[PATCH 3/3] media: cedrus: h264: Fix frame list construction

[Jernej Skrabec]

Current frame list construction algorithm assumes that decoded image
will be output into its own buffer. That is true for progressive content
but not for interlaced where each field is decoded separately into same
buffer.

Fix that by checking if capture buffer is listed in DPB. If it is, reuse
it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
---
 drivers/staging/media/sunxi/cedrus/cedrus_h264.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c
index c87717d17ec5..4f79386315ae 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c
@@ -102,7 +102,7 @@ static void cedrus_write_frame_list(struct cedrus_ctx *ctx,
 	struct cedrus_dev *dev = ctx->dev;
 	unsigned long used_dpbs = 0;
 	unsigned int position;
-	unsigned int output = 0;
+	int output = -1;
 	unsigned int i;
 
 	cap_q = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
@@ -125,6 +125,11 @@ static void cedrus_write_frame_list(struct cedrus_ctx *ctx,
 		position = cedrus_buf->codec.h264.position;
 		used_dpbs |= BIT(position);
 
+		if (run->dst->vb2_buf.timestamp == dpb->reference_ts) {
+			output = position;
+			continue;
+		}
+
 		if (!(dpb->flags & V4L2_H264_DPB_ENTRY_FLAG_ACTIVE))
 			continue;
 
@@ -132,13 +137,11 @@ static void cedrus_write_frame_list(struct cedrus_ctx *ctx,
 				    dpb->top_field_order_cnt,
 				    dpb->bottom_field_order_cnt,
 				    &pic_list[position]);
-
-		output = max(position, output);
 	}
 
-	position = find_next_zero_bit(&used_dpbs, CEDRUS_H264_FRAME_NUM,
-				      output);
-	if (position >= CEDRUS_H264_FRAME_NUM)
+	if (output >= 0)
+		position = output;
+	else
 		position = find_first_zero_bit(&used_dpbs, CEDRUS_H264_FRAME_NUM);
 
 	output_buf = vb2_to_cedrus_buffer(&run->dst->vb2_buf);
-- 
2.27.0