Re: [PATCH] media: venus: dynamic handling of bitrate

[Stanimir Varbanov]

On 11/1/18 4:31 PM, Tomasz Figa wrote:
> On Thu, Nov 1, 2018 at 11:23 PM Vikash Garodia <vgarodia@xxxxxxxxxxxxxx> wrote:
>>
>> On 2018-11-01 19:23, Tomasz Figa wrote:
>>> On Thu, Nov 1, 2018 at 10:01 PM <mgottam@xxxxxxxxxxxxxx> wrote:
>>>>
>>>> On 2018-11-01 17:48, Stanimir Varbanov wrote:
>>>>> Hi Malathi,
>>>>>
>>>>> Thanks for the patch!
>>>>>
>>>>> On 10/31/18 9:42 AM, Malathi Gottam wrote:
>>>>>> Any request for a change in bitrate after both planes
>>>>>> are streamed on is handled by setting the target bitrate
>>>>>> property to hardware.
>>>>>>
>>>>>> Signed-off-by: Malathi Gottam <mgottam@xxxxxxxxxxxxxx>
>>>>>> ---
>>>>>>  drivers/media/platform/qcom/venus/venc_ctrls.c | 11 +++++++++++
>>>>>>  1 file changed, 11 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/media/platform/qcom/venus/venc_ctrls.c
>>>>>> b/drivers/media/platform/qcom/venus/venc_ctrls.c
>>>>>> index 45910172..54f310c 100644
>>>>>> --- a/drivers/media/platform/qcom/venus/venc_ctrls.c
>>>>>> +++ b/drivers/media/platform/qcom/venus/venc_ctrls.c
>>>>>> @@ -79,7 +79,9 @@ 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_bitrate brate;
>>>>>>      u32 bframes;
>>>>>> +    u32 ptype;
>>>>>>      int ret;
>>>>>>
>>>>>>      switch (ctrl->id) {
>>>>>> @@ -88,6 +90,15 @@ static int venc_op_s_ctrl(struct v4l2_ctrl *ctrl)
>>>>>>              break;
>>>>>>      case V4L2_CID_MPEG_VIDEO_BITRATE:
>>>>>>              ctr->bitrate = ctrl->val;
>>>>>> +            if (inst->streamon_out && inst->streamon_cap) {
>>>>>
>>>>> Hmm, hfi_session_set_property already checks the instance state so I
>>>>> don't think those checks are needed. Another thing is that we need to
>>>>> take the instance mutex to check the instance state.
>>>>
>>>> Yes Stan, "hfi_session_set_property" this property check the instance
>>>> state,
>>>> but returns EINVAL if this is set at UNINIT instance state.
>>>>
>>>> Controls initialization happens much earlier than session init and
>>>> instance init.
>>>> So the instance is still in UNINIT state which causes failure while
>>>> setting.
>>>>
>>>> Through this patch we try to meet the client request of changing
>>>> bitrate
>>>> only
>>>> when both planes are streamed on.
>>>
>>> Where does this requirement come from? It should be possible to set
>>> the control at any time and it should apply to any encoding happening
>>> after the control is set.
>>>
>> With the patch, now video driver will set the control whenever client
>> sets
>> and will apply to encoder.
> 
> That's good, thanks for clarifying. I guess I misunderstood Malathi's comment.

OK, just wonder about locking when we check streamon_out/cap flags?

-- 
regards,
Stan