From 4ab9b256b5908afbdc030a8c3184ce243f5aca39 Mon Sep 17 00:00:00 2001 From: Andy Walls Date: Sat, 14 Mar 2009 23:20:49 -0300 Subject: 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 Signed-off-by: Mauro Carvalho Chehab diff --git a/drivers/media/video/cx18/cx18-vbi.c b/drivers/media/video/cx18/cx18-vbi.c index 99f9b2c..c2aef4a 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; -- cgit v0.10.2