korg/bluez
0
0
Fork 0
mirror of https://git.kernel.org/pub/scm/bluetooth/bluez.git synced 2024-11-29 15:14:31 +08:00
Code Issues Packages Projects Releases Wiki Activity
f36f66d1ca
bluez/sbc/sbc.c
Siarhei Siamashka 3df7c3e660 sbc: added saturated clipping of decoder output to 16-bit 
This prevents overflows and audible artefacts for the audio files which
originally had loudness maximized. Music from audio CD disks is an
example of such files, see http://en.wikipedia.org/wiki/Loudness_war
2009-04-17 19:00:24 +02:00

1259 lines
32 KiB
C
Raw Blame History

/*
*
* Bluetooth low-complexity, subband codec (SBC) library
*
* Copyright (C) 2004-2009 Marcel Holtmann <marcel@holtmann.org>
* Copyright (C) 2004-2005 Henryk Ploetz <henryk@ploetzli.ch>
* Copyright (C) 2005-2008 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
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <limits.h>
#include "sbc_math.h"
#include "sbc_tables.h"
#include "sbc.h"
#include "sbc_primitives.h"
#define SBC_SYNCWORD 0x9C
/* This structure contains an unpacked SBC frame.
Yes, there is probably quite some unused space herein */
struct sbc_frame {
uint8_t frequency;
uint8_t block_mode;
uint8_t blocks;
enum {
MONO = SBC_MODE_MONO,
DUAL_CHANNEL = SBC_MODE_DUAL_CHANNEL,
STEREO = SBC_MODE_STEREO,
JOINT_STEREO = SBC_MODE_JOINT_STEREO
} mode;
uint8_t channels;
enum {
LOUDNESS = SBC_AM_LOUDNESS,
SNR = SBC_AM_SNR
} allocation;
uint8_t subband_mode;
uint8_t subbands;
uint8_t bitpool;
uint16_t codesize;
uint8_t length;
/* bit number x set means joint stereo has been used in subband x */
uint8_t joint;
/* only the lower 4 bits of every element are to be used */
uint32_t scale_factor[2][8];
/* raw integer subband samples in the frame */
int32_t SBC_ALIGNED sb_sample_f[16][2][8];
/* modified subband samples */
int32_t SBC_ALIGNED sb_sample[16][2][8];
/* original pcm audio samples */
int16_t SBC_ALIGNED pcm_sample[2][16*8];
};
struct sbc_decoder_state {
int subbands;
int32_t V[2][170];
int offset[2][16];
};
/*
* 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 = frame->frequency;
if (frame->mode == MONO || frame->mode == DUAL_CHANNEL) {
int bitneed[2][8], loudness, max_bitneed, bitcount, slicecount, bitslice;
int ch, sb;
for (ch = 0; ch < frame->channels; ch++) {
max_bitneed = 0;
if (frame->allocation == SNR) {
for (sb = 0; sb < frame->subbands; sb++) {
bitneed[ch][sb] = frame->scale_factor[ch][sb];
if (bitneed[ch][sb] > max_bitneed)
max_bitneed = bitneed[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;
}
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;
}
}
for (sb = 0; bitcount < frame->bitpool && sb < frame->subbands; sb++) {
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;
}
}
for (sb = 0; bitcount < frame->bitpool && sb < frame->subbands; sb++) {
if (bits[ch][sb] < 16) {
bits[ch][sb]++;
bitcount++;
}
}
}
} else if (frame->mode == STEREO || frame->mode == JOINT_STEREO) {
int bitneed[2][8], loudness, max_bitneed, bitcount, slicecount, bitslice;
int ch, sb;
max_bitneed = 0;
if (frame->allocation == SNR) {
for (ch = 0; ch < 2; ch++) {
for (sb = 0; sb < frame->subbands; sb++) {
bitneed[ch][sb] = frame->scale_factor[ch][sb];
if (bitneed[ch][sb] > max_bitneed)
max_bitneed = bitneed[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;
}
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) {
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++;
if (sb >= frame->subbands) break;
} else
ch = 1;
}
ch = 0;
sb = 0;
while (bitcount < frame->bitpool) {
if (bits[ch][sb] < 16) {
bits[ch][sb]++;
bitcount++;
}
if (ch == 1) {
ch = 0;
sb++;
if (sb >= frame->subbands) break;
} 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)
{
unsigned 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;
int audio_sample;
int ch, sb, blk, bit; /* channel, subband, block and bit standard
counters */
int bits[2][8]; /* bits distribution */
uint32_t levels[2][8]; /* levels derived from that */
if (len < 4)
return -1;
if (data[0] != SBC_SYNCWORD)
return -2;
frame->frequency = (data[1] >> 6) & 0x03;
frame->block_mode = (data[1] >> 4) & 0x03;
switch (frame->block_mode) {
case SBC_BLK_4:
frame->blocks = 4;
break;
case SBC_BLK_8:
frame->blocks = 8;
break;
case SBC_BLK_12:
frame->blocks = 12;
break;
case SBC_BLK_16:
frame->blocks = 16;
break;
}
frame->mode = (data[1] >> 2) & 0x03;
switch (frame->mode) {
case MONO:
frame->channels = 1;
break;
case DUAL_CHANNEL: /* fall-through */
case STEREO:
case JOINT_STEREO:
frame->channels = 2;
break;
}
frame->allocation = (data[1] >> 1) & 0x01;
frame->subband_mode = (data[1] & 0x01);
frame->subbands = frame->subband_mode ? 8 : 4;
frame->bitpool = data[2];
if ((frame->mode == MONO || frame->mode == DUAL_CHANNEL) &&
frame->bitpool > 16 * frame->subbands)
return -4;
if ((frame->mode == STEREO || frame->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->mode == JOINT_STEREO) {
if (len * 8 < consumed + frame->subbands)
return -1;
frame->joint = 0x00;
for (sb = 0; sb < frame->subbands - 1; sb++)
frame->joint |= ((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);
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) {
audio_sample = 0;
for (bit = 0; bit < bits[ch][sb]; bit++) {
if (consumed > len * 8)
return -1;
if ((data[consumed >> 3] >> (7 - (consumed & 0x7))) & 0x01)
audio_sample |= 1 << (bits[ch][sb] - bit - 1);
consumed++;
}
frame->sb_sample[blk][ch][sb] =
(((audio_sample << 1) | 1) << frame->scale_factor[ch][sb]) /
levels[ch][sb] - (1 << frame->scale_factor[ch][sb]);
} else
frame->sb_sample[blk][ch][sb] = 0;
}
}
}
if (frame->mode == JOINT_STEREO) {
for (blk = 0; blk < frame->blocks; blk++) {
for (sb = 0; sb < frame->subbands; sb++) {
if (frame->joint & (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 SBC_ALWAYS_INLINE int16_t sbc_clip16(int32_t s)
{
if (s > 0x7FFF)
return 0x7FFF;
else if (s < -0x8000)
return -0x8000;
else
return s;
}
static inline void sbc_synthesize_four(struct sbc_decoder_state *state,
struct sbc_frame *frame, int ch, int blk)
{
int i, k, idx;
int32_t *v = state->V[ch];
int *offset = state->offset[ch];
for (i = 0; i < 8; i++) {
/* Shifting */
offset[i]--;
if (offset[i] < 0) {
offset[i] = 79;
memcpy(v + 80, v, 9 * sizeof(*v));
}
/* Distribute the new matrix value to the shifted position */
v[offset[i]] = SCALE4_STAGED1(
MULA(synmatrix4[i][0], frame->sb_sample[blk][ch][0],
MULA(synmatrix4[i][1], frame->sb_sample[blk][ch][1],
MULA(synmatrix4[i][2], frame->sb_sample[blk][ch][2],
MUL (synmatrix4[i][3], frame->sb_sample[blk][ch][3])))));
}
/* Compute the samples */
for (idx = 0, i = 0; i < 4; i++, idx += 5) {
k = (i + 4) & 0xf;
/* Store in output, Q0 */
frame->pcm_sample[ch][blk * 4 + i] = sbc_clip16(SCALE4_STAGED1(
MULA(v[offset[i] + 0], sbc_proto_4_40m0[idx + 0],
MULA(v[offset[k] + 1], sbc_proto_4_40m1[idx + 0],
MULA(v[offset[i] + 2], sbc_proto_4_40m0[idx + 1],
MULA(v[offset[k] + 3], sbc_proto_4_40m1[idx + 1],
MULA(v[offset[i] + 4], sbc_proto_4_40m0[idx + 2],
MULA(v[offset[k] + 5], sbc_proto_4_40m1[idx + 2],
MULA(v[offset[i] + 6], sbc_proto_4_40m0[idx + 3],
MULA(v[offset[k] + 7], sbc_proto_4_40m1[idx + 3],
MULA(v[offset[i] + 8], sbc_proto_4_40m0[idx + 4],
MUL( v[offset[k] + 9], sbc_proto_4_40m1[idx + 4]))))))))))));
}
}
static inline void sbc_synthesize_eight(struct sbc_decoder_state *state,
struct sbc_frame *frame, int ch, int blk)
{
int i, j, k, idx;
int *offset = state->offset[ch];
for (i = 0; i < 16; i++) {
/* Shifting */
offset[i]--;
if (offset[i] < 0) {
offset[i] = 159;
for (j = 0; j < 9; j++)
state->V[ch][j + 160] = state->V[ch][j];
}
/* Distribute the new matrix value to the shifted position */
state->V[ch][offset[i]] = SCALE8_STAGED1(
MULA(synmatrix8[i][0], frame->sb_sample[blk][ch][0],
MULA(synmatrix8[i][1], frame->sb_sample[blk][ch][1],
MULA(synmatrix8[i][2], frame->sb_sample[blk][ch][2],
MULA(synmatrix8[i][3], frame->sb_sample[blk][ch][3],
MULA(synmatrix8[i][4], frame->sb_sample[blk][ch][4],
MULA(synmatrix8[i][5], frame->sb_sample[blk][ch][5],
MULA(synmatrix8[i][6], frame->sb_sample[blk][ch][6],
MUL( synmatrix8[i][7], frame->sb_sample[blk][ch][7])))))))));
}
/* Compute the samples */
for (idx = 0, i = 0; i < 8; i++, idx += 5) {
k = (i + 8) & 0xf;
/* Store in output, Q0 */
frame->pcm_sample[ch][blk * 8 + i] = sbc_clip16(SCALE8_STAGED1(
MULA(state->V[ch][offset[i] + 0], sbc_proto_8_80m0[idx + 0],
MULA(state->V[ch][offset[k] + 1], sbc_proto_8_80m1[idx + 0],
MULA(state->V[ch][offset[i] + 2], sbc_proto_8_80m0[idx + 1],
MULA(state->V[ch][offset[k] + 3], sbc_proto_8_80m1[idx + 1],
MULA(state->V[ch][offset[i] + 4], sbc_proto_8_80m0[idx + 2],
MULA(state->V[ch][offset[k] + 5], sbc_proto_8_80m1[idx + 2],
MULA(state->V[ch][offset[i] + 6], sbc_proto_8_80m0[idx + 3],
MULA(state->V[ch][offset[k] + 7], sbc_proto_8_80m1[idx + 3],
MULA(state->V[ch][offset[i] + 8], sbc_proto_8_80m0[idx + 4],
MUL( state->V[ch][offset[k] + 9], sbc_proto_8_80m1[idx + 4]))))))))))));
}
}
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 int sbc_analyze_audio(struct sbc_encoder_state *state,
struct sbc_frame *frame)
{
int ch, blk;
int16_t *x;
switch (frame->subbands) {
case 4:
for (ch = 0; ch < frame->channels; ch++) {
x = &state->X[ch][state->position - 16 +
frame->blocks * 4];
for (blk = 0; blk < frame->blocks; blk += 4) {
state->sbc_analyze_4b_4s(
x,
frame->sb_sample_f[blk][ch],
frame->sb_sample_f[blk + 1][ch] -
frame->sb_sample_f[blk][ch]);
x -= 16;
}
}
return frame->blocks * 4;
case 8:
for (ch = 0; ch < frame->channels; ch++) {
x = &state->X[ch][state->position - 32 +
frame->blocks * 8];
for (blk = 0; blk < frame->blocks; blk += 4) {
state->sbc_analyze_4b_8s(
x,
frame->sb_sample_f[blk][ch],
frame->sb_sample_f[blk + 1][ch] -
frame->sb_sample_f[blk][ch]);
x -= 32;
}
}
return frame->blocks * 8;
default:
return -EIO;
}
}
/* Supplementary bitstream writing macros for 'sbc_pack_frame' */
#define PUT_BITS(data_ptr, bits_cache, bits_count, v, n) \
do { \
bits_cache = (v) | (bits_cache << (n)); \
bits_count += (n); \
if (bits_count >= 16) { \
bits_count -= 8; \
*data_ptr++ = (uint8_t) \
(bits_cache >> bits_count); \
bits_count -= 8; \
*data_ptr++ = (uint8_t) \
(bits_cache >> bits_count); \
} \
} while (0)
#define FLUSH_BITS(data_ptr, bits_cache, bits_count) \
do { \
while (bits_count >= 8) { \
bits_count -= 8; \
*data_ptr++ = (uint8_t) \
(bits_cache >> bits_count); \
} \
if (bits_count > 0) \
*data_ptr++ = (uint8_t) \
(bits_cache << (8 - bits_count)); \
} while (0)
/*
* 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 SBC_ALWAYS_INLINE int sbc_pack_frame_internal(uint8_t *data,
struct sbc_frame *frame, size_t len,
int frame_subbands, int frame_channels)
{
/* Bitstream writer starts from the fourth byte */
uint8_t *data_ptr = data + 4;
uint32_t bits_cache = 0;
uint32_t bits_count = 0;
/* 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;
uint32_t audio_sample;
int ch, sb, blk; /* channel, subband, block and bit counters */
int bits[2][8]; /* bits distribution */
uint32_t levels[2][8]; /* levels are derived from that */
uint32_t sb_sample_delta[2][8];
data[0] = SBC_SYNCWORD;
data[1] = (frame->frequency & 0x03) << 6;
data[1] |= (frame->block_mode & 0x03) << 4;
data[1] |= (frame->mode & 0x03) << 2;
data[1] |= (frame->allocation & 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->mode == MONO || frame->mode == DUAL_CHANNEL) &&
frame->bitpool > frame_subbands << 4)
return -5;
if ((frame->mode == STEREO || frame->mode == JOINT_STEREO) &&
frame->bitpool > frame_subbands << 5)
return -5;
/* Can't fill in crc yet */
crc_header[0] = data[1];
crc_header[1] = data[2];
crc_pos = 16;
if (frame->mode == JOINT_STEREO) {
/* like frame->sb_sample but joint stereo */
int32_t sb_sample_j[16][2];
/* scalefactor and scale_factor in joint case */
uint32_t scalefactor_j[2];
uint8_t scale_factor_j[2];
uint8_t joint = 0;
frame->joint = 0;
for (sb = 0; sb < frame_subbands - 1; sb++) {
scale_factor_j[0] = 0;
scalefactor_j[0] = 2 << SCALE_OUT_BITS;
scale_factor_j[1] = 0;
scalefactor_j[1] = 2 << SCALE_OUT_BITS;
for (blk = 0; blk < frame->blocks; blk++) {
uint32_t tmp;
/* Calculate joint stereo signal */
sb_sample_j[blk][0] =
ASR(frame->sb_sample_f[blk][0][sb], 1) +
ASR(frame->sb_sample_f[blk][1][sb], 1);
sb_sample_j[blk][1] =
ASR(frame->sb_sample_f[blk][0][sb], 1) -
ASR(frame->sb_sample_f[blk][1][sb], 1);
/* calculate scale_factor_j and scalefactor_j for joint case */
tmp = fabs(sb_sample_j[blk][0]);
while (scalefactor_j[0] < tmp) {
scale_factor_j[0]++;
scalefactor_j[0] *= 2;
}
tmp = fabs(sb_sample_j[blk][1]);
while (scalefactor_j[1] < tmp) {
scale_factor_j[1]++;
scalefactor_j[1] *= 2;
}
}
/* decide whether to join this subband */
if ((frame->scale_factor[0][sb] +
frame->scale_factor[1][sb]) >
(scale_factor_j[0] +
scale_factor_j[1])) {
/* use joint stereo for this subband */
joint |= 1 << (frame_subbands - 1 - sb);
frame->joint |= 1 << sb;
frame->scale_factor[0][sb] = scale_factor_j[0];
frame->scale_factor[1][sb] = scale_factor_j[1];
for (blk = 0; blk < frame->blocks; blk++) {
frame->sb_sample_f[blk][0][sb] =
sb_sample_j[blk][0];
frame->sb_sample_f[blk][1][sb] =
sb_sample_j[blk][1];
}
}
}
PUT_BITS(data_ptr, bits_cache, bits_count,
joint, frame_subbands);
crc_header[crc_pos >> 3] = joint;
crc_pos += frame_subbands;
}
for (ch = 0; ch < frame_channels; ch++) {
for (sb = 0; sb < frame_subbands; sb++) {
PUT_BITS(data_ptr, bits_cache, bits_count,
frame->scale_factor[ch][sb] & 0x0F, 4);
crc_header[crc_pos >> 3] <<= 4;
crc_header[crc_pos >> 3] |= frame->scale_factor[ch][sb] & 0x0F;
crc_pos += 4;
}
}
/* align the last crc byte */
if (crc_pos % 8)
crc_header[crc_pos >> 3] <<= 8 - (crc_pos % 8);
data[3] = sbc_crc8(crc_header, crc_pos);
sbc_calculate_bits(frame, bits);
for (ch = 0; ch < frame_channels; ch++) {
for (sb = 0; sb < frame_subbands; sb++) {
levels[ch][sb] = ((1 << bits[ch][sb]) - 1) <<
(32 - (frame->scale_factor[ch][sb] +
SCALE_OUT_BITS + 2));
sb_sample_delta[ch][sb] = (uint32_t) 1 <<
(frame->scale_factor[ch][sb] +
SCALE_OUT_BITS + 1);
}
}
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)
continue;
audio_sample = ((uint64_t) levels[ch][sb] *
(sb_sample_delta[ch][sb] +
frame->sb_sample_f[blk][ch][sb])) >> 32;
PUT_BITS(data_ptr, bits_cache, bits_count,
audio_sample, bits[ch][sb]);
}
}
}
FLUSH_BITS(data_ptr, bits_cache, bits_count);
return data_ptr - data;
}
static int sbc_pack_frame(uint8_t *data, struct sbc_frame *frame, size_t len)
{
if (frame->subbands == 4) {
if (frame->channels == 1)
return sbc_pack_frame_internal(data, frame, len, 4, 1);
else
return sbc_pack_frame_internal(data, frame, len, 4, 2);
} else {
if (frame->channels == 1)
return sbc_pack_frame_internal(data, frame, len, 8, 1);
else
return sbc_pack_frame_internal(data, frame, len, 8, 2);
}
}
static void sbc_encoder_init(struct sbc_encoder_state *state,
const struct sbc_frame *frame)
{
memset(&state->X, 0, sizeof(state->X));
state->position = (SBC_X_BUFFER_SIZE - frame->subbands * 9) & ~7;
sbc_init_primitives(state);
}
struct sbc_priv {
int init;
struct SBC_ALIGNED sbc_frame frame;
struct SBC_ALIGNED sbc_decoder_state dec_state;
struct SBC_ALIGNED sbc_encoder_state enc_state;
};
static void sbc_set_defaults(sbc_t *sbc, unsigned long flags)
{
sbc->frequency = SBC_FREQ_44100;
sbc->mode = SBC_MODE_STEREO;
sbc->subbands = SBC_SB_8;
sbc->blocks = SBC_BLK_16;
sbc->bitpool = 32;
#if __BYTE_ORDER == __LITTLE_ENDIAN
sbc->endian = SBC_LE;
#elif __BYTE_ORDER == __BIG_ENDIAN
sbc->endian = SBC_BE;
#else
#error "Unknown byte order"
#endif
}
int sbc_init(sbc_t *sbc, unsigned long flags)
{
if (!sbc)
return -EIO;
memset(sbc, 0, sizeof(sbc_t));
sbc->priv_alloc_base = malloc(sizeof(struct sbc_priv) + SBC_ALIGN_MASK);
if (!sbc->priv_alloc_base)
return -ENOMEM;
sbc->priv = (void *) (((uintptr_t) sbc->priv_alloc_base +
SBC_ALIGN_MASK) & ~((uintptr_t) SBC_ALIGN_MASK));
memset(sbc->priv, 0, sizeof(struct sbc_priv));
sbc_set_defaults(sbc, flags);
return 0;
}
ssize_t sbc_parse(sbc_t *sbc, const void *input, size_t input_len)
{
return sbc_decode(sbc, input, input_len, NULL, 0, NULL);
}
ssize_t sbc_decode(sbc_t *sbc, const void *input, size_t input_len,
void *output, size_t output_len, size_t *written)
{
struct sbc_priv *priv;
char *ptr;
int i, ch, framelen, samples;
if (!sbc || !input)
return -EIO;
priv = sbc->priv;
framelen = sbc_unpack_frame(input, &priv->frame, input_len);
if (!priv->init) {
sbc_decoder_init(&priv->dec_state, &priv->frame);
priv->init = 1;
sbc->frequency = priv->frame.frequency;
sbc->mode = priv->frame.mode;
sbc->subbands = priv->frame.subband_mode;
sbc->blocks = priv->frame.block_mode;
sbc->allocation = priv->frame.allocation;
sbc->bitpool = priv->frame.bitpool;
priv->frame.codesize = sbc_get_codesize(sbc);
priv->frame.length = framelen;
}
if (!output)
return framelen;
if (written)
*written = 0;
if (framelen <= 0)
return framelen;
samples = sbc_synthesize_audio(&priv->dec_state, &priv->frame);
ptr = output;
if (output_len < (size_t) (samples * priv->frame.channels * 2))
samples = output_len / (priv->frame.channels * 2);
for (i = 0; i < samples; i++) {
for (ch = 0; ch < priv->frame.channels; ch++) {
int16_t s;
s = priv->frame.pcm_sample[ch][i];
if (sbc->endian == SBC_BE) {
*ptr++ = (s & 0xff00) >> 8;
*ptr++ = (s & 0x00ff);
} else {
*ptr++ = (s & 0x00ff);
*ptr++ = (s & 0xff00) >> 8;
}
}
}
if (written)
*written = samples * priv->frame.channels * 2;
return framelen;
}
ssize_t sbc_encode(sbc_t *sbc, const void *input, size_t input_len,
void *output, size_t output_len, size_t *written)
{
struct sbc_priv *priv;
int framelen, samples;
int (*sbc_enc_process_input)(int position,
const uint8_t *pcm, int16_t X[2][SBC_X_BUFFER_SIZE],
int nsamples, int nchannels);
if (!sbc || !input)
return -EIO;
priv = sbc->priv;
if (written)
*written = 0;
if (!priv->init) {
priv->frame.frequency = sbc->frequency;
priv->frame.mode = sbc->mode;
priv->frame.channels = sbc->mode == SBC_MODE_MONO ? 1 : 2;
priv->frame.allocation = sbc->allocation;
priv->frame.subband_mode = sbc->subbands;
priv->frame.subbands = sbc->subbands ? 8 : 4;
priv->frame.block_mode = sbc->blocks;
priv->frame.blocks = 4 + (sbc->blocks * 4);
priv->frame.bitpool = sbc->bitpool;
priv->frame.codesize = sbc_get_codesize(sbc);
priv->frame.length = sbc_get_frame_length(sbc);
sbc_encoder_init(&priv->enc_state, &priv->frame);
priv->init = 1;
}
/* input must be large enough to encode a complete frame */
if (input_len < priv->frame.codesize)
return 0;
/* output must be large enough to receive the encoded frame */
if (!output || output_len < priv->frame.length)
return -ENOSPC;
/* Select the needed input data processing function and call it */
if (priv->frame.subbands == 8) {
if (sbc->endian == SBC_BE)
sbc_enc_process_input =
priv->enc_state.sbc_enc_process_input_8s_be;
else
sbc_enc_process_input =
priv->enc_state.sbc_enc_process_input_8s_le;
} else {
if (sbc->endian == SBC_BE)
sbc_enc_process_input =
priv->enc_state.sbc_enc_process_input_4s_be;
else
sbc_enc_process_input =
priv->enc_state.sbc_enc_process_input_4s_le;
}
priv->enc_state.position = sbc_enc_process_input(
priv->enc_state.position, (const uint8_t *) input,
priv->enc_state.X, priv->frame.subbands * priv->frame.blocks,
priv->frame.channels);
samples = sbc_analyze_audio(&priv->enc_state, &priv->frame);
priv->enc_state.sbc_calc_scalefactors(
priv->frame.sb_sample_f, priv->frame.scale_factor,
priv->frame.blocks, priv->frame.channels, priv->frame.subbands);
framelen = sbc_pack_frame(output, &priv->frame, output_len);
if (written)
*written = framelen;
return samples * priv->frame.channels * 2;
}
void sbc_finish(sbc_t *sbc)
{
if (!sbc)
return;
if (sbc->priv_alloc_base)
free(sbc->priv_alloc_base);
memset(sbc, 0, sizeof(sbc_t));
}
size_t sbc_get_frame_length(sbc_t *sbc)
{
int ret;
uint8_t subbands, channels, blocks, joint, bitpool;
struct sbc_priv *priv;
priv = sbc->priv;
if (priv->init)
return priv->frame.length;
subbands = sbc->subbands ? 8 : 4;
blocks = 4 + (sbc->blocks * 4);
channels = sbc->mode == SBC_MODE_MONO ? 1 : 2;
joint = sbc->mode == SBC_MODE_JOINT_STEREO ? 1 : 0;
bitpool = sbc->bitpool;
ret = 4 + (4 * subbands * channels) / 8;
/* This term is not always evenly divide so we round it up */
if (channels == 1)
ret += ((blocks * channels * bitpool) + 7) / 8;
else
ret += (((joint ? subbands : 0) + blocks * bitpool) + 7) / 8;
return ret;
}
unsigned sbc_get_frame_duration(sbc_t *sbc)
{
uint8_t subbands, blocks;
uint16_t frequency;
struct sbc_priv *priv;
priv = sbc->priv;
if (!priv->init) {
subbands = sbc->subbands ? 8 : 4;
blocks = 4 + (sbc->blocks * 4);
} else {
subbands = priv->frame.subbands;
blocks = priv->frame.blocks;
}
switch (sbc->frequency) {
case SBC_FREQ_16000:
frequency = 16000;
break;
case SBC_FREQ_32000:
frequency = 32000;
break;
case SBC_FREQ_44100:
frequency = 44100;
break;
case SBC_FREQ_48000:
frequency = 48000;
break;
default:
return 0;
}
return (1000000 * blocks * subbands) / frequency;
}
size_t sbc_get_codesize(sbc_t *sbc)
{
uint16_t subbands, channels, blocks;
struct sbc_priv *priv;
priv = sbc->priv;
if (!priv->init) {
subbands = sbc->subbands ? 8 : 4;
blocks = 4 + (sbc->blocks * 4);
channels = sbc->mode == SBC_MODE_MONO ? 1 : 2;
} else {
subbands = priv->frame.subbands;
blocks = priv->frame.blocks;
channels = priv->frame.channels;
}
return subbands * blocks * channels * 2;
}
const char *sbc_get_implementation_info(sbc_t *sbc)
{
struct sbc_priv *priv;
if (!sbc)
return NULL;
priv = sbc->priv;
if (!priv)
return NULL;
return priv->enc_state.implementation_info;
}
int sbc_reinit(sbc_t *sbc, unsigned long flags)
{
struct sbc_priv *priv;
if (!sbc || !sbc->priv)
return -EIO;
priv = sbc->priv;
if (priv->init == 1)
memset(sbc->priv, 0, sizeof(struct sbc_priv));
sbc_set_defaults(sbc, flags);
return 0;
}
Reference in New Issue View Git Blame Copy Permalink