ref: bbc06d6285e6a0fb59fbee906c9ce1b1580ecaf3
parent: 4aa76b22c3cdd8ae415bf8f9a1b196e505fa2bae
author: robs <robs>
date: Sat Feb 17 15:43:45 EST 2007
vol parser improvements
--- a/ChangeLog
+++ b/ChangeLog
@@ -18,6 +18,7 @@
o Added soft-knee companding. (robs)
o Show (with --octave) compand transfer function. (robs)
+ o Allow e.g. "vol 6dB" (as well as "vol 6 dB"). (robs)
Other new features:
--- a/sox.1
+++ b/sox.1
@@ -2123,7 +2123,7 @@
it. A value of 8000s will wait until 8000 samples are read before
starting to process audio.
.TP
-\fBvol \fIgain\fR [\fItype\fR [\fIlimitergain\fR]]
+\fBvol \fIgain\fR[[ ]\fItype\fR [\fIlimitergain\fR]]
Apply an amplification or an attenuation to the audio signal.
Unlike the
.B \-v
--- a/src/vol.c
+++ b/src/vol.c
@@ -6,90 +6,100 @@
* Cannot handle different number of channels.
* Cannot handle rate change.
*/
+#define vol_usage \
+ "Usage: vol gain[[ ]type [limitergain]]\n" \
+ "\t(default type=amplitude: 1 is constant, < 0 change phase;\n" \
+ "\ttype=power 1 is constant; type=dB: 0 is constant, +6 doubles ampl.)\n" \
+ "\tThe peak limiter has a gain much less than 1 (e.g. 0.05 or 0.02) and is\n" \
+ "\tonly used on peaks (to prevent clipping); default is no limiter."
#include "st_i.h"
#include <math.h> /* exp(), sqrt() */
-static st_effect_t st_vol_effect;
-
#define LOG_10_20 ((double)(0.1151292546497022842009e0))
typedef struct {double gain; /* amplitude gain. */
- int uselimiter; /* boolean: are we using the limiter? */
+ st_bool uselimiter;
double limiterthreshhold;
- double limitergain; /* limiter gain. */
+ double limitergain;
int limited; /* number of limited values to report. */
int totalprocessed;
} * vol_t;
+enum {VOL_amplitude, VOL_dB, VOL_power};+
+static enum_item const vol_types[] = {+ ENUM_ITEM(VOL_,amplitude)
+ ENUM_ITEM(VOL_,dB)
+ ENUM_ITEM(VOL_,power)
+ {0, 0}};+
/*
* Process options: gain (float) type (amplitude, power, dB)
*/
-static int st_vol_getopts(eff_t effp, int n, char **argv)
+static int getopts(eff_t effp, int n, char **argv)
{- vol_t vol = (vol_t) effp->priv;
- vol->gain = 1.0; /* default is no change */
- vol->uselimiter = 0; /* default is no limiter */
-
- if (n && (!sscanf(argv[0], "%lf", &vol->gain)))
- {- st_fail(st_vol_effect.usage);
- return ST_EOF;
- }
+ vol_t vol = (vol_t) effp->priv;
+ char string[11];
+ char * q = string;
+ char dummy; /* To check for extraneous chars. */
+ unsigned have_type;
- /* adjust gain depending on type (what a great parser;-) */
- if (n>1)
- {- switch (argv[1][0])
- {- case 'd': /* decibels to amplitude */
- case 'D':
- vol->gain = exp(vol->gain*LOG_10_20);
- break;
- case 'p':
- case 'P': /* power to amplitude, keep phase change */
- if (vol->gain > 0.0)
- vol->gain = sqrt(vol->gain);
- else
- vol->gain = -sqrt(-vol->gain);
- break;
- case 'a': /* amplitude */
- case 'A':
- default:
- break;
- }
+ vol->gain = 1; /* Default is no change. */
+ vol->uselimiter = st_false; /* Default is no limiter. */
+
+ if (!n || (have_type = sscanf(argv[0], "%lf %10s %c", &vol->gain, string, &dummy) - 1) > 1) {+ st_fail(effp->h->usage);
+ return ST_EOF;
+ }
+ ++argv, --n;
+
+ if (!have_type && n) {+ ++have_type;
+ q = *argv;
+ ++argv, --n;
+ }
+
+ if (have_type) {+ enum_item const * p = find_enum_text(q, vol_types);
+ if (!p) {+ st_fail(effp->h->usage);
+ return ST_EOF;
}
-
+ switch (p->value) {+ case VOL_dB: vol->gain = exp(vol->gain*LOG_10_20); break;
+ case VOL_power: /* power to amplitude, keep phase change */
+ vol->gain = vol->gain > 0 ? sqrt(vol->gain) : -sqrt(-vol->gain);
+ break;
+ }
+ }
- if (n>2)
- {- if ((fabs(vol->gain) < 1.0) || !sscanf(argv[2], "%lf", &vol->limitergain) || !((vol->limitergain > 0.0) && (vol->limitergain < 1.0)))
- {- st_fail(st_vol_effect.usage);
- return ST_EOF;
- }
-
- vol->uselimiter = 1; /* ok, we'll use it */
- /* The following equation is derived so that there is no
- * discontinuity in output amplitudes */
- /* and a ST_SAMPLE_MAX input always maps to a ST_SAMPLE_MAX output
- * when the limiter is activated. */
- /* (NOTE: There **WILL** be a discontinuity in the slope
- * of the output amplitudes when using the limiter.) */
- vol->limiterthreshhold = ST_SAMPLE_MAX * (1.0 - vol->limitergain) / (fabs(vol->gain) - vol->limitergain);
+ if (n) {+ if (fabs(vol->gain) < 1 || sscanf(*argv, "%lf %c", &vol->limitergain, &dummy) != 1 || vol->limitergain <= 0 || vol->limitergain >= 1) {+ st_fail(effp->h->usage);
+ return ST_EOF;
}
-
- return ST_SUCCESS;
+ vol->uselimiter = st_true;
+ /* The following equation is derived so that there is no
+ * discontinuity in output amplitudes */
+ /* and a ST_SAMPLE_MAX input always maps to a ST_SAMPLE_MAX output
+ * when the limiter is activated. */
+ /* (NOTE: There **WILL** be a discontinuity in the slope
+ * of the output amplitudes when using the limiter.) */
+ vol->limiterthreshhold = ST_SAMPLE_MAX * (1.0 - vol->limitergain) / (fabs(vol->gain) - vol->limitergain);
+ }
+ st_debug("mult=%g limit=%g", vol->gain, vol->limitergain);+ return ST_SUCCESS;
}
/*
* Start processing
*/
-static int st_vol_start(eff_t effp)
+static int start(eff_t effp)
{vol_t vol = (vol_t) effp->priv;
@@ -117,7 +127,7 @@
/*
* Process data.
*/
-static int st_vol_flow(eff_t effp, const st_sample_t *ibuf, st_sample_t *obuf,
+static int flow(eff_t effp, const st_sample_t *ibuf, st_sample_t *obuf,
st_size_t *isamp, st_size_t *osamp)
{vol_t vol = (vol_t) effp->priv;
@@ -175,38 +185,20 @@
return ST_SUCCESS;
}
-/*
- * Do anything required when you stop reading samples.
- * Don't close input file!
- */
-static int st_vol_stop(eff_t effp)
+static int stop(eff_t effp)
{- vol_t vol = (vol_t) effp->priv;
- if (vol->limited)
- {- st_warn("limited %d values (%d percent).", - vol->limited, (int) (vol->limited * 100.0 / vol->totalprocessed));
- }
- return ST_SUCCESS;
+ vol_t vol = (vol_t) effp->priv;
+ if (vol->limited) {+ st_warn("limited %d values (%d percent).", + vol->limited, (int) (vol->limited * 100.0 / vol->totalprocessed));
+ }
+ return ST_SUCCESS;
}
-static st_effect_t st_vol_effect = {- "vol",
- "Usage: vol gain [ type [ limitergain ] ]"
- " (default type=amplitude: 1.0 is constant, <0.0 change phase;\n"
- " type=power 1.0 is constant; type=dB: 0.0 is constant, +6 doubles ampl.)\n"
- " The peak limiter has a gain much less than 1.0 (ie 0.05 or 0.02) which is only\n"
- " used on peaks to prevent clipping. (default is no limiter)",
- ST_EFF_MCHAN,
- st_vol_getopts,
- st_vol_start,
- st_vol_flow,
- st_effect_nothing_drain,
- st_vol_stop,
- st_effect_nothing
-};
-
-const st_effect_t *st_vol_effect_fn(void)
+st_effect_t const * st_vol_effect_fn(void)
{- return &st_vol_effect;
+ static st_effect_t driver = {+ "vol", vol_usage, ST_EFF_MCHAN, getopts, start, flow, 0, stop, 0
+ };
+ return &driver;
}