Re: [PATCH v3] media: venus: add support for key frame

[Stanimir Varbanov <stanimir.varbanov@linaro.org>]

Hi Hans,

On 11/29/18 9:40 PM, Tomasz Figa wrote:
> On Thu, Nov 29, 2018 at 3:10 AM <mgottam@codeaurora.org> wrote:
>>
>>
>> Hi Stan,
>>
>> On 2018-11-29 16:01, Stanimir Varbanov wrote:
>>> Hi Tomasz,
>>>
>>> On 11/3/18 5:01 AM, Tomasz Figa wrote:
>>>> Hi Malathi,
>>>>
>>>> On Fri, Nov 2, 2018 at 9:58 PM Malathi Gottam <mgottam@codeaurora.org>
>>>> wrote:
>>>>>
>>>>> When client requests for a keyframe, set the property
>>>>> to hardware to generate the sync frame.
>>>>>
>>>>> Signed-off-by: Malathi Gottam <mgottam@codeaurora.org>
>>>>> ---
>>>>>  drivers/media/platform/qcom/venus/venc_ctrls.c | 20
>>>>> +++++++++++++++++++-
>>>>>  1 file changed, 19 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/media/platform/qcom/venus/venc_ctrls.c
>>>>> b/drivers/media/platform/qcom/venus/venc_ctrls.c
>>>>> index 45910172..59fe7fc 100644
>>>>> --- a/drivers/media/platform/qcom/venus/venc_ctrls.c
>>>>> +++ b/drivers/media/platform/qcom/venus/venc_ctrls.c
>>>>> @@ -79,8 +79,10 @@ static int venc_op_s_ctrl(struct v4l2_ctrl *ctrl)
>>>>>  {
>>>>>         struct venus_inst *inst = ctrl_to_inst(ctrl);
>>>>>         struct venc_controls *ctr = &inst->controls.enc;
>>>>> +       struct hfi_enable en = { .enable = 1 };
>>>>>         u32 bframes;
>>>>>         int ret;
>>>>> +       u32 ptype;
>>>>>
>>>>>         switch (ctrl->id) {
>>>>>         case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
>>>>> @@ -173,6 +175,19 @@ static int venc_op_s_ctrl(struct v4l2_ctrl
>>>>> *ctrl)
>>>>>
>>>>>                 ctr->num_b_frames = bframes;
>>>>>                 break;
>>>>> +       case V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME:
>>>>> +               mutex_lock(&inst->lock);
>>>>> +               if (inst->streamon_out && inst->streamon_cap) {
>>>>
>>>> We had a discussion on this in v2. I don't remember seeing any
>>>> conclusion.
>>>>
>>>> Obviously the hardware should generate a keyframe naturally when the
>>>> CAPTURE streaming starts, which is where the encoding starts, but the
>>>> state of the OUTPUT queue should not affect this.
>>>>
>>>> The application is free to stop and start streaming on the OUTPUT
>>>> queue as it goes and it shouldn't imply any side effects in the
>>>> encoded bitstream (e.g. a keyframe inserted). So:
>>>> - a sequence of STREAMOFF(OUTPUT),
>>>> S_CTRL(V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME), STREAMON(OUTPUT) should
>>>> explicitly generate a keyframe,
>>>
>>> I agree with you, but presently we don't follow strictly the stateful
>>> encoder spec. In this spirit I think proposed patch is applicable to
>>> the
>>> current state of the encoder driver, and your comment should be
>>> addressed in the follow-up patches where we have to re-factor a bit
>>> start/stop_streaming according to the encoder documentation.
>>>
>>> But until then we have to get that patch.
>>
>> So I can see that this patch is good implementation of forcing sync
>> frame
>> under current encoder state.
>>
>> Can you please ack the same.
> 
> Okay, assuming that when you start streaming you naturally get a
> keyframe, I'm okay with this patch, since it actually fixes the
> missing key frame request, so from the general encoder interface point
> of view:
> 
> Acked-by: Tomasz Figa <tfiga@chromium.org>

Thanks Tomasz!

Acked-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>

-- 
regards,
Stan