V4L/DVB (11040): gspca - most jpeg subdrivers: Have the JPEG quality settable.

The JPEG quality of the images (quantization tables) is now settable by the
VIDIOC_S_JPEGCOMP ioctl.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/gspca/mars.c b/drivers/media/video/gspca/mars.c
index 6eb813e..75e8d14 100644
--- a/drivers/media/video/gspca/mars.c
+++ b/drivers/media/video/gspca/mars.c
@@ -37,6 +37,9 @@
 	u8 gamma;
 	u8 sharpness;
 	u8 quality;
+#define QUALITY_MIN 40
+#define QUALITY_MAX 70
+#define QUALITY_DEF 50
 
 	u8 *jpeg_hdr;
 };
@@ -178,7 +181,7 @@
 	sd->colors = COLOR_DEF;
 	sd->gamma = GAMMA_DEF;
 	sd->sharpness = SHARPNESS_DEF;
-	sd->quality = 50;
+	sd->quality = QUALITY_DEF;
 	gspca_dev->nbalt = 9;		/* use the altsetting 08 */
 	return 0;
 }
@@ -445,6 +448,34 @@
 	return 0;
 }
 
+static int sd_set_jcomp(struct gspca_dev *gspca_dev,
+			struct v4l2_jpegcompression *jcomp)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	if (jcomp->quality < QUALITY_MIN)
+		sd->quality = QUALITY_MIN;
+	else if (jcomp->quality > QUALITY_MAX)
+		sd->quality = QUALITY_MAX;
+	else
+		sd->quality = jcomp->quality;
+	if (gspca_dev->streaming)
+		jpeg_set_qual(sd->jpeg_hdr, sd->quality);
+	return 0;
+}
+
+static int sd_get_jcomp(struct gspca_dev *gspca_dev,
+			struct v4l2_jpegcompression *jcomp)
+{
+	struct sd *sd = (struct sd *) gspca_dev;
+
+	memset(jcomp, 0, sizeof *jcomp);
+	jcomp->quality = sd->quality;
+	jcomp->jpeg_markers = V4L2_JPEG_MARKER_DHT
+			| V4L2_JPEG_MARKER_DQT;
+	return 0;
+}
+
 /* sub-driver description */
 static const struct sd_desc sd_desc = {
 	.name = MODULE_NAME,
@@ -456,6 +487,8 @@
 	.stopN = sd_stopN,
 	.stop0 = sd_stop0,
 	.pkt_scan = sd_pkt_scan,
+	.get_jcomp = sd_get_jcomp,
+	.set_jcomp = sd_set_jcomp,
 };
 
 /* -- module initialisation -- */