introduce V4L2_MPEG_VIDEO_BITRATE_MODE_MBR rate control to > limit the frame level maximum bit rate. > Encoder will choose appropriate quantization parameter and > do the smart bit allocation to set the frame maximum bitrate > level as per the Bitrate value configured. > > Signed-off-by: Sachin Kumar Garg <quic_sachinku@quicinc.com> > --- > Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 2 ++ > drivers/media/v4l2-core/v4l2-ctrls-defs.c | 1 + > include/uapi/linux/v4l2-controls.h | 1 + > 3 files changed, 4 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > index 2a165ae063fb..05ef4a70e3f5 100644 > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > @@ -576,6 +576,8 @@ enum v4l2_mpeg_video_bitrate_mode - > - Constant bitrate > * - ``V4L2_MPEG_VIDEO_BITRATE_MODE_CQ`` > - Constant quality > + * - ``V4L2_MPEG_VIDEO_BITRATE_MODE_MBR`` > + - Maximum bitrate I'm afraid for this one your documentation is too short. I believe your commit message helps, but this is not what our uAPI users will read. My understanding is that this feature is a form of constant quality (smart bit allocation) but with a maximum rate guaranty. Using a specific mode (rather then a constraint on top of a constant quality mode) is a Qualcomm specific design. I think presets are generally easier to use, so I kind of like it. What is missing (arguably all these modes documentation are also missing it) is the rate observation window. Would be nice to check if there is a way to specify that (or even configure it, if so add a cross reference). So I'd like to see some proper documentation for this one, remember that V4L2 documentation is also a specification and will serve to ensure drivers conforms to the preset expectations. regards, Nicolas > > > > diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c > index 8696eb1cdd61..e0597b61ffb9 100644 > --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c > +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c > @@ -154,6 +154,7 @@ const char * const *v4l2_ctrl_get_menu(u32 id) > "Variable Bitrate", > "Constant Bitrate", > "Constant Quality", > + "Maximum Bitrate", > NULL > }; > static const char * const mpeg_stream_type[] = { > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h > index 99c3f5e99da7..7c74d6c417d1 100644 > --- a/include/uapi/linux/v4l2-controls.h > +++ b/include/uapi/linux/v4l2-controls.h > @@ -393,6 +393,7 @@ enum v4l2_mpeg_video_bitrate_mode { > V4L2_MPEG_VIDEO_BITRATE_MODE_VBR = 0, > V4L2_MPEG_VIDEO_BITRATE_MODE_CBR = 1, > V4L2_MPEG_VIDEO_BITRATE_MODE_CQ = 2, > + V4L2_MPEG_VIDEO_BITRATE_MODE_MBR = 3, > }; > #define V4L2_CID_MPEG_VIDEO_BITRATE (V4L2_CID_CODEC_BASE+207) > #define V4L2_CID_MPEG_VIDEO_BITRATE_PEAK (V4L2_CID_CODEC_BASE+208)
diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst index 2a165ae063fb..05ef4a70e3f5 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst @@ -576,6 +576,8 @@ enum v4l2_mpeg_video_bitrate_mode - - Constant bitrate * - ``V4L2_MPEG_VIDEO_BITRATE_MODE_CQ`` - Constant quality + * - ``V4L2_MPEG_VIDEO_BITRATE_MODE_MBR`` + - Maximum bitrate diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c index 8696eb1cdd61..e0597b61ffb9 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c @@ -154,6 +154,7 @@ const char * const *v4l2_ctrl_get_menu(u32 id) "Variable Bitrate", "Constant Bitrate", "Constant Quality", + "Maximum Bitrate", NULL }; static const char * const mpeg_stream_type[] = { diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h index 99c3f5e99da7..7c74d6c417d1 100644 --- a/include/uapi/linux/v4l2-controls.h +++ b/include/uapi/linux/v4l2-controls.h @@ -393,6 +393,7 @@ enum v4l2_mpeg_video_bitrate_mode { V4L2_MPEG_VIDEO_BITRATE_MODE_VBR = 0, V4L2_MPEG_VIDEO_BITRATE_MODE_CBR = 1, V4L2_MPEG_VIDEO_BITRATE_MODE_CQ = 2, + V4L2_MPEG_VIDEO_BITRATE_MODE_MBR = 3, }; #define V4L2_CID_MPEG_VIDEO_BITRATE (V4L2_CID_CODEC_BASE+207) #define V4L2_CID_MPEG_VIDEO_BITRATE_PEAK (V4L2_CID_CODEC_BASE+208)
Introduce V4L2_MPEG_VIDEO_BITRATE_MODE_MBR rate control to limit the frame level maximum bit rate. Encoder will choose appropriate quantization parameter and do the smart bit allocation to set the frame maximum bitrate level as per the Bitrate value configured. Signed-off-by: Sachin Kumar Garg <quic_sachinku@quicinc.com> --- Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 2 ++ drivers/media/v4l2-core/v4l2-ctrls-defs.c | 1 + include/uapi/linux/v4l2-controls.h | 1 + 3 files changed, 4 insertions(+)