/* GStreamer * Copyright (C) 2013 David Schleef * * 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., 51 Franklin Street, Suite 500, * Boston, MA 02110-1335, USA. */ /** * SECTION:element-gstaudiochannelmix * @title: gstaudiochannelmix * * The audiochannelmix element mixes channels in stereo audio based on * properties set on the element. The primary purpose is reconstruct * equal left/right channels on an input stream that has audio in only * one channel. * * ## Example launch line * |[ * gst-launch-1.0 -v audiotestsrc ! audiochannelmix ! autoaudiosink * ]| * */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include "gstaudiochannelmix.h" #include GST_DEBUG_CATEGORY_STATIC (gst_audio_channel_mix_debug_category); #define GST_CAT_DEFAULT gst_audio_channel_mix_debug_category /* prototypes */ static void gst_audio_channel_mix_set_property (GObject * object, guint property_id, const GValue * value, GParamSpec * pspec); static void gst_audio_channel_mix_get_property (GObject * object, guint property_id, GValue * value, GParamSpec * pspec); static gboolean gst_audio_channel_mix_setup (GstAudioFilter * filter, const GstAudioInfo * info); static GstFlowReturn gst_audio_channel_mix_transform_ip (GstBaseTransform * trans, GstBuffer * buf); enum { PROP_0, PROP_LEFT_TO_LEFT, PROP_LEFT_TO_RIGHT, PROP_RIGHT_TO_LEFT, PROP_RIGHT_TO_RIGHT }; /* pad templates */ static GstStaticPadTemplate gst_audio_channel_mix_src_template = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-raw,format=S16LE,rate=[1,max]," "channels=2,layout=interleaved") ); static GstStaticPadTemplate gst_audio_channel_mix_sink_template = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-raw,format=S16LE,rate=[1,max]," "channels=2,layout=interleaved") ); /* class initialization */ G_DEFINE_TYPE_WITH_CODE (GstAudioChannelMix, gst_audio_channel_mix, GST_TYPE_AUDIO_FILTER, GST_DEBUG_CATEGORY_INIT (gst_audio_channel_mix_debug_category, "audiochannelmix", 0, "debug category for audiochannelmix element")); static void gst_audio_channel_mix_class_init (GstAudioChannelMixClass * klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); GstBaseTransformClass *base_transform_class = GST_BASE_TRANSFORM_CLASS (klass); GstAudioFilterClass *audio_filter_class = GST_AUDIO_FILTER_CLASS (klass); /* Setting up pads and setting metadata should be moved to base_class_init if you intend to subclass this class. */ gst_element_class_add_static_pad_template (GST_ELEMENT_CLASS (klass), &gst_audio_channel_mix_src_template); gst_element_class_add_static_pad_template (GST_ELEMENT_CLASS (klass), &gst_audio_channel_mix_sink_template); gst_element_class_set_static_metadata (GST_ELEMENT_CLASS (klass), "Simple stereo audio mixer", "Audio/Mixer", "Mixes left/right channels " "of stereo audio", "David Schleef "); gobject_class->set_property = gst_audio_channel_mix_set_property; gobject_class->get_property = gst_audio_channel_mix_get_property; audio_filter_class->setup = GST_DEBUG_FUNCPTR (gst_audio_channel_mix_setup); base_transform_class->transform_ip = GST_DEBUG_FUNCPTR (gst_audio_channel_mix_transform_ip); g_object_class_install_property (gobject_class, PROP_LEFT_TO_LEFT, g_param_spec_double ("left-to-left", "Left to Left", "Left channel to left channel gain", -G_MAXDOUBLE, G_MAXDOUBLE, 1.0, GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_LEFT_TO_RIGHT, g_param_spec_double ("left-to-right", "Left to Right", "Left channel to right channel gain", -G_MAXDOUBLE, G_MAXDOUBLE, 0.0, GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_RIGHT_TO_LEFT, g_param_spec_double ("right-to-left", "Right to Left", "Right channel to left channel gain", -G_MAXDOUBLE, G_MAXDOUBLE, 0.0, GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_RIGHT_TO_RIGHT, g_param_spec_double ("right-to-right", "Right to Right", "Right channel to right channel gain", -G_MAXDOUBLE, G_MAXDOUBLE, 1.0, GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); } static void gst_audio_channel_mix_init (GstAudioChannelMix * audiochannelmix) { audiochannelmix->left_to_left = 1.0; audiochannelmix->left_to_right = 0.0; audiochannelmix->right_to_left = 0.0; audiochannelmix->right_to_right = 1.0; } void gst_audio_channel_mix_set_property (GObject * object, guint property_id, const GValue * value, GParamSpec * pspec) { GstAudioChannelMix *audiochannelmix = GST_AUDIO_CHANNEL_MIX (object); GST_DEBUG_OBJECT (audiochannelmix, "set_property"); switch (property_id) { case PROP_LEFT_TO_LEFT: audiochannelmix->left_to_left = g_value_get_double (value); break; case PROP_LEFT_TO_RIGHT: audiochannelmix->left_to_right = g_value_get_double (value); break; case PROP_RIGHT_TO_LEFT: audiochannelmix->right_to_left = g_value_get_double (value); break; case PROP_RIGHT_TO_RIGHT: audiochannelmix->right_to_right = g_value_get_double (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec); break; } } void gst_audio_channel_mix_get_property (GObject * object, guint property_id, GValue * value, GParamSpec * pspec) { GstAudioChannelMix *audiochannelmix = GST_AUDIO_CHANNEL_MIX (object); GST_DEBUG_OBJECT (audiochannelmix, "get_property"); switch (property_id) { case PROP_LEFT_TO_LEFT: g_value_set_double (value, audiochannelmix->left_to_left); break; case PROP_LEFT_TO_RIGHT: g_value_set_double (value, audiochannelmix->left_to_right); break; case PROP_RIGHT_TO_LEFT: g_value_set_double (value, audiochannelmix->right_to_left); break; case PROP_RIGHT_TO_RIGHT: g_value_set_double (value, audiochannelmix->right_to_right); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec); break; } } static gboolean gst_audio_channel_mix_setup (GstAudioFilter * filter, const GstAudioInfo * info) { #ifndef GST_DISABLE_GST_DEBUG GstAudioChannelMix *audiochannelmix = GST_AUDIO_CHANNEL_MIX (filter); GST_DEBUG_OBJECT (audiochannelmix, "setup"); #endif return TRUE; } static GstFlowReturn gst_audio_channel_mix_transform_ip (GstBaseTransform * trans, GstBuffer * buf) { GstAudioChannelMix *audiochannelmix = GST_AUDIO_CHANNEL_MIX (trans); int n; GstMapInfo map; int i; double ll = audiochannelmix->left_to_left; double lr = audiochannelmix->left_to_right; double rl = audiochannelmix->right_to_left; double rr = audiochannelmix->right_to_right; int l, r; gint16 *data; GST_DEBUG_OBJECT (audiochannelmix, "transform_ip"); gst_buffer_map (buf, &map, GST_MAP_WRITE | GST_MAP_READ); n = gst_buffer_get_size (buf) >> 2; data = (gint16 *) map.data; for (i = 0; i < n; i++) { l = data[2 * i + 0]; r = data[2 * i + 1]; data[2 * i + 0] = CLAMP (rint (ll * l + rl * r), -32768, 32767); data[2 * i + 1] = CLAMP (rint (lr * l + rr * r), -32768, 32767); } gst_buffer_unmap (buf, &map); return GST_FLOW_OK; }