/*
 *
 *  Bluetooth low-complexity, subband codec (SBC) library
 *
 *  Copyright (C) 2004-2006  Marcel Holtmann <marcel@holtmann.org>
 *  Copyright (C) 2004-2005  Henryk Ploetz <henryk@ploetzli.ch>
 *  Copyright (C) 2005-2006  Brad Midgley <bmidgley@xmission.com>
 *
 *
 *  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
 *
 */

/* todo items:

  use a log2 table for byte integer scale factors calculation (sum log2 results for high and low bytes)
  fill bitpool by 16 bits instead of one at a time in bits allocation/bitpool generation
  port to the dsp 
  don't consume more bytes than passed into the encoder

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <errno.h>
#include <stdint.h>
#include <malloc.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>


#include "sbc_math.h"
#include "sbc_tables.h"

#include "sbc.h"

#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 {
	uint16_t sampling_frequency;	/* in kHz */
	uint8_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;
	uint8_t channels;
	enum {
		LOUDNESS	= SBC_AM_LOUDNESS,
		SNR		= SBC_AM_SNR
	} allocation_method;
	uint8_t subbands;
	uint8_t bitpool;
	uint8_t join;				/* bit number x set means joint stereo has been used in subband x */
	uint8_t scale_factor[2][8];		/* only the lower 4 bits of every element are to be used */
	uint16_t audio_sample[16][2][8];	/* raw integer subband samples in the frame */

	int32_t sb_sample_f[16][2][8];
	int32_t sb_sample[16][2][8];		/* modified subband samples */
	int16_t pcm_sample[2][16*8];		/* original pcm audio samples */
};

struct sbc_decoder_state {
	int subbands;
	int32_t V[2][170];
	int offset[2][16];
};

struct sbc_encoder_state {
	int subbands;
	int32_t X[2][80];
};

/*
 * Calculates the CRC-8 of the first len bits in data
 */
static const uint8_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 uint8_t sbc_crc8(const uint8_t * data, size_t len)
{
	uint8_t crc = 0x0f;
	size_t i;
	uint8_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], uint8_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 uint8_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 */
	uint8_t crc_header[11] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
	int crc_pos = 0;
	int32_t temp;

	uint8_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 */

	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 = 16000;
		break;
	case SBC_FS_32:
		frame->sampling_frequency = 32000;
		break;
	case SBC_FS_44:
		frame->sampling_frequency = 44100;
		break;
	case SBC_FS_48:
		frame->sampling_frequency = 48000;
		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;

		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;

	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 >> 3] >> (4 - (consumed & 0x7))) & 0x0F;
			crc_header[crc_pos >> 3] |= frame->scale_factor[ch][sb] << (4 - (crc_pos & 0x7));

			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)
					continue;

				for (bit = 0; bit < bits[ch][sb]; bit++) {
					int b;	/* A bit */
					if (consumed > len * 8)
						return -1;

					b = (data[consumed >> 3] >> (7 - (consumed & 0x7))) & 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;
		}
	}

	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] = 
						(((frame->audio_sample[blk][ch][sb] << 16) | 0x8000) / levels[ch][sb]) - 0x8000; 

					frame->sb_sample[blk][ch][sb] >>= 3;
					frame->sb_sample[blk][ch][sb] = (frame->sb_sample[blk][ch][sb] << (frame->scale_factor[ch][sb] + 1)); // Q13 

				} 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)) {
					temp = frame->sb_sample[blk][0][sb] + frame->sb_sample[blk][1][sb];
					frame->sb_sample[blk][1][sb] = frame->sb_sample[blk][0][sb] - frame->sb_sample[blk][1][sb];
					frame->sb_sample[blk][0][sb] = temp;
				}
			}
		}
	}

	if ((consumed & 0x7) != 0)
		consumed += 8 - (consumed & 0x7);

	
	return consumed >> 3;
}

static void sbc_decoder_init(struct sbc_decoder_state *state, const struct sbc_frame *frame)
{
	int i, ch;

	memset(state->V, 0, sizeof(state->V));
	state->subbands = frame->subbands;

	for (ch = 0; ch < 2; ch++)
		for (i = 0; i < frame->subbands * 2; i++)
			state->offset[ch][i] = (10 * i + 10);
}

static inline void sbc_synthesize_four(struct sbc_decoder_state *state,
				struct sbc_frame *frame, int ch, int blk)
{
	int i, j, k, idx;
	sbc_extended_t res;

	for(i = 0; i < 8; i++) {
		/* Shifting */
		state->offset[ch][i]--;
		if (state->offset[ch][i] < 0) {
			state->offset[ch][i] = 79;
			for(j = 0; j < 9; j++) {
				state->V[ch][j+80] = state->V[ch][j];
			}
		}
	}
	

	for(i = 0; i < 8; i++) {
		/* Distribute the new matrix value to the shifted position */
		SBC_FIXED_0(res);
		for (j = 0; j < 4; j++) {
			MULA(res, synmatrix4[i][j], frame->sb_sample[blk][ch][j]);
		}
		state->V[ch][state->offset[ch][i]] = SCALE4_STAGED1(res);
	}

	/* Compute the samples */
	for(idx = 0, i = 0; i < 4; i++) {
		k = (i + 4) & 0xf;
		SBC_FIXED_0(res);
		for(j = 0; j < 10; idx++) {
		MULA(res, state->V[ch][state->offset[ch][i]+j++], sbc_proto_4_40m0[idx]);
			MULA(res, state->V[ch][state->offset[ch][k]+j++], sbc_proto_4_40m1[idx]);
		}
		/* Store in output */
		frame->pcm_sample[ch][blk * 4 + i] = SCALE4_STAGED2(res); // Q0
	}
}

static inline void sbc_synthesize_eight(struct sbc_decoder_state *state,
				struct sbc_frame *frame, int ch, int blk)
{
	int i, j, k, idx;
	sbc_extended_t res;

	for(i = 0; i < 16; i++) {
		/* Shifting */
		state->offset[ch][i]--;
		if (state->offset[ch][i] < 0) {
			state->offset[ch][i] = 159;
			for(j = 0; j < 9; j++) {
				state->V[ch][j+160] = state->V[ch][j]; 
			}
		}
	}

	for(i = 0; i < 16; i++) {
		/* Distribute the new matrix value to the shifted position */
		SBC_FIXED_0(res);
		for (j = 0; j < 8; j++) {
			MULA(res, synmatrix8[i][j], frame->sb_sample[blk][ch][j]); // Q28 = Q15 * Q13
		}
		state->V[ch][state->offset[ch][i]] = SCALE8_STAGED1(res); // Q10
	}
	

	/* Compute the samples */
	for(idx = 0, i = 0; i < 8; i++) {
		k = (i + 8) & 0xf;
		SBC_FIXED_0(res);
		for(j = 0; j < 10; idx++) {
			MULA(res, state->V[ch][state->offset[ch][i]+j++], sbc_proto_8_80m0[idx]);
			MULA(res, state->V[ch][state->offset[ch][k]+j++], sbc_proto_8_80m1[idx]);
		}
		/* Store in output */
		frame->pcm_sample[ch][blk * 8 + i] = SCALE8_STAGED2(res); // Q0

	}
}

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++) {
			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++) {
			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->X, 0, sizeof(state->X));
	state->subbands = frame->subbands;
}

static inline void _sbc_analyze_four(const int32_t *in, int32_t *out)
{

	sbc_extended_t res;
	sbc_extended_t t[8];

	out[0] = out[1] = out[2] = out[3] = 0;

	MUL(res, _sbc_proto_4[0], (in[8] - in[32])); // Q18
	MULA(res, _sbc_proto_4[1], (in[16] - in[24]));
	t[0] = SCALE4_STAGE1(res); // Q8

	MUL(res, _sbc_proto_4[2], in[1]);
	MULA(res, _sbc_proto_4[3], in[9]);
	MULA(res, _sbc_proto_4[4], in[17]);
	MULA(res, _sbc_proto_4[5], in[25]);
	MULA(res, _sbc_proto_4[6], in[33]);
	t[1] = SCALE4_STAGE1(res);

	MUL(res, _sbc_proto_4[7], in[2]);
	MULA(res, _sbc_proto_4[8], in[10]);
	MULA(res, _sbc_proto_4[9], in[18]);
	MULA(res, _sbc_proto_4[10], in[26]);
	MULA(res, _sbc_proto_4[11], in[34]);
	t[2] = SCALE4_STAGE1(res);

	MUL(res, _sbc_proto_4[12], in[3]);
	MULA(res, _sbc_proto_4[13], in[11]);
	MULA(res, _sbc_proto_4[14], in[19]);
	MULA(res, _sbc_proto_4[15], in[27]);
	MULA(res, _sbc_proto_4[16], in[35]);
	t[3] = SCALE4_STAGE1(res);

	MUL(res, _sbc_proto_4[17], in[4]);
	MULA(res, _sbc_proto_4[18], (in[12] + in[28]));
	MULA(res, _sbc_proto_4[19], in[20]);
	MULA(res, _sbc_proto_4[17], in[36]);
	t[4] = SCALE4_STAGE1(res);

	MUL(res, _sbc_proto_4[16], in[5]);
	MULA(res, _sbc_proto_4[15], in[13]);
	MULA(res, _sbc_proto_4[14], in[21]);
	MULA(res, _sbc_proto_4[13], in[29]);
	MULA(res, _sbc_proto_4[12], in[37]);
	t[5] = SCALE4_STAGE1(res);

	MUL(res, _sbc_proto_4[11], in[6]);
	MULA(res, _sbc_proto_4[10], in[14]);
	MULA(res, _sbc_proto_4[9], in[22]);
	MULA(res, _sbc_proto_4[8], in[30]);
	MULA(res, _sbc_proto_4[7], in[38]);
	t[6] = SCALE4_STAGE1(res);

	MUL(res, _sbc_proto_4[6], in[7]);
	MULA(res, _sbc_proto_4[5], in[15]);
	MULA(res, _sbc_proto_4[4], in[23]);
	MULA(res, _sbc_proto_4[3], in[31]);
	MULA(res, _sbc_proto_4[2], in[39]);
	t[7] = SCALE4_STAGE1(res);

	MUL(res, _anamatrix4[0], t[0]);
	MULA(res, _anamatrix4[1], t[1]);
	MULA(res, _anamatrix4[2], t[2]);
	MULA(res, _anamatrix4[1], t[3]);
	MULA(res, _anamatrix4[0], t[4]);
	MULA(res, _anamatrix4[3], t[5]);
	MULA(res, -_anamatrix4[3], t[7]);
	out[0] = SCALE4_STAGE2(res); // Q0
	
	MUL(res, -_anamatrix4[0], t[0]);
	MULA(res, _anamatrix4[3], t[1]);
	MULA(res, _anamatrix4[2], t[2]);
	MULA(res, _anamatrix4[3], t[3]);
	MULA(res, -_anamatrix4[0], t[4]);
	MULA(res, -_anamatrix4[1], t[5]);
	MULA(res, _anamatrix4[1], t[7]);
	out[1] = SCALE4_STAGE2(res);


	MUL(res, -_anamatrix4[0], t[0]);
	MULA(res, -_anamatrix4[3], t[1]);
	MULA(res, _anamatrix4[2], t[2]);
	MULA(res, -_anamatrix4[3], t[3]);
	MULA(res, -_anamatrix4[0], t[4]);
	MULA(res, _anamatrix4[1], t[5]);
	MULA(res, -_anamatrix4[1], t[7]);
	out[2] = SCALE4_STAGE2(res);

	MUL(res, _anamatrix4[0], t[0]);
	MULA(res, -_anamatrix4[1], t[1]);
	MULA(res, _anamatrix4[2], t[2]);
	MULA(res, -_anamatrix4[1], t[3]);
	MULA(res, _anamatrix4[0], t[4]);
	MULA(res, -_anamatrix4[3], t[5]);
	MULA(res, _anamatrix4[3], t[7]);
	out[3] = SCALE4_STAGE2(res);
}
static inline void sbc_analyze_four(struct sbc_encoder_state *state,
				struct sbc_frame *frame, int ch, int blk)
{
	int i;
	/* 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)];
	_sbc_analyze_four(state->X[ch], frame->sb_sample_f[blk][ch]);
}

static inline void _sbc_analyze_eight(const int32_t *in, int32_t *out)
{
	sbc_extended_t res;
	sbc_extended_t t[8];

	out[0] = out[1] = out[2] = out[3] = out[4] = out[5] = out[6] = out[7] = 0;
	
	MUL(res,  _sbc_proto_8[0], (in[16] - in[64])); // Q18 = Q18 * Q0
	MULA(res, _sbc_proto_8[1], (in[32] - in[48]));
	MULA(res, _sbc_proto_8[2], in[4]);
	MULA(res, _sbc_proto_8[3], in[20]);
	MULA(res, _sbc_proto_8[4], in[36]);
	MULA(res, _sbc_proto_8[5], in[52]);
	t[0] = SCALE8_STAGE1(res); // Q10

	MUL(res,   _sbc_proto_8[6], in[2]);
	MULA(res,  _sbc_proto_8[7], in[18]);
	MULA(res,  _sbc_proto_8[8], in[34]);
	MULA(res,  _sbc_proto_8[9], in[50]);
	MULA(res, _sbc_proto_8[10], in[66]);
	t[1] = SCALE8_STAGE1(res);

	MUL(res,  _sbc_proto_8[11], in[1]);
	MULA(res, _sbc_proto_8[12], in[17]);
	MULA(res, _sbc_proto_8[13], in[33]);
	MULA(res, _sbc_proto_8[14], in[49]);
	MULA(res, _sbc_proto_8[15], in[65]);
	MULA(res, _sbc_proto_8[16], in[3]);
	MULA(res, _sbc_proto_8[17], in[19]);
	MULA(res, _sbc_proto_8[18], in[35]);
	MULA(res, _sbc_proto_8[19], in[51]);
	MULA(res, _sbc_proto_8[20], in[67]);
	t[2] = SCALE8_STAGE1(res);

	MUL(res,   _sbc_proto_8[21], in[5]);
	MULA(res,  _sbc_proto_8[22], in[21]);
	MULA(res,  _sbc_proto_8[23], in[37]);
	MULA(res,  _sbc_proto_8[24], in[53]);
	MULA(res,  _sbc_proto_8[25], in[69]);
	MULA(res, -_sbc_proto_8[15], in[15]);
	MULA(res, -_sbc_proto_8[14], in[31]);
	MULA(res, -_sbc_proto_8[13], in[47]);
	MULA(res, -_sbc_proto_8[12], in[63]);
	MULA(res, -_sbc_proto_8[11], in[79]);
	t[3] = SCALE8_STAGE1(res);

	MUL(res,   _sbc_proto_8[26], in[6]);
	MULA(res,  _sbc_proto_8[27], in[22]);
	MULA(res,  _sbc_proto_8[28], in[38]);
	MULA(res,  _sbc_proto_8[29], in[54]);
	MULA(res,  _sbc_proto_8[30], in[70]);
	MULA(res, -_sbc_proto_8[10], in[14]);
	MULA(res,  -_sbc_proto_8[9], in[30]);
	MULA(res,  -_sbc_proto_8[8], in[46]);
	MULA(res,  -_sbc_proto_8[7], in[62]);
	MULA(res,  -_sbc_proto_8[6], in[78]);
	t[4] = SCALE8_STAGE1(res);

	MUL(res,   _sbc_proto_8[31], in[7]);
	MULA(res,  _sbc_proto_8[32], in[23]);
	MULA(res,  _sbc_proto_8[33], in[39]);
	MULA(res,  _sbc_proto_8[34], in[55]);
	MULA(res,  _sbc_proto_8[35], in[71]);
	MULA(res, -_sbc_proto_8[20], in[13]);
	MULA(res, -_sbc_proto_8[19], in[29]);
	MULA(res, -_sbc_proto_8[18], in[45]);
	MULA(res, -_sbc_proto_8[17], in[61]);
	MULA(res, -_sbc_proto_8[16], in[77]);
	t[5] = SCALE8_STAGE1(res);

	MUL(res,   _sbc_proto_8[36], (in[8] + in[72]));
	MULA(res,  _sbc_proto_8[37], in[24]);
	MULA(res,  _sbc_proto_8[38], in[40]);
	MULA(res,  _sbc_proto_8[37], in[56]);
	MULA(res, -_sbc_proto_8[39], in[12]);
	MULA(res,  -_sbc_proto_8[5], in[28]);
	MULA(res,  -_sbc_proto_8[4], in[44]);
	MULA(res,  -_sbc_proto_8[3], in[60]);
	MULA(res,  -_sbc_proto_8[2], in[76]);
	t[6] = SCALE8_STAGE1(res);

	MUL(res,   _sbc_proto_8[35], in[9]);
	MULA(res,  _sbc_proto_8[34], in[25]);
	MULA(res,  _sbc_proto_8[33], in[41]);
	MULA(res,  _sbc_proto_8[32], in[57]);
	MULA(res,  _sbc_proto_8[31], in[73]);
	MULA(res, -_sbc_proto_8[25], in[11]);
	MULA(res, -_sbc_proto_8[24], in[27]);
	MULA(res, -_sbc_proto_8[23], in[43]);
	MULA(res, -_sbc_proto_8[22], in[59]);
	MULA(res, -_sbc_proto_8[21], in[75]);
	t[7] = SCALE8_STAGE1(res);

	MUL(res, _anamatrix8[0], t[0]); // = Q14 * Q10
	MULA(res, _anamatrix8[7], t[1]);
	MULA(res, _anamatrix8[2], t[2]);
	MULA(res, _anamatrix8[3], t[3]);
	MULA(res, _anamatrix8[6], t[4]);
	MULA(res, _anamatrix8[4], t[5]);
	MULA(res, _anamatrix8[1], t[6]);
	MULA(res, _anamatrix8[5], t[7]);
	out[0] = SCALE8_STAGE2(res); // Q0

	MUL(res, _anamatrix8[1], t[0]);
	MULA(res, _anamatrix8[7], t[1]);
	MULA(res, _anamatrix8[3], t[2]);
	MULA(res, -_anamatrix8[5], t[3]);
	MULA(res, -_anamatrix8[6], t[4]);
	MULA(res, -_anamatrix8[2], t[5]);
	MULA(res, -_anamatrix8[0], t[6]);
	MULA(res, -_anamatrix8[4], t[7]);
	out[1] = SCALE8_STAGE2(res);

	MUL(res, -_anamatrix8[1], t[0]);
	MULA(res, _anamatrix8[7], t[1]);
	MULA(res, _anamatrix8[4], t[2]);
	MULA(res, -_anamatrix8[2], t[3]);
	MULA(res, -_anamatrix8[6], t[4]);
	MULA(res, _anamatrix8[5], t[5]);
	MULA(res, _anamatrix8[0], t[6]);
	MULA(res, _anamatrix8[3], t[7]);
	out[2] = SCALE8_STAGE2(res);

	MUL(res, -_anamatrix8[0], t[0]);
	MULA(res, _anamatrix8[7], t[1]);
	MULA(res, _anamatrix8[5], t[2]);
	MULA(res, -_anamatrix8[4], t[3]);
	MULA(res, _anamatrix8[6], t[4]);
	MULA(res, _anamatrix8[3], t[5]);
	MULA(res, -_anamatrix8[1], t[6]);
	MULA(res, -_anamatrix8[2], t[7]);
	out[3] = SCALE8_STAGE2(res);

	MUL(res, -_anamatrix8[0], t[0]);
	MULA(res, _anamatrix8[7], t[1]);
	MULA(res, -_anamatrix8[5], t[2]);
	MULA(res, _anamatrix8[4], t[3]);
	MULA(res, _anamatrix8[6], t[4]);
	MULA(res, -_anamatrix8[3], t[5]);
	MULA(res, -_anamatrix8[1], t[6]);
	MULA(res, _anamatrix8[2], t[7]);
	out[4] = SCALE8_STAGE2(res);

	MUL(res, -_anamatrix8[1], t[0]);
	MULA(res, _anamatrix8[7], t[1]);
	MULA(res, -_anamatrix8[4], t[2]);
	MULA(res, _anamatrix8[2], t[3]);
	MULA(res, -_anamatrix8[6], t[4]);
	MULA(res, -_anamatrix8[5], t[5]);
	MULA(res, _anamatrix8[0], t[6]);
	MULA(res, -_anamatrix8[3], t[7]);
	out[5] = SCALE8_STAGE2(res);

	MUL(res, _anamatrix8[1], t[0]);
	MULA(res, _anamatrix8[7], t[1]);
	MULA(res, -_anamatrix8[3], t[2]);
	MULA(res, _anamatrix8[5], t[3]);
	MULA(res, -_anamatrix8[6], t[4]);
	MULA(res, _anamatrix8[2], t[5]);
	MULA(res, -_anamatrix8[0], t[6]);
	MULA(res, _anamatrix8[4], t[7]);
	out[6] = SCALE8_STAGE2(res);

	MUL(res, _anamatrix8[0], t[0]);
	MULA(res, _anamatrix8[7], t[1]);
	MULA(res, -_anamatrix8[2], t[2]);
	MULA(res, -_anamatrix8[3], t[3]);
	MULA(res, _anamatrix8[6], t[4]);
	MULA(res, -_anamatrix8[4], t[5]);
	MULA(res, _anamatrix8[1], t[6]);
	MULA(res, -_anamatrix8[5], t[7]);
	out[7] = SCALE8_STAGE2(res);
}

static inline void sbc_analyze_eight(struct sbc_encoder_state *state,
				     struct sbc_frame *frame, int ch, int blk)
{
	int i;

	/* 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)];
	_sbc_analyze_eight(state->X[ch], frame->sb_sample_f[blk][ch]);
}

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++) {
				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++) {
				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(uint8_t * data, struct sbc_frame *frame, size_t len)
{
	int produced;
	/* Will copy the header parts for CRC-8 calculation here */
	uint8_t crc_header[11] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
	int crc_pos = 0;

	uint8_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 */

	u_int32_t 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 == 16000) {
		data[1] |= (SBC_FS_16 & 0x03) << 6;
		sf = SBC_FS_16;
	} else if (frame->sampling_frequency == 32000) {
		data[1] |= (SBC_FS_32 & 0x03) << 6;
		sf = SBC_FS_32;
	} else if (frame->sampling_frequency == 44100) {
		data[1] |= (SBC_FS_44 & 0x03) << 6;
		sf = SBC_FS_44;
	} else if (frame->sampling_frequency == 48000) {
		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_f[blk][ch][sb])) {
					frame->scale_factor[ch][sb]++;
					scalefactor[ch][sb] *= 2;
				}
			}
		}
	}

	if (frame->channel_mode == JOINT_STEREO) {
		int32_t 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_f[blk][0][sb] +  frame->sb_sample_f[blk][1][sb]) >> 1;
				sb_sample_j[blk][1][sb] = (frame->sb_sample_f[blk][0][sb] -  frame->sb_sample_f[blk][1][sb]) >> 1;
			}
		}

		/* 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_f[blk][0][sb] = sb_sample_j[blk][0][sb];
					frame->sb_sample_f[blk][1][sb] = sb_sample_j[blk][1][sb];
				}
			}
		}

		if (len * 8 < produced + frame->subbands)
			return -1;

		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;

	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] =
						(uint16_t) ((((frame->sb_sample_f[blk][ch][sb]*levels[ch][sb]) >> (frame->scale_factor[ch][sb] + 1)) +
						levels[ch][sb]) >> 1);
				} 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->joint = 0;
	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;
		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;
			s = 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 = sbc->rate;
		priv->frame.channels = sbc->channels;

		if (sbc->channels > 1) {
			if (sbc->joint)
				priv->frame.channel_mode = JOINT_STEREO;
			else
				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);
			ptr += 2;
			priv->frame.pcm_sample[ch][i] = 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));
}