ref: db11a831b5188094f926527ba4b72eca392f9ecb
parent: 3e264d195ae38ae281cec5c3cc3632a56bb9cb1c
author: Rob Sykes <robs@users.sourceforge.net>
date: Tue Aug 30 06:03:21 EDT 2011
add upsample effect
--- a/sox.1
+++ b/sox.1
@@ -3979,6 +3979,11 @@
it. A value of 8000s for the \fIstart\fR parameter will wait until
8000 samples are read before starting to process audio.
.TP
+\fBupsample [\fIfactor\fR]
+Upsample the signal by an integer factor: \fIfactor\fR\-1 zero-value
+samples are inserted between each input sample. Typically use is in
+combination with filtering effects.
+.TP
\fBvad \fR[\fIoptions\fR]
Voice Activity Detector. Attempts to trim silence and quiet
background sounds from the ends of (fairly high resolution
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -30,9 +30,9 @@
compandt fade noiseprof reverse tempo
contrast fft4g noisered silence tremolo
crop filter output sinc trim
- dcshift fir overdrive skeleff vad
- delay firfit pad speed vol
- dft_filter flanger pan splice
+ dcshift fir overdrive skeleff upsample
+ delay firfit pad speed vad
+ dft_filter flanger pan splice vol
)
set(formats_srcs
8svx dat htk s2-fmt u2-fmt
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -77,7 +77,7 @@
rate_poly_fir.h remix.c repeat.c reverb.c reverse.c silence.c \
sinc.c skeleff.c speed.c speexdsp.c splice.c stat.c stats.c \
stretch.c swap.c synth.c tempo.c tremolo.c trim.c vad.c vol.c \
- ignore-warning.h
+ ignore-warning.h upsample.c
if HAVE_PNG
libsox_la_SOURCES += spectrogram.c
endif
--- a/src/effects.h
+++ b/src/effects.h
@@ -91,5 +91,6 @@
EFFECT(treble)
EFFECT(tremolo)
EFFECT(trim)
+ EFFECT(upsample)
EFFECT(vad)
EFFECT(vol)
--- /dev/null
+++ b/src/upsample.c
@@ -1,0 +1,67 @@
+/* libSoX effect: Upsample (zero stuff) (c) 2011 robs@users.sourceforge.net
+ *
+ * Sometimes filters perform better at higher sampling rates, so e.g.
+ * sox -r 48k input output upsample 4 filter rate 48k vol 4
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "sox_i.h"
+
+typedef struct {unsigned factor, pos;} priv_t;+
+static int create(sox_effect_t * effp, int argc, char * * argv)
+{+ priv_t * p = (priv_t *)effp->priv;
+ p->factor = 2;
+ --argc, ++argv;
+ do {NUMERIC_PARAMETER(factor, 1, 256)} while (0);+ /* TODO: something like this may be needed here to inform libSoX client
+ * that the rate change indicated in start() is intended to be the final rate:
+ effp->out_signal.rate = effp->in_signal.rate * p->factor; */
+ return argc? lsx_usage(effp) : SOX_SUCCESS;
+}
+
+static int start(sox_effect_t * effp)
+{+ priv_t * p = (priv_t *) effp->priv;
+ effp->out_signal.rate = effp->in_signal.rate * p->factor;
+ return p->factor == 1? SOX_EFF_NULL : SOX_SUCCESS;
+}
+
+static int flow(sox_effect_t * effp, const sox_sample_t * ibuf,
+ sox_sample_t * obuf, size_t * isamp, size_t * osamp)
+{+ priv_t * p = (priv_t *)effp->priv;
+ size_t ilen = *isamp, olen = *osamp;
+ while (sox_true) {+ for (; p->pos && olen; p->pos = (p->pos + 1) % p->factor, --olen)
+ *obuf++ = 0;
+ if (!ilen || !olen)
+ break;
+ *obuf++ = *ibuf++;
+ --olen, --ilen;
+ ++p->pos;
+ }
+ *isamp -= ilen, *osamp -= olen;
+ return SOX_SUCCESS;
+}
+
+sox_effect_handler_t const * lsx_upsample_effect_fn(void)
+{+ static sox_effect_handler_t handler = {"upsample", "[factor (2)]",+ SOX_EFF_RATE, create, start, flow, NULL, NULL, NULL, sizeof(priv_t)};
+ return &handler;
+}