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media: v4l2: Reorder field reflist

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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@collabora.com>
Reviewed-by: Sebastian Fricke <sebastian.fricke@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
This commit is contained in:
Nicolas Dufresne 2022-05-13 22:29:09 +02:00 committed by Mauro Carvalho Chehab
parent 6cafdc8cc0
commit 1b72999863
1 changed files with 42 additions and 0 deletions
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42
drivers/media/v4l2-core/v4l2-h264.c
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@ -250,6 +250,40 @@ 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
* 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) {
@ -360,6 +394,9 @@ 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);
@ -393,6 +430,11 @@ 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]);