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1 /* GStreamer A-Law to PCM conversion |
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2 * Copyright (C) 2000 by Abramo Bagnara <abramo@alsa-project.org> |
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3 * |
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4 * This library is free software; you can redistribute it and/or |
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5 * modify it under the terms of the GNU Library General Public |
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6 * License as published by the Free Software Foundation; either |
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7 * version 2.1 of the License, or (at your option) any later version. |
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8 * |
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9 * This library is distributed in the hope that it will be useful, |
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10 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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12 * Library General Public License for more details. |
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13 * |
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14 * You should have received a copy of the GNU Library General Public |
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15 * License along with this library; if not, write to the |
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16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
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17 * Boston, MA 02111-1307, USA. |
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18 */ |
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19 /** |
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20 * SECTION:element-alawdec |
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21 * |
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22 * This element decodes alaw audio. Alaw coding is also known as G.711. |
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23 */ |
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24 |
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25 #ifdef HAVE_CONFIG_H |
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26 #include "config.h" |
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27 #endif |
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28 |
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29 #include "alaw-decode.h" |
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30 |
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31 extern GstStaticPadTemplate alaw_dec_src_factory; |
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32 extern GstStaticPadTemplate alaw_dec_sink_factory; |
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33 |
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34 GST_DEBUG_CATEGORY_STATIC (alaw_dec_debug); |
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35 #define GST_CAT_DEFAULT alaw_dec_debug |
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36 |
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37 static GstStateChangeReturn |
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38 gst_alaw_dec_change_state (GstElement * element, GstStateChange transition); |
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39 static GstFlowReturn gst_alaw_dec_chain (GstPad * pad, GstBuffer * buffer); |
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40 |
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41 GST_BOILERPLATE (GstALawDec, gst_alaw_dec, GstElement, GST_TYPE_ELEMENT); |
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42 |
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43 /* some day we might have defines in gstconfig.h that tell us about the |
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44 * desired cpu/memory/binary size trade-offs */ |
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45 #define GST_ALAW_DEC_USE_TABLE |
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46 |
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47 #ifdef GST_ALAW_DEC_USE_TABLE |
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48 |
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49 static const gint alaw_to_s16_table[256] = { |
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50 -5504, -5248, -6016, -5760, -4480, -4224, -4992, -4736, |
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51 -7552, -7296, -8064, -7808, -6528, -6272, -7040, -6784, |
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52 -2752, -2624, -3008, -2880, -2240, -2112, -2496, -2368, |
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53 -3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392, |
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54 -22016, -20992, -24064, -23040, -17920, -16896, -19968, -18944, |
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55 -30208, -29184, -32256, -31232, -26112, -25088, -28160, -27136, |
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56 -11008, -10496, -12032, -11520, -8960, -8448, -9984, -9472, |
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57 -15104, -14592, -16128, -15616, -13056, -12544, -14080, -13568, |
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58 -344, -328, -376, -360, -280, -264, -312, -296, |
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59 -472, -456, -504, -488, -408, -392, -440, -424, |
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60 -88, -72, -120, -104, -24, -8, -56, -40, |
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61 -216, -200, -248, -232, -152, -136, -184, -168, |
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62 -1376, -1312, -1504, -1440, -1120, -1056, -1248, -1184, |
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63 -1888, -1824, -2016, -1952, -1632, -1568, -1760, -1696, |
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64 -688, -656, -752, -720, -560, -528, -624, -592, |
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65 -944, -912, -1008, -976, -816, -784, -880, -848, |
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66 5504, 5248, 6016, 5760, 4480, 4224, 4992, 4736, |
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67 7552, 7296, 8064, 7808, 6528, 6272, 7040, 6784, |
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68 2752, 2624, 3008, 2880, 2240, 2112, 2496, 2368, |
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69 3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392, |
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70 22016, 20992, 24064, 23040, 17920, 16896, 19968, 18944, |
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71 30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136, |
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72 11008, 10496, 12032, 11520, 8960, 8448, 9984, 9472, |
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73 15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568, |
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74 344, 328, 376, 360, 280, 264, 312, 296, |
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75 472, 456, 504, 488, 408, 392, 440, 424, |
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76 88, 72, 120, 104, 24, 8, 56, 40, |
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77 216, 200, 248, 232, 152, 136, 184, 168, |
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78 1376, 1312, 1504, 1440, 1120, 1056, 1248, 1184, |
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79 1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696, |
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80 688, 656, 752, 720, 560, 528, 624, 592, |
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81 944, 912, 1008, 976, 816, 784, 880, 848 |
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82 }; |
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83 |
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84 static inline gint |
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85 alaw_to_s16 (guint8 a_val) |
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86 { |
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87 return alaw_to_s16_table[a_val]; |
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88 } |
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89 |
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90 #else /* GST_ALAW_DEC_USE_TABLE */ |
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91 |
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92 static inline gint |
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93 alaw_to_s16 (guint8 a_val) |
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94 { |
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95 gint t; |
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96 gint seg; |
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97 |
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98 a_val ^= 0x55; |
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99 t = a_val & 0x7f; |
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100 if (t < 16) |
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101 t = (t << 4) + 8; |
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102 else { |
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103 seg = (t >> 4) & 0x07; |
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104 t = ((t & 0x0f) << 4) + 0x108; |
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105 t <<= seg - 1; |
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106 } |
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107 return ((a_val & 0x80) ? t : -t); |
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108 } |
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109 |
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110 #endif /* GST_ALAW_DEC_USE_TABLE */ |
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111 |
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112 static gboolean |
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113 gst_alaw_dec_sink_setcaps (GstPad * pad, GstCaps * caps) |
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114 { |
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115 GstALawDec *alawdec; |
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116 GstStructure *structure; |
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117 int rate, channels; |
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118 gboolean ret; |
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119 GstCaps *outcaps; |
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120 |
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121 alawdec = GST_ALAW_DEC (GST_PAD_PARENT (pad)); |
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122 |
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123 structure = gst_caps_get_structure (caps, 0); |
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124 |
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125 ret = gst_structure_get_int (structure, "rate", &rate); |
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126 ret &= gst_structure_get_int (structure, "channels", &channels); |
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127 if (!ret) |
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128 return FALSE; |
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129 |
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130 outcaps = gst_caps_new_simple ("audio/x-raw-int", |
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131 "width", G_TYPE_INT, 16, |
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132 "depth", G_TYPE_INT, 16, |
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133 "endianness", G_TYPE_INT, G_BYTE_ORDER, |
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134 "signed", G_TYPE_BOOLEAN, TRUE, |
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135 "rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, channels, NULL); |
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136 |
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137 ret = gst_pad_set_caps (alawdec->srcpad, outcaps); |
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138 gst_caps_unref (outcaps); |
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139 |
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140 if (ret) { |
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141 GST_DEBUG_OBJECT (alawdec, "rate=%d, channels=%d", rate, channels); |
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142 alawdec->rate = rate; |
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143 alawdec->channels = channels; |
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144 } |
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145 return ret; |
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146 } |
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147 |
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148 static GstCaps * |
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149 gst_alaw_dec_getcaps (GstPad * pad) |
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150 { |
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151 GstALawDec *alawdec; |
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152 GstPad *otherpad; |
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153 GstCaps *othercaps, *result; |
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154 const GstCaps *templ; |
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155 gchar *name; |
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156 gint i; |
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157 |
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158 alawdec = GST_ALAW_DEC (GST_PAD_PARENT (pad)); |
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159 |
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160 /* figure out the name of the caps we are going to return */ |
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161 if (pad == alawdec->srcpad) { |
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162 name = "audio/x-raw-int"; |
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163 otherpad = alawdec->sinkpad; |
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164 } else { |
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165 name = "audio/x-alaw"; |
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166 otherpad = alawdec->srcpad; |
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167 } |
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168 /* get caps from the peer, this can return NULL when there is no peer */ |
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169 othercaps = gst_pad_peer_get_caps (otherpad); |
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170 |
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171 /* get the template caps to make sure we return something acceptable */ |
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172 templ = gst_pad_get_pad_template_caps (pad); |
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173 |
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174 if (othercaps) { |
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175 /* there was a peer */ |
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176 othercaps = gst_caps_make_writable (othercaps); |
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177 |
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178 /* go through the caps and remove the fields we don't want */ |
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179 for (i = 0; i < gst_caps_get_size (othercaps); i++) { |
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180 GstStructure *structure; |
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181 |
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182 structure = gst_caps_get_structure (othercaps, i); |
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183 |
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184 /* adjust the name */ |
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185 gst_structure_set_name (structure, name); |
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186 |
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187 if (pad == alawdec->sinkpad) { |
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188 /* remove the fields we don't want */ |
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189 gst_structure_remove_fields (structure, "width", "depth", "endianness", |
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190 "signed", NULL); |
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191 } else { |
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192 /* add fixed fields */ |
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193 gst_structure_set (structure, "width", G_TYPE_INT, 16, |
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194 "depth", G_TYPE_INT, 16, |
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195 "endianness", G_TYPE_INT, G_BYTE_ORDER, |
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196 "signed", G_TYPE_BOOLEAN, TRUE, NULL); |
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197 } |
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198 } |
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199 /* filter against the allowed caps of the pad to return our result */ |
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200 result = gst_caps_intersect (othercaps, templ); |
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201 gst_caps_unref (othercaps); |
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202 } else { |
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203 /* there was no peer, return the template caps */ |
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204 result = gst_caps_copy (templ); |
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205 } |
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206 |
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207 return result; |
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208 } |
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209 |
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210 static void |
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211 gst_alaw_dec_base_init (gpointer klass) |
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212 { |
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213 GstElementClass *element_class = GST_ELEMENT_CLASS (klass); |
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214 |
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215 gst_element_class_add_pad_template (element_class, |
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216 gst_static_pad_template_get (&alaw_dec_src_factory)); |
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217 gst_element_class_add_pad_template (element_class, |
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218 gst_static_pad_template_get (&alaw_dec_sink_factory)); |
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219 |
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220 gst_element_class_set_details_simple (element_class, "A Law audio decoder", |
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221 "Codec/Decoder/Audio", "Convert 8bit A law to 16bit PCM", |
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222 "Zaheer Abbas Merali <zaheerabbas at merali dot org>"); |
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223 |
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224 GST_DEBUG_CATEGORY_INIT (alaw_dec_debug, "alawdec", 0, "A Law audio decoder"); |
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225 } |
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226 |
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227 static void |
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228 gst_alaw_dec_class_init (GstALawDecClass * klass) |
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229 { |
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230 GstElementClass *element_class = (GstElementClass *) klass; |
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231 |
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232 element_class->change_state = GST_DEBUG_FUNCPTR (gst_alaw_dec_change_state); |
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233 } |
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234 |
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235 static void |
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236 gst_alaw_dec_init (GstALawDec * alawdec, GstALawDecClass * klass) |
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237 { |
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238 alawdec->sinkpad = |
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239 gst_pad_new_from_static_template (&alaw_dec_sink_factory, "sink"); |
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240 gst_pad_set_setcaps_function (alawdec->sinkpad, |
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241 GST_DEBUG_FUNCPTR (gst_alaw_dec_sink_setcaps)); |
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242 gst_pad_set_getcaps_function (alawdec->sinkpad, |
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243 GST_DEBUG_FUNCPTR (gst_alaw_dec_getcaps)); |
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244 gst_pad_set_chain_function (alawdec->sinkpad, |
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245 GST_DEBUG_FUNCPTR (gst_alaw_dec_chain)); |
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246 gst_element_add_pad (GST_ELEMENT (alawdec), alawdec->sinkpad); |
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247 |
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248 alawdec->srcpad = |
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249 gst_pad_new_from_static_template (&alaw_dec_src_factory, "src"); |
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250 gst_pad_use_fixed_caps (alawdec->srcpad); |
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251 gst_pad_set_getcaps_function (alawdec->srcpad, |
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252 GST_DEBUG_FUNCPTR (gst_alaw_dec_getcaps)); |
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253 gst_element_add_pad (GST_ELEMENT (alawdec), alawdec->srcpad); |
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254 } |
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255 |
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256 static GstFlowReturn |
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257 gst_alaw_dec_chain (GstPad * pad, GstBuffer * buffer) |
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258 { |
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259 GstALawDec *alawdec; |
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260 gint16 *linear_data; |
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261 guint8 *alaw_data; |
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262 guint alaw_size; |
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263 GstBuffer *outbuf; |
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264 gint i; |
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265 GstFlowReturn ret; |
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266 |
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267 alawdec = GST_ALAW_DEC (GST_PAD_PARENT (pad)); |
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268 |
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269 if (G_UNLIKELY (alawdec->rate == 0)) |
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270 goto not_negotiated; |
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271 |
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272 GST_LOG_OBJECT (alawdec, "buffer with ts=%" GST_TIME_FORMAT, |
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273 GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer))); |
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274 |
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275 alaw_data = GST_BUFFER_DATA (buffer); |
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276 alaw_size = GST_BUFFER_SIZE (buffer); |
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277 |
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278 ret = |
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279 gst_pad_alloc_buffer_and_set_caps (alawdec->srcpad, |
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280 GST_BUFFER_OFFSET_NONE, alaw_size * 2, GST_PAD_CAPS (alawdec->srcpad), |
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281 &outbuf); |
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282 if (ret != GST_FLOW_OK) |
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283 goto alloc_failed; |
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284 |
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285 linear_data = (gint16 *) GST_BUFFER_DATA (outbuf); |
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286 |
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287 /* copy discont flag */ |
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288 if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT)) |
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289 GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DISCONT); |
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290 |
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291 GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer); |
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292 GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer); |
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293 gst_buffer_set_caps (outbuf, GST_PAD_CAPS (alawdec->srcpad)); |
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294 |
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295 for (i = 0; i < alaw_size; i++) { |
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296 linear_data[i] = alaw_to_s16 (alaw_data[i]); |
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297 } |
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298 gst_buffer_unref (buffer); |
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299 |
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300 ret = gst_pad_push (alawdec->srcpad, outbuf); |
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301 |
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302 return ret; |
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303 |
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304 not_negotiated: |
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305 { |
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306 gst_buffer_unref (buffer); |
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307 GST_WARNING_OBJECT (alawdec, "no input format set: not-negotiated"); |
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308 return GST_FLOW_NOT_NEGOTIATED; |
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309 } |
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310 alloc_failed: |
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311 { |
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312 gst_buffer_unref (buffer); |
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313 GST_DEBUG_OBJECT (alawdec, "pad alloc failed, flow: %s", |
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314 gst_flow_get_name (ret)); |
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315 return ret; |
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316 } |
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317 } |
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318 |
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319 static GstStateChangeReturn |
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320 gst_alaw_dec_change_state (GstElement * element, GstStateChange transition) |
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321 { |
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322 GstStateChangeReturn ret; |
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323 GstALawDec *dec = GST_ALAW_DEC (element); |
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324 |
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325 switch (transition) { |
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326 default: |
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327 break; |
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328 } |
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329 |
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330 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition); |
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331 if (ret != GST_STATE_CHANGE_SUCCESS) |
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332 return ret; |
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333 |
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334 switch (transition) { |
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335 case GST_STATE_CHANGE_PAUSED_TO_READY: |
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336 dec->rate = 0; |
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337 dec->channels = 0; |
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338 break; |
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339 default: |
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340 break; |
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341 } |
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342 |
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343 return ret; |
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344 } |