Skip to content

Commit

Permalink
[media] gspca_zc3xx: Fix JPEG quality setting code
Browse files Browse the repository at this point in the history 
The current code is using bits 0-1 of register 8 of the zc3xx controller
to set the JPEG quality, but the correct bits are bits 1-2. Bit 0 selects
between truncation or rounding in the quantization phase of the compression,
since rounding generally gives better results it should thus always be 1.

This patch also corrects the quality percentages which belong to the 4
different settings.

Last this patch removes the different reg 8 defaults depending on the sensor
type. Some of them where going for a default quality setting of 50%, which
generally is not necessary in any way and results in poor image quality.
75% is a good default to use for all scenarios.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
  • Loading branch information
Hans de Goede authored and Mauro Carvalho Chehab committed May 14, 2012
1 parent fba11fe commit 83fb2e2
Showing 1 changed file with 22 additions and 42 deletions.
64 changes: 22 additions & 42 deletions drivers/media/video/gspca/zc3xx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,7 +32,7 @@ MODULE_LICENSE("GPL");

static int force_sensor = -1;

#define REG08_DEF 3 /* default JPEG compression (70%) */
#define REG08_DEF 3 /* default JPEG compression (75%) */
#include "zc3xx-reg.h"

/* controls */
Expand Down Expand Up @@ -193,10 +193,10 @@ static const struct ctrl sd_ctrls[NCTRLS] = {
.id = V4L2_CID_JPEG_COMPRESSION_QUALITY,
.type = V4L2_CTRL_TYPE_INTEGER,
.name = "Compression Quality",
.minimum = 40,
.maximum = 70,
.minimum = 50,
.maximum = 94,
.step = 1,
.default_value = 70 /* updated in sd_init() */
.default_value = 75,
},
.set = sd_setquality
},
Expand Down Expand Up @@ -241,8 +241,8 @@ static const struct v4l2_pix_format sif_mode[] = {
.priv = 0},
};

/* bridge reg08 -> JPEG quality conversion table */
static u8 jpeg_qual[] = {40, 50, 60, 70, /*80*/};
/* bridge reg08 bits 1-2 -> JPEG quality conversion table */
static u8 jpeg_qual[] = {50, 75, 87, 94};

/* usb exchanges */
struct usb_action {
Expand Down Expand Up @@ -5923,7 +5923,7 @@ static void setquality(struct gspca_dev *gspca_dev)
struct sd *sd = (struct sd *) gspca_dev;
s8 reg07;

jpeg_set_qual(sd->jpeg_hdr, jpeg_qual[sd->reg08]);
jpeg_set_qual(sd->jpeg_hdr, jpeg_qual[sd->reg08 >> 1]);

reg07 = 0;
switch (sd->sensor) {
Expand Down Expand Up @@ -6079,11 +6079,12 @@ static void transfer_update(struct work_struct *work)
struct sd *sd = container_of(work, struct sd, work);
struct gspca_dev *gspca_dev = &sd->gspca_dev;
int change, good;
u8 reg07, reg11;
u8 reg07, qual, reg11;

/* synchronize with the main driver and initialize the registers */
mutex_lock(&gspca_dev->usb_lock);
reg07 = 0; /* max */
qual = sd->reg08 >> 1;
reg_w(gspca_dev, reg07, 0x0007);
reg_w(gspca_dev, sd->reg08, ZC3XX_R008_CLOCKSETTING);
mutex_unlock(&gspca_dev->usb_lock);
Expand All @@ -6109,9 +6110,9 @@ static void transfer_update(struct work_struct *work)
case 0: /* max */
reg07 = sd->sensor == SENSOR_HV7131R
? 0x30 : 0x32;
if (sd->reg08 != 0) {
if (qual != 0) {
change = 3;
sd->reg08--;
qual--;
}
break;
case 0x32:
Expand Down Expand Up @@ -6144,10 +6145,10 @@ static void transfer_update(struct work_struct *work)
}
}
} else { /* reg07 max */
if (sd->reg08 < sizeof jpeg_qual - 1) {
if (qual < sizeof jpeg_qual - 1) {
good++;
if (good > 10) {
sd->reg08++;
qual++;
change = 2;
}
}
Expand All @@ -6162,15 +6163,16 @@ static void transfer_update(struct work_struct *work)
goto err;
}
if (change & 2) {
sd->reg08 = (qual << 1) | 1;
reg_w(gspca_dev, sd->reg08,
ZC3XX_R008_CLOCKSETTING);
if (gspca_dev->usb_err < 0
|| !gspca_dev->present
|| !gspca_dev->streaming)
goto err;
sd->ctrls[QUALITY].val = jpeg_qual[sd->reg08];
sd->ctrls[QUALITY].val = jpeg_qual[qual];
jpeg_set_qual(sd->jpeg_hdr,
jpeg_qual[sd->reg08]);
jpeg_qual[qual]);
}
}
mutex_unlock(&gspca_dev->usb_lock);
Expand Down Expand Up @@ -6562,27 +6564,6 @@ static int sd_init(struct gspca_dev *gspca_dev)
[SENSOR_PO2030] = 1,
[SENSOR_TAS5130C] = 1,
};
static const u8 reg08_tb[SENSOR_MAX] = {
[SENSOR_ADCM2700] = 1,
[SENSOR_CS2102] = 3,
[SENSOR_CS2102K] = 3,
[SENSOR_GC0303] = 2,
[SENSOR_GC0305] = 3,
[SENSOR_HDCS2020] = 1,
[SENSOR_HV7131B] = 3,
[SENSOR_HV7131R] = 3,
[SENSOR_ICM105A] = 3,
[SENSOR_MC501CB] = 3,
[SENSOR_MT9V111_1] = 3,
[SENSOR_MT9V111_3] = 3,
[SENSOR_OV7620] = 1,
[SENSOR_OV7630C] = 3,
[SENSOR_PAS106] = 3,
[SENSOR_PAS202B] = 3,
[SENSOR_PB0330] = 3,
[SENSOR_PO2030] = 2,
[SENSOR_TAS5130C] = 3,
};

sensor = zcxx_probeSensor(gspca_dev);
if (sensor >= 0)
Expand Down Expand Up @@ -6734,8 +6715,7 @@ static int sd_init(struct gspca_dev *gspca_dev)
}

sd->ctrls[GAMMA].def = gamma[sd->sensor];
sd->reg08 = reg08_tb[sd->sensor];
sd->ctrls[QUALITY].def = jpeg_qual[sd->reg08];
sd->ctrls[QUALITY].def = jpeg_qual[sd->reg08 >> 1];
sd->ctrls[QUALITY].min = jpeg_qual[0];
sd->ctrls[QUALITY].max = jpeg_qual[ARRAY_SIZE(jpeg_qual) - 1];

Expand Down Expand Up @@ -7030,17 +7010,17 @@ static int sd_querymenu(struct gspca_dev *gspca_dev,
static int sd_setquality(struct gspca_dev *gspca_dev, __s32 val)
{
struct sd *sd = (struct sd *) gspca_dev;
int i;
int i, qual = sd->reg08 >> 1;

for (i = 0; i < ARRAY_SIZE(jpeg_qual) - 1; i++) {
for (i = 0; i < ARRAY_SIZE(jpeg_qual); i++) {
if (val <= jpeg_qual[i])
break;
}
if (i > 0
&& i == sd->reg08
&& val < jpeg_qual[sd->reg08])
&& i == qual
&& val < jpeg_qual[i])
i--;
sd->reg08 = i;
sd->reg08 = (i << 1) | 1;
sd->ctrls[QUALITY].val = jpeg_qual[i];
if (gspca_dev->streaming)
setquality(gspca_dev);
Expand Down

0 comments on commit 83fb2e2

Please sign in to comment.