2 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
20 * SECTION:element-mulawdec
22 * This element decodes mulaw audio. Mulaw coding is also known as G.711.
30 #include "mulaw-decode.h"
31 #include "mulaw-conversion.h"
33 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
34 #define INT_FORMAT "S16_LE"
36 #define INT_FORMAT "S16_BE"
39 extern GstStaticPadTemplate mulaw_dec_src_factory;
40 extern GstStaticPadTemplate mulaw_dec_sink_factory;
42 /* Stereo signals and args */
54 static GstStateChangeReturn
55 gst_mulawdec_change_state (GstElement * element, GstStateChange transition);
57 static gboolean gst_mulawdec_event (GstPad * pad, GstEvent * event);
58 static GstFlowReturn gst_mulawdec_chain (GstPad * pad, GstBuffer * buffer);
60 #define gst_mulawdec_parent_class parent_class
61 G_DEFINE_TYPE (GstMuLawDec, gst_mulawdec, GST_TYPE_ELEMENT);
64 mulawdec_setcaps (GstMuLawDec * mulawdec, GstCaps * caps)
66 GstStructure *structure;
71 structure = gst_caps_get_structure (caps, 0);
72 ret = gst_structure_get_int (structure, "rate", &rate);
73 ret = ret && gst_structure_get_int (structure, "channels", &channels);
77 outcaps = gst_caps_new_simple ("audio/x-raw",
78 "format", G_TYPE_STRING, INT_FORMAT,
79 "rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, channels, NULL);
80 ret = gst_pad_set_caps (mulawdec->srcpad, outcaps);
81 gst_caps_unref (outcaps);
84 GST_DEBUG_OBJECT (mulawdec, "rate=%d, channels=%d", rate, channels);
85 mulawdec->rate = rate;
86 mulawdec->channels = channels;
92 mulawdec_getcaps (GstPad * pad, GstCaps * filter)
94 GstMuLawDec *mulawdec;
96 GstCaps *othercaps, *result;
101 mulawdec = GST_MULAWDEC (GST_PAD_PARENT (pad));
103 /* figure out the name of the caps we are going to return */
104 if (pad == mulawdec->srcpad) {
105 name = "audio/x-raw";
106 otherpad = mulawdec->sinkpad;
108 name = "audio/x-mulaw";
109 otherpad = mulawdec->srcpad;
111 /* get caps from the peer, this can return NULL when there is no peer */
112 othercaps = gst_pad_peer_get_caps (otherpad, filter);
114 /* get the template caps to make sure we return something acceptable */
115 templ = gst_pad_get_pad_template_caps (pad);
118 /* there was a peer */
119 othercaps = gst_caps_make_writable (othercaps);
121 /* go through the caps and remove the fields we don't want */
122 for (i = 0; i < gst_caps_get_size (othercaps); i++) {
123 GstStructure *structure;
125 structure = gst_caps_get_structure (othercaps, i);
127 /* adjust the name */
128 gst_structure_set_name (structure, name);
130 if (pad == mulawdec->sinkpad) {
131 /* remove the fields we don't want */
132 gst_structure_remove_fields (structure, "format", NULL);
134 /* add fixed fields */
135 gst_structure_set (structure, "format", G_TYPE_STRING, INT_FORMAT,
139 /* filter against the allowed caps of the pad to return our result */
140 result = gst_caps_intersect (othercaps, templ);
141 gst_caps_unref (othercaps);
143 /* there was no peer, return the template caps */
144 result = gst_caps_copy (templ);
150 gst_mulawdec_class_init (GstMuLawDecClass * klass)
152 GstElementClass *element_class = (GstElementClass *) klass;
154 gst_element_class_add_pad_template (element_class,
155 gst_static_pad_template_get (&mulaw_dec_src_factory));
156 gst_element_class_add_pad_template (element_class,
157 gst_static_pad_template_get (&mulaw_dec_sink_factory));
159 gst_element_class_set_details_simple (element_class, "Mu Law audio decoder",
160 "Codec/Decoder/Audio",
161 "Convert 8bit mu law to 16bit PCM",
162 "Zaheer Abbas Merali <zaheerabbas at merali dot org>");
164 element_class->change_state = GST_DEBUG_FUNCPTR (gst_mulawdec_change_state);
168 gst_mulawdec_init (GstMuLawDec * mulawdec)
171 gst_pad_new_from_static_template (&mulaw_dec_sink_factory, "sink");
172 gst_pad_set_getcaps_function (mulawdec->sinkpad, mulawdec_getcaps);
173 gst_pad_set_event_function (mulawdec->sinkpad, gst_mulawdec_event);
174 gst_pad_set_chain_function (mulawdec->sinkpad, gst_mulawdec_chain);
175 gst_element_add_pad (GST_ELEMENT (mulawdec), mulawdec->sinkpad);
178 gst_pad_new_from_static_template (&mulaw_dec_src_factory, "src");
179 gst_pad_use_fixed_caps (mulawdec->srcpad);
180 gst_pad_set_getcaps_function (mulawdec->srcpad, mulawdec_getcaps);
181 gst_element_add_pad (GST_ELEMENT (mulawdec), mulawdec->srcpad);
185 gst_mulawdec_event (GstPad * pad, GstEvent * event)
187 GstMuLawDec *mulawdec;
190 mulawdec = GST_MULAWDEC (GST_PAD_PARENT (pad));
192 switch (GST_EVENT_TYPE (event)) {
197 gst_event_parse_caps (event, &caps);
198 mulawdec_setcaps (mulawdec, caps);
199 gst_event_unref (event);
205 res = gst_pad_event_default (pad, event);
212 gst_mulawdec_chain (GstPad * pad, GstBuffer * buffer)
214 GstMuLawDec *mulawdec;
217 gsize mulaw_size, linear_size;
221 mulawdec = GST_MULAWDEC (GST_PAD_PARENT (pad));
223 if (G_UNLIKELY (mulawdec->rate == 0))
226 mulaw_data = gst_buffer_map (buffer, &mulaw_size, NULL, GST_MAP_READ);
228 linear_size = mulaw_size * 2;
230 outbuf = gst_buffer_new_allocate (NULL, linear_size, 0);
231 linear_data = gst_buffer_map (outbuf, NULL, NULL, GST_MAP_WRITE);
233 /* copy discont flag */
234 if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
235 GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DISCONT);
237 GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
238 if (GST_BUFFER_DURATION (outbuf) == GST_CLOCK_TIME_NONE)
239 GST_BUFFER_DURATION (outbuf) = gst_util_uint64_scale_int (GST_SECOND,
240 linear_size, 2 * mulawdec->rate * mulawdec->channels);
242 GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);
244 mulaw_decode (mulaw_data, linear_data, mulaw_size);
246 gst_buffer_unmap (outbuf, linear_data, -1);
247 gst_buffer_unmap (buffer, mulaw_data, -1);
248 gst_buffer_unref (buffer);
250 ret = gst_pad_push (mulawdec->srcpad, outbuf);
257 GST_WARNING_OBJECT (mulawdec, "no input format set: not-negotiated");
258 gst_buffer_unref (buffer);
259 return GST_FLOW_NOT_NEGOTIATED;
263 static GstStateChangeReturn
264 gst_mulawdec_change_state (GstElement * element, GstStateChange transition)
266 GstStateChangeReturn ret;
267 GstMuLawDec *dec = GST_MULAWDEC (element);
269 switch (transition) {
274 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
275 if (ret != GST_STATE_CHANGE_SUCCESS)
278 switch (transition) {
279 case GST_STATE_CHANGE_PAUSED_TO_READY: