1 /*
2 * Farsight
3 * GStreamer GSM encoder
4 * Copyright (C) 2005 Philippe Khalaf <burger@speedy.org>
5 *
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 of the License, or (at your option) any later version.
10 *
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.
15 *
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., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 */
21
22
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26 #include <string.h>
27
28 #include "gstgsmdec.h"
29
30 GST_DEBUG_CATEGORY_STATIC (gsmdec_debug);
31 #define GST_CAT_DEFAULT (gsmdec_debug)
32
33 /* GSMDec signals and args */
34 enum
35 {
36 /* FILL ME */
37 LAST_SIGNAL
38 };
39
40 enum
41 {
42 /* FILL ME */
43 ARG_0
44 };
45
46 static gboolean gst_gsmdec_start (GstAudioDecoder * dec);
47 static gboolean gst_gsmdec_stop (GstAudioDecoder * dec);
48 static gboolean gst_gsmdec_set_format (GstAudioDecoder * dec, GstCaps * caps);
49 static GstFlowReturn gst_gsmdec_parse (GstAudioDecoder * dec,
50 GstAdapter * adapter, gint * offset, gint * length);
51 static GstFlowReturn gst_gsmdec_handle_frame (GstAudioDecoder * dec,
52 GstBuffer * in_buf);
53
54 /*static guint gst_gsmdec_signals[LAST_SIGNAL] = { 0 }; */
55
56 #define ENCODED_SAMPLES 160
57
58 static GstStaticPadTemplate gsmdec_sink_template =
59 GST_STATIC_PAD_TEMPLATE ("sink",
60 GST_PAD_SINK,
61 GST_PAD_ALWAYS,
62 GST_STATIC_CAPS ("audio/x-gsm, rate = (int) 8000, channels = (int) 1; "
63 "audio/ms-gsm, rate = (int) [1, MAX], channels = (int) 1")
64 );
65
66 static GstStaticPadTemplate gsmdec_src_template =
67 GST_STATIC_PAD_TEMPLATE ("src",
68 GST_PAD_SRC,
69 GST_PAD_ALWAYS,
70 GST_STATIC_CAPS ("audio/x-raw, "
71 "format = (string) " GST_AUDIO_NE (S16) ", "
72 "layout = (string) interleaved, "
73 "rate = (int) [1, MAX], channels = (int) 1")
74 );
75
76 G_DEFINE_TYPE (GstGSMDec, gst_gsmdec, GST_TYPE_AUDIO_DECODER);
77
78 static void
gst_gsmdec_class_init(GstGSMDecClass * klass)79 gst_gsmdec_class_init (GstGSMDecClass * klass)
80 {
81 GstElementClass *element_class;
82 GstAudioDecoderClass *base_class;
83
84 element_class = (GstElementClass *) klass;
85 base_class = (GstAudioDecoderClass *) klass;
86
87 gst_element_class_add_static_pad_template (element_class,
88 &gsmdec_sink_template);
89 gst_element_class_add_static_pad_template (element_class,
90 &gsmdec_src_template);
91 gst_element_class_set_static_metadata (element_class, "GSM audio decoder",
92 "Codec/Decoder/Audio", "Decodes GSM encoded audio",
93 "Philippe Khalaf <burger@speedy.org>");
94
95 base_class->start = GST_DEBUG_FUNCPTR (gst_gsmdec_start);
96 base_class->stop = GST_DEBUG_FUNCPTR (gst_gsmdec_stop);
97 base_class->set_format = GST_DEBUG_FUNCPTR (gst_gsmdec_set_format);
98 base_class->parse = GST_DEBUG_FUNCPTR (gst_gsmdec_parse);
99 base_class->handle_frame = GST_DEBUG_FUNCPTR (gst_gsmdec_handle_frame);
100
101 GST_DEBUG_CATEGORY_INIT (gsmdec_debug, "gsmdec", 0, "GSM Decoder");
102 }
103
104 static void
gst_gsmdec_init(GstGSMDec * gsmdec)105 gst_gsmdec_init (GstGSMDec * gsmdec)
106 {
107 gst_audio_decoder_set_needs_format (GST_AUDIO_DECODER (gsmdec), TRUE);
108 gst_audio_decoder_set_use_default_pad_acceptcaps (GST_AUDIO_DECODER_CAST
109 (gsmdec), TRUE);
110 GST_PAD_SET_ACCEPT_TEMPLATE (GST_AUDIO_DECODER_SINK_PAD (gsmdec));
111 }
112
113 static gboolean
gst_gsmdec_start(GstAudioDecoder * dec)114 gst_gsmdec_start (GstAudioDecoder * dec)
115 {
116 GstGSMDec *gsmdec = GST_GSMDEC (dec);
117
118 GST_DEBUG_OBJECT (dec, "start");
119
120 gsmdec->state = gsm_create ();
121
122 return TRUE;
123 }
124
125 static gboolean
gst_gsmdec_stop(GstAudioDecoder * dec)126 gst_gsmdec_stop (GstAudioDecoder * dec)
127 {
128 GstGSMDec *gsmdec = GST_GSMDEC (dec);
129
130 GST_DEBUG_OBJECT (dec, "stop");
131
132 gsm_destroy (gsmdec->state);
133
134 return TRUE;
135 }
136
137 static gboolean
gst_gsmdec_set_format(GstAudioDecoder * dec,GstCaps * caps)138 gst_gsmdec_set_format (GstAudioDecoder * dec, GstCaps * caps)
139 {
140 GstGSMDec *gsmdec;
141 GstStructure *s;
142 gboolean ret = FALSE;
143 gint rate;
144 GstAudioInfo info;
145
146 gsmdec = GST_GSMDEC (dec);
147
148 s = gst_caps_get_structure (caps, 0);
149 if (s == NULL)
150 goto wrong_caps;
151
152 /* figure out if we deal with plain or MSGSM */
153 if (gst_structure_has_name (s, "audio/x-gsm"))
154 gsmdec->use_wav49 = 0;
155 else if (gst_structure_has_name (s, "audio/ms-gsm"))
156 gsmdec->use_wav49 = 1;
157 else
158 goto wrong_caps;
159
160 gsmdec->needed = 33;
161
162 if (!gst_structure_get_int (s, "rate", &rate)) {
163 GST_WARNING_OBJECT (gsmdec, "missing sample rate parameter from sink caps");
164 goto beach;
165 }
166
167 /* MSGSM needs different framing */
168 gsm_option (gsmdec->state, GSM_OPT_WAV49, &gsmdec->use_wav49);
169
170 /* Setting up src caps based on the input sample rate. */
171 gst_audio_info_init (&info);
172 gst_audio_info_set_format (&info, GST_AUDIO_FORMAT_S16, rate, 1, NULL);
173
174 ret = gst_audio_decoder_set_output_format (dec, &info);
175
176 return ret;
177
178 /* ERRORS */
179 wrong_caps:
180
181 GST_ERROR_OBJECT (gsmdec, "invalid caps received");
182
183 beach:
184
185 return ret;
186 }
187
188 static GstFlowReturn
gst_gsmdec_parse(GstAudioDecoder * dec,GstAdapter * adapter,gint * offset,gint * length)189 gst_gsmdec_parse (GstAudioDecoder * dec, GstAdapter * adapter,
190 gint * offset, gint * length)
191 {
192 GstGSMDec *gsmdec = GST_GSMDEC (dec);
193 guint size;
194
195 size = gst_adapter_available (adapter);
196
197 /* if input format is TIME each buffer should be self-contained and
198 * the data is presumably packetised, and we should start with a clean
199 * slate/state at the beginning of each buffer (for wav49 case) */
200 if (dec->input_segment.format == GST_FORMAT_TIME) {
201 *offset = 0;
202 *length = size;
203 gsmdec->needed = 33;
204 return GST_FLOW_OK;
205 }
206
207 g_return_val_if_fail (size > 0, GST_FLOW_ERROR);
208
209 if (size < gsmdec->needed)
210 return GST_FLOW_EOS;
211
212 *offset = 0;
213 *length = gsmdec->needed;
214
215 /* WAV49 requires alternating 33 and 32 bytes of input */
216 if (gsmdec->use_wav49) {
217 gsmdec->needed = (gsmdec->needed == 33 ? 32 : 33);
218 }
219
220 return GST_FLOW_OK;
221 }
222
223 static guint
gst_gsmdec_get_frame_count(GstGSMDec * dec,gsize buffer_size)224 gst_gsmdec_get_frame_count (GstGSMDec * dec, gsize buffer_size)
225 {
226 guint count;
227
228 if (dec->use_wav49) {
229 count = (buffer_size / (33 + 32)) * 2;
230 if (buffer_size % (33 + 32) >= dec->needed)
231 ++count;
232 } else {
233 count = buffer_size / 33;
234 }
235
236 return count;
237 }
238
239 static GstFlowReturn
gst_gsmdec_handle_frame(GstAudioDecoder * dec,GstBuffer * buffer)240 gst_gsmdec_handle_frame (GstAudioDecoder * dec, GstBuffer * buffer)
241 {
242 GstGSMDec *gsmdec;
243 gsm_signal *out_data;
244 gsm_byte *data;
245 GstFlowReturn ret = GST_FLOW_OK;
246 GstBuffer *outbuf;
247 GstMapInfo map, omap;
248 gsize outsize;
249 guint frames, i, errors = 0;
250
251 /* no fancy draining */
252 if (G_UNLIKELY (!buffer))
253 return GST_FLOW_OK;
254
255 gsmdec = GST_GSMDEC (dec);
256
257 gst_buffer_map (buffer, &map, GST_MAP_READ);
258
259 frames = gst_gsmdec_get_frame_count (gsmdec, map.size);
260
261 /* always the same amount of output samples (20ms worth per frame) */
262 outsize = ENCODED_SAMPLES * frames * sizeof (gsm_signal);
263 outbuf = gst_buffer_new_and_alloc (outsize);
264
265 gst_buffer_map (outbuf, &omap, GST_MAP_WRITE);
266 out_data = (gsm_signal *) omap.data;
267 data = (gsm_byte *) map.data;
268
269 for (i = 0; i < frames; ++i) {
270 /* now encode frame into the output buffer */
271 if (gsm_decode (gsmdec->state, data, out_data) < 0) {
272 /* invalid frame */
273 GST_AUDIO_DECODER_ERROR (gsmdec, 1, STREAM, DECODE, (NULL),
274 ("tried to decode an invalid frame"), ret);
275 memset (out_data, 0, ENCODED_SAMPLES * sizeof (gsm_signal));
276 ++errors;
277 }
278 out_data += ENCODED_SAMPLES;
279 data += gsmdec->needed;
280 if (gsmdec->use_wav49)
281 gsmdec->needed = (gsmdec->needed == 33 ? 32 : 33);
282 }
283
284 gst_buffer_unmap (outbuf, &omap);
285 gst_buffer_unmap (buffer, &map);
286
287 if (errors == frames) {
288 gst_buffer_unref (outbuf);
289 outbuf = NULL;
290 }
291
292 gst_audio_decoder_finish_frame (dec, outbuf, 1);
293
294 return ret;
295 }
296