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

[Tomasz Figa]

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.

Best regards,
Tomasz