Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyrightm (C) 2010 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Chia-chi Yeh | f88fc1f | 2010-09-30 08:51:59 +0800 | [diff] [blame] | 17 | #include <string.h> |
| 18 | |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 19 | #include "AudioCodec.h" |
| 20 | |
| 21 | #include "gsmamr_dec.h" |
| 22 | #include "gsmamr_enc.h" |
| 23 | |
| 24 | namespace { |
| 25 | |
Chia-chi Yeh | f88fc1f | 2010-09-30 08:51:59 +0800 | [diff] [blame] | 26 | const int gFrameBits[8] = {95, 103, 118, 134, 148, 159, 204, 244}; |
| 27 | |
| 28 | //------------------------------------------------------------------------------ |
| 29 | |
| 30 | // See RFC 4867 for the encoding details. |
| 31 | |
| 32 | class AmrCodec : public AudioCodec |
| 33 | { |
| 34 | public: |
| 35 | AmrCodec() { |
| 36 | if (AMREncodeInit(&mEncoder, &mSidSync, false)) { |
| 37 | mEncoder = NULL; |
| 38 | } |
| 39 | if (GSMInitDecode(&mDecoder, (Word8 *)"RTP")) { |
| 40 | mDecoder = NULL; |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | ~AmrCodec() { |
| 45 | if (mEncoder) { |
| 46 | AMREncodeExit(&mEncoder, &mSidSync); |
| 47 | } |
| 48 | if (mDecoder) { |
| 49 | GSMDecodeFrameExit(&mDecoder); |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | int set(int sampleRate, const char *fmtp); |
| 54 | int encode(void *payload, int16_t *samples); |
Chia-chi Yeh | 35d05dc | 2011-09-06 14:18:37 -0700 | [diff] [blame] | 55 | int decode(int16_t *samples, int count, void *payload, int length); |
Chia-chi Yeh | f88fc1f | 2010-09-30 08:51:59 +0800 | [diff] [blame] | 56 | |
| 57 | private: |
| 58 | void *mEncoder; |
| 59 | void *mSidSync; |
| 60 | void *mDecoder; |
| 61 | |
| 62 | int mMode; |
| 63 | int mModeSet; |
| 64 | bool mOctetAligned; |
| 65 | }; |
| 66 | |
| 67 | int AmrCodec::set(int sampleRate, const char *fmtp) |
| 68 | { |
| 69 | // These parameters are not supported. |
| 70 | if (strcasestr(fmtp, "crc=1") || strcasestr(fmtp, "robust-sorting=1") || |
| 71 | strcasestr(fmtp, "interleaving=")) { |
| 72 | return -1; |
| 73 | } |
| 74 | |
| 75 | // Handle mode-set and octet-align. |
Chia-chi Yeh | 53aa6ef | 2010-11-30 13:10:31 +0800 | [diff] [blame] | 76 | const char *modes = strcasestr(fmtp, "mode-set="); |
Chia-chi Yeh | f88fc1f | 2010-09-30 08:51:59 +0800 | [diff] [blame] | 77 | if (modes) { |
| 78 | mMode = 0; |
| 79 | mModeSet = 0; |
| 80 | for (char c = *modes; c && c != ' '; c = *++modes) { |
| 81 | if (c >= '0' && c <= '7') { |
| 82 | int mode = c - '0'; |
| 83 | if (mode > mMode) { |
| 84 | mMode = mode; |
| 85 | } |
| 86 | mModeSet |= 1 << mode; |
| 87 | } |
| 88 | } |
| 89 | } else { |
| 90 | mMode = 7; |
| 91 | mModeSet = 0xFF; |
| 92 | } |
| 93 | mOctetAligned = (strcasestr(fmtp, "octet-align=1") != NULL); |
| 94 | |
| 95 | // TODO: handle mode-change-*. |
| 96 | |
| 97 | return (sampleRate == 8000 && mEncoder && mDecoder) ? 160 : -1; |
| 98 | } |
| 99 | |
| 100 | int AmrCodec::encode(void *payload, int16_t *samples) |
| 101 | { |
| 102 | unsigned char *bytes = (unsigned char *)payload; |
| 103 | Frame_Type_3GPP type; |
| 104 | |
| 105 | int length = AMREncode(mEncoder, mSidSync, (Mode)mMode, |
| 106 | samples, bytes + 1, &type, AMR_TX_WMF); |
| 107 | |
| 108 | if (type != mMode || length != (8 + gFrameBits[mMode] + 7) >> 3) { |
| 109 | return -1; |
| 110 | } |
| 111 | |
| 112 | if (mOctetAligned) { |
| 113 | bytes[0] = 0xF0; |
| 114 | bytes[1] = (mMode << 3) | 0x04; |
| 115 | ++length; |
| 116 | } else { |
| 117 | // CMR = 15 (4-bit), F = 0 (1-bit), FT = mMode (4-bit), Q = 1 (1-bit). |
| 118 | bytes[0] = 0xFF; |
| 119 | bytes[1] = 0xC0 | (mMode << 1) | 1; |
| 120 | |
| 121 | // Shift left 6 bits and update the length. |
| 122 | bytes[length + 1] = 0; |
| 123 | for (int i = 0; i <= length; ++i) { |
| 124 | bytes[i] = (bytes[i] << 6) | (bytes[i + 1] >> 2); |
| 125 | } |
| 126 | length = (10 + gFrameBits[mMode] + 7) >> 3; |
| 127 | } |
| 128 | return length; |
| 129 | } |
| 130 | |
Chia-chi Yeh | 35d05dc | 2011-09-06 14:18:37 -0700 | [diff] [blame] | 131 | int AmrCodec::decode(int16_t *samples, int count, void *payload, int length) |
Chia-chi Yeh | f88fc1f | 2010-09-30 08:51:59 +0800 | [diff] [blame] | 132 | { |
| 133 | unsigned char *bytes = (unsigned char *)payload; |
| 134 | Frame_Type_3GPP type; |
| 135 | if (length < 2) { |
| 136 | return -1; |
| 137 | } |
| 138 | int request = bytes[0] >> 4; |
| 139 | |
| 140 | if (mOctetAligned) { |
| 141 | if ((bytes[1] & 0xC4) != 0x04) { |
| 142 | return -1; |
| 143 | } |
| 144 | type = (Frame_Type_3GPP)(bytes[1] >> 3); |
| 145 | if (length != (16 + gFrameBits[type] + 7) >> 3) { |
| 146 | return -1; |
| 147 | } |
| 148 | length -= 2; |
| 149 | bytes += 2; |
| 150 | } else { |
| 151 | if ((bytes[0] & 0x0C) || !(bytes[1] & 0x40)) { |
| 152 | return -1; |
| 153 | } |
| 154 | type = (Frame_Type_3GPP)((bytes[0] << 1 | bytes[1] >> 7) & 0x07); |
| 155 | if (length != (10 + gFrameBits[type] + 7) >> 3) { |
| 156 | return -1; |
| 157 | } |
| 158 | |
| 159 | // Shift left 2 bits and update the length. |
| 160 | --length; |
| 161 | for (int i = 1; i < length; ++i) { |
| 162 | bytes[i] = (bytes[i] << 2) | (bytes[i + 1] >> 6); |
| 163 | } |
| 164 | bytes[length] <<= 2; |
| 165 | length = (gFrameBits[type] + 7) >> 3; |
| 166 | ++bytes; |
| 167 | } |
| 168 | |
| 169 | if (AMRDecode(mDecoder, type, bytes, samples, MIME_IETF) != length) { |
| 170 | return -1; |
| 171 | } |
| 172 | |
| 173 | // Handle CMR |
| 174 | if (request < 8 && request != mMode) { |
| 175 | for (int i = request; i >= 0; --i) { |
| 176 | if (mModeSet & (1 << i)) { |
| 177 | mMode = request; |
| 178 | break; |
| 179 | } |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | return 160; |
| 184 | } |
| 185 | |
| 186 | //------------------------------------------------------------------------------ |
| 187 | |
| 188 | // See RFC 3551 for the encoding details. |
| 189 | |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 190 | class GsmEfrCodec : public AudioCodec |
| 191 | { |
| 192 | public: |
| 193 | GsmEfrCodec() { |
| 194 | if (AMREncodeInit(&mEncoder, &mSidSync, false)) { |
| 195 | mEncoder = NULL; |
| 196 | } |
| 197 | if (GSMInitDecode(&mDecoder, (Word8 *)"RTP")) { |
| 198 | mDecoder = NULL; |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | ~GsmEfrCodec() { |
| 203 | if (mEncoder) { |
| 204 | AMREncodeExit(&mEncoder, &mSidSync); |
| 205 | } |
| 206 | if (mDecoder) { |
| 207 | GSMDecodeFrameExit(&mDecoder); |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | int set(int sampleRate, const char *fmtp) { |
| 212 | return (sampleRate == 8000 && mEncoder && mDecoder) ? 160 : -1; |
| 213 | } |
| 214 | |
| 215 | int encode(void *payload, int16_t *samples); |
Chia-chi Yeh | 35d05dc | 2011-09-06 14:18:37 -0700 | [diff] [blame] | 216 | int decode(int16_t *samples, int count, void *payload, int length); |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 217 | |
| 218 | private: |
| 219 | void *mEncoder; |
| 220 | void *mSidSync; |
| 221 | void *mDecoder; |
| 222 | }; |
| 223 | |
| 224 | int GsmEfrCodec::encode(void *payload, int16_t *samples) |
| 225 | { |
| 226 | unsigned char *bytes = (unsigned char *)payload; |
| 227 | Frame_Type_3GPP type; |
| 228 | |
| 229 | int length = AMREncode(mEncoder, mSidSync, MR122, |
| 230 | samples, bytes, &type, AMR_TX_WMF); |
| 231 | |
| 232 | if (type == AMR_122 && length == 32) { |
| 233 | bytes[0] = 0xC0 | (bytes[1] >> 4); |
| 234 | for (int i = 1; i < 31; ++i) { |
| 235 | bytes[i] = (bytes[i] << 4) | (bytes[i + 1] >> 4); |
| 236 | } |
| 237 | return 31; |
| 238 | } |
| 239 | return -1; |
| 240 | } |
| 241 | |
Chia-chi Yeh | 35d05dc | 2011-09-06 14:18:37 -0700 | [diff] [blame] | 242 | int GsmEfrCodec::decode(int16_t *samples, int count, void *payload, int length) |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 243 | { |
| 244 | unsigned char *bytes = (unsigned char *)payload; |
Chia-chi Yeh | 35d05dc | 2011-09-06 14:18:37 -0700 | [diff] [blame] | 245 | int n = 0; |
| 246 | while (n + 160 <= count && length >= 31 && (bytes[0] >> 4) == 0x0C) { |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 247 | for (int i = 0; i < 30; ++i) { |
| 248 | bytes[i] = (bytes[i] << 4) | (bytes[i + 1] >> 4); |
| 249 | } |
| 250 | bytes[30] <<= 4; |
| 251 | |
Chia-chi Yeh | 35d05dc | 2011-09-06 14:18:37 -0700 | [diff] [blame] | 252 | if (AMRDecode(mDecoder, AMR_122, bytes, &samples[n], MIME_IETF) != 31) { |
| 253 | break; |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 254 | } |
Chia-chi Yeh | 35d05dc | 2011-09-06 14:18:37 -0700 | [diff] [blame] | 255 | n += 160; |
| 256 | length -= 31; |
| 257 | bytes += 31; |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 258 | } |
Chia-chi Yeh | 35d05dc | 2011-09-06 14:18:37 -0700 | [diff] [blame] | 259 | return n; |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 260 | } |
| 261 | |
| 262 | } // namespace |
| 263 | |
Chia-chi Yeh | f88fc1f | 2010-09-30 08:51:59 +0800 | [diff] [blame] | 264 | AudioCodec *newAmrCodec() |
| 265 | { |
| 266 | return new AmrCodec; |
| 267 | } |
| 268 | |
Chia-chi Yeh | f4ae942 | 2010-09-30 03:04:06 +0800 | [diff] [blame] | 269 | AudioCodec *newGsmEfrCodec() |
| 270 | { |
| 271 | return new GsmEfrCodec; |
| 272 | } |