@@ -10,6 +10,7 @@ version <next>:

 - perms and aperms filters

 - audio filtering support in ffplay

 - 10% faster aac encoding on x86 and MIPS

+- sine audio filter source

 version 1.2:

@@ -1653,6 +1653,57 @@ 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 sine

+

+Generate an audio signal made of a sine wave with amplitude 1/8.

+

+The audio signal is bit-exact.

+

+It accepts a list of options in the form of @var{key}=@var{value} pairs

+separated by ":". If the option name is omitted, the first option is the

+frequency and the second option is the beep factor.

+

+The supported options are:

+

+@table @option

+

+@item frequency, f

+Set the carrier frequency. Default is 440 Hz.

+

+@item beep_factor, b

+Enable a periodic beep every second with frequency @var{beep_factor} times

+the carrier frequency. Default is 0, meaning the beep is disabled.

+

+@item sample_rate, s

+Specify the sample rate, default is 44100.

+

+@item duration, d

+Specify the duration of the generated audio stream.

+

+@item samples_per_frame

+Set the number of samples per output frame, default is 1024.

+@end table

+

+@subsection Examples

+

+@itemize

+

+@item

+Generate a simple 440 Hz sine wave:

+@example

+sine

+@end example

+

+@item

+Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:

+@example

+sine=220:4:d=5

+sine=f=220:b=4:d=5

+sine=frequency=220:beep_factor=4:duration=5

+@end example

+

+@end itemize

+

 @c man end AUDIO SOURCES

 @chapter Audio Sinks

@@ -90,6 +90,7 @@ OBJS-$(CONFIG_VOLUMEDETECT_FILTER)           += af_volumedetect.o

 OBJS-$(CONFIG_AEVALSRC_FILTER)               += asrc_aevalsrc.o

 OBJS-$(CONFIG_ANULLSRC_FILTER)               += asrc_anullsrc.o

 OBJS-$(CONFIG_FLITE_FILTER)                  += asrc_flite.o

+OBJS-$(CONFIG_SINE_FILTER)                   += asrc_sine.o

 OBJS-$(CONFIG_ANULLSINK_FILTER)              += asink_anullsink.o

@@ -86,6 +86,7 @@ void avfilter_register_all(void)

     REGISTER_FILTER(AEVALSRC,       aevalsrc,       asrc);

     REGISTER_FILTER(ANULLSRC,       anullsrc,       asrc);

     REGISTER_FILTER(FLITE,          flite,          asrc);

+    REGISTER_FILTER(SINE,           sine,           asrc);

     REGISTER_FILTER(ANULLSINK,      anullsink,      asink);

new file mode 100644

@@ -0,0 +1,228 @@

+/*

+ * Copyright (c) 2013 Nicolas George

+ *

+ * 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 "libavutil/avassert.h"

+#include "libavutil/channel_layout.h"

+#include "libavutil/opt.h"

+#include "audio.h"

+#include "avfilter.h"

+#include "internal.h"

+

+typedef struct {

+    const AVClass *class;

+    double frequency;

+    double beep_factor;

+    int samples_per_frame;

+    int sample_rate;

+    int64_t duration;

+    int16_t *sin;

+    int64_t pts;

+    uint32_t phi;  ///< current phase of the sine (2pi = 1<<32)

+    uint32_t dphi; ///< phase increment between two samples

+    unsigned beep_period;

+    unsigned beep_index;

+    unsigned beep_length;

+    uint32_t phi_beep;  ///< current phase of the beep

+    uint32_t dphi_beep; ///< phase increment of the beep

+} SineContext;

+

+#define CONTEXT SineContext

+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

+

+#define OPT_GENERIC(name, field, def, min, max, descr, type, deffield, ...) \

+    { name, descr, offsetof(CONTEXT, field), AV_OPT_TYPE_ ## type,          \

+      { .deffield = def }, min, max, FLAGS, __VA_ARGS__ }

+

+#define OPT_INT(name, field, def, min, max, descr, ...) \

+    OPT_GENERIC(name, field, def, min, max, descr, INT, i64, __VA_ARGS__)

+

+#define OPT_DBL(name, field, def, min, max, descr, ...) \

+    OPT_GENERIC(name, field, def, min, max, descr, DOUBLE, dbl, __VA_ARGS__)

+

+#define OPT_DUR(name, field, def, min, max, descr, ...) \

+    OPT_GENERIC(name, field, def, min, max, descr, DURATION, str, __VA_ARGS__)

+

+static const AVOption sine_options[] = {

+    OPT_DBL("frequency",         frequency,            440, 0, INFINITY,  "set the sine frequency"),

+    OPT_DBL("f",                 frequency,            440, 0, INFINITY,  "set the sine frequency"),

+    OPT_DBL("beep_factor",       beep_factor,            0, 0, INFINITY,  "set the beep fequency factor"),

+    OPT_DBL("b",                 beep_factor,            0, 0, INFINITY,  "set the beep fequency factor"),

+    OPT_INT("sample_rate",       sample_rate,        44100, 1, INT_MAX,   "set the sample rate"),

+    OPT_INT("r",                 sample_rate,        44100, 1, INT_MAX,   "set the sample rate"),

+    OPT_DUR("duration",          duration,               0, 0, INT64_MAX, "set the audio duration"),

+    OPT_DUR("d",                 duration,               0, 0, INT64_MAX, "set the audio duration"),

+    OPT_INT("samples_per_frame", samples_per_frame,   1024, 0, INT_MAX,   "set the number of samples per frame"),

+    {NULL},

+};

+

+AVFILTER_DEFINE_CLASS(sine);

+

+#define LOG_PERIOD 15

+#define AMPLITUDE 4095

+#define AMPLITUDE_SHIFT 3

+

+static void make_sin_table(int16_t *sin)

+{

+    unsigned half_pi = 1 << (LOG_PERIOD - 2);

+    unsigned ampls = AMPLITUDE << AMPLITUDE_SHIFT;

+    uint64_t unit2 = (uint64_t)(ampls * ampls) << 32;

+    unsigned step, i, c, s, k, new_k, n2;

+

+    /* Principle: if u = exp(i*a1) and v = exp(i*a2), then

+       exp(i*(a1+a2)/2) = (u+v) / length(u+v) */

+    sin[0] = 0;

+    sin[half_pi] = ampls;

+    for (step = half_pi; step > 1; step /= 2) {

+        /* k = (1 << 16) * amplitude / length(u+v)

+           In exact values, k is constant at a given step */

+        k = 0x10000;

+        for (i = 0; i < half_pi / 2; i += step) {

+            s = sin[i] + sin[i + step];

+            c = sin[half_pi - i] + sin[half_pi - i - step];

+            n2 = s * s + c * c;

+            /* Newton's method to solve n² * k² = unit² */

+            while (1) {

+                new_k = (k + unit2 / ((uint64_t)k * n2) + 1) >> 1;

+                if (k == new_k)

+                    break;

+                k = new_k;

+            }

+            sin[i + step / 2] = (k * s + 0x7FFF) >> 16;

+            sin[half_pi - i - step / 2] = (k * c + 0x8000) >> 16;

+        }

+    }

+    /* Unshift amplitude */

+    for (i = 0; i <= half_pi; i++)

+        sin[i] = (sin[i] + (1 << (AMPLITUDE_SHIFT - 1))) >> AMPLITUDE_SHIFT;

+    /* Use symmetries to fill the other three quarters */

+    for (i = 0; i < half_pi; i++)

+        sin[half_pi * 2 - i] = sin[i];

+    for (i = 0; i < 2 * half_pi; i++)

+        sin[i + 2 * half_pi] = -sin[i];

+}

+

+static av_cold int init(AVFilterContext *ctx, const char *args)

+{

+    SineContext *sine = ctx->priv;

+    static const char *shorthand[] = { "frequency", "beep_factor", NULL };

+    int ret;

+

+    sine->class = &sine_class;

+    av_opt_set_defaults(sine);

+

+    if ((ret = av_opt_set_from_string(sine, args, shorthand, "=", ":")) < 0)

+        return ret;

+    if (!(sine->sin = av_malloc(sizeof(*sine->sin) << LOG_PERIOD)))

+        return AVERROR(ENOMEM);

+    sine->dphi = ldexp(sine->frequency, 32) / sine->sample_rate + 0.5;

+    make_sin_table(sine->sin);

+

+    if (sine->beep_factor) {

+        sine->beep_period = sine->sample_rate;

+        sine->beep_length = sine->beep_period / 25;

+        sine->dphi_beep = ldexp(sine->beep_factor * sine->frequency, 32) /

+                          sine->sample_rate + 0.5;

+    }

+

+    return 0;

+}

+

+static av_cold void uninit(AVFilterContext *ctx)

+{

+    SineContext *sine = ctx->priv;

+

+    av_freep(&sine->sin);

+}

+

+static av_cold int query_formats(AVFilterContext *ctx)

+{

+    SineContext *sine = ctx->priv;

+    static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };

+    int sample_rates[] = { sine->sample_rate, -1 };

+    static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16,

+                                                       AV_SAMPLE_FMT_NONE };

+

+    ff_set_common_formats (ctx, ff_make_format_list(sample_fmts));

+    ff_set_common_channel_layouts(ctx, avfilter_make_format64_list(chlayouts));

+    ff_set_common_samplerates(ctx, ff_make_format_list(sample_rates));

+    return 0;

+}

+

+static av_cold int config_props(AVFilterLink *outlink)

+{

+    SineContext *sine = outlink->src->priv;

+    sine->duration = av_rescale(sine->duration, sine->sample_rate, AV_TIME_BASE);

+    return 0;

+}

+

+static int request_frame(AVFilterLink *outlink)

+{

+    SineContext *sine = outlink->src->priv;

+    AVFrame *frame;

+    int i, nb_samples = sine->samples_per_frame;

+    int16_t *samples;

+

+    if (sine->duration) {

+        nb_samples = FFMIN(nb_samples, sine->duration - sine->pts);

+        av_assert1(nb_samples >= 0);

+        if (!nb_samples)

+            return AVERROR_EOF;

+    }

+    if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))

+        return AVERROR(ENOMEM);

+    samples = (int16_t *)frame->data[0];

+

+    for (i = 0; i < nb_samples; i++) {

+        samples[i] = sine->sin[sine->phi >> (32 - LOG_PERIOD)];

+        sine->phi += sine->dphi;

+        if (sine->beep_index < sine->beep_length) {

+            samples[i] += sine->sin[sine->phi_beep >> (32 - LOG_PERIOD)] << 1;

+            sine->phi_beep += sine->dphi_beep;

+        }

+        if (++sine->beep_index == sine->beep_period)

+            sine->beep_index = 0;

+    }

+

+    frame->pts = sine->pts;

+    sine->pts += nb_samples;

+    return ff_filter_frame(outlink, frame);

+}

+

+static const AVFilterPad sine_outputs[] = {

+    {

+        .name          = "default",

+        .type          = AVMEDIA_TYPE_AUDIO,

+        .request_frame = request_frame,

+        .config_props  = config_props,

+    },

+    { NULL }

+};

+

+AVFilter avfilter_asrc_sine = {

+    .name          = "sine",

+    .description   = NULL_IF_CONFIG_SMALL("Generate sine wave audio signal."),

+    .query_formats = query_formats,

+    .init          = init,

+    .uninit        = uninit,

+    .priv_size     = sizeof(SineContext),

+    .inputs        = NULL,

+    .outputs       = sine_outputs,

+    .priv_class    = &sine_class,

+};

@@ -29,8 +29,8 @@

 #include "libavutil/avutil.h"

 #define LIBAVFILTER_VERSION_MAJOR  3

-#define LIBAVFILTER_VERSION_MINOR  47

-#define LIBAVFILTER_VERSION_MICRO 104

+#define LIBAVFILTER_VERSION_MINOR  48

+#define LIBAVFILTER_VERSION_MICRO 100

 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

                                                LIBAVFILTER_VERSION_MINOR, \