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From: Hans Verkuil <hverkuil@xs4all.nl>
To: Pawel Osciak <posciak@chromium.org>
Cc: "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	k.debski@samsung.com
Subject: Re: [PATCH v1 16/19] v4l: Add encoding camera controls.
Date: Mon, 09 Sep 2013 09:52:30 +0200	[thread overview]
Message-ID: <522D7E3E.8070104@xs4all.nl> (raw)
In-Reply-To: <CACHYQ-oGaAS1TVLqm-wRsPSg5xDqBTuvj9PcMAmu5vEc-aVb1A@mail.gmail.com>

On 09/09/2013 05:48 AM, Pawel Osciak wrote:
> Hi Hans,
> Thanks for the comments, one question inline.
> 
> On Fri, Aug 30, 2013 at 3:48 PM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
>> On 08/30/2013 04:17 AM, Pawel Osciak wrote:
>>> Add defines for controls found in UVC 1.5 encoding cameras.
>>>
>>> Signed-off-by: Pawel Osciak <posciak@chromium.org>
>>> ---
>>>  drivers/media/v4l2-core/v4l2-ctrls.c | 29 +++++++++++++++++++++++++++++
>>>  include/uapi/linux/v4l2-controls.h   | 31 +++++++++++++++++++++++++++++++
>>>  2 files changed, 60 insertions(+)
>>>
>>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
>>> index c3f0803..0b3a632 100644
>>> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
>>> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
>>> @@ -781,6 +781,35 @@ const char *v4l2_ctrl_get_name(u32 id)
>>>       case V4L2_CID_AUTO_FOCUS_STATUS:        return "Auto Focus, Status";
>>>       case V4L2_CID_AUTO_FOCUS_RANGE:         return "Auto Focus, Range";
>>>
>>> +     case V4L2_CID_ENCODER_MIN_FRAME_INTERVAL: return "Encoder, min. frame interval";
>>> +     case V4L2_CID_ENCODER_RATE_CONTROL_MODE: return "Encoder, rate control mode";
>>> +     case V4L2_CID_ENCODER_AVERAGE_BITRATE:  return "Encoder, average bitrate";
>>> +     case V4L2_CID_ENCODER_CPB_SIZE:         return "Encoder, CPB size";
>>> +     case V4L2_CID_ENCODER_PEAK_BIT_RATE:    return "Encoder, peak bit rate";
>>> +     case V4L2_CID_ENCODER_QP_PARAM_I:       return "Encoder, QP param for I frames";
>>> +     case V4L2_CID_ENCODER_QP_PARAM_P:       return "Encoder, QP param for P frames";
>>> +     case V4L2_CID_ENCODER_QP_PARAM_BG:      return "Encoder, QP param for B/G frames";
>>
>> A lot of these exist already. E.g. V4L2_CID_MPEG_VIDEO_MPEG4_I/P/B_FRAME_QP.
>>
>> Samsung added support for many of these parameters for their MFC encoder (including
>> VP8 support) so you should use them as well. As mentioned in v4l2-controls.h the
>> MPEG part of the control name is historical. Interpret it as 'CODEC', not MPEG.
>>
> 
> We have QP controls separately for H264, H263 and MPEG4. Why is that?
> Which one should I use for VP8? Shouldn't we unify them instead?

I can't quite remember the details, so I've CCed Kamil since he added those controls.
At least the H264 QP controls are different from the others as they have a different
range. What's the range for VP8?

I'm not sure why the H263/MPEG4 controls weren't unified: it might be that since the
H264 range was different we decided to split it up per codec. But I seem to remember
that there was another reason as well.

Regards,

	Hans

  reply	other threads:[~2013-09-09  7:52 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-30  2:16 [PATCH v1 00/19] UVC 1.5 VP8 support for uvcvideo Pawel Osciak
2013-08-30  2:17 ` [PATCH v1 01/19] uvcvideo: Add UVC query tracing Pawel Osciak
2013-09-03 20:17   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 02/19] uvcvideo: Return 0 when setting probe control succeeds Pawel Osciak
2013-09-03 20:21   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 03/19] uvcvideo: Add support for multiple chains with common roots Pawel Osciak
2013-11-10 20:37   ` Laurent Pinchart
2013-11-11 13:55     ` Paulo Assis
2013-08-30  2:17 ` [PATCH v1 04/19] uvcvideo: Create separate debugfs entries for each streaming interface Pawel Osciak
2013-09-03 20:28   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 05/19] uvcvideo: Add support for UVC1.5 P&C control Pawel Osciak
2013-09-03 20:42   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 06/19] uvcvideo: Recognize UVC 1.5 encoding units Pawel Osciak
2013-11-10 21:46   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 07/19] uvcvideo: Unify error reporting during format descriptor parsing Pawel Osciak
2013-09-03 20:55   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 08/19] uvcvideo: Add UVC1.5 VP8 format support Pawel Osciak
2013-11-10 22:30   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 09/19] uvcvideo: Reorganize uvc_{get,set}_le_value Pawel Osciak
2013-11-10 22:34   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 10/19] uvcvideo: Support UVC 1.5 runtime control property Pawel Osciak
2013-08-30  6:36   ` Hans Verkuil
2013-11-10 22:51   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 11/19] uvcvideo: Support V4L2_CTRL_TYPE_BITMASK controls Pawel Osciak
2013-11-10 22:57   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 12/19] uvcvideo: Reorganize next buffer handling Pawel Osciak
2013-11-10 23:43   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 13/19] uvcvideo: Unify UVC payload header parsing Pawel Osciak
2013-11-11  1:27   ` Laurent Pinchart
2013-11-11  1:46   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 14/19] v4l: Add v4l2_buffer flags for VP8-specific special frames Pawel Osciak
2013-08-30  6:42   ` Hans Verkuil
     [not found]     ` <CACHYQ-pUhmPhMrbE8QWM+r6OWbBnOx7g6vjQvOxBSoodnPk4+Q@mail.gmail.com>
2013-08-30  8:12       ` Hans Verkuil
2013-08-31 17:42         ` Sakari Ailus
2013-08-31 17:44   ` Sakari Ailus
2013-11-11  1:27   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 15/19] uvcvideo: Add support for VP8 special frame flags Pawel Osciak
2013-11-11  1:49   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 16/19] v4l: Add encoding camera controls Pawel Osciak
2013-08-30  6:48   ` Hans Verkuil
2013-09-09  3:48     ` Pawel Osciak
2013-09-09  7:52       ` Hans Verkuil [this message]
2013-09-09  7:59         ` Pawel Osciak
2013-09-09  9:00           ` Kamil Debski
2013-09-09  9:09             ` Sylwester Nawrocki
2013-09-10  9:17               ` Hans Verkuil
2013-09-12  1:10                 ` Pawel Osciak
2013-09-12  4:20                   ` Hans Verkuil
2013-11-11  1:53   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 17/19] uvcvideo: Add UVC 1.5 Encoding Unit controls Pawel Osciak
2013-11-11  2:33   ` Laurent Pinchart
2013-08-30  2:17 ` [PATCH v1 18/19] v4l: Add V4L2_PIX_FMT_VP8_SIMULCAST format Pawel Osciak
2013-08-31 17:52   ` Sakari Ailus
2013-08-30  2:17 ` [PATCH v1 19/19] uvcvideo: Add support for UVC 1.5 VP8 simulcast Pawel Osciak
2013-10-10 10:27 ` [PATCH v1 00/19] UVC 1.5 VP8 support for uvcvideo Paulo Assis
2013-11-11  2:05   ` Laurent Pinchart
2013-11-11 10:00     ` Paulo Assis

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