ref: 1faf05aacdd69ad8071ad6cb0e47c1536c7479c5
parent: 3cda6b3e056b68f4d46af3c7e25e226bd6b70592
author: robs <robs>
date: Mon Mar 23 15:59:19 EDT 2009
add equal power cross-fade
--- a/src/splice.c
+++ b/src/splice.c
@@ -18,12 +18,12 @@
#include "sox_i.h"
-static float difference(const float * a, const float * b, size_t length)
+static double difference(const sox_sample_t * a, const sox_sample_t * b, size_t length)
{- float diff = 0;
+ double diff = 0;
size_t i = 0;
- #define _ diff += sqr(a[i] - b[i]), ++i; /* Loop optimisation */
+ #define _ diff += sqr((double)a[i] - b[i]), ++i; /* Loop optimisation */
do {_ _ _ _ _ _ _ _} while (i < length); /* N.B. length ≡ 0 (mod 8) */#undef _
return diff;
@@ -30,11 +30,11 @@
}
/* Find where the two segments are most alike over the overlap period. */
-static size_t best_overlap_position(float const * f1, float const * f2,
+static size_t best_overlap_position(sox_sample_t const * f1, sox_sample_t const * f2,
size_t overlap, size_t search, size_t channels)
{size_t i, best_pos = 0;
- float diff, least_diff = difference(f2, f1, channels * overlap);
+ double diff, least_diff = difference(f2, f1, channels * overlap);
for (i = 1; i < search; ++i) { /* linear search */diff = difference(f2 + channels * i, f1, channels * overlap);
@@ -44,30 +44,8 @@
return best_pos;
}
-static void splice(const float * in1, const float * in2,
- float * output, size_t overlap, size_t channels)
-{- size_t i, j, k = 0;
- float fade_step = 1.0f / (float) overlap;
-
- for (i = 0; i < overlap; ++i) {- float fade_in = fade_step * (float) i;
- float fade_out = 1.0f - fade_in;
- for (j = 0; j < channels; ++j, ++k)
- output[k] = in1[k] * fade_out + in2[k] * fade_in;
- }
-}
-
-static size_t do_splice(float * f, size_t overlap, size_t search, size_t channels)
-{- size_t offset = search? best_overlap_position(
- f, f + overlap * channels, overlap, search, channels) : 0;
- splice(f, f + (overlap + offset) * channels,
- f + (overlap + offset) * channels, overlap, channels);
- return overlap + offset;
-}
-
typedef struct {+ sox_bool uncorrelated;
unsigned nsplices; /* Number of splices requested */
struct {char * str; /* Command-line argument to parse for this splice */
@@ -80,10 +58,49 @@
unsigned splices_pos; /* Number of splices completed so far */
size_t buffer_pos; /* Number of samples through the current splice */
size_t max_buffer_size;
- float * buffer;
+ sox_sample_t * buffer;
unsigned state;
} priv_t;
+static void splice(sox_effect_t * effp, const sox_sample_t * in1, const
+ sox_sample_t * in2, sox_sample_t * output, size_t overlap, size_t channels)
+{+ priv_t * p = (priv_t *)effp->priv;
+ size_t i, j, k = 0;
+
+ if (p->uncorrelated) { /* Fade for constant RMS level (`power') */+ double fade_step = M_PI_2 / overlap;
+ for (i = 0; i < overlap; ++i) {+ double fade_in = sin(i * fade_step);
+ double fade_out = cos(i * fade_step);
+ for (j = 0; j < channels; ++j, ++k) {+ double d = in1[k] * fade_out + in2[k] * fade_in;
+ output[k] = SOX_ROUND_CLIP_COUNT(d, effp->clips); /* Might clip */
+ }
+ }
+ }
+ else { /* Fade for constant peak level (`gain') */+ double fade_step = 1. / overlap;
+ for (i = 0; i < overlap; ++i) {+ double fade_in = fade_step * i;
+ double fade_out = 1 - fade_in;
+ for (j = 0; j < channels; ++j, ++k) {+ double d = in1[k] * fade_out + in2[k] * fade_in;
+ output[k] = SOX_ROUND_CLIP_COUNT(d, effp->clips); /* Should not clip */
+ }
+ }
+ }
+}
+
+static size_t do_splice(sox_effect_t * effp, sox_sample_t * f, size_t overlap, size_t search, size_t channels)
+{+ size_t offset = search? best_overlap_position(
+ f, f + overlap * channels, overlap, search, channels) : 0;
+ splice(effp, f, f + (overlap + offset) * channels,
+ f + (overlap + offset) * channels, overlap, channels);
+ return overlap + offset;
+}
+
static int parse(sox_effect_t * effp, char * * argv, sox_rate_t rate)
{priv_t * p = (priv_t *)effp->priv;
@@ -129,6 +146,8 @@
{priv_t * p = (priv_t *)effp->priv;
--argc, ++argv;
+ if (argc && !strcmp(*argv, "-u"))
+ --argc, ++argv, p->uncorrelated = sox_true;
p->splices = lsx_calloc(p->nsplices = argc, sizeof(*p->splices));
return parse(effp, argv, 1e5); /* No rate yet; parse with dummy */
}
@@ -143,8 +162,11 @@
p->in_pos = p->buffer_pos = p->splices_pos = 0;
p->state = p->splices_pos != p->nsplices && p->in_pos == p->splices[p->splices_pos].start;
for (i = 0; i < p->nsplices; ++i)
- if (p->splices[i].overlap)
+ if (p->splices[i].overlap) {+ if (p->uncorrelated && effp->in_signal.mult)
+ *effp->in_signal.mult *= pow(.5, .5);
return SOX_SUCCESS;
+ }
return SOX_EFF_NULL;
}
@@ -153,7 +175,6 @@
{priv_t * p = (priv_t *)effp->priv;
size_t c, idone = 0, odone = 0;
- SOX_SAMPLE_LOCALS;
*isamp /= effp->in_signal.channels;
*osamp /= effp->in_signal.channels;
@@ -176,7 +197,7 @@
size_t buffer_size = (2 * p->splices[p->splices_pos].overlap + p->splices[p->splices_pos].search) * effp->in_signal.channels;
for (; idone < *isamp; ++idone, ++p->in_pos) { if (p->buffer_pos == buffer_size) {- p->buffer_pos = do_splice(p->buffer,
+ p->buffer_pos = do_splice(effp, p->buffer,
p->splices[p->splices_pos].overlap,
p->splices[p->splices_pos].search,
(size_t)effp->in_signal.channels) * effp->in_signal.channels;
@@ -185,7 +206,7 @@
break;
}
for (c = 0; c < effp->in_signal.channels; ++c)
- p->buffer[p->buffer_pos++] = SOX_SAMPLE_TO_FLOAT_32BIT(*ibuf++, effp->clips);
+ p->buffer[p->buffer_pos++] = *ibuf++;
}
break;
}
@@ -201,7 +222,7 @@
goto copying;
}
for (c = 0; c < effp->in_signal.channels; ++c)
- *obuf++ = SOX_FLOAT_32BIT_TO_SAMPLE(p->buffer[p->buffer_pos++], effp->clips);
+ *obuf++ = p->buffer[p->buffer_pos++];
}
break;
}
@@ -240,7 +261,13 @@
sox_effect_handler_t const * lsx_splice_effect_fn(void)
{ static sox_effect_handler_t handler = {- "splice", "{position[,excess[,leeway]]}", SOX_EFF_MCHAN|SOX_EFF_LENGTH,+ "splice", "[-u] {position[,excess[,leeway]]}"+ "\n (default) Correlated audio: fade for constant peak"
+ "\n -u Uncorrelated audio (e.g. cross-fade): fade for constant RMS"
+ "\n position The length of part 1 (including the excess)"
+ "\n excess At the end of part 1 & the start of part2 (default 0.005)"
+ "\n leeway Before part2 (default 0.005; set to 0 for cross-fade)",
+ SOX_EFF_MCHAN|SOX_EFF_LENGTH,
create, start, flow, drain, stop, kill, sizeof(priv_t)
};
return &handler;