1 /* GStreamer PCM to A-Law conversion
2 * Copyright (C) 2000 by Abramo Bagnara <abramo@alsa-project.org>
3 *
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.
8 *
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.
13 *
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., 51 Franklin St, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 */
19 /**
20 * SECTION:element-alawenc
21 * @title: alawenc
22 *
23 * This element encode alaw audio. Alaw coding is also known as G.711.
24 */
25
26 #ifdef HAVE_CONFIG_H
27 #include "config.h"
28 #endif
29
30 #include <gst/audio/audio.h>
31
32 #include "alaw-encode.h"
33
34 GST_DEBUG_CATEGORY_STATIC (alaw_enc_debug);
35 #define GST_CAT_DEFAULT alaw_enc_debug
36
37 extern GstStaticPadTemplate alaw_enc_src_factory;
38 extern GstStaticPadTemplate alaw_enc_sink_factory;
39
40 G_DEFINE_TYPE (GstALawEnc, gst_alaw_enc, GST_TYPE_AUDIO_ENCODER);
41 GST_ELEMENT_REGISTER_DEFINE (alawenc, "alawenc", GST_RANK_PRIMARY,
42 GST_TYPE_ALAW_ENC);
43
44 static gboolean gst_alaw_enc_start (GstAudioEncoder * audioenc);
45 static gboolean gst_alaw_enc_set_format (GstAudioEncoder * enc,
46 GstAudioInfo * info);
47 static GstFlowReturn gst_alaw_enc_handle_frame (GstAudioEncoder * enc,
48 GstBuffer * buffer);
49
50 /* some day we might have defines in gstconfig.h that tell us about the
51 * desired cpu/memory/binary size trade-offs */
52 #define GST_ALAW_ENC_USE_TABLE
53
54 #ifdef GST_ALAW_ENC_USE_TABLE
55
56 static const guint8 alaw_encode[2048 + 1] = {
57 0xd5, 0xd4, 0xd7, 0xd6, 0xd1, 0xd0, 0xd3, 0xd2, 0xdd, 0xdc, 0xdf, 0xde,
58 0xd9, 0xd8, 0xdb, 0xda, 0xc5, 0xc4, 0xc7, 0xc6, 0xc1, 0xc0, 0xc3, 0xc2,
59 0xcd, 0xcc, 0xcf, 0xce, 0xc9, 0xc8, 0xcb, 0xca, 0xf5, 0xf5, 0xf4, 0xf4,
60 0xf7, 0xf7, 0xf6, 0xf6, 0xf1, 0xf1, 0xf0, 0xf0, 0xf3, 0xf3, 0xf2, 0xf2,
61 0xfd, 0xfd, 0xfc, 0xfc, 0xff, 0xff, 0xfe, 0xfe, 0xf9, 0xf9, 0xf8, 0xf8,
62 0xfb, 0xfb, 0xfa, 0xfa, 0xe5, 0xe5, 0xe5, 0xe5, 0xe4, 0xe4, 0xe4, 0xe4,
63 0xe7, 0xe7, 0xe7, 0xe7, 0xe6, 0xe6, 0xe6, 0xe6, 0xe1, 0xe1, 0xe1, 0xe1,
64 0xe0, 0xe0, 0xe0, 0xe0, 0xe3, 0xe3, 0xe3, 0xe3, 0xe2, 0xe2, 0xe2, 0xe2,
65 0xed, 0xed, 0xed, 0xed, 0xec, 0xec, 0xec, 0xec, 0xef, 0xef, 0xef, 0xef,
66 0xee, 0xee, 0xee, 0xee, 0xe9, 0xe9, 0xe9, 0xe9, 0xe8, 0xe8, 0xe8, 0xe8,
67 0xeb, 0xeb, 0xeb, 0xeb, 0xea, 0xea, 0xea, 0xea, 0x95, 0x95, 0x95, 0x95,
68 0x95, 0x95, 0x95, 0x95, 0x94, 0x94, 0x94, 0x94, 0x94, 0x94, 0x94, 0x94,
69 0x97, 0x97, 0x97, 0x97, 0x97, 0x97, 0x97, 0x97, 0x96, 0x96, 0x96, 0x96,
70 0x96, 0x96, 0x96, 0x96, 0x91, 0x91, 0x91, 0x91, 0x91, 0x91, 0x91, 0x91,
71 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x93, 0x93, 0x93, 0x93,
72 0x93, 0x93, 0x93, 0x93, 0x92, 0x92, 0x92, 0x92, 0x92, 0x92, 0x92, 0x92,
73 0x9d, 0x9d, 0x9d, 0x9d, 0x9d, 0x9d, 0x9d, 0x9d, 0x9c, 0x9c, 0x9c, 0x9c,
74 0x9c, 0x9c, 0x9c, 0x9c, 0x9f, 0x9f, 0x9f, 0x9f, 0x9f, 0x9f, 0x9f, 0x9f,
75 0x9e, 0x9e, 0x9e, 0x9e, 0x9e, 0x9e, 0x9e, 0x9e, 0x99, 0x99, 0x99, 0x99,
76 0x99, 0x99, 0x99, 0x99, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98,
77 0x9b, 0x9b, 0x9b, 0x9b, 0x9b, 0x9b, 0x9b, 0x9b, 0x9a, 0x9a, 0x9a, 0x9a,
78 0x9a, 0x9a, 0x9a, 0x9a, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85,
79 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x84, 0x84, 0x84, 0x84,
80 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84,
81 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87,
82 0x87, 0x87, 0x87, 0x87, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86,
83 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x81, 0x81, 0x81, 0x81,
84 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
85 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
86 0x80, 0x80, 0x80, 0x80, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83,
87 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x82, 0x82, 0x82, 0x82,
88 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82,
89 0x8d, 0x8d, 0x8d, 0x8d, 0x8d, 0x8d, 0x8d, 0x8d, 0x8d, 0x8d, 0x8d, 0x8d,
90 0x8d, 0x8d, 0x8d, 0x8d, 0x8c, 0x8c, 0x8c, 0x8c, 0x8c, 0x8c, 0x8c, 0x8c,
91 0x8c, 0x8c, 0x8c, 0x8c, 0x8c, 0x8c, 0x8c, 0x8c, 0x8f, 0x8f, 0x8f, 0x8f,
92 0x8f, 0x8f, 0x8f, 0x8f, 0x8f, 0x8f, 0x8f, 0x8f, 0x8f, 0x8f, 0x8f, 0x8f,
93 0x8e, 0x8e, 0x8e, 0x8e, 0x8e, 0x8e, 0x8e, 0x8e, 0x8e, 0x8e, 0x8e, 0x8e,
94 0x8e, 0x8e, 0x8e, 0x8e, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89,
95 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x88, 0x88, 0x88, 0x88,
96 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88,
97 0x8b, 0x8b, 0x8b, 0x8b, 0x8b, 0x8b, 0x8b, 0x8b, 0x8b, 0x8b, 0x8b, 0x8b,
98 0x8b, 0x8b, 0x8b, 0x8b, 0x8a, 0x8a, 0x8a, 0x8a, 0x8a, 0x8a, 0x8a, 0x8a,
99 0x8a, 0x8a, 0x8a, 0x8a, 0x8a, 0x8a, 0x8a, 0x8a, 0xb5, 0xb5, 0xb5, 0xb5,
100 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5,
101 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5, 0xb5,
102 0xb5, 0xb5, 0xb5, 0xb5, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4,
103 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4,
104 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4,
105 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7,
106 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7,
107 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb7, 0xb6, 0xb6, 0xb6, 0xb6,
108 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6,
109 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6, 0xb6,
110 0xb6, 0xb6, 0xb6, 0xb6, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1,
111 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1,
112 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1, 0xb1,
113 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0,
114 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0,
115 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb0, 0xb3, 0xb3, 0xb3, 0xb3,
116 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3,
117 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3, 0xb3,
118 0xb3, 0xb3, 0xb3, 0xb3, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2,
119 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2,
120 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2, 0xb2,
121 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd,
122 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd,
123 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbd, 0xbc, 0xbc, 0xbc, 0xbc,
124 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc,
125 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc, 0xbc,
126 0xbc, 0xbc, 0xbc, 0xbc, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf,
127 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf,
128 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf,
129 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe,
130 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe,
131 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xbe, 0xb9, 0xb9, 0xb9, 0xb9,
132 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9,
133 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9, 0xb9,
134 0xb9, 0xb9, 0xb9, 0xb9, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8,
135 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8,
136 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8, 0xb8,
137 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb,
138 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb,
139 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0xba, 0xba, 0xba, 0xba,
140 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba,
141 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba, 0xba,
142 0xba, 0xba, 0xba, 0xba, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
143 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
144 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
145 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
146 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
147 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa4, 0xa4, 0xa4, 0xa4,
148 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4,
149 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4,
150 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4,
151 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4,
152 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4, 0xa4,
153 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7,
154 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7,
155 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7,
156 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7,
157 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7, 0xa7,
158 0xa7, 0xa7, 0xa7, 0xa7, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6,
159 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6,
160 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6,
161 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6,
162 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6,
163 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa6, 0xa1, 0xa1, 0xa1, 0xa1,
164 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1,
165 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1,
166 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1,
167 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1,
168 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1, 0xa1,
169 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0,
170 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0,
171 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0,
172 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0,
173 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0, 0xa0,
174 0xa0, 0xa0, 0xa0, 0xa0, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3,
175 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3,
176 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3,
177 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3,
178 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3,
179 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa3, 0xa2, 0xa2, 0xa2, 0xa2,
180 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2,
181 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2,
182 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2,
183 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2,
184 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2, 0xa2,
185 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad,
186 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad,
187 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad,
188 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad,
189 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad, 0xad,
190 0xad, 0xad, 0xad, 0xad, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac,
191 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac,
192 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac,
193 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac,
194 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac,
195 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xac, 0xaf, 0xaf, 0xaf, 0xaf,
196 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf,
197 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf,
198 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf,
199 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf,
200 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf, 0xaf,
201 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae,
202 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae,
203 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae,
204 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae,
205 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae, 0xae,
206 0xae, 0xae, 0xae, 0xae, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9,
207 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9,
208 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9,
209 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9,
210 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9,
211 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa9, 0xa8, 0xa8, 0xa8, 0xa8,
212 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8,
213 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8,
214 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8,
215 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8,
216 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8, 0xa8,
217 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab,
218 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab,
219 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab,
220 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab,
221 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab, 0xab,
222 0xab, 0xab, 0xab, 0xab, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
223 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
224 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
225 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
226 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
227 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0x2a
228 };
229
230 static inline guint8
s16_to_alaw(gint16 pcm_val)231 s16_to_alaw (gint16 pcm_val)
232 {
233 if (pcm_val >= 0)
234 return alaw_encode[pcm_val / 16];
235 else
236 return (0x7F & alaw_encode[pcm_val / -16]);
237 }
238
239 #else /* GST_ALAW_ENC_USE_TABLE */
240
241 /*
242 * s16_to_alaw() - Convert a 16-bit linear PCM value to 8-bit A-law
243 *
244 * s16_to_alaw() accepts an 16-bit integer and encodes it as A-law data.
245 *
246 * Linear Input Code Compressed Code
247 * ------------------------ ---------------
248 * 0000000wxyza 000wxyz
249 * 0000001wxyza 001wxyz
250 * 000001wxyzab 010wxyz
251 * 00001wxyzabc 011wxyz
252 * 0001wxyzabcd 100wxyz
253 * 001wxyzabcde 101wxyz
254 * 01wxyzabcdef 110wxyz
255 * 1wxyzabcdefg 111wxyz
256 *
257 * For further information see John C. Bellamy's Digital Telephony, 1982,
258 * John Wiley & Sons, pps 98-111 and 472-476.
259 */
260
261 static inline gint
val_seg(gint val)262 val_seg (gint val)
263 {
264 gint r = 1;
265
266 val >>= 8;
267 if (val & 0xf0) {
268 val >>= 4;
269 r += 4;
270 }
271 if (val & 0x0c) {
272 val >>= 2;
273 r += 2;
274 }
275 if (val & 0x02)
276 r += 1;
277 return r;
278 }
279
280 static inline guint8
s16_to_alaw(gint pcm_val)281 s16_to_alaw (gint pcm_val)
282 {
283 gint seg;
284 guint8 mask;
285 guint8 aval;
286
287 if (pcm_val >= 0) {
288 mask = 0xD5;
289 } else {
290 mask = 0x55;
291 pcm_val = -pcm_val;
292 if (pcm_val > 0x7fff)
293 pcm_val = 0x7fff;
294 }
295
296 if (pcm_val < 256)
297 aval = pcm_val >> 4;
298 else {
299 /* Convert the scaled magnitude to segment number. */
300 seg = val_seg (pcm_val);
301 aval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0x0f);
302 }
303 return aval ^ mask;
304 }
305
306 #endif /* GST_ALAW_ENC_USE_TABLE */
307
308 GstStaticPadTemplate alaw_enc_sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
309 GST_PAD_SINK,
310 GST_PAD_ALWAYS,
311 GST_STATIC_CAPS ("audio/x-raw, "
312 "format = (string) " GST_AUDIO_NE (S16) ", "
313 "layout = (string) interleaved, "
314 "rate = (int) [ 8000, 192000 ], " "channels = (int) [ 1, 2 ]")
315 );
316
317 GstStaticPadTemplate alaw_enc_src_factory = GST_STATIC_PAD_TEMPLATE ("src",
318 GST_PAD_SRC,
319 GST_PAD_ALWAYS,
320 GST_STATIC_CAPS ("audio/x-alaw, "
321 "rate = [ 8000 , 192000 ], " "channels = [ 1 , 2 ]")
322 );
323
324 static gboolean
gst_alaw_enc_start(GstAudioEncoder * audioenc)325 gst_alaw_enc_start (GstAudioEncoder * audioenc)
326 {
327 GstALawEnc *alawenc = GST_ALAW_ENC (audioenc);
328
329 alawenc->channels = 0;
330 alawenc->rate = 0;
331
332 return TRUE;
333 }
334
335 static gboolean
gst_alaw_enc_set_format(GstAudioEncoder * audioenc,GstAudioInfo * info)336 gst_alaw_enc_set_format (GstAudioEncoder * audioenc, GstAudioInfo * info)
337 {
338 GstCaps *base_caps;
339 GstStructure *structure;
340 GstALawEnc *alawenc = GST_ALAW_ENC (audioenc);
341 gboolean ret;
342
343 alawenc->rate = info->rate;
344 alawenc->channels = info->channels;
345
346 base_caps =
347 gst_pad_get_pad_template_caps (GST_AUDIO_ENCODER_SRC_PAD (audioenc));
348 g_assert (base_caps);
349 base_caps = gst_caps_make_writable (base_caps);
350 g_assert (base_caps);
351
352 structure = gst_caps_get_structure (base_caps, 0);
353 g_assert (structure);
354 gst_structure_set (structure, "rate", G_TYPE_INT, alawenc->rate, NULL);
355 gst_structure_set (structure, "channels", G_TYPE_INT, alawenc->channels,
356 NULL);
357
358 ret = gst_audio_encoder_set_output_format (audioenc, base_caps);
359 gst_caps_unref (base_caps);
360
361 return ret;
362 }
363
364 static GstFlowReturn
gst_alaw_enc_handle_frame(GstAudioEncoder * audioenc,GstBuffer * buffer)365 gst_alaw_enc_handle_frame (GstAudioEncoder * audioenc, GstBuffer * buffer)
366 {
367 GstALawEnc *alawenc;
368 GstMapInfo inmap, outmap;
369 gint16 *linear_data;
370 gsize linear_size;
371 guint8 *alaw_data;
372 guint alaw_size;
373 GstBuffer *outbuf;
374 GstFlowReturn ret;
375 gint i;
376
377 if (!buffer) {
378 ret = GST_FLOW_OK;
379 goto done;
380 }
381
382 alawenc = GST_ALAW_ENC (audioenc);
383
384 if (!alawenc->rate || !alawenc->channels)
385 goto not_negotiated;
386
387 gst_buffer_map (buffer, &inmap, GST_MAP_READ);
388 linear_data = (gint16 *) inmap.data;
389 linear_size = inmap.size;
390
391 alaw_size = linear_size / 2;
392
393 outbuf = gst_audio_encoder_allocate_output_buffer (audioenc, alaw_size);
394
395 g_assert (outbuf);
396
397 gst_buffer_map (outbuf, &outmap, GST_MAP_WRITE);
398 alaw_data = outmap.data;
399
400 for (i = 0; i < alaw_size; i++) {
401 alaw_data[i] = s16_to_alaw (linear_data[i]);
402 }
403
404 gst_buffer_unmap (outbuf, &outmap);
405 gst_buffer_unmap (buffer, &inmap);
406
407 ret = gst_audio_encoder_finish_frame (audioenc, outbuf, -1);
408
409 done:
410 return ret;
411
412 not_negotiated:
413 {
414 GST_DEBUG_OBJECT (alawenc, "no format negotiated");
415 ret = GST_FLOW_NOT_NEGOTIATED;
416 goto done;
417 }
418 }
419
420 static void
gst_alaw_enc_class_init(GstALawEncClass * klass)421 gst_alaw_enc_class_init (GstALawEncClass * klass)
422 {
423 GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
424 GstAudioEncoderClass *audio_encoder_class = GST_AUDIO_ENCODER_CLASS (klass);
425
426 audio_encoder_class->start = GST_DEBUG_FUNCPTR (gst_alaw_enc_start);
427 audio_encoder_class->set_format = GST_DEBUG_FUNCPTR (gst_alaw_enc_set_format);
428 audio_encoder_class->handle_frame =
429 GST_DEBUG_FUNCPTR (gst_alaw_enc_handle_frame);
430
431 gst_element_class_add_static_pad_template (element_class,
432 &alaw_enc_src_factory);
433 gst_element_class_add_static_pad_template (element_class,
434 &alaw_enc_sink_factory);
435
436 gst_element_class_set_static_metadata (element_class,
437 "A Law audio encoder", "Codec/Encoder/Audio",
438 "Convert 16bit PCM to 8bit A law",
439 "Zaheer Abbas Merali <zaheerabbas at merali dot org>");
440 GST_DEBUG_CATEGORY_INIT (alaw_enc_debug, "alawenc", 0, "A Law audio encoder");
441 }
442
443 static void
gst_alaw_enc_init(GstALawEnc * alawenc)444 gst_alaw_enc_init (GstALawEnc * alawenc)
445 {
446 GST_PAD_SET_ACCEPT_TEMPLATE (GST_AUDIO_ENCODER_SINK_PAD (alawenc));
447 }
448