diff options
author | Marcel Holtmann <marcel@holtmann.org> | 2005-02-10 21:02:07 +0000 |
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committer | Marcel Holtmann <marcel@holtmann.org> | 2005-02-10 21:02:07 +0000 |
commit | 490afac7bc8ca6b283499fe5b026a14a7f7df0cb (patch) | |
tree | e4c58b785fd904924661bcb789b59859ecabf8f6 /alsa/sbc.c | |
parent | 77f2ea7f02d5981deab6ec22d05570e06d46836e (diff) |
Add SBC library support
Diffstat (limited to 'alsa/sbc.c')
-rw-r--r-- | alsa/sbc.c | 1355 |
1 files changed, 1355 insertions, 0 deletions
diff --git a/alsa/sbc.c b/alsa/sbc.c new file mode 100644 index 00000000..bd767768 --- /dev/null +++ b/alsa/sbc.c @@ -0,0 +1,1355 @@ +/* + * + * Bluetooth low-complexity, subband codec (SBC) library + * + * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org> + * Copyright (C) 2004-2005 Henryk Ploetz <henryk@ploetzli.ch> + * + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <errno.h> +#include <malloc.h> +#include <string.h> +#include <sys/types.h> + +#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)); + + 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; + } + + 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; + + 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 = 8; + priv->frame.blocks = 16; + priv->frame.bitpool = 32; + + 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; + + 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)); +} |