Re: [PATCH v4 2/2] media: hevc: Embedded indexes in RPS

[Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>]

On Tue, Jan 04, 2022 at 08:38:42AM +0100, Benjamin Gaignard wrote:
> Reference Picture Set lists provide indexes of short and long term
> reference in DBP array.
> Fix Hantro to not do a look up in DBP entries.
> Make documentation more clear about it.
> 
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>

Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

> ---
>  .../media/v4l/ext-ctrls-codec.rst             |  6 ++---
>  .../staging/media/hantro/hantro_g2_hevc_dec.c | 25 +++++--------------
>  2 files changed, 9 insertions(+), 22 deletions(-)
> 
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> index 38da33e61c3d..b12ad5b3eaba 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> @@ -3381,15 +3381,15 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
>      * - __u8
>        - ``poc_st_curr_before[V4L2_HEVC_DPB_ENTRIES_NUM_MAX]``
>        - PocStCurrBefore as described in section 8.3.2 "Decoding process for reference
> -        picture set.
> +        picture set": provides the index of the short term before references in DPB array.
>      * - __u8
>        - ``poc_st_curr_after[V4L2_HEVC_DPB_ENTRIES_NUM_MAX]``
>        - PocStCurrAfter as described in section 8.3.2 "Decoding process for reference
> -        picture set.
> +        picture set": provides the index of the short term after references in DPB array.
>      * - __u8
>        - ``poc_lt_curr[V4L2_HEVC_DPB_ENTRIES_NUM_MAX]``
>        - PocLtCurr as described in section 8.3.2 "Decoding process for reference
> -        picture set.
> +        picture set": provides the index of the long term references in DPB array.
>      * - __u64
>        - ``flags``
>        - See :ref:`Decode Parameters Flags <hevc_decode_params_flags>`
> diff --git a/drivers/staging/media/hantro/hantro_g2_hevc_dec.c b/drivers/staging/media/hantro/hantro_g2_hevc_dec.c
> index 14e0e6414100..c524af41baf5 100644
> --- a/drivers/staging/media/hantro/hantro_g2_hevc_dec.c
> +++ b/drivers/staging/media/hantro/hantro_g2_hevc_dec.c
> @@ -255,24 +255,11 @@ static void set_params(struct hantro_ctx *ctx)
>  	hantro_reg_write(vpu, &g2_apf_threshold, 8);
>  }
>  
> -static int find_ref_pic_index(const struct v4l2_hevc_dpb_entry *dpb, int pic_order_cnt)
> -{
> -	int i;
> -
> -	for (i = 0; i < V4L2_HEVC_DPB_ENTRIES_NUM_MAX; i++) {
> -		if (dpb[i].pic_order_cnt[0] == pic_order_cnt)
> -			return i;
> -	}
> -
> -	return 0x0;
> -}
> -
>  static void set_ref_pic_list(struct hantro_ctx *ctx)
>  {
>  	const struct hantro_hevc_dec_ctrls *ctrls = &ctx->hevc_dec.ctrls;
>  	struct hantro_dev *vpu = ctx->dev;
>  	const struct v4l2_ctrl_hevc_decode_params *decode_params = ctrls->decode_params;
> -	const struct v4l2_hevc_dpb_entry *dpb = decode_params->dpb;
>  	u32 list0[V4L2_HEVC_DPB_ENTRIES_NUM_MAX] = {};
>  	u32 list1[V4L2_HEVC_DPB_ENTRIES_NUM_MAX] = {};
>  	static const struct hantro_reg ref_pic_regs0[] = {
> @@ -316,11 +303,11 @@ static void set_ref_pic_list(struct hantro_ctx *ctx)
>  	/* List 0 contains: short term before, short term after and long term */
>  	j = 0;
>  	for (i = 0; i < decode_params->num_poc_st_curr_before && j < ARRAY_SIZE(list0); i++)
> -		list0[j++] = find_ref_pic_index(dpb, decode_params->poc_st_curr_before[i]);
> +		list0[j++] = decode_params->poc_st_curr_before[i];
>  	for (i = 0; i < decode_params->num_poc_st_curr_after && j < ARRAY_SIZE(list0); i++)
> -		list0[j++] = find_ref_pic_index(dpb, decode_params->poc_st_curr_after[i]);
> +		list0[j++] = decode_params->poc_st_curr_after[i];
>  	for (i = 0; i < decode_params->num_poc_lt_curr && j < ARRAY_SIZE(list0); i++)
> -		list0[j++] = find_ref_pic_index(dpb, decode_params->poc_lt_curr[i]);
> +		list0[j++] = decode_params->poc_lt_curr[i];
>  
>  	/* Fill the list, copying over and over */
>  	i = 0;
> @@ -329,11 +316,11 @@ static void set_ref_pic_list(struct hantro_ctx *ctx)
>  
>  	j = 0;
>  	for (i = 0; i < decode_params->num_poc_st_curr_after && j < ARRAY_SIZE(list1); i++)
> -		list1[j++] = find_ref_pic_index(dpb, decode_params->poc_st_curr_after[i]);
> +		list1[j++] = decode_params->poc_st_curr_after[i];
>  	for (i = 0; i < decode_params->num_poc_st_curr_before && j < ARRAY_SIZE(list1); i++)
> -		list1[j++] = find_ref_pic_index(dpb, decode_params->poc_st_curr_before[i]);
> +		list1[j++] = decode_params->poc_st_curr_before[i];
>  	for (i = 0; i < decode_params->num_poc_lt_curr && j < ARRAY_SIZE(list1); i++)
> -		list1[j++] = find_ref_pic_index(dpb, decode_params->poc_lt_curr[i]);
> +		list1[j++] = decode_params->poc_lt_curr[i];
>  
>  	i = 0;
>  	while (j < ARRAY_SIZE(list1))
> -- 
> 2.30.2
>