Signed-off-by: Kyle Swanson <k...@ylo.ph>
---
Changelog | 1 +
doc/filters.texi | 30 ++++++++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/asrc_noise.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++
libavfilter/version.h | 2 +-
6 files changed, 175 insertions(+), 1 deletion(-)
create mode 100644 libavfilter/asrc_noise.c
diff --git a/Changelog b/Changelog
index c49e383..d2ea2e1 100644
--- a/Changelog
+++ b/Changelog
@@ -29,6 +29,7 @@ version <next>:
- vibrato filter
- innoHeim/Rsupport Screen Capture Codec decoder
- ADPCM AICA decoder
+- noise audio source
version 2.8:
diff --git a/doc/filters.texi b/doc/filters.texi
index 15ea77a..0d901cc 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3193,6 +3193,36 @@ ffplay -f lavfi flite=text='No more be grieved for which
that thou hast done.'
For more information about libflite, check:
@url{http://www.speech.cs.cmu.edu/flite/}
+@section noise
+
+Generate a white noise audio signal.
+
+The filter accepts the following options:
+
+@table @option
+
+@item sample_rate, r
+Specify the sample rate. Default value is 48000 Hz.
+
+@item duration, d
+Specify the duration of the generated audio stream. Default value is 10
seconds.
+
+@item amplitude, a
+Specify the amplitude (0.0 - 1.0) of the generated audio stream. Default value
is 1.0.
+
+@end table
+
+@subsection Examples
+
+@itemize
+
+@item
+Generate 60 seconds of white noise, with a 44.1 kHz sampling rate and an
amplitude of 0.5:
+@example
+noise=d=60:r=44100:a=0.5
+@end example
+@end itemize
+
@section sine
Generate an audio signal made of a sine wave with amplitude 1/8.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index c5819d4..a0b2232 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -93,6 +93,7 @@ OBJS-$(CONFIG_VOLUMEDETECT_FILTER) +=
af_volumedetect.o
OBJS-$(CONFIG_AEVALSRC_FILTER) += aeval.o
OBJS-$(CONFIG_ANULLSRC_FILTER) += asrc_anullsrc.o
OBJS-$(CONFIG_FLITE_FILTER) += asrc_flite.o
+OBJS-$(CONFIG_NOISE_FILTER) += asrc_noise.o
OBJS-$(CONFIG_SINE_FILTER) += asrc_sine.o
OBJS-$(CONFIG_ANULLSINK_FILTER) += asink_anullsink.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index a538b81..f820441 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -115,6 +115,7 @@ void avfilter_register_all(void)
REGISTER_FILTER(AEVALSRC, aevalsrc, asrc);
REGISTER_FILTER(ANULLSRC, anullsrc, asrc);
REGISTER_FILTER(FLITE, flite, asrc);
+ REGISTER_FILTER(NOISE, noise, asrc);
REGISTER_FILTER(SINE, sine, asrc);
REGISTER_FILTER(ANULLSINK, anullsink, asink);
diff --git a/libavfilter/asrc_noise.c b/libavfilter/asrc_noise.c
new file mode 100644
index 0000000..00370a6
--- /dev/null
+++ b/libavfilter/asrc_noise.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2015 Kyle Swanson <k...@ylo.ph>.
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <float.h>
+
+#include "libavutil/opt.h"
+#include "audio.h"
+#include "avfilter.h"
+#include "internal.h"
+#include "libavutil/lfg.h"
+
+typedef struct {
+ const AVClass *class;
+ int sample_rate;
+ double amplitude;
+ double dur_sec;
+ int64_t dur_samp;
+ AVLFG c;
+} NoiseContext;
+
+#define OFFSET(x) offsetof(NoiseContext, x)
+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption noise_options[] = {
+ { "sample_rate", "set sample rate", OFFSET(sample_rate),
AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
+ { "r", "set sample rate", OFFSET(sample_rate),
AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
+ { "amplitude", "set amplitude", OFFSET(amplitude),
AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
+ { "a", "set amplitude", OFFSET(amplitude),
AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
+ { "duration", "set duration", OFFSET(dur_sec),
AV_OPT_TYPE_DOUBLE, {.dbl = 10.}, 0., DBL_MAX, FLAGS },
+ { "d", "set duration", OFFSET(dur_sec),
AV_OPT_TYPE_DOUBLE, {.dbl = 10.}, 0., DBL_MAX, FLAGS },
+ {NULL}
+};
+
+AVFILTER_DEFINE_CLASS(noise);
+
+static av_cold int query_formats(AVFilterContext *ctx)
+{
+ NoiseContext *s = ctx->priv;
+ static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
+ int sample_rates[] = { s->sample_rate, -1 };
+ static const enum AVSampleFormat sample_fmts[] = {
+ AV_SAMPLE_FMT_DBL,
+ AV_SAMPLE_FMT_NONE
+ };
+
+ AVFilterFormats *formats;
+ AVFilterChannelLayouts *layouts;
+ int ret;
+
+ formats = ff_make_format_list(sample_fmts);
+ if (!formats)
+ return AVERROR(ENOMEM);
+ ret = ff_set_common_formats (ctx, formats);
+ if (ret < 0)
+ return ret;
+
+ layouts = avfilter_make_format64_list(chlayouts);
+ if (!layouts)
+ return AVERROR(ENOMEM);
+ ret = ff_set_common_channel_layouts(ctx, layouts);
+ if (ret < 0)
+ return ret;
+
+ formats = ff_make_format_list(sample_rates);
+ if (!formats)
+ return AVERROR(ENOMEM);
+ return ff_set_common_samplerates(ctx, formats);
+}
+
+static av_cold int config_props(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ NoiseContext *s = ctx->priv;
+ s->dur_samp = s->dur_sec * s->sample_rate;
+ return 0;
+}
+
+static int request_frame(AVFilterLink *outlink) {
+ AVFilterContext *ctx = outlink->src;
+ NoiseContext *s = ctx->priv;
+ AVFrame *frame;
+ int nb_samples, i;
+ double *dst;
+
+ nb_samples = 1024;
+ if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
+ return AVERROR(ENOMEM);
+ dst = (double *)frame->data[0];
+
+ for (i = 0; i < nb_samples; i++) {
+ dst[i]= s->amplitude * ((2 * ((double) av_lfg_get(&s->c) /
0xffffffff)) - 1);
+ s->dur_samp--;
+ if (s->dur_samp <= 0)
+ return AVERROR_EOF;
+ }
+ return ff_filter_frame(outlink, frame);
+}
+
+static av_cold int init(AVFilterContext *ctx) {
+ NoiseContext *s = ctx->priv;
+ av_lfg_init(&s->c, 0);
+ return 0;
+}
+
+static const AVFilterPad noise_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .request_frame = request_frame,
+ .config_props = config_props,
+ },
+ { NULL }
+};
+
+AVFilter ff_asrc_noise = {
+ .name = "noise",
+ .description = NULL_IF_CONFIG_SMALL("Generate white noise audio
signal."),
+ .init = init,
+ .query_formats = query_formats,
+ .priv_size = sizeof(NoiseContext),
+ .inputs = NULL,
+ .outputs = noise_outputs,
+ .priv_class = &noise_class,
+};
diff --git a/libavfilter/version.h b/libavfilter/version.h
index c3ecf91..05b0735 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -30,7 +30,7 @@
#include "libavutil/version.h"
#define LIBAVFILTER_VERSION_MAJOR 6
-#define LIBAVFILTER_VERSION_MINOR 14
+#define LIBAVFILTER_VERSION_MINOR 15
#define LIBAVFILTER_VERSION_MICRO 101
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
--
2.6.2
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