[v2,for,5.4,3/4] media: hantro: Fix motion vectors usage condition
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Message ID 20191007174505.10681-4-ezequiel@collabora.com
State New
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Series
  • media: hantro: Collected fixes for v5.4
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Commit Message

Ezequiel Garcia Oct. 7, 2019, 5:45 p.m. UTC
From: Francois Buergisser <fbuergisser@chromium.org>

The setting of the motion vectors usage and the setting of motion
vectors address are currently done under different conditions.

When decoding pre-recorded videos, this results of leaving the motion
vectors address unset, resulting in faulty memory accesses. Fix it
by using the same condition everywhere, which matches the profiles
that support motion vectors.

Fixes: dea0a82f3d22 ("media: hantro: Add support for H264 decoding on G1")
Signed-off-by: Francois Buergisser <fbuergisser@chromium.org>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
---
v2:
* New patch.

 drivers/staging/media/hantro/hantro_g1_h264_dec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Jonas Karlman Oct. 7, 2019, 6:33 p.m. UTC | #1
On 2019-10-07 19:45, Ezequiel Garcia wrote:
> From: Francois Buergisser <fbuergisser@chromium.org>
>
> The setting of the motion vectors usage and the setting of motion
> vectors address are currently done under different conditions.
>
> When decoding pre-recorded videos, this results of leaving the motion
> vectors address unset, resulting in faulty memory accesses. Fix it
> by using the same condition everywhere, which matches the profiles
> that support motion vectors.

This does not fully match hantro sdk:

  enable direct MV writing and POC tables for high/main streams.
  enable it also for any "baseline" stream which have main/high tools enabled.

  (sps->profile_idc > 66 && sps->constrained_set0_flag == 0) ||
  sps->frame_mbs_only_flag != 1 ||
  sps->chroma_format_idc != 1 ||
  sps->scaling_matrix_present_flag != 0 ||
  pps->entropy_coding_mode_flag != 0 ||
  pps->weighted_pred_flag != 0 ||
  pps->weighted_bi_pred_idc != 0 ||
  pps->transform8x8_flag != 0 ||
  pps->scaling_matrix_present_flag != 0

Above check is used when DIR_MV_BASE should be written.
And WRITE_MVS_E is set to nal_ref_idc != 0 when above is true.

I think it may be safer to always set DIR_MV_BASE and keep the existing nal_ref_idc check for WRITE_MVS_E.
(That is what I did in my "media: hantro: H264 fixes and improvements" series, v2 is incoming)
Or have you found any video that is having issues in such case?

Regards,
Jonas

>
> Fixes: dea0a82f3d22 ("media: hantro: Add support for H264 decoding on G1")
> Signed-off-by: Francois Buergisser <fbuergisser@chromium.org>
> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> ---
> v2:
> * New patch.
>
>  drivers/staging/media/hantro/hantro_g1_h264_dec.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/media/hantro/hantro_g1_h264_dec.c b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> index 7ab534936843..c92460407613 100644
> --- a/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> +++ b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> @@ -35,7 +35,7 @@ static void set_params(struct hantro_ctx *ctx)
>  	if (sps->flags & V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD)
>  		reg |= G1_REG_DEC_CTRL0_SEQ_MBAFF_E;
>  	reg |= G1_REG_DEC_CTRL0_PICORD_COUNT_E;
> -	if (dec_param->nal_ref_idc)
> +	if (sps->profile_idc > 66)
>  		reg |= G1_REG_DEC_CTRL0_WRITE_MVS_E;
>  
>  	if (!(sps->flags & V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY) &&
Tomasz Figa Oct. 8, 2019, 3:29 a.m. UTC | #2
Hi Jonas,

On Tue, Oct 8, 2019 at 3:33 AM Jonas Karlman <jonas@kwiboo.se> wrote:
>
> On 2019-10-07 19:45, Ezequiel Garcia wrote:
> > From: Francois Buergisser <fbuergisser@chromium.org>
> >
> > The setting of the motion vectors usage and the setting of motion
> > vectors address are currently done under different conditions.
> >
> > When decoding pre-recorded videos, this results of leaving the motion
> > vectors address unset, resulting in faulty memory accesses. Fix it
> > by using the same condition everywhere, which matches the profiles
> > that support motion vectors.
>
> This does not fully match hantro sdk:
>
>   enable direct MV writing and POC tables for high/main streams.
>   enable it also for any "baseline" stream which have main/high tools enabled.
>
>   (sps->profile_idc > 66 && sps->constrained_set0_flag == 0) ||
>   sps->frame_mbs_only_flag != 1 ||
>   sps->chroma_format_idc != 1 ||
>   sps->scaling_matrix_present_flag != 0 ||
>   pps->entropy_coding_mode_flag != 0 ||
>   pps->weighted_pred_flag != 0 ||
>   pps->weighted_bi_pred_idc != 0 ||
>   pps->transform8x8_flag != 0 ||
>   pps->scaling_matrix_present_flag != 0

Thanks for double checking this. I can confirm that it's what Hantro
SDK does indeed.

However, would a stream with sps->profile_idc <= 66 and those other
conditions met be still a compliant stream?

>
> Above check is used when DIR_MV_BASE should be written.
> And WRITE_MVS_E is set to nal_ref_idc != 0 when above is true.
>
> I think it may be safer to always set DIR_MV_BASE and keep the existing nal_ref_idc check for WRITE_MVS_E.

That might have a performance penalty or some other side effects,
though. Otherwise Hantro SDK wouldn't have enable it conditionally.

> (That is what I did in my "media: hantro: H264 fixes and improvements" series, v2 is incoming)
> Or have you found any video that is having issues in such case?

We've been running the code with sps->profile_idc > 66 in production
for 4 years and haven't seen any reports of a stream that wasn't
decoded correctly.

If we decide to go with a different behavior, I'd suggest thoroughly
verifying the behavior on a big number of streams, including some
performance measurements.

Best regards,
Tomasz

>
> Regards,
> Jonas
>
> >
> > Fixes: dea0a82f3d22 ("media: hantro: Add support for H264 decoding on G1")
> > Signed-off-by: Francois Buergisser <fbuergisser@chromium.org>
> > Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> > ---
> > v2:
> > * New patch.
> >
> >  drivers/staging/media/hantro/hantro_g1_h264_dec.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/staging/media/hantro/hantro_g1_h264_dec.c b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> > index 7ab534936843..c92460407613 100644
> > --- a/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> > +++ b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> > @@ -35,7 +35,7 @@ static void set_params(struct hantro_ctx *ctx)
> >       if (sps->flags & V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD)
> >               reg |= G1_REG_DEC_CTRL0_SEQ_MBAFF_E;
> >       reg |= G1_REG_DEC_CTRL0_PICORD_COUNT_E;
> > -     if (dec_param->nal_ref_idc)
> > +     if (sps->profile_idc > 66)
> >               reg |= G1_REG_DEC_CTRL0_WRITE_MVS_E;
> >
> >       if (!(sps->flags & V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY) &&
>
Jonas Karlman Oct. 8, 2019, 6:23 a.m. UTC | #3
On 2019-10-08 05:29, Tomasz Figa wrote:
> Hi Jonas,
>
> On Tue, Oct 8, 2019 at 3:33 AM Jonas Karlman <jonas@kwiboo.se> wrote:
>> On 2019-10-07 19:45, Ezequiel Garcia wrote:
>>> From: Francois Buergisser <fbuergisser@chromium.org>
>>>
>>> The setting of the motion vectors usage and the setting of motion
>>> vectors address are currently done under different conditions.
>>>
>>> When decoding pre-recorded videos, this results of leaving the motion
>>> vectors address unset, resulting in faulty memory accesses. Fix it
>>> by using the same condition everywhere, which matches the profiles
>>> that support motion vectors.
>> This does not fully match hantro sdk:
>>
>>   enable direct MV writing and POC tables for high/main streams.
>>   enable it also for any "baseline" stream which have main/high tools enabled.
>>
>>   (sps->profile_idc > 66 && sps->constrained_set0_flag == 0) ||
>>   sps->frame_mbs_only_flag != 1 ||
>>   sps->chroma_format_idc != 1 ||
>>   sps->scaling_matrix_present_flag != 0 ||
>>   pps->entropy_coding_mode_flag != 0 ||
>>   pps->weighted_pred_flag != 0 ||
>>   pps->weighted_bi_pred_idc != 0 ||
>>   pps->transform8x8_flag != 0 ||
>>   pps->scaling_matrix_present_flag != 0
> Thanks for double checking this. I can confirm that it's what Hantro
> SDK does indeed.
>
> However, would a stream with sps->profile_idc <= 66 and those other
> conditions met be still a compliant stream?

You are correct, if a non-compliant video is having decoding problems it should probably be handled
on userspace side (by not reporting baseline profile) and not in kernel.
All my video samples that was having the issue fixed in this patch are now decoded correctly.

>
>> Above check is used when DIR_MV_BASE should be written.
>> And WRITE_MVS_E is set to nal_ref_idc != 0 when above is true.
>>
>> I think it may be safer to always set DIR_MV_BASE and keep the existing nal_ref_idc check for WRITE_MVS_E.
> That might have a performance penalty or some other side effects,
> though. Otherwise Hantro SDK wouldn't have enable it conditionally.
>
>> (That is what I did in my "media: hantro: H264 fixes and improvements" series, v2 is incoming)
>> Or have you found any video that is having issues in such case?
> We've been running the code with sps->profile_idc > 66 in production
> for 4 years and haven't seen any reports of a stream that wasn't
> decoded correctly.
>
> If we decide to go with a different behavior, I'd suggest thoroughly
> verifying the behavior on a big number of streams, including some
> performance measurements.

I agree, I would however suggest to change the if statement to the following (or similar)
as that should be the optimal for performance reasons and match the hantro sdk.

if (sps->profile_idc > 66 && dec_param->nal_ref_idc)

Regards,
Jonas

>
> Best regards,
> Tomasz
>
>> Regards,
>> Jonas
>>
>>> Fixes: dea0a82f3d22 ("media: hantro: Add support for H264 decoding on G1")
>>> Signed-off-by: Francois Buergisser <fbuergisser@chromium.org>
>>> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
>>> ---
>>> v2:
>>> * New patch.
>>>
>>>  drivers/staging/media/hantro/hantro_g1_h264_dec.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/staging/media/hantro/hantro_g1_h264_dec.c b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
>>> index 7ab534936843..c92460407613 100644
>>> --- a/drivers/staging/media/hantro/hantro_g1_h264_dec.c
>>> +++ b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
>>> @@ -35,7 +35,7 @@ static void set_params(struct hantro_ctx *ctx)
>>>       if (sps->flags & V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD)
>>>               reg |= G1_REG_DEC_CTRL0_SEQ_MBAFF_E;
>>>       reg |= G1_REG_DEC_CTRL0_PICORD_COUNT_E;
>>> -     if (dec_param->nal_ref_idc)
>>> +     if (sps->profile_idc > 66)
>>>               reg |= G1_REG_DEC_CTRL0_WRITE_MVS_E;
>>>
>>>       if (!(sps->flags & V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY) &&
Tomasz Figa Oct. 8, 2019, 10:26 a.m. UTC | #4
On Tue, Oct 8, 2019 at 3:23 PM Jonas Karlman <jonas@kwiboo.se> wrote:
>
> On 2019-10-08 05:29, Tomasz Figa wrote:
> > Hi Jonas,
> >
> > On Tue, Oct 8, 2019 at 3:33 AM Jonas Karlman <jonas@kwiboo.se> wrote:
> >> On 2019-10-07 19:45, Ezequiel Garcia wrote:
> >>> From: Francois Buergisser <fbuergisser@chromium.org>
> >>>
> >>> The setting of the motion vectors usage and the setting of motion
> >>> vectors address are currently done under different conditions.
> >>>
> >>> When decoding pre-recorded videos, this results of leaving the motion
> >>> vectors address unset, resulting in faulty memory accesses. Fix it
> >>> by using the same condition everywhere, which matches the profiles
> >>> that support motion vectors.
> >> This does not fully match hantro sdk:
> >>
> >>   enable direct MV writing and POC tables for high/main streams.
> >>   enable it also for any "baseline" stream which have main/high tools enabled.
> >>
> >>   (sps->profile_idc > 66 && sps->constrained_set0_flag == 0) ||
> >>   sps->frame_mbs_only_flag != 1 ||
> >>   sps->chroma_format_idc != 1 ||
> >>   sps->scaling_matrix_present_flag != 0 ||
> >>   pps->entropy_coding_mode_flag != 0 ||
> >>   pps->weighted_pred_flag != 0 ||
> >>   pps->weighted_bi_pred_idc != 0 ||
> >>   pps->transform8x8_flag != 0 ||
> >>   pps->scaling_matrix_present_flag != 0
> > Thanks for double checking this. I can confirm that it's what Hantro
> > SDK does indeed.
> >
> > However, would a stream with sps->profile_idc <= 66 and those other
> > conditions met be still a compliant stream?
>
> You are correct, if a non-compliant video is having decoding problems it should probably be handled
> on userspace side (by not reporting baseline profile) and not in kernel.
> All my video samples that was having the issue fixed in this patch are now decoded correctly.
>
> >
> >> Above check is used when DIR_MV_BASE should be written.
> >> And WRITE_MVS_E is set to nal_ref_idc != 0 when above is true.
> >>
> >> I think it may be safer to always set DIR_MV_BASE and keep the existing nal_ref_idc check for WRITE_MVS_E.
> > That might have a performance penalty or some other side effects,
> > though. Otherwise Hantro SDK wouldn't have enable it conditionally.
> >
> >> (That is what I did in my "media: hantro: H264 fixes and improvements" series, v2 is incoming)
> >> Or have you found any video that is having issues in such case?
> > We've been running the code with sps->profile_idc > 66 in production
> > for 4 years and haven't seen any reports of a stream that wasn't
> > decoded correctly.
> >
> > If we decide to go with a different behavior, I'd suggest thoroughly
> > verifying the behavior on a big number of streams, including some
> > performance measurements.
>
> I agree, I would however suggest to change the if statement to the following (or similar)
> as that should be the optimal for performance reasons and match the hantro sdk.
>
> if (sps->profile_idc > 66 && dec_param->nal_ref_idc)

Sorry for my ignorance, but could you elaborate on this? What's the
meaning of nal_ref_idc? I don't see it being checked in the Hantro SDK
condition you mentioned earlier.

>
> Regards,
> Jonas
>
> >
> > Best regards,
> > Tomasz
> >
> >> Regards,
> >> Jonas
> >>
> >>> Fixes: dea0a82f3d22 ("media: hantro: Add support for H264 decoding on G1")
> >>> Signed-off-by: Francois Buergisser <fbuergisser@chromium.org>
> >>> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> >>> ---
> >>> v2:
> >>> * New patch.
> >>>
> >>>  drivers/staging/media/hantro/hantro_g1_h264_dec.c | 2 +-
> >>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/staging/media/hantro/hantro_g1_h264_dec.c b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> >>> index 7ab534936843..c92460407613 100644
> >>> --- a/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> >>> +++ b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> >>> @@ -35,7 +35,7 @@ static void set_params(struct hantro_ctx *ctx)
> >>>       if (sps->flags & V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD)
> >>>               reg |= G1_REG_DEC_CTRL0_SEQ_MBAFF_E;
> >>>       reg |= G1_REG_DEC_CTRL0_PICORD_COUNT_E;
> >>> -     if (dec_param->nal_ref_idc)
> >>> +     if (sps->profile_idc > 66)
> >>>               reg |= G1_REG_DEC_CTRL0_WRITE_MVS_E;
> >>>
> >>>       if (!(sps->flags & V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY) &&
>
Jonas Karlman Oct. 8, 2019, 1:57 p.m. UTC | #5
On 2019-10-08 12:26, Tomasz Figa wrote:
> On Tue, Oct 8, 2019 at 3:23 PM Jonas Karlman <jonas@kwiboo.se> wrote:
>> On 2019-10-08 05:29, Tomasz Figa wrote:
>>> Hi Jonas,
>>>
>>> On Tue, Oct 8, 2019 at 3:33 AM Jonas Karlman <jonas@kwiboo.se> wrote:
>>>> On 2019-10-07 19:45, Ezequiel Garcia wrote:
>>>>> From: Francois Buergisser <fbuergisser@chromium.org>
>>>>>
>>>>> The setting of the motion vectors usage and the setting of motion
>>>>> vectors address are currently done under different conditions.
>>>>>
>>>>> When decoding pre-recorded videos, this results of leaving the motion
>>>>> vectors address unset, resulting in faulty memory accesses. Fix it
>>>>> by using the same condition everywhere, which matches the profiles
>>>>> that support motion vectors.
>>>> This does not fully match hantro sdk:
>>>>
>>>>   enable direct MV writing and POC tables for high/main streams.
>>>>   enable it also for any "baseline" stream which have main/high tools enabled.
>>>>
>>>>   (sps->profile_idc > 66 && sps->constrained_set0_flag == 0) ||
>>>>   sps->frame_mbs_only_flag != 1 ||
>>>>   sps->chroma_format_idc != 1 ||
>>>>   sps->scaling_matrix_present_flag != 0 ||
>>>>   pps->entropy_coding_mode_flag != 0 ||
>>>>   pps->weighted_pred_flag != 0 ||
>>>>   pps->weighted_bi_pred_idc != 0 ||
>>>>   pps->transform8x8_flag != 0 ||
>>>>   pps->scaling_matrix_present_flag != 0
>>> Thanks for double checking this. I can confirm that it's what Hantro
>>> SDK does indeed.
>>>
>>> However, would a stream with sps->profile_idc <= 66 and those other
>>> conditions met be still a compliant stream?
>> You are correct, if a non-compliant video is having decoding problems it should probably be handled
>> on userspace side (by not reporting baseline profile) and not in kernel.
>> All my video samples that was having the issue fixed in this patch are now decoded correctly.
>>
>>>> Above check is used when DIR_MV_BASE should be written.
>>>> And WRITE_MVS_E is set to nal_ref_idc != 0 when above is true.
>>>>
>>>> I think it may be safer to always set DIR_MV_BASE and keep the existing nal_ref_idc check for WRITE_MVS_E.
>>> That might have a performance penalty or some other side effects,
>>> though. Otherwise Hantro SDK wouldn't have enable it conditionally.
>>>
>>>> (That is what I did in my "media: hantro: H264 fixes and improvements" series, v2 is incoming)
>>>> Or have you found any video that is having issues in such case?
>>> We've been running the code with sps->profile_idc > 66 in production
>>> for 4 years and haven't seen any reports of a stream that wasn't
>>> decoded correctly.
>>>
>>> If we decide to go with a different behavior, I'd suggest thoroughly
>>> verifying the behavior on a big number of streams, including some
>>> performance measurements.
>> I agree, I would however suggest to change the if statement to the following (or similar)
>> as that should be the optimal for performance reasons and match the hantro sdk.
>>
>> if (sps->profile_idc > 66 && dec_param->nal_ref_idc)
> Sorry for my ignorance, but could you elaborate on this? What's the
> meaning of nal_ref_idc? I don't see it being checked in the Hantro SDK
> condition you mentioned earlier.

My somewhat limited understanding of h264 spec is that nal_ref_idc should be 0 for non-reference field/frame/pictures
and because of this there should not be any need to write motion vector data as the field/frame should not be referenced.

My base for the hantro sdk code is the imx8 imx-vpu-hantro package and it uses (simplified):
  SetDecRegister(h264_regs, HWIF_WRITE_MVS_E, nal_ref_idc != 0)
for MVC there is an additional condition.

Regards,
Jonas

>
>> Regards,
>> Jonas
>>
>>> Best regards,
>>> Tomasz
>>>
>>>> Regards,
>>>> Jonas
>>>>
>>>>> Fixes: dea0a82f3d22 ("media: hantro: Add support for H264 decoding on G1")
>>>>> Signed-off-by: Francois Buergisser <fbuergisser@chromium.org>
>>>>> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
>>>>> ---
>>>>> v2:
>>>>> * New patch.
>>>>>
>>>>>  drivers/staging/media/hantro/hantro_g1_h264_dec.c | 2 +-
>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/staging/media/hantro/hantro_g1_h264_dec.c b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
>>>>> index 7ab534936843..c92460407613 100644
>>>>> --- a/drivers/staging/media/hantro/hantro_g1_h264_dec.c
>>>>> +++ b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
>>>>> @@ -35,7 +35,7 @@ static void set_params(struct hantro_ctx *ctx)
>>>>>       if (sps->flags & V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD)
>>>>>               reg |= G1_REG_DEC_CTRL0_SEQ_MBAFF_E;
>>>>>       reg |= G1_REG_DEC_CTRL0_PICORD_COUNT_E;
>>>>> -     if (dec_param->nal_ref_idc)
>>>>> +     if (sps->profile_idc > 66)
>>>>>               reg |= G1_REG_DEC_CTRL0_WRITE_MVS_E;
>>>>>
>>>>>       if (!(sps->flags & V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY) &&
Tomasz Figa Oct. 10, 2019, 7:36 a.m. UTC | #6
On Tue, Oct 8, 2019 at 10:57 PM Jonas Karlman <jonas@kwiboo.se> wrote:
>
> On 2019-10-08 12:26, Tomasz Figa wrote:
> > On Tue, Oct 8, 2019 at 3:23 PM Jonas Karlman <jonas@kwiboo.se> wrote:
> >> On 2019-10-08 05:29, Tomasz Figa wrote:
> >>> Hi Jonas,
> >>>
> >>> On Tue, Oct 8, 2019 at 3:33 AM Jonas Karlman <jonas@kwiboo.se> wrote:
> >>>> On 2019-10-07 19:45, Ezequiel Garcia wrote:
> >>>>> From: Francois Buergisser <fbuergisser@chromium.org>
> >>>>>
> >>>>> The setting of the motion vectors usage and the setting of motion
> >>>>> vectors address are currently done under different conditions.
> >>>>>
> >>>>> When decoding pre-recorded videos, this results of leaving the motion
> >>>>> vectors address unset, resulting in faulty memory accesses. Fix it
> >>>>> by using the same condition everywhere, which matches the profiles
> >>>>> that support motion vectors.
> >>>> This does not fully match hantro sdk:
> >>>>
> >>>>   enable direct MV writing and POC tables for high/main streams.
> >>>>   enable it also for any "baseline" stream which have main/high tools enabled.
> >>>>
> >>>>   (sps->profile_idc > 66 && sps->constrained_set0_flag == 0) ||
> >>>>   sps->frame_mbs_only_flag != 1 ||
> >>>>   sps->chroma_format_idc != 1 ||
> >>>>   sps->scaling_matrix_present_flag != 0 ||
> >>>>   pps->entropy_coding_mode_flag != 0 ||
> >>>>   pps->weighted_pred_flag != 0 ||
> >>>>   pps->weighted_bi_pred_idc != 0 ||
> >>>>   pps->transform8x8_flag != 0 ||
> >>>>   pps->scaling_matrix_present_flag != 0
> >>> Thanks for double checking this. I can confirm that it's what Hantro
> >>> SDK does indeed.
> >>>
> >>> However, would a stream with sps->profile_idc <= 66 and those other
> >>> conditions met be still a compliant stream?
> >> You are correct, if a non-compliant video is having decoding problems it should probably be handled
> >> on userspace side (by not reporting baseline profile) and not in kernel.
> >> All my video samples that was having the issue fixed in this patch are now decoded correctly.
> >>
> >>>> Above check is used when DIR_MV_BASE should be written.
> >>>> And WRITE_MVS_E is set to nal_ref_idc != 0 when above is true.
> >>>>
> >>>> I think it may be safer to always set DIR_MV_BASE and keep the existing nal_ref_idc check for WRITE_MVS_E.
> >>> That might have a performance penalty or some other side effects,
> >>> though. Otherwise Hantro SDK wouldn't have enable it conditionally.
> >>>
> >>>> (That is what I did in my "media: hantro: H264 fixes and improvements" series, v2 is incoming)
> >>>> Or have you found any video that is having issues in such case?
> >>> We've been running the code with sps->profile_idc > 66 in production
> >>> for 4 years and haven't seen any reports of a stream that wasn't
> >>> decoded correctly.
> >>>
> >>> If we decide to go with a different behavior, I'd suggest thoroughly
> >>> verifying the behavior on a big number of streams, including some
> >>> performance measurements.
> >> I agree, I would however suggest to change the if statement to the following (or similar)
> >> as that should be the optimal for performance reasons and match the hantro sdk.
> >>
> >> if (sps->profile_idc > 66 && dec_param->nal_ref_idc)
> > Sorry for my ignorance, but could you elaborate on this? What's the
> > meaning of nal_ref_idc? I don't see it being checked in the Hantro SDK
> > condition you mentioned earlier.
>
> My somewhat limited understanding of h264 spec is that nal_ref_idc should be 0 for non-reference field/frame/pictures
> and because of this there should not be any need to write motion vector data as the field/frame should not be referenced.
>
> My base for the hantro sdk code is the imx8 imx-vpu-hantro package and it uses (simplified):
>   SetDecRegister(h264_regs, HWIF_WRITE_MVS_E, nal_ref_idc != 0)
> for MVC there is an additional condition.

Aha, completely makes sense. Thanks for clarifying.

Best regards,
Tomasz

>
> Regards,
> Jonas
>
> >
> >> Regards,
> >> Jonas
> >>
> >>> Best regards,
> >>> Tomasz
> >>>
> >>>> Regards,
> >>>> Jonas
> >>>>
> >>>>> Fixes: dea0a82f3d22 ("media: hantro: Add support for H264 decoding on G1")
> >>>>> Signed-off-by: Francois Buergisser <fbuergisser@chromium.org>
> >>>>> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> >>>>> ---
> >>>>> v2:
> >>>>> * New patch.
> >>>>>
> >>>>>  drivers/staging/media/hantro/hantro_g1_h264_dec.c | 2 +-
> >>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>>
> >>>>> diff --git a/drivers/staging/media/hantro/hantro_g1_h264_dec.c b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> >>>>> index 7ab534936843..c92460407613 100644
> >>>>> --- a/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> >>>>> +++ b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
> >>>>> @@ -35,7 +35,7 @@ static void set_params(struct hantro_ctx *ctx)
> >>>>>       if (sps->flags & V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD)
> >>>>>               reg |= G1_REG_DEC_CTRL0_SEQ_MBAFF_E;
> >>>>>       reg |= G1_REG_DEC_CTRL0_PICORD_COUNT_E;
> >>>>> -     if (dec_param->nal_ref_idc)
> >>>>> +     if (sps->profile_idc > 66)
> >>>>>               reg |= G1_REG_DEC_CTRL0_WRITE_MVS_E;
> >>>>>
> >>>>>       if (!(sps->flags & V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY) &&
>

Patch
diff mbox series

diff --git a/drivers/staging/media/hantro/hantro_g1_h264_dec.c b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
index 7ab534936843..c92460407613 100644
--- a/drivers/staging/media/hantro/hantro_g1_h264_dec.c
+++ b/drivers/staging/media/hantro/hantro_g1_h264_dec.c
@@ -35,7 +35,7 @@  static void set_params(struct hantro_ctx *ctx)
 	if (sps->flags & V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD)
 		reg |= G1_REG_DEC_CTRL0_SEQ_MBAFF_E;
 	reg |= G1_REG_DEC_CTRL0_PICORD_COUNT_E;
-	if (dec_param->nal_ref_idc)
+	if (sps->profile_idc > 66)
 		reg |= G1_REG_DEC_CTRL0_WRITE_MVS_E;
 
 	if (!(sps->flags & V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY) &&