Commit 1b729998 authored by Nicolas Dufresne's avatar Nicolas Dufresne Committed by Mauro Carvalho Chehab
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media: v4l2: Reorder field reflist 



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: default avatarNicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: default avatarSebastian Fricke <sebastian.fricke@collabora.com>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent 6cafdc8c

drivers/media/v4l2-core/v4l2-h264.c

+42 −0
Original line number Diff line number Diff line
@@ -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]);