gstreamer/gst/cutter/gstcutter.c
2012-04-10 00:51:41 +01:00

490 lines
16 KiB
C

/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
* Copyright (C) 2002,2003,2005
* Thomas Vander Stichele <thomas at apestaart dot org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-cutter
*
* Analyses the audio signal for periods of silence. The start and end of
* silence is signalled by bus messages named
* <classname>&quot;cutter&quot;</classname>.
* The message's structure contains two fields:
* <itemizedlist>
* <listitem>
* <para>
* #GstClockTime
* <classname>&quot;timestamp&quot;</classname>:
* the timestamp of the buffer that triggered the message.
* </para>
* </listitem>
* <listitem>
* <para>
* gboolean
* <classname>&quot;above&quot;</classname>:
* %TRUE for begin of silence and %FALSE for end of silence.
* </para>
* </listitem>
* </itemizedlist>
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch -m filesrc location=foo.ogg ! decodebin ! audioconvert ! cutter ! autoaudiosink
* ]| Show cut messages.
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/audio/audio.h>
#include "gstcutter.h"
#include "math.h"
GST_DEBUG_CATEGORY_STATIC (cutter_debug);
#define GST_CAT_DEFAULT cutter_debug
#define CUTTER_DEFAULT_THRESHOLD_LEVEL 0.1
#define CUTTER_DEFAULT_THRESHOLD_LENGTH (500 * GST_MSECOND)
#define CUTTER_DEFAULT_PRE_LENGTH (200 * GST_MSECOND)
static GstStaticPadTemplate cutter_src_factory = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw, "
"format = (string) { " GST_AUDIO_NE (S8) "," GST_AUDIO_NE (S16) " }, "
"rate = (int) [ 1, MAX ], " "channels = (int) [ 1, MAX ], "
"layout = (string) interleaved")
);
static GstStaticPadTemplate cutter_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw, "
"format = (string) { " GST_AUDIO_NE (S8) "," GST_AUDIO_NE (S16) " }, "
"rate = (int) [ 1, MAX ], " "channels = (int) [ 1, MAX ], "
"layout = (string) interleaved")
);
enum
{
PROP_0,
PROP_THRESHOLD,
PROP_THRESHOLD_DB,
PROP_RUN_LENGTH,
PROP_PRE_LENGTH,
PROP_LEAKY
};
#define gst_cutter_parent_class parent_class
G_DEFINE_TYPE (GstCutter, gst_cutter, GST_TYPE_ELEMENT);
static void gst_cutter_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_cutter_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static gboolean gst_cutter_event (GstPad * pad, GstObject * parent,
GstEvent * event);
static GstFlowReturn gst_cutter_chain (GstPad * pad, GstObject * parent,
GstBuffer * buffer);
static void
gst_cutter_class_init (GstCutterClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *element_class;
gobject_class = (GObjectClass *) klass;
element_class = (GstElementClass *) klass;
gobject_class->set_property = gst_cutter_set_property;
gobject_class->get_property = gst_cutter_get_property;
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_THRESHOLD,
g_param_spec_double ("threshold", "Threshold",
"Volume threshold before trigger",
-G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_THRESHOLD_DB,
g_param_spec_double ("threshold-dB", "Threshold (dB)",
"Volume threshold before trigger (in dB)",
-G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_RUN_LENGTH,
g_param_spec_uint64 ("run-length", "Run length",
"Length of drop below threshold before cut_stop (in nanoseconds)",
0, G_MAXUINT64, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_PRE_LENGTH,
g_param_spec_uint64 ("pre-length", "Pre-recording buffer length",
"Length of pre-recording buffer (in nanoseconds)",
0, G_MAXUINT64, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_LEAKY,
g_param_spec_boolean ("leaky", "Leaky",
"do we leak buffers when below threshold ?",
FALSE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
GST_DEBUG_CATEGORY_INIT (cutter_debug, "cutter", 0, "Audio cutting");
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&cutter_src_factory));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&cutter_sink_factory));
gst_element_class_set_static_metadata (element_class, "Audio cutter",
"Filter/Editor/Audio",
"Audio Cutter to split audio into non-silent bits",
"Thomas Vander Stichele <thomas at apestaart dot org>");
}
static void
gst_cutter_init (GstCutter * filter)
{
filter->sinkpad =
gst_pad_new_from_static_template (&cutter_sink_factory, "sink");
gst_pad_set_chain_function (filter->sinkpad, gst_cutter_chain);
gst_pad_set_event_function (filter->sinkpad, gst_cutter_event);
gst_pad_use_fixed_caps (filter->sinkpad);
gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
filter->srcpad =
gst_pad_new_from_static_template (&cutter_src_factory, "src");
gst_pad_use_fixed_caps (filter->srcpad);
gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);
filter->threshold_level = CUTTER_DEFAULT_THRESHOLD_LEVEL;
filter->threshold_length = CUTTER_DEFAULT_THRESHOLD_LENGTH;
filter->silent_run_length = 0 * GST_SECOND;
filter->silent = TRUE;
filter->silent_prev = FALSE; /* previous value of silent */
filter->pre_length = CUTTER_DEFAULT_PRE_LENGTH;
filter->pre_run_length = 0 * GST_SECOND;
filter->pre_buffer = NULL;
filter->leaky = FALSE;
}
static GstMessage *
gst_cutter_message_new (GstCutter * c, gboolean above, GstClockTime timestamp)
{
GstStructure *s;
s = gst_structure_new ("cutter",
"above", G_TYPE_BOOLEAN, above,
"timestamp", GST_TYPE_CLOCK_TIME, timestamp, NULL);
return gst_message_new_element (GST_OBJECT (c), s);
}
/* Calculate the Normalized Cumulative Square over a buffer of the given type
* and over all channels combined */
#define DEFINE_CUTTER_CALCULATOR(TYPE, RESOLUTION) \
static void inline \
gst_cutter_calculate_##TYPE (TYPE * in, guint num, \
double *NCS) \
{ \
register int j; \
double squaresum = 0.0; /* square sum of the integer samples */ \
register double square = 0.0; /* Square */ \
gdouble normalizer; /* divisor to get a [-1.0, 1.0] range */ \
\
*NCS = 0.0; /* Normalized Cumulative Square */ \
\
normalizer = (double) (1 << (RESOLUTION * 2)); \
\
for (j = 0; j < num; j++) \
{ \
square = ((double) in[j]) * in[j]; \
squaresum += square; \
} \
\
\
*NCS = squaresum / normalizer; \
}
DEFINE_CUTTER_CALCULATOR (gint16, 15);
DEFINE_CUTTER_CALCULATOR (gint8, 7);
static gboolean
gst_cutter_setcaps (GstCutter * filter, GstCaps * caps)
{
GstAudioInfo info;
if (!gst_audio_info_from_caps (&info, caps))
return FALSE;
filter->info = info;
return gst_pad_set_caps (filter->srcpad, caps);
}
static gboolean
gst_cutter_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
gboolean ret;
GstCutter *filter;
filter = GST_CUTTER (parent);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_CAPS:
{
GstCaps *caps;
gst_event_parse_caps (event, &caps);
ret = gst_cutter_setcaps (filter, caps);
gst_event_unref (event);
break;
}
default:
ret = gst_pad_event_default (pad, parent, event);
break;
}
return ret;
}
static GstFlowReturn
gst_cutter_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
GstFlowReturn ret = GST_FLOW_OK;
GstCutter *filter;
GstMapInfo map;
gint16 *in_data;
gint bpf, rate;
gsize in_size;
guint num_samples;
gdouble NCS = 0.0; /* Normalized Cumulative Square of buffer */
gdouble RMS = 0.0; /* RMS of signal in buffer */
gdouble NMS = 0.0; /* Normalized Mean Square of buffer */
GstBuffer *prebuf; /* pointer to a prebuffer element */
GstClockTime duration;
filter = GST_CUTTER (parent);
if (GST_AUDIO_INFO_FORMAT (&filter->info) == GST_AUDIO_FORMAT_UNKNOWN)
goto not_negotiated;
bpf = GST_AUDIO_INFO_BPF (&filter->info);
rate = GST_AUDIO_INFO_RATE (&filter->info);
gst_buffer_map (buf, &map, GST_MAP_READ);
in_data = (gint16 *) map.data;
in_size = map.size;
GST_LOG_OBJECT (filter, "length of prerec buffer: %" GST_TIME_FORMAT,
GST_TIME_ARGS (filter->pre_run_length));
/* calculate mean square value on buffer */
switch (GST_AUDIO_INFO_FORMAT (&filter->info)) {
case GST_AUDIO_FORMAT_S16:
num_samples = in_size / 2;
gst_cutter_calculate_gint16 (in_data, num_samples, &NCS);
NMS = NCS / num_samples;
break;
case GST_AUDIO_FORMAT_S8:
num_samples = in_size;
gst_cutter_calculate_gint8 ((gint8 *) in_data, num_samples, &NCS);
NMS = NCS / num_samples;
break;
default:
/* this shouldn't happen */
g_warning ("no mean square function for format");
break;
}
gst_buffer_unmap (buf, &map);
filter->silent_prev = filter->silent;
duration = gst_util_uint64_scale (in_size / bpf, GST_SECOND, rate);
RMS = sqrt (NMS);
/* if RMS below threshold, add buffer length to silent run length count
* if not, reset
*/
GST_LOG_OBJECT (filter, "buffer stats: NMS %f, RMS %f, audio length %f", NMS,
RMS, gst_guint64_to_gdouble (duration));
if (RMS < filter->threshold_level)
filter->silent_run_length += gst_guint64_to_gdouble (duration);
else {
filter->silent_run_length = 0 * GST_SECOND;
filter->silent = FALSE;
}
if (filter->silent_run_length > filter->threshold_length)
/* it has been silent long enough, flag it */
filter->silent = TRUE;
/* has the silent status changed ? if so, send right signal
* and, if from silent -> not silent, flush pre_record buffer
*/
if (filter->silent != filter->silent_prev) {
if (filter->silent) {
GstMessage *m =
gst_cutter_message_new (filter, FALSE, GST_BUFFER_TIMESTAMP (buf));
GST_DEBUG_OBJECT (filter, "signaling CUT_STOP");
gst_element_post_message (GST_ELEMENT (filter), m);
} else {
gint count = 0;
GstMessage *m =
gst_cutter_message_new (filter, TRUE, GST_BUFFER_TIMESTAMP (buf));
GST_DEBUG_OBJECT (filter, "signaling CUT_START");
gst_element_post_message (GST_ELEMENT (filter), m);
/* first of all, flush current buffer */
GST_DEBUG_OBJECT (filter, "flushing buffer of length %" GST_TIME_FORMAT,
GST_TIME_ARGS (filter->pre_run_length));
while (filter->pre_buffer) {
prebuf = (g_list_first (filter->pre_buffer))->data;
filter->pre_buffer = g_list_remove (filter->pre_buffer, prebuf);
gst_pad_push (filter->srcpad, prebuf);
++count;
}
GST_DEBUG_OBJECT (filter, "flushed %d buffers", count);
filter->pre_run_length = 0 * GST_SECOND;
}
}
/* now check if we have to send the new buffer to the internal buffer cache
* or to the srcpad */
if (filter->silent) {
filter->pre_buffer = g_list_append (filter->pre_buffer, buf);
filter->pre_run_length += gst_guint64_to_gdouble (duration);
while (filter->pre_run_length > filter->pre_length) {
GstClockTime pduration;
gsize psize;
prebuf = (g_list_first (filter->pre_buffer))->data;
g_assert (GST_IS_BUFFER (prebuf));
psize = gst_buffer_get_size (prebuf);
pduration = gst_util_uint64_scale (psize / bpf, GST_SECOND, rate);
filter->pre_buffer = g_list_remove (filter->pre_buffer, prebuf);
filter->pre_run_length -= gst_guint64_to_gdouble (pduration);
/* only pass buffers if we don't leak */
if (!filter->leaky)
ret = gst_pad_push (filter->srcpad, prebuf);
else
gst_buffer_unref (prebuf);
}
} else
ret = gst_pad_push (filter->srcpad, buf);
return ret;
/* ERRORS */
not_negotiated:
{
return GST_FLOW_NOT_NEGOTIATED;
}
}
static void
gst_cutter_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstCutter *filter;
g_return_if_fail (GST_IS_CUTTER (object));
filter = GST_CUTTER (object);
switch (prop_id) {
case PROP_THRESHOLD:
filter->threshold_level = g_value_get_double (value);
GST_DEBUG ("DEBUG: set threshold level to %f", filter->threshold_level);
break;
case PROP_THRESHOLD_DB:
/* set the level given in dB
* value in dB = 20 * log (value)
* values in dB < 0 result in values between 0 and 1
*/
filter->threshold_level = pow (10, g_value_get_double (value) / 20);
GST_DEBUG_OBJECT (filter, "set threshold level to %f",
filter->threshold_level);
break;
case PROP_RUN_LENGTH:
/* set the minimum length of the silent run required */
filter->threshold_length =
gst_guint64_to_gdouble (g_value_get_uint64 (value));
break;
case PROP_PRE_LENGTH:
/* set the length of the pre-record block */
filter->pre_length = gst_guint64_to_gdouble (g_value_get_uint64 (value));
break;
case PROP_LEAKY:
/* set if the pre-record buffer is leaky or not */
filter->leaky = g_value_get_boolean (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_cutter_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstCutter *filter;
g_return_if_fail (GST_IS_CUTTER (object));
filter = GST_CUTTER (object);
switch (prop_id) {
case PROP_RUN_LENGTH:
g_value_set_uint64 (value, filter->threshold_length);
break;
case PROP_THRESHOLD:
g_value_set_double (value, filter->threshold_level);
break;
case PROP_THRESHOLD_DB:
g_value_set_double (value, 20 * log (filter->threshold_level));
break;
case PROP_PRE_LENGTH:
g_value_set_uint64 (value, filter->pre_length);
break;
case PROP_LEAKY:
g_value_set_boolean (value, filter->leaky);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
plugin_init (GstPlugin * plugin)
{
if (!gst_element_register (plugin, "cutter", GST_RANK_NONE, GST_TYPE_CUTTER))
return FALSE;
return TRUE;
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
cutter,
"Audio Cutter to split audio into non-silent bits",
plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);