/* GStreamer * Copyright (C) <1999> Erik Walthinsen * Copyright (C) 2002,2003,2005 * Thomas Vander Stichele * * 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 * "cutter". * The message's structure contains two fields: * * * * #GstClockTime * "timestamp": * the timestamp of the buffer that triggered the message. * * * * * gboolean * "above": * %TRUE for begin of silence and %FALSE for end of silence. * * * * * * Example launch line * |[ * gst-launch-1.0 -m filesrc location=foo.ogg ! decodebin ! audioconvert ! cutter ! autoaudiosink * ]| Show cut messages. * */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #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 "); } 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);