2 * Copyright (C) 1999 Erik Walthinsen <omega@cse.ogi.edu>
3 * PCM - A-Law conversion
4 * Copyright (C) 2000 by Abramo Bagnara <abramo@alsa-project.org>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
26 #include "alaw-decode.h"
28 extern GstPadTemplate *alawdec_src_template, *alawdec_sink_template;
30 /* elementfactory information */
31 static GstElementDetails alawdec_details = {
32 "A Law to PCM conversion",
33 "Codec/Decoder/Audio",
34 "Convert 8bit A law to 16bit PCM",
35 "Zaheer Merali <zaheer@bellworldwide.net>"
38 /* Stereo signals and args */
48 static void gst_alawdec_class_init (GstALawDecClass *klass);
49 static void gst_alawdec_base_init (GstALawDecClass *klass);
50 static void gst_alawdec_init (GstALawDec *alawdec);
52 static void gst_alawdec_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
53 static void gst_alawdec_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
55 static void gst_alawdec_chain (GstPad *pad, GstData *_data);
58 static GstElementClass *parent_class = NULL;
59 /*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 }; */
62 * alaw_to_s16() - Convert an A-law value to 16-bit linear PCM
65 static gint alaw_to_s16(guint8 a_val)
75 seg = (t >> 4) & 0x07;
76 t = ((t & 0x0f) << 4) + 0x108;
79 return ((a_val & 0x80) ? t : -t);
82 static GstPadLinkReturn
83 alawdec_link (GstPad *pad, const GstCaps *caps)
87 GstStructure *structure;
90 GstALawDec* alawdec = GST_ALAWDEC (GST_OBJECT_PARENT (pad));
92 structure = gst_caps_get_structure (caps, 0);
94 ret = gst_structure_get_int (structure, "rate", &rate);
95 ret &= gst_structure_get_int (structure, "channels", &channels);
96 if (!ret) return GST_PAD_LINK_REFUSED;
98 tempcaps = gst_caps_new_simple ( "audio/x-raw-int",
99 "depth", G_TYPE_INT, 16,
100 "width", G_TYPE_INT, 16,
101 "signed", G_TYPE_BOOLEAN, TRUE,
102 "endianness", G_TYPE_INT, G_BYTE_ORDER,
103 "rate", G_TYPE_INT, rate,
104 "channels", G_TYPE_INT, channels,
107 return gst_pad_try_set_caps (alawdec->srcpad, tempcaps);
111 gst_alawdec_get_type(void) {
112 static GType alawdec_type = 0;
115 static const GTypeInfo alawdec_info = {
116 sizeof(GstALawDecClass),
117 (GBaseInitFunc)gst_alawdec_base_init,
119 (GClassInitFunc)gst_alawdec_class_init,
124 (GInstanceInitFunc)gst_alawdec_init,
126 alawdec_type = g_type_register_static(GST_TYPE_ELEMENT, "GstALawDec", &alawdec_info, 0);
132 gst_alawdec_base_init (GstALawDecClass *klass)
134 GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
136 gst_element_class_add_pad_template (element_class, alawdec_src_template);
137 gst_element_class_add_pad_template (element_class, alawdec_sink_template);
138 gst_element_class_set_details (element_class, &alawdec_details);
142 gst_alawdec_class_init (GstALawDecClass *klass)
144 GObjectClass *gobject_class;
145 GstElementClass *gstelement_class;
147 gobject_class = (GObjectClass*)klass;
148 gstelement_class = (GstElementClass*)klass;
150 parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
152 gobject_class->set_property = gst_alawdec_set_property;
153 gobject_class->get_property = gst_alawdec_get_property;
157 gst_alawdec_init (GstALawDec *alawdec)
159 alawdec->sinkpad = gst_pad_new_from_template(alawdec_sink_template,"sink");
160 alawdec->srcpad = gst_pad_new_from_template(alawdec_src_template,"src");
161 gst_pad_set_link_function(alawdec->sinkpad, alawdec_link);
163 gst_element_add_pad(GST_ELEMENT(alawdec),alawdec->sinkpad);
164 gst_pad_set_chain_function(alawdec->sinkpad,gst_alawdec_chain);
165 gst_element_add_pad(GST_ELEMENT(alawdec),alawdec->srcpad);
169 gst_alawdec_chain (GstPad *pad,GstData *_data)
171 GstBuffer *buf = GST_BUFFER (_data);
178 g_return_if_fail(pad != NULL);
179 g_return_if_fail(GST_IS_PAD(pad));
180 g_return_if_fail(buf != NULL);
182 alawdec = GST_ALAWDEC(GST_OBJECT_PARENT (pad));
183 g_return_if_fail(alawdec != NULL);
184 g_return_if_fail(GST_IS_ALAWDEC(alawdec));
186 alaw_data = (guint8 *)GST_BUFFER_DATA(buf);
187 outbuf=gst_buffer_new();
188 GST_BUFFER_DATA(outbuf) = (gchar*)g_new(gint16,GST_BUFFER_SIZE(buf));
189 GST_BUFFER_SIZE(outbuf) = GST_BUFFER_SIZE(buf)*2;
191 linear_data = (gint16*)GST_BUFFER_DATA(outbuf);
192 for (i = 0; i < GST_BUFFER_SIZE(buf); i++) {
193 *linear_data = alaw_to_s16 (*alaw_data);
198 gst_buffer_unref(buf);
199 gst_pad_push(alawdec->srcpad,GST_DATA (outbuf));
203 gst_alawdec_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
207 /* it's not null if we got it, but it might not be ours */
208 g_return_if_fail(GST_IS_ALAWDEC(object));
209 alawdec = GST_ALAWDEC(object);
218 gst_alawdec_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
222 /* it's not null if we got it, but it might not be ours */
223 g_return_if_fail(GST_IS_ALAWDEC(object));
224 alawdec = GST_ALAWDEC(object);
228 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);