On 05/04/2022 22:44, Nicolas Dufresne wrote:
> As per spec, the field reflist requires interleaving top and bottom
> field in a specific way that does not fit inside the sort operation.
> The process consist of alternating references parity, starting with
> a reference of the same parity as the current picture. This
> processs is done twice, once for short term references and a second
> time for the long term references.
>
> Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
> Reviewed-by: Sebastian Fricke <sebastian.fricke@xxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-h264.c | 42 +++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-h264.c b/drivers/media/v4l2-core/v4l2-h264.c
> index 7e1eba03099a..d2d1f3bed7e8 100644
> --- a/drivers/media/v4l2-core/v4l2-h264.c
> +++ b/drivers/media/v4l2-core/v4l2-h264.c
> @@ -244,6 +244,40 @@ static int v4l2_h264_b1_ref_list_cmp(const void *ptra, const void *ptrb,
> return poca < pocb ? -1 : 1;
> }
>
> +/*
> + * The references need to be reordered so that references are alternating
> + * between top and bottom field references starting with the current picture
> + * parity. This has to be * done for short term and long term references
^
Spurious *.
Regards,
Hans
> + * separately.
> + */
> +static void reorder_field_reflist(const struct v4l2_h264_reflist_builder *b,
> + struct v4l2_h264_reference *reflist)
> +{
> + struct v4l2_h264_reference tmplist[V4L2_H264_REF_LIST_LEN];
> + u8 lt, i = 0, j = 0, k = 0;
> +
> + memcpy(tmplist, reflist, sizeof(tmplist[0]) * b->num_valid);
> +
> + for (lt = 0; lt <= 1; lt++) {
> + do {
> + for (; i < b->num_valid && b->refs[tmplist[i].index].longterm == lt; i++) {
> + if (tmplist[i].fields == b->cur_pic_fields) {
> + reflist[k++] = tmplist[i++];
> + break;
> + }
> + }
> +
> + for (; j < b->num_valid && b->refs[tmplist[j].index].longterm == lt; j++) {
> + if (tmplist[j].fields != b->cur_pic_fields) {
> + reflist[k++] = tmplist[j++];
> + break;
> + }
> + }
> + } while ((i < b->num_valid && b->refs[tmplist[i].index].longterm == lt) ||
> + (j < b->num_valid && b->refs[tmplist[j].index].longterm == lt));
> + }
> +}
> +
> static char ref_type_to_char (u8 ref_type)
> {
> switch (ref_type) {
> @@ -346,6 +380,9 @@ v4l2_h264_build_p_ref_list(const struct v4l2_h264_reflist_builder *builder,
> sort_r(reflist, builder->num_valid, sizeof(*reflist),
> v4l2_h264_p_ref_list_cmp, NULL, builder);
>
> + if (builder->cur_pic_fields != V4L2_H264_FRAME_REF)
> + reorder_field_reflist(builder, reflist);
> +
> print_ref_list_p(builder, reflist);
> }
> EXPORT_SYMBOL_GPL(v4l2_h264_build_p_ref_list);
> @@ -379,6 +416,11 @@ v4l2_h264_build_b_ref_lists(const struct v4l2_h264_reflist_builder *builder,
> sort_r(b1_reflist, builder->num_valid, sizeof(*b1_reflist),
> v4l2_h264_b1_ref_list_cmp, NULL, builder);
>
> + if (builder->cur_pic_fields != V4L2_H264_FRAME_REF) {
> + reorder_field_reflist(builder, b0_reflist);
> + reorder_field_reflist(builder, b1_reflist);
> + }
> +
> if (builder->num_valid > 1 &&
> !memcmp(b1_reflist, b0_reflist, builder->num_valid))
> swap(b1_reflist[0], b1_reflist[1]);
