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Date: Tue, 2 Jul 2013 13:56:38 +0200
From: Lubomir Rintel <lkundrak@...sk>
To: linux-media@...r.kernel.org
Cc: Lubomir Rintel <lkundrak@...sk>,
Hans Verkuil <hans.verkuil@...co.com>,
Mauro Carvalho Chehab <mchehab@...hat.com>,
linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] [media] usbtv: Fix deinterlacing
The image data is laid out a bit more weirdly and thus needs more work to
properly interlace. What we get from hardware is V4L2_FIELD_ALTERNATE, but
since userspace support for it is practically nonexistent, thus we make
V4L2_FIELD_INTERLACED from it so that it's more easily interpreted.
Signed-off-by: Lubomir Rintel <lkundrak@...sk>
Cc: Hans Verkuil <hans.verkuil@...co.com>
Cc: Mauro Carvalho Chehab <mchehab@...hat.com>
Cc: linux-kernel@...r.kernel.org
Cc: linux-media@...r.kernel.org
---
drivers/media/usb/usbtv/usbtv.c | 36 +++++++++++++++++++++++++-----------
1 files changed, 25 insertions(+), 11 deletions(-)
diff --git a/drivers/media/usb/usbtv/usbtv.c b/drivers/media/usb/usbtv/usbtv.c
index d44fa63..bdb87d7 100644
--- a/drivers/media/usb/usbtv/usbtv.c
+++ b/drivers/media/usb/usbtv/usbtv.c
@@ -57,7 +57,7 @@
#define USBTV_CHUNK_SIZE 256
#define USBTV_CHUNK 240
#define USBTV_CHUNKS (USBTV_WIDTH * USBTV_HEIGHT \
- / 2 / USBTV_CHUNK)
+ / 4 / USBTV_CHUNK)
/* Chunk header. */
#define USBTV_MAGIC_OK(chunk) ((be32_to_cpu(chunk[0]) & 0xff000000) \
@@ -202,6 +202,26 @@ static int usbtv_setup_capture(struct usbtv *usbtv)
return 0;
}
+/* Copy data from chunk into a frame buffer, deinterlacing the data
+ * into every second line. Unfortunately, they don't align nicely into
+ * 720 pixel lines, as the chunk is 240 words long, which is 480 pixels.
+ * Therefore, we break down the chunk into two halves before copyting,
+ * so that we can interleave a line if needed. */
+static void usbtv_chunk_to_vbuf(u32 *frame, u32 *src, int chunk_no, int odd)
+{
+ int half;
+
+ for (half = 0; half < 2; half++) {
+ int part_no = chunk_no * 2 + half;
+ int line = part_no / 3;
+ int part_index = (line * 2 + !odd) * 3 + (part_no % 3);
+
+ u32 *dst = &frame[part_index * USBTV_CHUNK/2];
+ memcpy(dst, src, USBTV_CHUNK/2 * sizeof(*src));
+ src += USBTV_CHUNK/2;
+ }
+}
+
/* Called for each 256-byte image chunk.
* First word identifies the chunk, followed by 240 words of image
* data and padding. */
@@ -218,11 +238,6 @@ static void usbtv_image_chunk(struct usbtv *usbtv, u32 *chunk)
frame_id = USBTV_FRAME_ID(chunk);
odd = USBTV_ODD(chunk);
chunk_no = USBTV_CHUNK_NO(chunk);
-
- /* Deinterlace. TODO: Use interlaced frame format. */
- chunk_no = (chunk_no - chunk_no % 3) * 2 + chunk_no % 3;
- chunk_no += !odd * 3;
-
if (chunk_no >= USBTV_CHUNKS)
return;
@@ -241,12 +256,11 @@ static void usbtv_image_chunk(struct usbtv *usbtv, u32 *chunk)
buf = list_first_entry(&usbtv->bufs, struct usbtv_buf, list);
frame = vb2_plane_vaddr(&buf->vb, 0);
- /* Copy the chunk. */
- memcpy(&frame[chunk_no * USBTV_CHUNK], &chunk[1],
- USBTV_CHUNK * sizeof(chunk[1]));
+ /* Copy the chunk data. */
+ usbtv_chunk_to_vbuf(frame, &chunk[1], chunk_no, odd);
/* Last chunk in a frame, signalling an end */
- if (usbtv->frame_id && chunk_no == USBTV_CHUNKS-1) {
+ if (odd && chunk_no == USBTV_CHUNKS-1) {
int size = vb2_plane_size(&buf->vb, 0);
buf->vb.v4l2_buf.field = V4L2_FIELD_INTERLACED;
@@ -518,7 +532,7 @@ static int usbtv_queue_setup(struct vb2_queue *vq,
if (*nbuffers == 0)
*nbuffers = 2;
*nplanes = 1;
- sizes[0] = USBTV_CHUNK * USBTV_CHUNKS * sizeof(u32);
+ sizes[0] = USBTV_WIDTH * USBTV_HEIGHT / 2 * sizeof(u32);
return 0;
}
--
1.7.1
--
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