From: Márton Németh <[email protected]> Add comment about the meaning of the fixed JPEG header bytes used to create each image.
The change was tested with Labtec Webcam 2200. Signed-off-by: Márton Németh <[email protected]> --- diff -upr e/drivers/media/video/gspca/pac7311.c f/drivers/media/video/gspca/pac7311.c --- e/drivers/media/video/gspca/pac7311.c 2009-10-03 16:23:37.000000000 +0200 +++ f/drivers/media/video/gspca/pac7311.c 2009-10-03 19:56:21.000000000 +0200 @@ -801,13 +801,32 @@ static void do_autogain(struct gspca_dev sd->autogain_ignore_frames = PAC_AUTOGAIN_IGNORE_FRAMES; } +/* JPEG header, part 1 */ static const unsigned char pac7311_jpeg_header1[] = { - 0xff, 0xd8, 0xff, 0xc0, 0x00, 0x11, 0x08 + 0xff, 0xd8, /* SOI: Start of Image */ + + 0xff, 0xc0, /* SOF0: Start of Frame (Baseline DCT) */ + 0x00, 0x11, /* length = 17 bytes (including this length field) */ + 0x08 /* Precision: 8 */ + /* 2 bytes is placed here: number of image lines */ + /* 2 bytes is placed here: samples per line */ }; +/* JPEG header, continued */ static const unsigned char pac7311_jpeg_header2[] = { - 0x03, 0x01, 0x21, 0x00, 0x02, 0x11, 0x01, 0x03, 0x11, 0x01, 0xff, 0xda, - 0x00, 0x0c, 0x03, 0x01, 0x00, 0x02, 0x11, 0x03, 0x11, 0x00, 0x3f, 0x00 + 0x03, /* Number of image components: 3 */ + 0x01, 0x21, 0x00, /* ID=1, Subsampling 1x1, Quantization table: 0 */ + 0x02, 0x11, 0x01, /* ID=2, Subsampling 2x1, Quantization table: 1 */ + 0x03, 0x11, 0x01, /* ID=3, Subsampling 2x1, Quantization table: 1 */ + + 0xff, 0xda, /* SOS: Start Of Scan */ + 0x00, 0x0c, /* length = 12 bytes (including this length field) */ + 0x03, /* number of components: 3 */ + 0x01, 0x00, /* selector 1, table 0x00 */ + 0x02, 0x11, /* selector 2, table 0x11 */ + 0x03, 0x11, /* selector 3, table 0x11 */ + 0x00, 0x3f, /* Spectral selection: 0 .. 63 */ + 0x00 /* Successive approximation: 0 */ }; /* this function is run at interrupt level */ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
