1 /* GStreamer A-Law to PCM conversion
2 * Copyright (C) 2000 by Abramo Bagnara <abramo@alsa-project.org>
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 2.1 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-alawdec
22 * This element decodes alaw audio. Alaw coding is also known as G.711.
29 #include "alaw-decode.h"
31 extern GstStaticPadTemplate alaw_dec_src_factory;
32 extern GstStaticPadTemplate alaw_dec_sink_factory;
34 GST_DEBUG_CATEGORY_STATIC (alaw_dec_debug);
35 #define GST_CAT_DEFAULT alaw_dec_debug
37 static GstStateChangeReturn
38 gst_alaw_dec_change_state (GstElement * element, GstStateChange transition);
40 static gboolean gst_alaw_dec_event (GstPad * pad, GstObject * parent,
42 static GstFlowReturn gst_alaw_dec_chain (GstPad * pad, GstObject * parent,
45 #define gst_alaw_dec_parent_class parent_class
46 G_DEFINE_TYPE (GstALawDec, gst_alaw_dec, GST_TYPE_ELEMENT);
48 /* some day we might have defines in gstconfig.h that tell us about the
49 * desired cpu/memory/binary size trade-offs */
50 #define GST_ALAW_DEC_USE_TABLE
52 #ifdef GST_ALAW_DEC_USE_TABLE
54 static const gint alaw_to_s16_table[256] = {
55 -5504, -5248, -6016, -5760, -4480, -4224, -4992, -4736,
56 -7552, -7296, -8064, -7808, -6528, -6272, -7040, -6784,
57 -2752, -2624, -3008, -2880, -2240, -2112, -2496, -2368,
58 -3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392,
59 -22016, -20992, -24064, -23040, -17920, -16896, -19968, -18944,
60 -30208, -29184, -32256, -31232, -26112, -25088, -28160, -27136,
61 -11008, -10496, -12032, -11520, -8960, -8448, -9984, -9472,
62 -15104, -14592, -16128, -15616, -13056, -12544, -14080, -13568,
63 -344, -328, -376, -360, -280, -264, -312, -296,
64 -472, -456, -504, -488, -408, -392, -440, -424,
65 -88, -72, -120, -104, -24, -8, -56, -40,
66 -216, -200, -248, -232, -152, -136, -184, -168,
67 -1376, -1312, -1504, -1440, -1120, -1056, -1248, -1184,
68 -1888, -1824, -2016, -1952, -1632, -1568, -1760, -1696,
69 -688, -656, -752, -720, -560, -528, -624, -592,
70 -944, -912, -1008, -976, -816, -784, -880, -848,
71 5504, 5248, 6016, 5760, 4480, 4224, 4992, 4736,
72 7552, 7296, 8064, 7808, 6528, 6272, 7040, 6784,
73 2752, 2624, 3008, 2880, 2240, 2112, 2496, 2368,
74 3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392,
75 22016, 20992, 24064, 23040, 17920, 16896, 19968, 18944,
76 30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136,
77 11008, 10496, 12032, 11520, 8960, 8448, 9984, 9472,
78 15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568,
79 344, 328, 376, 360, 280, 264, 312, 296,
80 472, 456, 504, 488, 408, 392, 440, 424,
81 88, 72, 120, 104, 24, 8, 56, 40,
82 216, 200, 248, 232, 152, 136, 184, 168,
83 1376, 1312, 1504, 1440, 1120, 1056, 1248, 1184,
84 1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696,
85 688, 656, 752, 720, 560, 528, 624, 592,
86 944, 912, 1008, 976, 816, 784, 880, 848
90 alaw_to_s16 (guint8 a_val)
92 return alaw_to_s16_table[a_val];
95 #else /* GST_ALAW_DEC_USE_TABLE */
98 alaw_to_s16 (guint8 a_val)
108 seg = (t >> 4) & 0x07;
109 t = ((t & 0x0f) << 4) + 0x108;
112 return ((a_val & 0x80) ? t : -t);
115 #endif /* GST_ALAW_DEC_USE_TABLE */
118 gst_alaw_dec_setcaps (GstALawDec * alawdec, GstCaps * caps)
120 GstStructure *structure;
125 structure = gst_caps_get_structure (caps, 0);
127 ret = gst_structure_get_int (structure, "rate", &rate);
128 ret &= gst_structure_get_int (structure, "channels", &channels);
132 outcaps = gst_caps_new_simple ("audio/x-raw-int",
133 "width", G_TYPE_INT, 16,
134 "depth", G_TYPE_INT, 16,
135 "endianness", G_TYPE_INT, G_BYTE_ORDER,
136 "signed", G_TYPE_BOOLEAN, TRUE,
137 "rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, channels, NULL);
139 ret = gst_pad_set_caps (alawdec->srcpad, outcaps);
140 gst_caps_unref (outcaps);
143 GST_DEBUG_OBJECT (alawdec, "rate=%d, channels=%d", rate, channels);
144 alawdec->rate = rate;
145 alawdec->channels = channels;
151 gst_alaw_dec_getcaps (GstPad * pad, GstCaps * filter)
155 GstCaps *othercaps, *result;
156 const GstCaps *templ;
160 alawdec = GST_ALAW_DEC (GST_PAD_PARENT (pad));
162 /* figure out the name of the caps we are going to return */
163 if (pad == alawdec->srcpad) {
164 name = "audio/x-raw-int";
165 otherpad = alawdec->sinkpad;
167 name = "audio/x-alaw";
168 otherpad = alawdec->srcpad;
170 /* get caps from the peer, this can return NULL when there is no peer */
171 othercaps = gst_pad_peer_query_caps (otherpad, filter);
173 /* get the template caps to make sure we return something acceptable */
174 templ = gst_pad_get_pad_template_caps (pad);
177 /* there was a peer */
178 othercaps = gst_caps_make_writable (othercaps);
180 /* go through the caps and remove the fields we don't want */
181 for (i = 0; i < gst_caps_get_size (othercaps); i++) {
182 GstStructure *structure;
184 structure = gst_caps_get_structure (othercaps, i);
186 /* adjust the name */
187 gst_structure_set_name (structure, name);
189 if (pad == alawdec->sinkpad) {
190 /* remove the fields we don't want */
191 gst_structure_remove_fields (structure, "width", "depth", "endianness",
194 /* add fixed fields */
195 gst_structure_set (structure, "width", G_TYPE_INT, 16,
196 "depth", G_TYPE_INT, 16,
197 "endianness", G_TYPE_INT, G_BYTE_ORDER,
198 "signed", G_TYPE_BOOLEAN, TRUE, NULL);
201 /* filter against the allowed caps of the pad to return our result */
202 result = gst_caps_intersect (othercaps, templ);
203 gst_caps_unref (othercaps);
205 /* there was no peer, return the template caps */
206 result = gst_caps_copy (templ);
213 gst_alaw_dec_query (GstPad * pad, GstObject * parent, GstQuery * query)
217 switch (GST_QUERY_TYPE (query)) {
220 GstCaps *filter, *caps;
222 gst_query_parse_caps (query, &filter);
223 caps = gst_alaw_dec_getcaps (pad, filter);
224 gst_query_set_caps_result (query, caps);
225 gst_caps_unref (caps);
231 res = gst_pad_query_default (pad, parent, query);
238 gst_alaw_dec_class_init (GstALawDecClass * klass)
240 GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
242 gst_element_class_add_pad_template (element_class,
243 gst_static_pad_template_get (&alaw_dec_src_factory));
244 gst_element_class_add_pad_template (element_class,
245 gst_static_pad_template_get (&alaw_dec_sink_factory));
247 gst_element_class_set_details_simple (element_class, "A Law audio decoder",
248 "Codec/Decoder/Audio", "Convert 8bit A law to 16bit PCM",
249 "Zaheer Abbas Merali <zaheerabbas at merali dot org>");
251 element_class->change_state = GST_DEBUG_FUNCPTR (gst_alaw_dec_change_state);
253 GST_DEBUG_CATEGORY_INIT (alaw_dec_debug, "alawdec", 0, "A Law audio decoder");
257 gst_alaw_dec_init (GstALawDec * alawdec)
260 gst_pad_new_from_static_template (&alaw_dec_sink_factory, "sink");
261 gst_pad_set_query_function (alawdec->sinkpad,
262 GST_DEBUG_FUNCPTR (gst_alaw_dec_query));
263 gst_pad_set_event_function (alawdec->sinkpad,
264 GST_DEBUG_FUNCPTR (gst_alaw_dec_event));
265 gst_pad_set_chain_function (alawdec->sinkpad,
266 GST_DEBUG_FUNCPTR (gst_alaw_dec_chain));
267 gst_element_add_pad (GST_ELEMENT (alawdec), alawdec->sinkpad);
270 gst_pad_new_from_static_template (&alaw_dec_src_factory, "src");
271 gst_pad_use_fixed_caps (alawdec->srcpad);
272 gst_pad_set_query_function (alawdec->srcpad,
273 GST_DEBUG_FUNCPTR (gst_alaw_dec_query));
274 gst_element_add_pad (GST_ELEMENT (alawdec), alawdec->srcpad);
278 gst_alaw_dec_event (GstPad * pad, GstObject * parent, GstEvent * event)
283 alawdec = GST_ALAW_DEC (parent);
285 switch (GST_EVENT_TYPE (event)) {
290 gst_event_parse_caps (event, &caps);
291 gst_alaw_dec_setcaps (alawdec, caps);
292 gst_event_unref (event);
298 res = gst_pad_event_default (pad, parent, event);
305 gst_alaw_dec_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
315 alawdec = GST_ALAW_DEC (parent);
317 if (G_UNLIKELY (alawdec->rate == 0))
320 GST_LOG_OBJECT (alawdec, "buffer with ts=%" GST_TIME_FORMAT,
321 GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)));
323 alaw_data = gst_buffer_map (buffer, &alaw_size, NULL, GST_MAP_READ);
325 outbuf = gst_buffer_new_allocate (NULL, alaw_size, 0);
327 linear_data = gst_buffer_map (outbuf, NULL, NULL, GST_MAP_WRITE);
329 /* copy discont flag */
330 if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
331 GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DISCONT);
333 GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
334 GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);
336 for (i = 0; i < alaw_size; i++) {
337 linear_data[i] = alaw_to_s16 (alaw_data[i]);
340 gst_buffer_unmap (outbuf, linear_data, -1);
341 gst_buffer_unmap (buffer, alaw_data, -1);
342 gst_buffer_unref (buffer);
344 ret = gst_pad_push (alawdec->srcpad, outbuf);
350 gst_buffer_unref (buffer);
351 GST_WARNING_OBJECT (alawdec, "no input format set: not-negotiated");
352 return GST_FLOW_NOT_NEGOTIATED;
356 static GstStateChangeReturn
357 gst_alaw_dec_change_state (GstElement * element, GstStateChange transition)
359 GstStateChangeReturn ret;
360 GstALawDec *dec = GST_ALAW_DEC (element);
362 switch (transition) {
367 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
368 if (ret != GST_STATE_CHANGE_SUCCESS)
371 switch (transition) {
372 case GST_STATE_CHANGE_PAUSED_TO_READY: