Re: [PATCH v1 04/24] media: h264: Store current picture fields

Sebastian Fricke
2022-03-29T09:07:42Z

Hey Nicolas,

On 28.03.2022 15:59, Nicolas Dufresne wrote:
>This information, also called picture structure will be needed to construct

s/picture structure/picture structure,/
(minor.. but still ;))

>reference list when decoding field.

s/will be needed to construct reference list when decoding field./
is required in field decoding mode to construct reference lists./

>
>Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Sebastian Fricke <sebastian.fricke@collabora.com>

>---
> drivers/media/v4l2-core/v4l2-h264.c | 10 +++++++---
> include/media/v4l2-h264.h | 4 ++++
> 2 files changed, 11 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/media/v4l2-core/v4l2-h264.c b/drivers/media/v4l2-core/v4l2-h264.c
>index aebed1cbe05a..4c6bfb057bda 100644
>--- a/drivers/media/v4l2-core/v4l2-h264.c
>+++ b/drivers/media/v4l2-core/v4l2-h264.c
>@@ -34,13 +34,17 @@ v4l2_h264_init_reflist_builder(struct v4l2_h264_reflist_builder *b,
> cur_frame_num = dec_params->frame_num;
>
> memset(b, 0, sizeof(*b));
>- if (!(dec_params->flags & V4L2_H264_DECODE_PARAM_FLAG_FIELD_PIC))
>+ if (!(dec_params->flags & V4L2_H264_DECODE_PARAM_FLAG_FIELD_PIC)) {
> b->cur_pic_order_count = min(dec_params->bottom_field_order_cnt,
> dec_params->top_field_order_cnt);
>- else if (dec_params->flags & V4L2_H264_DECODE_PARAM_FLAG_BOTTOM_FIELD)
>+ b->cur_pic_fields = V4L2_H264_FRAME_REF;
>+ } else if (dec_params->flags & V4L2_H264_DECODE_PARAM_FLAG_BOTTOM_FIELD) {
> b->cur_pic_order_count = dec_params->bottom_field_order_cnt;
>- else
>+ b->cur_pic_fields = V4L2_H264_BOTTOM_FIELD_REF;
>+ } else {
> b->cur_pic_order_count = dec_params->top_field_order_cnt;
>+ b->cur_pic_fields = V4L2_H264_TOP_FIELD_REF;
>+ }
>
> for (i = 0; i < V4L2_H264_NUM_DPB_ENTRIES; i++) {
> u32 pic_order_count;
>diff --git a/include/media/v4l2-h264.h b/include/media/v4l2-h264.h
>index e282fb16ac58..e165a54c68fa 100644
>--- a/include/media/v4l2-h264.h
>+++ b/include/media/v4l2-h264.h
>@@ -21,6 +21,7 @@
> * @refs.longterm: set to true for a long term reference
> * @refs: array of references
> * @cur_pic_order_count: picture order count of the frame being decoded
>+ * @cur_pic_fields: fields present in the frame being decoded

As there are only three choices:
```
#define V4L2_H264_TOP_FIELD_REF 0x1
#define V4L2_H264_BOTTOM_FIELD_REF 0x2
#define V4L2_H264_FRAME_REF 0x3
```

Maybe it would help to say:
* @cur_pic_fields: fields present in the frame being decoded (top/bottom/both)

Greetings,
Sebastian

> * @unordered_reflist: unordered list of references. Will be used to generate
> * ordered P/B0/B1 lists
> * @num_valid: number of valid references in the refs array
>@@ -36,7 +37,10 @@ struct v4l2_h264_reflist_builder {
> u32 pic_num;
> u16 longterm : 1;
> } refs[V4L2_H264_NUM_DPB_ENTRIES];
>+
> s32 cur_pic_order_count;
>+ u8 cur_pic_fields;
>+
> struct v4l2_h264_reference unordered_reflist[V4L2_H264_REF_LIST_LEN];
> u8 num_valid;
> };
>--
>2.34.1
>