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authorAndy Walls <awalls@radix.net>2009-03-14 23:20:49 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-03-30 12:43:28 -0300
commit4ab9b256b5908afbdc030a8c3184ce243f5aca39 (patch)
tree25f604c5794dbae544a6a42c90e4c37ac77082c5
parent6e1a63720228ef7fc3bd00b04dfb608064fbab4e (diff)
V4L/DVB (11092): cx18: Optimize processing of VBI buffers from the capture unit
Removed some unnecessary memcpy()'s by reworking the compress_*_vbi_buf() functions. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/media/video/cx18/cx18-vbi.c103
1 files changed, 49 insertions, 54 deletions
diff --git a/drivers/media/video/cx18/cx18-vbi.c b/drivers/media/video/cx18/cx18-vbi.c
index 99f9b2c86b0..c2aef4add31 100644
--- a/drivers/media/video/cx18/cx18-vbi.c
+++ b/drivers/media/video/cx18/cx18-vbi.c
@@ -105,54 +105,72 @@ static void copy_vbi_data(struct cx18 *cx, int lines, u32 pts_stamp)
/* Compress raw VBI format, removes leading SAV codes and surplus space
after the frame. Returns new compressed size. */
-static u32 compress_raw_buf(struct cx18 *cx, u8 *buf, u32 size)
+static u32 compress_raw_buf(struct cx18 *cx, u8 *buf, u32 size, u32 hdr_size)
{
u32 line_size = vbi_active_samples;
u32 lines = cx->vbi.count * 2;
- u8 sav1 = raw_vbi_sav_rp[0];
- u8 sav2 = raw_vbi_sav_rp[1];
u8 *q = buf;
u8 *p;
int i;
+ /* Skip the header */
+ buf += hdr_size;
+
for (i = 0; i < lines; i++) {
p = buf + i * line_size;
/* Look for SAV code */
if (p[0] != 0xff || p[1] || p[2] ||
- (p[3] != sav1 && p[3] != sav2))
+ (p[3] != raw_vbi_sav_rp[0] &&
+ p[3] != raw_vbi_sav_rp[1]))
break;
- memcpy(q, p + 4, line_size - 4);
- q += line_size - 4;
+ if (i == lines - 1) {
+ /* last line is hdr_size bytes short - extrapolate it */
+ memcpy(q, p + 4, line_size - 4 - hdr_size);
+ q += line_size - 4 - hdr_size;
+ p += line_size - hdr_size - 1;
+ memset(q, (int) *p, hdr_size);
+ } else {
+ memcpy(q, p + 4, line_size - 4);
+ q += line_size - 4;
+ }
}
return lines * (line_size - 4);
}
-
-/* Compressed VBI format, all found sliced blocks put next to one another
- Returns new compressed size */
-static u32 compress_sliced_buf(struct cx18 *cx, u32 line, u8 *buf,
- u32 size, u8 eav)
+static u32 compress_sliced_buf(struct cx18 *cx, u8 *buf, u32 size,
+ const u32 hdr_size)
{
struct v4l2_decode_vbi_line vbi;
int i;
+ u32 line = 0;
u32 line_size = cx->is_60hz ? vbi_hblank_samples_60Hz
: vbi_hblank_samples_50Hz;
/* find the first valid line */
- for (i = 0; i < size; i++, buf++) {
- if (buf[0] == 0xff && !buf[1] && !buf[2] && buf[3] == eav)
+ for (i = hdr_size, buf += hdr_size; i < size; i++, buf++) {
+ if (buf[0] == 0xff && !buf[1] && !buf[2] &&
+ (buf[3] == sliced_vbi_eav_rp[0] ||
+ buf[3] == sliced_vbi_eav_rp[1]))
break;
}
- size -= i;
+ /*
+ * The last line is short by hdr_size bytes, but for the remaining
+ * checks against size, we pretend that it is not, by counting the
+ * header bytes we knowingly skipped
+ */
+ size -= (i - hdr_size);
if (size < line_size)
return line;
+
for (i = 0; i < size / line_size; i++) {
u8 *p = buf + i * line_size;
/* Look for EAV code */
- if (p[0] != 0xff || p[1] || p[2] || p[3] != eav)
+ if (p[0] != 0xff || p[1] || p[2] ||
+ (p[3] != sliced_vbi_eav_rp[0] &&
+ p[3] != sliced_vbi_eav_rp[1]))
continue;
vbi.p = p + 4;
v4l2_subdev_call(cx->sd_av, video, decode_vbi_line, &vbi);
@@ -170,8 +188,17 @@ static u32 compress_sliced_buf(struct cx18 *cx, u32 line, u8 *buf,
void cx18_process_vbi_data(struct cx18 *cx, struct cx18_buffer *buf,
int streamtype)
{
+ /*
+ * The CX23418 provides a 12 byte header in its raw VBI buffers to us:
+ * 0x3fffffff [4 bytes of something] [4 byte presentation time stamp]
+ */
+ struct vbi_data_hdr {
+ __be32 magic;
+ __be32 unknown;
+ __be32 pts;
+ } *hdr = (struct vbi_data_hdr *) buf->buf;
+
u8 *p = (u8 *) buf->buf;
- __be32 *q = (__be32 *) buf->buf;
u32 size = buf->bytesused;
u32 pts;
int lines;
@@ -182,32 +209,15 @@ void cx18_process_vbi_data(struct cx18 *cx, struct cx18_buffer *buf,
/*
* The CX23418 sends us data that is 32 bit little-endian swapped,
* but we want the raw VBI bytes in the order they were in the raster
- * line. This has a side effect of making the 12 byte header big endian
+ * line. This has a side effect of making the header big endian
*/
cx18_buf_swap(buf);
- /*
- * The CX23418 provides a 12 byte header in it's raw VBI buffers to us:
- * 0x3fffffff [4 bytes of something] [4 byte presentation time stamp?]
- */
-
/* Raw VBI data */
if (cx18_raw_vbi(cx)) {
- u8 type;
-
- /*
- * We've set up to get a frame's worth of VBI data at a time.
- * Skip 12 bytes of header prefixing the first field.
- */
- size -= 12;
- memcpy(p, &buf->buf[12], size);
- type = p[3];
- /* Extrapolate the last 12 bytes of the frame's last line */
- memset(&p[size], (int) p[size - 1], 12);
- size += 12;
-
- size = buf->bytesused = compress_raw_buf(cx, p, size);
+ size = buf->bytesused =
+ compress_raw_buf(cx, p, size, sizeof(struct vbi_data_hdr));
/*
* Hack needed for compatibility with old VBI software.
@@ -221,26 +231,11 @@ void cx18_process_vbi_data(struct cx18 *cx, struct cx18_buffer *buf,
/* Sliced VBI data with data insertion */
- pts = (be32_to_cpu(q[0]) == 0x3fffffff) ? be32_to_cpu(q[2]) : 0;
+ pts = (be32_to_cpu(hdr->magic) == 0x3fffffff) ? be32_to_cpu(hdr->pts)
+ : 0;
- /*
- * For calls to compress_sliced_buf(), ensure there are an integral
- * number of lines by shifting the real data up over the 12 bytes header
- * that got stuffed in.
- * FIXME - there's a smarter way to do this with pointers, but for some
- * reason I can't get it to work correctly right now.
- */
- memcpy(p, &buf->buf[12], size-12);
+ lines = compress_sliced_buf(cx, p, size, sizeof(struct vbi_data_hdr));
- /* first field */
- lines = compress_sliced_buf(cx, 0, p, size / 2, sliced_vbi_eav_rp[0]);
- /*
- * second field
- * In case the second half does not always begin at the exact address,
- * start a bit earlier (hence 32).
- */
- lines = compress_sliced_buf(cx, lines, p + size / 2 - 32,
- size / 2 + 32, sliced_vbi_eav_rp[1]);
/* always return at least one empty line */
if (lines == 0) {
cx->vbi.sliced_data[0].id = 0;