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

[mgottam]

On 2018-11-03 08:31, Tomasz Figa wrote:
> Hi Malathi,
>
> On Fri, Nov 2, 2018 at 9:58 PM Malathi Gottam <mgottam@xxxxxxxxxxxxxx> 
> wrote:
> > When client requests for a keyframe, set the property
> > to hardware to generate the sync frame.
> >
> > Signed-off-by: Malathi Gottam <mgottam@xxxxxxxxxxxxxx>
> > ---
> >  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,
> - a sequence of STREAMOFF(OUTPUT), STREAMON(OUTPUT) should _not_
> explicitly generate a keyframe (the hardware may generate one, if the
> periodic keyframe counter is active or a scene detection algorithm
> decides so).
>
> Please refer to the specification (v2 is the latest for the time being
> -> https://lore.kernel.org/patchwork/patch/1002476/) for further
> details and feel free to leave any comment for it.
>
> Best regards,
> Tomasz

Gentle reminder!!

Stan, please provide your view on this.

Thanks,
Malathi.