/* * * Bluetooth low-complexity, subband codec (SBC) library * * Copyright (C) 2004-2006 Marcel Holtmann * Copyright (C) 2004-2005 Henryk Ploetz * * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include "sbc.h" /* A2DP specification: Appendix B, page 69 */ static const int sbc_offset4[4][4] = { { -1, 0, 0, 0 }, { -2, 0, 0, 1 }, { -2, 0, 0, 1 }, { -2, 0, 0, 1 } }; /* A2DP specification: Appendix B, page 69 */ static const int sbc_offset8[4][8] = { { -2, 0, 0, 0, 0, 0, 0, 1 }, { -3, 0, 0, 0, 0, 0, 1, 2 }, { -4, 0, 0, 0, 0, 0, 1, 2 }, { -4, 0, 0, 0, 0, 0, 1, 2 } }; /* A2DP specification: Appendix B, page 70 */ static const float sbc_proto_4_40[40] = { 0.00000000E+00, 5.36548976E-04, 1.49188357E-03, 2.73370904E-03, 3.83720193E-03, 3.89205149E-03, 1.86581691E-03, -3.06012286E-03, 1.09137620E-02, 2.04385087E-02, 2.88757392E-02, 3.21939290E-02, 2.58767811E-02, 6.13245186E-03, -2.88217274E-02, -7.76463494E-02, 1.35593274E-01, 1.94987841E-01, 2.46636662E-01, 2.81828203E-01, 2.94315332E-01, 2.81828203E-01, 2.46636662E-01, 1.94987841E-01, -1.35593274E-01, -7.76463494E-02, -2.88217274E-02, 6.13245186E-03, 2.58767811E-02, 3.21939290E-02, 2.88757392E-02, 2.04385087E-02, -1.09137620E-02, -3.06012286E-03, 1.86581691E-03, 3.89205149E-03, 3.83720193E-03, 2.73370904E-03, 1.49188357E-03, 5.36548976E-04 }; /* A2DP specification: Appendix B, page 70 */ static const float sbc_proto_8_80[80] = { 0.00000000E+00, 1.56575398E-04, 3.43256425E-04, 5.54620202E-04, 8.23919506E-04, 1.13992507E-03, 1.47640169E-03, 1.78371725E-03, 2.01182542E-03, 2.10371989E-03, 1.99454554E-03, 1.61656283E-03, 9.02154502E-04, -1.78805361E-04, -1.64973098E-03, -3.49717454E-03, 5.65949473E-03, 8.02941163E-03, 1.04584443E-02, 1.27472335E-02, 1.46525263E-02, 1.59045603E-02, 1.62208471E-02, 1.53184106E-02, 1.29371806E-02, 8.85757540E-03, 2.92408442E-03, -4.91578024E-03, -1.46404076E-02, -2.61098752E-02, -3.90751381E-02, -5.31873032E-02, 6.79989431E-02, 8.29847578E-02, 9.75753918E-02, 1.11196689E-01, 1.23264548E-01, 1.33264415E-01, 1.40753505E-01, 1.45389847E-01, 1.46955068E-01, 1.45389847E-01, 1.40753505E-01, 1.33264415E-01, 1.23264548E-01, 1.11196689E-01, 9.75753918E-02, 8.29847578E-02, -6.79989431E-02, -5.31873032E-02, -3.90751381E-02, -2.61098752E-02, -1.46404076E-02, -4.91578024E-03, 2.92408442E-03, 8.85757540E-03, 1.29371806E-02, 1.53184106E-02, 1.62208471E-02, 1.59045603E-02, 1.46525263E-02, 1.27472335E-02, 1.04584443E-02, 8.02941163E-03, -5.65949473E-03, -3.49717454E-03, -1.64973098E-03, -1.78805361E-04, 9.02154502E-04, 1.61656283E-03, 1.99454554E-03, 2.10371989E-03, 2.01182542E-03, 1.78371725E-03, 1.47640169E-03, 1.13992507E-03, 8.23919506E-04, 5.54620202E-04, 3.43256425E-04, 1.56575398E-04 }; /* Precomputed: synmatrix4[k][i] = cos( (i+0.5) * (k+2.0) * pi/4.0 ) */ static const float synmatrix4[8][4] = { { 0.707106781186548, -0.707106781186547, -0.707106781186548, 0.707106781186547 }, { 0.38268343236509, -0.923879532511287, 0.923879532511287, -0.38268343236509 }, { 0, 0, 0, 0 }, { -0.38268343236509, 0.923879532511287, -0.923879532511287, 0.382683432365091 }, { -0.707106781186547, 0.707106781186548, 0.707106781186547, -0.707106781186547 }, { -0.923879532511287, -0.38268343236509, 0.382683432365091, 0.923879532511288 }, { -1, -1, -1, -1 }, { -0.923879532511287, -0.382683432365091, 0.38268343236509, 0.923879532511287 } }; /* Precomputed: synmatrix8[k][i] = cos( (i+0.5) * (k+4.0) * pi/8.0 ) */ static const float synmatrix8[16][8] = { { 0.707106781186548, -0.707106781186547, -0.707106781186548, 0.707106781186547, 0.707106781186548, -0.707106781186547, -0.707106781186547, 0.707106781186547 }, { 0.555570233019602, -0.98078528040323, 0.195090322016128, 0.831469612302545, -0.831469612302545, -0.195090322016128, 0.980785280403231, -0.555570233019602 }, { 0.38268343236509, -0.923879532511287, 0.923879532511287, -0.38268343236509, -0.382683432365091, 0.923879532511287, -0.923879532511286, 0.38268343236509 }, { 0.195090322016128, -0.555570233019602, 0.831469612302545, -0.980785280403231, 0.98078528040323, -0.831469612302545, 0.555570233019602, -0.195090322016129 }, { 0, 0, 0, 0, 0, 0, 0, 0 }, { -0.195090322016128, 0.555570233019602, -0.831469612302545, 0.98078528040323, -0.980785280403231, 0.831469612302545, -0.555570233019603, 0.19509032201613 }, { -0.38268343236509, 0.923879532511287, -0.923879532511287, 0.382683432365091, 0.38268343236509, -0.923879532511287, 0.923879532511288, -0.382683432365091 }, { -0.555570233019602, 0.98078528040323, -0.195090322016128, -0.831469612302545, 0.831469612302545, 0.195090322016128, -0.98078528040323, 0.555570233019606 }, { -0.707106781186547, 0.707106781186548, 0.707106781186547, -0.707106781186547, -0.707106781186546, 0.707106781186548, 0.707106781186546, -0.707106781186548 }, { -0.831469612302545, 0.195090322016129, 0.980785280403231, 0.555570233019602, -0.555570233019603, -0.98078528040323, -0.195090322016128, 0.831469612302547 }, { -0.923879532511287, -0.38268343236509, 0.382683432365091, 0.923879532511288, 0.923879532511287, 0.382683432365089, -0.382683432365091, -0.923879532511287 }, { -0.98078528040323, -0.831469612302545, -0.555570233019602, -0.195090322016129, 0.19509032201613, 0.555570233019606, 0.831469612302547, 0.980785280403231 }, { -1, -1, -1, -1, -1, -1, -1, -1 }, { -0.98078528040323, -0.831469612302546, -0.555570233019603, -0.19509032201613, 0.195090322016128, 0.555570233019604, 0.831469612302545, 0.98078528040323 }, { -0.923879532511287, -0.382683432365091, 0.38268343236509, 0.923879532511287, 0.923879532511288, 0.382683432365088, -0.382683432365089, -0.923879532511285 }, { -0.831469612302545, 0.195090322016127, 0.98078528040323, 0.555570233019603, -0.555570233019601, -0.98078528040323, -0.195090322016131, 0.831469612302545 } }; /* Precomputed: anamatrix4[i][k] = cos( (i+0.5) * (k-2) * pi/4 ) */ static const float anamatrix4[4][8] = { { 0.707106781186548, 0.923879532511287, 1, 0.923879532511287, 0.707106781186548, 0.38268343236509, 0, -0.38268343236509 }, { -0.707106781186547, 0.38268343236509, 1, 0.38268343236509, -0.707106781186547, -0.923879532511287, 0, 0.923879532511287 }, { -0.707106781186548, -0.38268343236509, 1, -0.38268343236509, -0.707106781186548, 0.923879532511287, 0, -0.923879532511287 }, { 0.707106781186547, -0.923879532511287, 1, -0.923879532511287, 0.707106781186547, -0.38268343236509, 0, 0.382683432365091 } }; /* Precomputed: anamatrix8[i][k] = cos( (i+0.5) * (k-4) * pi/8) */ static const float anamatrix8[8][16] = { { 0.923879532511287, 0.98078528040323, 1, 0.98078528040323, 0.923879532511287, 0.831469612302545, 0.707106781186548, 0.555570233019602, 0.38268343236509, 0.195090322016128, 0, -0.195090322016128, -0.38268343236509, -0.555570233019602, -0.707106781186547, -0.831469612302545 }, { 0.38268343236509, 0.831469612302545, 1, 0.831469612302545, 0.38268343236509, -0.195090322016128, -0.707106781186547, -0.98078528040323, -0.923879532511287, -0.555570233019602, 0, 0.555570233019602, 0.923879532511287, 0.98078528040323, 0.707106781186548, 0.195090322016129 }, { -0.38268343236509, 0.555570233019602, 1, 0.555570233019602, -0.38268343236509, -0.98078528040323, -0.707106781186548, 0.195090322016128, 0.923879532511287, 0.831469612302545, 0, -0.831469612302545, -0.923879532511287, -0.195090322016128, 0.707106781186547, 0.980785280403231 }, { -0.923879532511287, 0.195090322016128, 1, 0.195090322016128, -0.923879532511287, -0.555570233019602, 0.707106781186547, 0.831469612302545, -0.38268343236509, -0.980785280403231, 0, 0.98078528040323, 0.382683432365091, -0.831469612302545, -0.707106781186547, 0.555570233019602 }, { -0.923879532511287, -0.195090322016128, 1, -0.195090322016128, -0.923879532511287, 0.555570233019602, 0.707106781186548, -0.831469612302545, -0.382683432365091, 0.98078528040323, 0, -0.980785280403231, 0.38268343236509, 0.831469612302545, -0.707106781186546, -0.555570233019603 }, { -0.38268343236509, -0.555570233019602, 1, -0.555570233019602, -0.38268343236509, 0.98078528040323, -0.707106781186547, -0.195090322016128, 0.923879532511287, -0.831469612302545, 0, 0.831469612302545, -0.923879532511287, 0.195090322016128, 0.707106781186548, -0.98078528040323 }, { 0.38268343236509, -0.831469612302545, 1, -0.831469612302545, 0.38268343236509, 0.195090322016129, -0.707106781186547, 0.980785280403231, -0.923879532511286, 0.555570233019602, 0, -0.555570233019603, 0.923879532511288, -0.98078528040323, 0.707106781186546, -0.195090322016128 }, { 0.923879532511287, -0.98078528040323, 1, -0.98078528040323, 0.923879532511287, -0.831469612302545, 0.707106781186547, -0.555570233019602, 0.38268343236509, -0.195090322016129, 0, 0.19509032201613, -0.382683432365091, 0.555570233019606, -0.707106781186548, 0.831469612302547 } }; #define fabs(x) ((x) < 0 ? (-x) : (x)) #define SBC_SYNCWORD 0x9C /* sampling frequency */ #define SBC_FS_16 0x00 #define SBC_FS_32 0x01 #define SBC_FS_44 0x02 #define SBC_FS_48 0x03 /* nrof_blocks */ #define SBC_NB_4 0x00 #define SBC_NB_8 0x01 #define SBC_NB_12 0x02 #define SBC_NB_16 0x03 /* channel mode */ #define SBC_CM_MONO 0x00 #define SBC_CM_DUAL_CHANNEL 0x01 #define SBC_CM_STEREO 0x02 #define SBC_CM_JOINT_STEREO 0x03 /* allocation mode */ #define SBC_AM_LOUDNESS 0x00 #define SBC_AM_SNR 0x01 /* subbands */ #define SBC_SB_4 0x00 #define SBC_SB_8 0x01 /* This structure contains an unpacked SBC frame. Yes, there is probably quite some unused space herein */ struct sbc_frame { double sampling_frequency; /* in kHz */ u_int8_t blocks; enum { MONO = SBC_CM_MONO, DUAL_CHANNEL = SBC_CM_DUAL_CHANNEL, STEREO = SBC_CM_STEREO, JOINT_STEREO = SBC_CM_JOINT_STEREO } channel_mode; u_int8_t channels; enum { LOUDNESS = SBC_AM_LOUDNESS, SNR = SBC_AM_SNR } allocation_method; u_int8_t subbands; u_int8_t bitpool; u_int8_t join; /* bit number x set means joint stereo has been used in subband x */ u_int8_t scale_factor[2][8]; /* only the lower 4 bits of every element are to be used */ u_int16_t audio_sample[16][2][8]; /* raw integer subband samples in the frame */ double sb_sample[16][2][8]; /* modified subband samples */ double pcm_sample[2][16*8]; /* original pcm audio samples */ }; struct sbc_decoder_state { int subbands; float S[2][8]; /* Subband samples */ float X[2][8]; /* Audio samples */ float V[2][160], U[2][80], W[2][80]; /* Vectors */ }; struct sbc_encoder_state { int subbands; float S[2][8]; /* Subband samples */ float X[2][80], Y[2][16], Z[2][80]; /* Vectors */ }; /* * Calculates the CRC-8 of the first len bits in data */ static const u_int8_t crc_table[256] = { 0x00, 0x1D, 0x3A, 0x27, 0x74, 0x69, 0x4E, 0x53, 0xE8, 0xF5, 0xD2, 0xCF, 0x9C, 0x81, 0xA6, 0xBB, 0xCD, 0xD0, 0xF7, 0xEA, 0xB9, 0xA4, 0x83, 0x9E, 0x25, 0x38, 0x1F, 0x02, 0x51, 0x4C, 0x6B, 0x76, 0x87, 0x9A, 0xBD, 0xA0, 0xF3, 0xEE, 0xC9, 0xD4, 0x6F, 0x72, 0x55, 0x48, 0x1B, 0x06, 0x21, 0x3C, 0x4A, 0x57, 0x70, 0x6D, 0x3E, 0x23, 0x04, 0x19, 0xA2, 0xBF, 0x98, 0x85, 0xD6, 0xCB, 0xEC, 0xF1, 0x13, 0x0E, 0x29, 0x34, 0x67, 0x7A, 0x5D, 0x40, 0xFB, 0xE6, 0xC1, 0xDC, 0x8F, 0x92, 0xB5, 0xA8, 0xDE, 0xC3, 0xE4, 0xF9, 0xAA, 0xB7, 0x90, 0x8D, 0x36, 0x2B, 0x0C, 0x11, 0x42, 0x5F, 0x78, 0x65, 0x94, 0x89, 0xAE, 0xB3, 0xE0, 0xFD, 0xDA, 0xC7, 0x7C, 0x61, 0x46, 0x5B, 0x08, 0x15, 0x32, 0x2F, 0x59, 0x44, 0x63, 0x7E, 0x2D, 0x30, 0x17, 0x0A, 0xB1, 0xAC, 0x8B, 0x96, 0xC5, 0xD8, 0xFF, 0xE2, 0x26, 0x3B, 0x1C, 0x01, 0x52, 0x4F, 0x68, 0x75, 0xCE, 0xD3, 0xF4, 0xE9, 0xBA, 0xA7, 0x80, 0x9D, 0xEB, 0xF6, 0xD1, 0xCC, 0x9F, 0x82, 0xA5, 0xB8, 0x03, 0x1E, 0x39, 0x24, 0x77, 0x6A, 0x4D, 0x50, 0xA1, 0xBC, 0x9B, 0x86, 0xD5, 0xC8, 0xEF, 0xF2, 0x49, 0x54, 0x73, 0x6E, 0x3D, 0x20, 0x07, 0x1A, 0x6C, 0x71, 0x56, 0x4B, 0x18, 0x05, 0x22, 0x3F, 0x84, 0x99, 0xBE, 0xA3, 0xF0, 0xED, 0xCA, 0xD7, 0x35, 0x28, 0x0F, 0x12, 0x41, 0x5C, 0x7B, 0x66, 0xDD, 0xC0, 0xE7, 0xFA, 0xA9, 0xB4, 0x93, 0x8E, 0xF8, 0xE5, 0xC2, 0xDF, 0x8C, 0x91, 0xB6, 0xAB, 0x10, 0x0D, 0x2A, 0x37, 0x64, 0x79, 0x5E, 0x43, 0xB2, 0xAF, 0x88, 0x95, 0xC6, 0xDB, 0xFC, 0xE1, 0x5A, 0x47, 0x60, 0x7D, 0x2E, 0x33, 0x14, 0x09, 0x7F, 0x62, 0x45, 0x58, 0x0B, 0x16, 0x31, 0x2C, 0x97, 0x8A, 0xAD, 0xB0, 0xE3, 0xFE, 0xD9, 0xC4 }; static u_int8_t sbc_crc8(const u_int8_t * data, size_t len) { u_int8_t crc = 0x0f; size_t i; u_int8_t octet; for (i = 0; i < len / 8; i++) crc = crc_table[crc ^ data[i]]; octet = data[i]; for (i = 0; i < len % 8; i++) { char bit = ((octet ^ crc) & 0x80) >> 7; crc = ((crc & 0x7f) << 1) ^ (bit ? 0x1d : 0); octet = octet << 1; } return crc; } /* * Code straight from the spec to calculate the bits array * Takes a pointer to the frame in question, a pointer to the bits array and the sampling frequency (as 2 bit integer) */ static void sbc_calculate_bits(const struct sbc_frame *frame, int (*bits)[8], u_int8_t sf) { if (frame->channel_mode == MONO || frame->channel_mode == DUAL_CHANNEL) { int bitneed[2][8], loudness, max_bitneed, bitcount, slicecount, bitslice; int ch, sb; for (ch = 0; ch < frame->channels; ch++) { if (frame->allocation_method == SNR) { for (sb = 0; sb < frame->subbands; sb++) { bitneed[ch][sb] = frame->scale_factor[ch][sb]; } } else { for (sb = 0; sb < frame->subbands; sb++) { if (frame->scale_factor[ch][sb] == 0) { bitneed[ch][sb] = -5; } else { if (frame->subbands == 4) { loudness = frame->scale_factor[ch][sb] - sbc_offset4[sf][sb]; } else { loudness = frame->scale_factor[ch][sb] - sbc_offset8[sf][sb]; } if (loudness > 0) { bitneed[ch][sb] = loudness / 2; } else { bitneed[ch][sb] = loudness; } } } } max_bitneed = 0; for (sb = 0; sb < frame->subbands; sb++) { if (bitneed[ch][sb] > max_bitneed) max_bitneed = bitneed[ch][sb]; } bitcount = 0; slicecount = 0; bitslice = max_bitneed + 1; do { bitslice--; bitcount += slicecount; slicecount = 0; for (sb = 0; sb < frame->subbands; sb++) { if ((bitneed[ch][sb] > bitslice + 1) && (bitneed[ch][sb] < bitslice + 16)) { slicecount++; } else if (bitneed[ch][sb] == bitslice + 1) { slicecount += 2; } } } while (bitcount + slicecount < frame->bitpool); if (bitcount + slicecount == frame->bitpool) { bitcount += slicecount; bitslice--; } for (sb = 0; sb < frame->subbands; sb++) { if (bitneed[ch][sb] < bitslice + 2) { bits[ch][sb] = 0; } else { bits[ch][sb] = bitneed[ch][sb] - bitslice; if (bits[ch][sb] > 16) bits[ch][sb] = 16; } } sb = 0; while (bitcount < frame->bitpool && sb < frame->subbands) { if ((bits[ch][sb] >= 2) && (bits[ch][sb] < 16)) { bits[ch][sb]++; bitcount++; } else if ((bitneed[ch][sb] == bitslice + 1) && (frame->bitpool > bitcount + 1)) { bits[ch][sb] = 2; bitcount += 2; } sb++; } sb = 0; while (bitcount < frame->bitpool && sb < frame->subbands) { if (bits[ch][sb] < 16) { bits[ch][sb]++; bitcount++; } sb++; } } } else if (frame->channel_mode == STEREO || frame->channel_mode == JOINT_STEREO) { int bitneed[2][8], loudness, max_bitneed, bitcount, slicecount, bitslice; int ch, sb; if (frame->allocation_method == SNR) { for (ch = 0; ch < 2; ch++) { for (sb = 0; sb < frame->subbands; sb++) { bitneed[ch][sb] = frame->scale_factor[ch][sb]; } } } else { for (ch = 0; ch < 2; ch++) { for (sb = 0; sb < frame->subbands; sb++) { if (frame->scale_factor[ch][sb] == 0) { bitneed[ch][sb] = -5; } else { if (frame->subbands == 4) { loudness = frame->scale_factor[ch][sb] - sbc_offset4[sf][sb]; } else { loudness = frame->scale_factor[ch][sb] - sbc_offset8[sf][sb]; } if (loudness > 0) { bitneed[ch][sb] = loudness / 2; } else { bitneed[ch][sb] = loudness; } } } } } max_bitneed = 0; for (ch = 0; ch < 2; ch++) { for (sb = 0; sb < frame->subbands; sb++) { if (bitneed[ch][sb] > max_bitneed) max_bitneed = bitneed[ch][sb]; } } bitcount = 0; slicecount = 0; bitslice = max_bitneed + 1; do { bitslice--; bitcount += slicecount; slicecount = 0; for (ch = 0; ch < 2; ch++) { for (sb = 0; sb < frame->subbands; sb++) { if ((bitneed[ch][sb] > bitslice + 1) && (bitneed[ch][sb] < bitslice + 16)) { slicecount++; } else if (bitneed[ch][sb] == bitslice + 1) { slicecount += 2; } } } } while (bitcount + slicecount < frame->bitpool); if (bitcount + slicecount == frame->bitpool) { bitcount += slicecount; bitslice--; } for (ch = 0; ch < 2; ch++) { for (sb = 0; sb < frame->subbands; sb++) { if (bitneed[ch][sb] < bitslice + 2) { bits[ch][sb] = 0; } else { bits[ch][sb] = bitneed[ch][sb] - bitslice; if (bits[ch][sb] > 16) bits[ch][sb] = 16; } } } ch = 0; sb = 0; while ((bitcount < frame->bitpool) && (sb < frame->subbands)) { if ((bits[ch][sb] >= 2) && (bits[ch][sb] < 16)) { bits[ch][sb]++; bitcount++; } else if ((bitneed[ch][sb] == bitslice + 1) && (frame->bitpool > bitcount + 1)) { bits[ch][sb] = 2; bitcount += 2; } if (ch == 1) { ch = 0; sb++; } else { ch = 1; } } ch = 0; sb = 0; while ((bitcount < frame->bitpool) && (sb < frame->subbands)) { if (bits[ch][sb] < 16) { bits[ch][sb]++; bitcount++; } if (ch == 1) { ch = 0; sb++; } else { ch = 1; } } } } /* * Unpacks a SBC frame at the beginning of the stream in data, * which has at most len bytes into frame. * Returns the length in bytes of the packed frame, or a negative * value on error. The error codes are: * * -1 Data stream too short * -2 Sync byte incorrect * -3 CRC8 incorrect * -4 Bitpool value out of bounds */ static int sbc_unpack_frame(const u_int8_t * data, struct sbc_frame *frame, size_t len) { int consumed; /* Will copy the parts of the header that are relevant to crc calculation here */ u_int8_t crc_header[11] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; int crc_pos = 0; u_int8_t sf; /* sampling_frequency, temporarily needed as array index */ int ch, sb, blk, bit; /* channel, subband, block and bit standard counters */ int bits[2][8]; /* bits distribution */ int levels[2][8]; /* levels derived from that */ double scalefactor[2][8]; /* derived from frame->scale_factors */ if (len < 4) { return -1; } if (data[0] != SBC_SYNCWORD) { return -2; } sf = (data[1] >> 6) & 0x03; switch (sf) { case SBC_FS_16: frame->sampling_frequency = 16; break; case SBC_FS_32: frame->sampling_frequency = 32; break; case SBC_FS_44: frame->sampling_frequency = 44.1; break; case SBC_FS_48: frame->sampling_frequency = 48; break; } switch ((data[1] >> 4) & 0x03) { case SBC_NB_4: frame->blocks = 4; break; case SBC_NB_8: frame->blocks = 8; break; case SBC_NB_12: frame->blocks = 12; break; case SBC_NB_16: frame->blocks = 16; break; } frame->channel_mode = (data[1] >> 2) & 0x03; switch (frame->channel_mode) { case MONO: frame->channels = 1; break; case DUAL_CHANNEL: /* fall-through */ case STEREO: case JOINT_STEREO: frame->channels = 2; break; } frame->allocation_method = (data[1] >> 1) & 0x01; frame->subbands = (data[1] & 0x01) ? 8 : 4; frame->bitpool = data[2]; if (((frame->channel_mode == MONO || frame->channel_mode == DUAL_CHANNEL) && frame->bitpool > 16 * frame->subbands) || ((frame->channel_mode == STEREO || frame->channel_mode == JOINT_STEREO) && frame->bitpool > 32 * frame->subbands)) { return -4; } /* data[3] is crc, we're checking it later */ consumed = 32; crc_header[0] = data[1]; crc_header[1] = data[2]; crc_pos = 16; if (frame->channel_mode == JOINT_STEREO) { if (len * 8 < consumed + frame->subbands) { return -1; } else { frame->join = 0x00; for (sb = 0; sb < frame->subbands - 1; sb++) { frame->join |= ((data[4] >> (7 - sb)) & 0x01) << sb; } if (frame->subbands == 4) { crc_header[crc_pos / 8] = data[4] & 0xf0; } else { crc_header[crc_pos / 8] = data[4]; } consumed += frame->subbands; crc_pos += frame->subbands; } } if (len * 8 < consumed + (4 * frame->subbands * frame->channels)) { return -1; } else { for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { /* FIXME assert(consumed % 4 == 0); */ frame->scale_factor[ch][sb] = (data[consumed / 8] >> (4 - (consumed % 8))) & 0x0F; crc_header[crc_pos / 8] |= frame->scale_factor[ch][sb] << (4 - (crc_pos % 8)); consumed += 4; crc_pos += 4; } } } if (data[3] != sbc_crc8(crc_header, crc_pos)) { return -3; } sbc_calculate_bits(frame, bits, sf); for (blk = 0; blk < frame->blocks; blk++) { for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { frame->audio_sample[blk][ch][sb] = 0; if (bits[ch][sb] != 0) { for (bit = 0; bit < bits[ch][sb]; bit++) { int b; /* A bit */ if (consumed > len * 8) { return -1; } b = (data[consumed / 8] >> (7 - (consumed % 8))) & 0x01; frame->audio_sample[blk][ch][sb] |= b << (bits[ch][sb] - bit - 1); consumed++; } } } } } for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { levels[ch][sb] = (1 << bits[ch][sb]) - 1; scalefactor[ch][sb] = 2 << frame->scale_factor[ch][sb]; } } for (blk = 0; blk < frame->blocks; blk++) { for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { if (levels[ch][sb] > 0) { frame->sb_sample[blk][ch][sb] = scalefactor[ch][sb] * ((frame->audio_sample[blk][ch][sb] * 2.0 + 1.0) / levels[ch][sb] - 1.0); } else { frame->sb_sample[blk][ch][sb] = 0; } } } } if (frame->channel_mode == JOINT_STEREO) { for (blk = 0; blk < frame->blocks; blk++) { for (sb = 0; sb < frame->subbands; sb++) { if (frame->join & (0x01 << sb)) { frame->sb_sample[blk][0][sb] = frame->sb_sample[blk][0][sb] + frame->sb_sample[blk][1][sb]; frame->sb_sample[blk][1][sb] = frame->sb_sample[blk][0][sb] - 2 * frame->sb_sample[blk][1][sb]; } } } } if (consumed % 8 != 0) consumed += 8 - (consumed % 8); return consumed / 8; } static void sbc_decoder_init(struct sbc_decoder_state *state, const struct sbc_frame *frame) { memset(&state->S, 0, sizeof(state->S)); memset(&state->X, 0, sizeof(state->X)); memset(&state->V, 0, sizeof(state->V)); memset(&state->U, 0, sizeof(state->U)); memset(&state->W, 0, sizeof(state->W)); state->subbands = frame->subbands; } static inline void sbc_synthesize_four(struct sbc_decoder_state *state, struct sbc_frame *frame, int ch, int blk) { int i, j, k; /* Input 4 New Subband Samples */ for (i = 0; i < 4; i++) state->S[ch][i] = frame->sb_sample[blk][ch][i]; /* Shifting */ for (i = 79; i >= 8; i--) state->V[ch][i] = state->V[ch][i - 8]; /* Matrixing */ for (k = 0; k < 8; k++) { state->V[ch][k] = 0; for (i = 0; i < 4; i++) state->V[ch][k] += synmatrix4[k][i] * state->S[ch][i]; } /* Build a 40 values vector U */ for (i = 0; i <= 4; i++) { for (j = 0; j < 4; j++) { state->U[ch][i * 8 + j] = state->V[ch][i * 16 + j]; state->U[ch][i * 8 + j + 4] = state->V[ch][i * 16 + j + 12]; } } /* Window by 40 coefficients */ for (i = 0; i < 40; i++) state->W[ch][i] = state->U[ch][i] * sbc_proto_4_40[i] * (-4); /* Calculate 4 audio samples */ for (j = 0; j < 4; j++) { state->X[ch][j] = 0; for (i = 0; i < 10; i++) state->X[ch][j] += state->W[ch][j + 4 * i]; } /* Output 4 reconstructed Audio Samples */ for (i = 0; i < 4; i++) frame->pcm_sample[ch][blk * 4 + i] = state->X[ch][i]; } static inline void sbc_synthesize_eight(struct sbc_decoder_state *state, struct sbc_frame *frame, int ch, int blk) { int i, j, k; /* Input 8 New Subband Samples */ for (i = 0; i < 8; i++) state->S[ch][i] = frame->sb_sample[blk][ch][i]; /* Shifting */ for (i = 159; i >= 16; i--) state->V[ch][i] = state->V[ch][i - 16]; /* Matrixing */ for (k = 0; k < 16; k++) { state->V[ch][k] = 0; for (i = 0; i < 8; i++) { state->V[ch][k] += synmatrix8[k][i] * state->S[ch][i]; } } /* Build a 80 values vector U */ for (i = 0; i <= 4; i++) { for (j = 0; j < 8; j++) { state->U[ch][i * 16 + j] = state->V[ch][i * 32 + j]; state->U[ch][i * 16 + j + 8] = state->V[ch][i * 32 + j + 24]; } } /* Window by 80 coefficients */ for (i = 0; i < 80; i++) state->W[ch][i] = state->U[ch][i] * sbc_proto_8_80[i] * (-4); /* Calculate 8 audio samples */ for (j = 0; j < 8; j++) { state->X[ch][j] = 0; for (i = 0; i < 10; i++) state->X[ch][j] += state->W[ch][j + 8 * i]; } /* Ouput 8 reconstructed Audio Samples */ for (i = 0; i < 8; i++) frame->pcm_sample[ch][blk * 8 + i] = state->X[ch][i]; } static int sbc_synthesize_audio(struct sbc_decoder_state *state, struct sbc_frame *frame) { int ch, blk; switch (frame->subbands) { case 4: for (ch = 0; ch < frame->channels; ch++) { memset(frame->pcm_sample[ch], 0, sizeof(frame->pcm_sample[ch])); for (blk = 0; blk < frame->blocks; blk++) sbc_synthesize_four(state, frame, ch, blk); } return frame->blocks * 4; case 8: for (ch = 0; ch < frame->channels; ch++) { memset(frame->pcm_sample[ch], 0, sizeof(frame->pcm_sample[ch])); for (blk = 0; blk < frame->blocks; blk++) sbc_synthesize_eight(state, frame, ch, blk); } return frame->blocks * 8; default: return -EIO; } } static void sbc_encoder_init(struct sbc_encoder_state *state, const struct sbc_frame *frame) { memset(&state->S, 0, sizeof(state->S)); memset(&state->X, 0, sizeof(state->X)); memset(&state->Y, 0, sizeof(state->Y)); memset(&state->Z, 0, sizeof(state->Z)); state->subbands = frame->subbands; } static inline void sbc_analyze_four(struct sbc_encoder_state *state, struct sbc_frame *frame, int ch, int blk) { int i, k; /* Input 4 New Audio Samples */ for (i = 39; i >= 4; i--) state->X[ch][i] = state->X[ch][i - 4]; for (i = 3; i >= 0; i--) state->X[ch][i] = frame->pcm_sample[ch][blk * 4 + (3 - i)]; /* Windowing by 40 coefficients */ for (i = 0; i < 40; i++) state->Z[ch][i] = sbc_proto_4_40[i] * state->X[ch][i]; /* Partial calculation */ for (i = 0; i < 8; i++) { state->Y[ch][i] = 0; for (k = 0; k < 5; k++) state->Y[ch][i] += state->Z[ch][i + k * 8]; } /* Calculate 4 subband samples by Matrixing */ for (i = 0; i < 4; i++) { state->S[ch][i] = 0; for (k = 0; k < 8; k++) state->S[ch][i] += anamatrix4[i][k] * state->Y[ch][k]; } /* Output 4 Subband Samples */ for (i = 0; i < 4; i++) frame->sb_sample[blk][ch][i] = state->S[ch][i]; } static inline void sbc_analyze_eight(struct sbc_encoder_state *state, struct sbc_frame *frame, int ch, int blk) { int i, k; /* Input 8 Audio Samples */ for (i = 79; i >= 8; i--) state->X[ch][i] = state->X[ch][i - 8]; for (i = 7; i >= 0; i--) state->X[ch][i] = frame->pcm_sample[ch][blk * 8 + (7 - i)]; /* Windowing by 80 coefficients */ for (i = 0; i < 80; i++) state->Z[ch][i] = sbc_proto_8_80[i] * state->X[ch][i]; /* Partial calculation */ for (i = 0; i < 16; i++) { state->Y[ch][i] = 0; for (k = 0; k < 5; k++) state->Y[ch][i] += state->Z[ch][i + k * 16]; } /* Calculate 8 subband samples by Matrixing */ for (i = 0; i < 8; i++) { state->S[ch][i] = 0; for (k = 0; k < 16; k++) state->S[ch][i] += anamatrix8[i][k] * state->Y[ch][k]; } /* Output 8 Subband Samples */ for (i = 0; i < 8; i++) frame->sb_sample[blk][ch][i] = state->S[ch][i]; } static int sbc_analyze_audio(struct sbc_encoder_state *state, struct sbc_frame *frame) { int ch, blk; switch (frame->subbands) { case 4: for (ch = 0; ch < frame->channels; ch++) for (blk = 0; blk < frame->blocks; blk++) { memset(frame->sb_sample[blk][ch], 0, sizeof(frame->sb_sample[blk][ch])); sbc_analyze_four(state, frame, ch, blk); } return frame->blocks * 4; case 8: for (ch = 0; ch < frame->channels; ch++) for (blk = 0; blk < frame->blocks; blk++) { memset(frame->sb_sample[blk][ch], 0, sizeof(frame->sb_sample[blk][ch])); sbc_analyze_eight(state, frame, ch, blk); } return frame->blocks * 8; default: return -EIO; } } /* * Packs the SBC frame from frame into the memory at data. At most len * bytes will be used, should more memory be needed an appropriate * error code will be returned. Returns the length of the packed frame * on success or a negative value on error. * * The error codes are: * -1 Not enough memory reserved * -2 Unsupported sampling rate * -3 Unsupported number of blocks * -4 Unsupported number of subbands * -5 Bitpool value out of bounds * -99 not implemented */ static int sbc_pack_frame(u_int8_t * data, struct sbc_frame *frame, size_t len) { int produced; /* Will copy the header parts for CRC-8 calculation here */ u_int8_t crc_header[11] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; int crc_pos = 0; u_int8_t sf; /* Sampling frequency as temporary value for table lookup */ int ch, sb, blk, bit; /* channel, subband, block and bit counters */ int bits[2][8]; /* bits distribution */ int levels[2][8]; /* levels are derived from that */ double scalefactor[2][8]; /* derived from frame->scale_factor */ if (len < 4) { return -1; } /* Clear first 4 bytes of data (that's the constant length part of the SBC header) */ memset(data, 0, 4); data[0] = SBC_SYNCWORD; if (frame->sampling_frequency == 16) { data[1] |= (SBC_FS_16 & 0x03) << 6; sf = SBC_FS_16; } else if (frame->sampling_frequency == 32) { data[1] |= (SBC_FS_32 & 0x03) << 6; sf = SBC_FS_32; } else if (frame->sampling_frequency == 44.1) { data[1] |= (SBC_FS_44 & 0x03) << 6; sf = SBC_FS_44; } else if (frame->sampling_frequency == 48) { data[1] |= (SBC_FS_48 & 0x03) << 6; sf = SBC_FS_48; } else { return -2; } switch (frame->blocks) { case 4: data[1] |= (SBC_NB_4 & 0x03) << 4; break; case 8: data[1] |= (SBC_NB_8 & 0x03) << 4; break; case 12: data[1] |= (SBC_NB_12 & 0x03) << 4; break; case 16: data[1] |= (SBC_NB_16 & 0x03) << 4; break; default: return -3; break; } data[1] |= (frame->channel_mode & 0x03) << 2; data[1] |= (frame->allocation_method & 0x01) << 1; switch (frame->subbands) { case 4: /* Nothing to do */ break; case 8: data[1] |= 0x01; break; default: return -4; break; } data[2] = frame->bitpool; if (((frame->channel_mode == MONO || frame->channel_mode == DUAL_CHANNEL) && frame->bitpool > 16 * frame->subbands) || ((frame->channel_mode == STEREO || frame->channel_mode == JOINT_STEREO) && frame->bitpool > 32 * frame->subbands)) { return -5; } /* Can't fill in crc yet */ produced = 32; crc_header[0] = data[1]; crc_header[1] = data[2]; crc_pos = 16; for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { frame->scale_factor[ch][sb] = 0; scalefactor[ch][sb] = 2; for (blk = 0; blk < frame->blocks; blk++) { while (scalefactor[ch][sb] < fabs(frame->sb_sample[blk][ch][sb])) { frame->scale_factor[ch][sb]++; scalefactor[ch][sb] *= 2; } } } } if (frame->channel_mode == JOINT_STEREO) { float sb_sample_j[16][2][7]; /* like frame->sb_sample but joint stereo */ int scalefactor_j[2][7], scale_factor_j[2][7]; /* scalefactor and scale_factor in joint case */ /* Calculate joint stereo signal */ for (sb = 0; sb < frame->subbands - 1; sb++) { for (blk = 0; blk < frame->blocks; blk++) { sb_sample_j[blk][0][sb] = (frame->sb_sample[blk][0][sb] + frame->sb_sample[blk][1][sb]) / 2; sb_sample_j[blk][1][sb] = (frame->sb_sample[blk][0][sb] - frame->sb_sample[blk][1][sb]) / 2; } } /* calculate scale_factor_j and scalefactor_j for joint case */ for (ch = 0; ch < 2; ch++) { for (sb = 0; sb < frame->subbands - 1; sb++) { scale_factor_j[ch][sb] = 0; scalefactor_j[ch][sb] = 2; for (blk = 0; blk < frame->blocks; blk++) { while (scalefactor_j[ch][sb] < fabs(sb_sample_j[blk][ch][sb])) { scale_factor_j[ch][sb]++; scalefactor_j[ch][sb] *= 2; } } } } /* decide which subbands to join */ frame->join = 0; for (sb = 0; sb < frame->subbands - 1; sb++) { if ( (scalefactor[0][sb] + scalefactor[1][sb]) > (scalefactor_j[0][sb] + scalefactor_j[1][sb]) ) { /* use joint stereo for this subband */ frame->join |= 1 << sb; frame->scale_factor[0][sb] = scale_factor_j[0][sb]; frame->scale_factor[1][sb] = scale_factor_j[1][sb]; scalefactor[0][sb] = scalefactor_j[0][sb]; scalefactor[1][sb] = scalefactor_j[1][sb]; for (blk = 0; blk < frame->blocks; blk++) { frame->sb_sample[blk][0][sb] = sb_sample_j[blk][0][sb]; frame->sb_sample[blk][1][sb] = sb_sample_j[blk][1][sb]; } } } if (len * 8 < produced + frame->subbands) { return -1; } else { data[4] = 0; for (sb = 0; sb < frame->subbands - 1; sb++) { data[4] |= ((frame->join >> sb) & 0x01) << (7 - sb); } if (frame->subbands == 4) { crc_header[crc_pos / 8] = data[4] & 0xf0; } else { crc_header[crc_pos / 8] = data[4]; } produced += frame->subbands; crc_pos += frame->subbands; } } if (len * 8 < produced + (4 * frame->subbands * frame->channels)) { return -1; } else { for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { if (produced % 8 == 0) data[produced / 8] = 0; data[produced / 8] |= ((frame->scale_factor[ch][sb] & 0x0F) << (4 - (produced % 8))); crc_header[crc_pos / 8] |= ((frame->scale_factor[ch][sb] & 0x0F) << (4 - (crc_pos % 8))); produced += 4; crc_pos += 4; } } } data[3] = sbc_crc8(crc_header, crc_pos); sbc_calculate_bits(frame, bits, sf); for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { levels[ch][sb] = (1 << bits[ch][sb]) - 1; } } for (blk = 0; blk < frame->blocks; blk++) { for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { if (levels[ch][sb] > 0) { frame->audio_sample[blk][ch][sb] = (u_int16_t) (((frame->sb_sample[blk][ch][sb] / scalefactor[ch][sb] + 1.0) * levels[ch][sb]) / 2.0); } else { frame->audio_sample[blk][ch][sb] = 0; } } } } for (blk = 0; blk < frame->blocks; blk++) { for (ch = 0; ch < frame->channels; ch++) { for (sb = 0; sb < frame->subbands; sb++) { if (bits[ch][sb] != 0) { for (bit = 0; bit < bits[ch][sb]; bit++) { int b; /* A bit */ if (produced > len * 8) { return -1; } if (produced % 8 == 0) { data[produced / 8] = 0; } b = ((frame->audio_sample[blk][ch][sb]) >> (bits[ch][sb] - bit - 1)) & 0x01; data[produced / 8] |= b << (7 - (produced % 8)); produced++; } } } } } if (produced % 8 != 0) { produced += 8 - (produced % 8); } return produced / 8; } struct sbc_priv { int init; struct sbc_frame frame; struct sbc_decoder_state dec_state; struct sbc_encoder_state enc_state; }; int sbc_init(sbc_t *sbc, unsigned long flags) { if (!sbc) return -EIO; memset(sbc, 0, sizeof(sbc_t)); sbc->priv = malloc(sizeof(struct sbc_priv)); if (!sbc->priv) return -ENOMEM; memset(sbc->priv, 0, sizeof(struct sbc_priv)); sbc->rate = 44100; sbc->channels = 2; sbc->subbands = 8; sbc->blocks = 16; sbc->bitpool = 32; return 0; } int sbc_decode(sbc_t *sbc, void *data, int count) { struct sbc_priv *priv; char *ptr; int i, ch, framelen, samples; if (!sbc) return -EIO; priv = sbc->priv; framelen = sbc_unpack_frame(data, &priv->frame, count); if (!priv->init) { sbc_decoder_init(&priv->dec_state, &priv->frame); priv->init = 1; sbc->rate = priv->frame.sampling_frequency * 1000; sbc->channels = priv->frame.channels; sbc->subbands = priv->frame.subbands; sbc->blocks = priv->frame.blocks; sbc->bitpool = priv->frame.bitpool; } samples = sbc_synthesize_audio(&priv->dec_state, &priv->frame); if (!sbc->data) { sbc->size = samples * priv->frame.channels * 2; sbc->data = malloc(sbc->size); } if (sbc->size < samples * priv->frame.channels * 2) { sbc->size = samples * priv->frame.channels * 2; sbc->data = realloc(sbc->data, sbc->size); } if (!sbc->data) { sbc->size = 0; return -ENOMEM; } ptr = sbc->data; for (i = 0; i < samples; i++) { for (ch = 0; ch < priv->frame.channels; ch++) { int16_t s = (int16_t)(priv->frame.pcm_sample[ch][i]); *ptr++ = (s & 0xff00) >> 8; *ptr++ = (s & 0x00ff); } } sbc->len = samples * priv->frame.channels * 2; sbc->duration = (1000000 * priv->frame.subbands * priv->frame.blocks) / sbc->rate; return framelen; } int sbc_encode(sbc_t *sbc, void *data, int count) { struct sbc_priv *priv; char *ptr; int i, ch, framelen, samples; if (!sbc) return -EIO; priv = sbc->priv; if (!priv->init) { priv->frame.sampling_frequency = ((double) sbc->rate) / 1000; priv->frame.channels = sbc->channels; if (sbc->channels > 1) priv->frame.channel_mode = STEREO; else priv->frame.channel_mode = MONO; priv->frame.allocation_method = SNR; priv->frame.subbands = sbc->subbands; priv->frame.blocks = sbc->blocks; priv->frame.bitpool = sbc->bitpool; sbc_encoder_init(&priv->enc_state, &priv->frame); priv->init = 1; } ptr = data; for (i = 0; i < priv->frame.subbands * priv->frame.blocks; i++) { for (ch = 0; ch < sbc->channels; ch++) { //int16_t s = (ptr[0] & 0xff) << 8 | (ptr[1] & 0xff); int16_t s = (ptr[1] & 0xff) << 8 | (ptr[2] & 0xff); ptr += 2; priv->frame.pcm_sample[ch][i] = ((double) s); } } samples = sbc_analyze_audio(&priv->enc_state, &priv->frame); if (!sbc->data) { sbc->size = 1024; sbc->data = malloc(sbc->size); } if (!sbc->data) { sbc->size = 0; return -ENOMEM; } framelen = sbc_pack_frame(sbc->data, &priv->frame, sbc->size); sbc->len = framelen; sbc->duration = (1000000 * priv->frame.subbands * priv->frame.blocks) / sbc->rate; return samples * sbc->channels * 2; } void sbc_finish(sbc_t *sbc) { if (!sbc) return; if (sbc->data) free(sbc->data); if (sbc->priv) free(sbc->priv); memset(sbc, 0, sizeof(sbc_t)); }