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

[Tomasz Figa <tfiga@chromium.org>]

On Thu, Nov 1, 2018 at 10:01 PM <mgottam@codeaurora.org> 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@codeaurora.org>
> >> ---
> >>  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.

Best regards,
Tomasz