At Mon, 04 Sep 2006 15:31:31 +0200,
I wrote:
>
> At Mon, 04 Sep 2006 13:40:13 +0100,
> James Courtier-Dutton wrote:
> >
> > Takashi Iwai wrote:
> > > Hi,
> > >
> > > I found that some hardwares require the combination of dB scale
> > > ranges. For example, es1938 has volume controls with two curves,
> > > e.g. the volume step in the value 0-8 is 3 dB while it's 1.5 dB in the
> > > values 8-15.
> > >
> > > The patch below introduces a new TLV type, DB_RANGE, to implement
> > > the compound dB scales. It can contain one or more child TLVs,
> > > together with min and max values for each.
> > >
> > > The first patch is for the kernel and the second for alsa-lib.
> > >
> > > Any comments?
> > >
> > >
> > > Takashi
> > >
> > +static int do_convert_to_dB(unsigned int *tlv, long rangemin, long
> > rangemax,
> > + long volume, long *db_gain)
> > +{
> > + switch (tlv[0]) {
> > + case SND_CTL_TLVT_DB_RANGE: {
> > + unsigned int pos, len;
> > + len = tlv[1] / sizeof(int);
> > + pos = 2;
> >
> > Be careful with this len limit in the while loop. I suggest adding a
> > further comparison to limit the loop to a constant size:
> > e.g.
> > while (pos + 4 <= len && (pos + 4 < MAX_BUFFER_SIZE) ) {
> > There are similar cases elsewhere in the patch.
>
> Yes, it'd be safer. Will fix them.
The below is the fixed version.
Takashi
diff -r 0c766669b691 include/control.h
--- a/include/control.h Thu Aug 31 10:06:08 2006 +0200
+++ b/include/control.h Fri Sep 01 19:12:02 2006 +0200
@@ -172,6 +172,8 @@ typedef enum _snd_ctl_event_type {
#define SND_CTL_TLVT_DB_SCALE 0x0001
/** TLV type - linear volume */
#define SND_CTL_TLVT_DB_LINEAR 0x0002
+/** TLV type - dB range container */
+#define SND_CTL_TLVT_DB_RANGE 0x0003
/** Mute state */
#define SND_CTL_TLV_DB_GAIN_MUTE -9999999
diff -r 0c766669b691 src/mixer/simple_none.c
--- a/src/mixer/simple_none.c Thu Aug 31 10:06:08 2006 +0200
+++ b/src/mixer/simple_none.c Mon Sep 04 16:54:31 2006 +0200
@@ -974,6 +974,9 @@ static int init_db_range(snd_hctl_elem_t
/* convert to index of integer array */
#define int_index(size) (((size) + sizeof(int) - 1) / sizeof(int))
+/* max size of a TLV entry for dB information (including compound one) */
+#define MAX_TLV_RANGE_SIZE 256
+
/* parse TLV stream and retrieve dB information
* return 0 if successly found and stored to rec,
* return 1 if no information is found,
@@ -1011,8 +1014,18 @@ static int parse_db_range(struct selem_s
#ifndef HAVE_SOFT_FLOAT
case SND_CTL_TLVT_DB_LINEAR:
#endif
- if (size < 2 * sizeof(int)) {
+ case SND_CTL_TLVT_DB_RANGE: {
+ unsigned int minsize;
+ if (type == SND_CTL_TLVT_DB_RANGE)
+ minsize = 4 * sizeof(int);
+ else
+ minsize = 2 * sizeof(int);
+ if (size < minsize) {
SNDERR("Invalid dB_scale TLV size");
+ return -EINVAL;
+ }
+ if (size > MAX_TLV_RANGE_SIZE) {
+ SNDERR("Too big dB_scale TLV size: %d", size);
return -EINVAL;
}
rec->db_info = malloc(size + sizeof(int) * 2);
@@ -1020,6 +1033,7 @@ static int parse_db_range(struct selem_s
return -ENOMEM;
memcpy(rec->db_info, tlv, size + sizeof(int) * 2);
return 0;
+ }
default:
break;
}
@@ -1029,35 +1043,49 @@ static int parse_db_range(struct selem_s
/* convert the given raw volume value to a dB gain
*/
-static int convert_to_dB(snd_hctl_elem_t *ctl, struct selem_str *rec,
- long volume, long *db_gain)
-{
- if (init_db_range(ctl, rec) < 0)
+static int do_convert_to_dB(unsigned int *tlv, long rangemin, long rangemax,
+ long volume, long *db_gain)
+{
+ switch (tlv[0]) {
+ case SND_CTL_TLVT_DB_RANGE: {
+ unsigned int pos, len;
+ len = tlv[1] / sizeof(int);
+ if (len > MAX_TLV_RANGE_SIZE)
+ return -EINVAL;
+ pos = 2;
+ while (pos + 4 <= len) {
+ rangemin = (int)tlv[pos];
+ rangemax = (int)tlv[pos + 1];
+ if (volume >= rangemin && volume <= rangemax)
+ return do_convert_to_dB(tlv + pos + 2,
+ rangemin, rangemax,
+ volume, db_gain);
+ pos += tlv[pos + 3] + 4;
+ }
return -EINVAL;
-
- switch (rec->db_info[0]) {
+ }
case SND_CTL_TLVT_DB_SCALE: {
int min, step, mute;
- min = rec->db_info[2];
- step = (rec->db_info[3] & 0xffff);
- mute = (rec->db_info[3] >> 16) & 1;
- if (mute && volume == rec->min)
+ min = tlv[2];
+ step = (tlv[3] & 0xffff);
+ mute = (tlv[3] >> 16) & 1;
+ if (mute && volume == rangemin)
*db_gain = SND_CTL_TLV_DB_GAIN_MUTE;
else
- *db_gain = (volume - rec->min) * step + min;
+ *db_gain = (volume - rangemin) * step + min;
return 0;
}
#ifndef HAVE_SOFT_FLOAT
case SND_CTL_TLVT_DB_LINEAR: {
- int mindb = rec->db_info[2];
- int maxdb = rec->db_info[3];
- if (volume <= rec->min || rec->max <= rec->min)
+ int mindb = tlv[2];
+ int maxdb = tlv[3];
+ if (volume <= rangemin || rangemax <= rangemin)
*db_gain = mindb;
- else if (volume >= rec->max)
+ else if (volume >= rangemax)
*db_gain = maxdb;
else {
- double val = (double)(volume - rec->min) /
- (double)(rec->max - rec->min);
+ double val = (double)(volume - rangemin) /
+ (double)(rangemax - rangemin);
if (mindb <= SND_CTL_TLV_DB_GAIN_MUTE)
*db_gain = (long)(100.0 * 20.0 * log10(val)) +
maxdb;
@@ -1074,6 +1102,15 @@ static int convert_to_dB(snd_hctl_elem_t
#endif
}
return -EINVAL;
+}
+
+static int convert_to_dB(snd_hctl_elem_t *ctl, struct selem_str *rec,
+ long volume, long *db_gain)
+{
+ if (init_db_range(ctl, rec) < 0)
+ return -EINVAL;
+ return do_convert_to_dB(rec->db_info, rec->min, rec->max,
+ volume, db_gain);
}
/* initialize dB range information, reading TLV via hcontrol
@@ -1133,26 +1170,57 @@ static selem_ctl_t *get_selem_ctl(selem_
/* Get the dB min/max values
*/
+static int do_get_dB_range(unsigned int *tlv, long rangemin, long rangemax,
+ long *min, long *max)
+{
+ switch (tlv[0]) {
+ case SND_CTL_TLVT_DB_RANGE: {
+ unsigned int pos, len;
+ len = tlv[1] / sizeof(int);
+ if (len > MAX_TLV_RANGE_SIZE)
+ return -EINVAL;
+ pos = 2;
+ while (pos + 4 <= len) {
+ long rmin, rmax;
+ rangemin = (int)tlv[pos];
+ rangemax = (int)tlv[pos + 1];
+ do_get_dB_range(tlv + pos + 2, rangemin, rangemax,
+ &rmin, &rmax);
+ if (pos > 2) {
+ if (rmin < *min)
+ *min = rmin;
+ if (rmax > *max)
+ *max = rmax;
+ } else {
+ *min = rmin;
+ *max = rmax;
+ }
+ pos += tlv[pos + 3] + 4;
+ }
+ return 0;
+ }
+ case SND_CTL_TLVT_DB_SCALE: {
+ int step;
+ *min = (int)tlv[2];
+ step = (tlv[3] & 0xffff);
+ *max = *min + (long)(step * (rangemax - rangemin));
+ return 0;
+ }
+ case SND_CTL_TLVT_DB_LINEAR:
+ *min = (int)tlv[2];
+ *max = (int)tlv[3];
+ return 0;
+ }
+ return -EINVAL;
+}
+
static int get_dB_range(snd_hctl_elem_t *ctl, struct selem_str *rec,
long *min, long *max)
{
- int step;
-
if (init_db_range(ctl, rec) < 0)
return -EINVAL;
- switch (rec->db_info[0]) {
- case SND_CTL_TLVT_DB_SCALE:
- *min = (int)rec->db_info[2];
- step = (rec->db_info[3] & 0xffff);
- *max = *min + (long)(step * (rec->max - rec->min));
- return 0;
- case SND_CTL_TLVT_DB_LINEAR:
- *min = (int)rec->db_info[2];
- *max = (int)rec->db_info[3];
- return 0;
- }
- return -EINVAL;
+ return do_get_dB_range(rec->db_info, rec->min, rec->max, min, max);
}
static int get_dB_range_ops(snd_mixer_elem_t *elem, int dir,
@@ -1160,7 +1228,6 @@ static int get_dB_range_ops(snd_mixer_el
{
selem_none_t *s = snd_mixer_elem_get_private(elem);
selem_ctl_t *c;
- int err;
c = get_selem_ctl(s, dir);
if (! c)
@@ -1171,27 +1238,44 @@ static int get_dB_range_ops(snd_mixer_el
/* Convert from dB gain to the corresponding raw value.
* The value is round up when xdir > 0.
*/
-static int convert_from_dB(snd_hctl_elem_t *ctl, struct selem_str *rec,
- long db_gain, long *value, int xdir)
-{
- if (init_db_range(ctl, rec) < 0)
+static int do_convert_from_dB(unsigned int *tlv, long rangemin, long rangemax,
+ long db_gain, long *value, int xdir)
+{
+ switch (tlv[0]) {
+ case SND_CTL_TLVT_DB_RANGE: {
+ unsigned int pos, len;
+ len = tlv[1] / sizeof(int);
+ if (len > MAX_TLV_RANGE_SIZE)
+ return -EINVAL;
+ pos = 2;
+ while (pos + 4 <= len) {
+ long dbmin, dbmax;
+ rangemin = (int)tlv[pos];
+ rangemax = (int)tlv[pos + 1];
+ if (! do_get_dB_range(tlv + pos + 2, rangemin, rangemax,
+ &dbmin, &dbmax) &&
+ db_gain >= dbmin && db_gain <= dbmax)
+ return do_convert_from_dB(tlv + pos + 2,
+ rangemin, rangemax,
+ db_gain, value, xdir);
+ pos += tlv[pos + 3] + 4;
+ }
return -EINVAL;
-
- switch (rec->db_info[0]) {
+ }
case SND_CTL_TLVT_DB_SCALE: {
int min, step, max;
- min = rec->db_info[2];
- step = (rec->db_info[3] & 0xffff);
- max = min + (int)(step * rec->max);
+ min = tlv[2];
+ step = (tlv[3] & 0xffff);
+ max = min + (int)(step * rangemax);
if (db_gain <= min)
- *value = rec->min;
+ *value = rangemin;
else if (db_gain >= max)
- *value = rec->max;
+ *value = rangemax;
else {
- long v = (db_gain - min) * (rec->max - rec->min);
+ long v = (db_gain - min) * (rangemax - rangemin);
if (xdir > 0)
v += (max - min) - 1;
- v = v / (max - min) + rec->min;
+ v = v / (max - min) + rangemin;
*value = v;
}
return 0;
@@ -1199,12 +1283,12 @@ static int convert_from_dB(snd_hctl_elem
#ifndef HAVE_SOFT_FLOAT
case SND_CTL_TLVT_DB_LINEAR: {
int min, max;
- min = rec->db_info[2];
- max = rec->db_info[3];
+ min = tlv[2];
+ max = tlv[3];
if (db_gain <= min)
- *value = rec->min;
+ *value = rangemin;
else if (db_gain >= max)
- *value = rec->max;
+ *value = rangemax;
else {
/* FIXME: precalculate and cache vmin and vmax */
double vmin, vmax, v;
@@ -1212,10 +1296,10 @@ static int convert_from_dB(snd_hctl_elem
pow(10.0, (double)min / 20.0);
vmax = !max ? 1.0 : pow(10.0, (double)max / 20.0);
v = pow(10.0, (double)db_gain / 20.0);
- v = (v - vmin) * (rec->max - rec->min) / (vmax - vmin);
+ v = (v - vmin) * (rangemax - rangemin) / (vmax - vmin);
if (xdir > 0)
v = ceil(v);
- *value = (long)v + rec->min;
+ *value = (long)v + rangemin;
}
return 0;
}
@@ -1224,6 +1308,16 @@ static int convert_from_dB(snd_hctl_elem
break;
}
return -EINVAL;
+}
+
+static int convert_from_dB(snd_hctl_elem_t *ctl, struct selem_str *rec,
+ long db_gain, long *value, int xdir)
+{
+ if (init_db_range(ctl, rec) < 0)
+ return -EINVAL;
+
+ return do_convert_from_dB(rec->db_info, rec->min, rec->max,
+ db_gain, value, xdir);
}
static int get_dB_ops(snd_mixer_elem_t *elem,
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