Re: [PATCH] media: venus: amend buffer size for bitstream plane

[Stanimir Varbanov]

Hi Tomasz,

On 11/13/18 11:13 AM, Tomasz Figa wrote:
> On Tue, Nov 13, 2018 at 5:12 PM Stanimir Varbanov
> <stanimir.varbanov@xxxxxxxxxx> wrote:
>>
>> Hi Malathi,
>>
>> On 11/13/18 9:28 AM, mgottam@xxxxxxxxxxxxxx wrote:
>>> On 2018-11-12 18:04, Stanimir Varbanov wrote:
>>>> Hi Tomasz,
>>>>
>>>> On 10/23/2018 05:50 AM, Tomasz Figa wrote:
>>>>> Hi Malathi,
>>>>>
>>>>> On Tue, Oct 9, 2018 at 4:58 PM Malathi Gottam
>>>>> <mgottam@xxxxxxxxxxxxxx> wrote:
>>>>>>
>>>>>> For lower resolutions, incase of encoder, the compressed
>>>>>> frame size is more than half of the corresponding input
>>>>>> YUV. Keep the size as same as YUV considering worst case.
>>>>>>
>>>>>> Signed-off-by: Malathi Gottam <mgottam@xxxxxxxxxxxxxx>
>>>>>> ---
>>>>>>  drivers/media/platform/qcom/venus/helpers.c | 2 +-
>>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/drivers/media/platform/qcom/venus/helpers.c
>>>>>> b/drivers/media/platform/qcom/venus/helpers.c
>>>>>> index 2679adb..05c5423 100644
>>>>>> --- a/drivers/media/platform/qcom/venus/helpers.c
>>>>>> +++ b/drivers/media/platform/qcom/venus/helpers.c
>>>>>> @@ -649,7 +649,7 @@ u32 venus_helper_get_framesz(u32 v4l2_fmt, u32
>>>>>> width, u32 height)
>>>>>>         }
>>>>>>
>>>>>>         if (compressed) {
>>>>>> -               sz = ALIGN(height, 32) * ALIGN(width, 32) * 3 / 2 / 2;
>>>>>> +               sz = ALIGN(height, 32) * ALIGN(width, 32) * 3 / 2;
>>>>>>                 return ALIGN(sz, SZ_4K);
>>>>>>         }
>>>>>
>>>>> Note that the driver should not enforce one particular buffer size for
>>>>> bitstream buffers unless it's a workaround for broken firmware or
>>>>> hardware. The userspace should be able to select the desired size.
>>>>
>>>> Good point! Yes, we have to extend set_fmt to allow bigger sizeimage for
>>>> the compressed buffers (not only for encoder).
>>>
>>> So Stan you meant to say that we should allow s_fmt to accept client
>>> specified size?
>>
>> yes but I do expect:
>>
>> new_sizeimage = max(user_sizeimage, venus_helper_get_framesz)
>>
>> and also user_sizeimage should be sanitized.
>>
>>> If so should we set the inst->input_buf_size here in venc_s_fmt?
>>>
>>> @@ -333,10 +333,10 @@static const struct venus_format *
>>> venc_try_fmt_common(struct venus_inst *inst, struct v4l2_format *f)
>>>
>>>         pixmp->num_planes = fmt->num_planes;
>>>         pixmp->flags = 0;
>>> -
>>> -       pfmt[0].sizeimage = venus_helper_get_framesz(pixmp->pixelformat,
>>> -                                                    pixmp->width,
>>> -                                                    pixmp->height);
>>> +       if (!pfmt[0].sizeimage)
>>> +               pfmt[0].sizeimage =
>>> venus_helper_get_framesz(pixmp->pixelformat,
>>> +                                                            pixmp->width,
>>> +
>>> pixmp->height);
>>
>> yes, but please make
>>
>> pfmt[0].sizeimage = max(pfmt[0].sizeimage, venus_helper_get_framesz)
>>
>> and IMO this should be only for CAPTURE queue i.e. inst->output_buf_size
>>
>> I'm still not sure do we need it for OUTPUT encoder queue.
>>
> 
> This would be indeed only for the queues that operate on a coded
> bitstream, i.e. both encoder CAPTURE and decoder OUTPUT.

Thanks for the confirmation.

> 
> For image formats, sizeimage should be calculated by the driver based
> on the bytesperline and height. (Bytesperline may be fixed, if the
> hardware doesn't support flexible strides, but if it does, it's
> strongly recommended to use the bytesperline coming from the
> application as the stride +/- any necessary sanity checks.)

the hw should support stride but I'm not sure is that exposed by the
firmware interface.

-- 
regards,
Stan