From e52a5574de9d3bb297a26566871eabcbdfab13b5 Mon Sep 17 00:00:00 2001 From: Jean-Francois Moine Date: Wed, 3 Sep 2008 16:47:21 -0300 Subject: [PATCH] V4L/DVB (8660): gspca: Simplify the scan of URB packets in pac7311. Signed-off-by: Jean-Francois Moine Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/gspca/pac7311.c | 206 +++++++++++++++------------- 1 file changed, 110 insertions(+), 96 deletions(-) diff --git a/drivers/media/video/gspca/pac7311.c b/drivers/media/video/gspca/pac7311.c index 815bea6edc44..caa33292a08a 100644 --- a/drivers/media/video/gspca/pac7311.c +++ b/drivers/media/video/gspca/pac7311.c @@ -40,7 +40,8 @@ struct sd { unsigned char colors; unsigned char autogain; - char ffseq; + char ffnb; /* number of 'ff' in the previous frame */ + char tosof; /* number of bytes before next start of frame */ signed char ag_cnt; #define AG_CNT_START 13 }; @@ -335,6 +336,10 @@ static int sd_open(struct gspca_dev *gspca_dev) static void sd_start(struct gspca_dev *gspca_dev) { + struct sd *sd = (struct sd *) gspca_dev; + + sd->ffnb = 0; + sd->tosof = 0; reg_w(gspca_dev, 0xff, 0x01); reg_w_buf(gspca_dev, 0x0002, "\x48\x0a\x40\x08\x00\x00\x08\x00", 8); reg_w_buf(gspca_dev, 0x000a, "\x06\xff\x11\xff\x5a\x30\x90\x4c", 8); @@ -511,114 +516,123 @@ static void do_autogain(struct gspca_dev *gspca_dev) } } +/* output the jpeg header */ +static void put_jpeg_head(struct gspca_dev *gspca_dev, + struct gspca_frame *frame) +{ + unsigned char tmpbuf[4]; + + gspca_frame_add(gspca_dev, FIRST_PACKET, frame, + (__u8 *) pac7311_jpeg_header, + 12); + tmpbuf[0] = gspca_dev->height >> 8; + tmpbuf[1] = gspca_dev->height & 0xff; + tmpbuf[2] = gspca_dev->width >> 8; + tmpbuf[3] = gspca_dev->width & 0xff; + gspca_frame_add(gspca_dev, INTER_PACKET, frame, + tmpbuf, 4); + gspca_frame_add(gspca_dev, INTER_PACKET, frame, + (__u8 *) &pac7311_jpeg_header[16], + PAC7311_JPEG_HEADER_SIZE - 16); +} + +/* this function is run at interrupt level */ static void sd_pkt_scan(struct gspca_dev *gspca_dev, struct gspca_frame *frame, /* target */ __u8 *data, /* isoc packet */ int len) /* iso packet length */ { struct sd *sd = (struct sd *) gspca_dev; - unsigned char tmpbuf[4]; - int i, p, ffseq; - -/* if (len < 5) { */ - if (len < 6) { -/* gspca_dev->last_packet_type = DISCARD_PACKET; */ - return; - } - - ffseq = sd->ffseq; - - for (p = 0; p < len - 6; p++) { - if ((data[0 + p] == 0xff) - && (data[1 + p] == 0xff) - && (data[2 + p] == 0x00) - && (data[3 + p] == 0xff) - && (data[4 + p] == 0x96)) { - - /* start of frame */ - if (sd->ag_cnt >= 0 && p > 28) { - sd->lum_sum += data[p - 23]; - if (--sd->ag_cnt < 0) { - sd->ag_cnt = AG_CNT_START; - atomic_set(&sd->avg_lum, - sd->lum_sum / AG_CNT_START); - sd->lum_sum = 0; - atomic_set(&sd->do_gain, 1); + int i; + +#define INTER_FRAME 0x53 +#define LUM_OFFSET 0x1e /* reverse offset / start of frame */ + + /* + * inside a frame, there may be: + * escaped ff ('ff 00') + * sequences'ff ff ff xx' to remove + * end of frame ('ff d9') + * at the end of frame, there are: + * ff d9 end of frame + * 0x33 bytes + * one byte luminosity + * 0x16 bytes + * ff ff 00 ff 96 62 44 start of frame header + */ + + if (sd->tosof == 0) { /* if inside a frame */ + + /* check for 'ff ff ff xx' at start and at end of packet */ + /* (len is always >= 3) */ + switch (sd->ffnb) { + case 1: + if (data[0] != 0xff) + break; /* keep 'ff 00' */ + /* fall thru */ + case 2: + case 3: + data += 4 - sd->ffnb; + len -= 4 - sd->ffnb; + sd->ffnb = 0; + break; + } + if (data[len - 1] == 0xff) { + if (data[len - 2] == 0xff) { + if (data[len - 3] == 0xff) { + sd->ffnb = 3; + len -= 3; + } else { + sd->ffnb = 2; + len -= 2; } + } else { + sd->ffnb = 1; + len--; } - - /* copy the end of data to the current frame */ - frame = gspca_frame_add(gspca_dev, LAST_PACKET, frame, - data, p); - - /* put the JPEG header in the new frame */ - gspca_frame_add(gspca_dev, FIRST_PACKET, frame, - (unsigned char *) pac7311_jpeg_header, - 12); - tmpbuf[0] = gspca_dev->height >> 8; - tmpbuf[1] = gspca_dev->height & 0xff; - tmpbuf[2] = gspca_dev->width >> 8; - tmpbuf[3] = gspca_dev->width & 0xff; - gspca_frame_add(gspca_dev, INTER_PACKET, frame, - tmpbuf, 4); - gspca_frame_add(gspca_dev, INTER_PACKET, frame, - (unsigned char *) &pac7311_jpeg_header[16], - PAC7311_JPEG_HEADER_SIZE - 16); - - data += p + 7; - len -= p + 7; - ffseq = 0; - break; } + } else { /* outside a frame */ + + /* + * get the luminosity + * and go to the start of frame + */ + data += sd->tosof; + len -= sd->tosof; + if (sd->tosof > LUM_OFFSET) + sd->lum_sum += data[-LUM_OFFSET]; + put_jpeg_head(gspca_dev, frame); + sd->tosof = 0; } - /* remove the 'ff ff ff xx' sequences */ - switch (ffseq) { - case 3: - data += 1; - len -= 1; - break; - case 2: - if (data[0] == 0xff) { - data += 2; - len -= 2; - frame->data_end -= 2; - } - break; - case 1: - if (data[0] == 0xff - && data[1] == 0xff) { - data += 3; - len -= 3; - frame->data_end -= 1; - } - break; - } - for (i = 0; i < len - 4; i++) { - if (data[i] == 0xff - && data[i + 1] == 0xff - && data[i + 2] == 0xff) { - memmove(&data[i], &data[i + 4], len - i - 4); - len -= 4; + for (i = 0; i < len; i++) { + if (data[i] != 0xff) + continue; + switch (data[i + 1]) { + case 0xd9: /* end of frame */ + frame = gspca_frame_add(gspca_dev, + LAST_PACKET, + frame, data, i + 1); + data += INTER_FRAME; + len -= INTER_FRAME; + i = 0; + if (len > LUM_OFFSET) + sd->lum_sum += data[-LUM_OFFSET]; + if (len < 0) { + sd->tosof = -len; + break; + } + put_jpeg_head(gspca_dev, frame); + break; + case 0xff: /* 'ff ff ff xx' */ + gspca_frame_add(gspca_dev, INTER_PACKET, + frame, data, i); + data += i + 4; + len -= i + 4; + i = 0; + break; } } - ffseq = 0; - if (data[len - 4] == 0xff) { - if (data[len - 3] == 0xff - && data[len - 2] == 0xff) { - len -= 4; - } - } else if (data[len - 3] == 0xff) { - if (data[len - 2] == 0xff - && data[len - 1] == 0xff) - ffseq = 3; - } else if (data[len - 2] == 0xff) { - if (data[len - 1] == 0xff) - ffseq = 2; - } else if (data[len - 1] == 0xff) - ffseq = 1; - sd->ffseq = ffseq; - gspca_frame_add(gspca_dev, INTER_PACKET, frame, data, len); } static void getbrightness(struct gspca_dev *gspca_dev) -- 2.20.1