[PATCH v4 15/19] media: cedrus: h264: Fix frame list construction

[Ezequiel Garcia <ezequiel@collabora.com>]

From: Jernej Skrabec <jernej.skrabec@siol.net>

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@siol.net>
---
 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 1e89a8438f36..fe041b444385 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c
@@ -101,7 +101,7 @@ 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);
@@ -124,6 +124,11 @@ 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;
 
@@ -131,13 +136,11 @@ 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