/*
*
* 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) 2005-2006 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
*
*/
#include <stdint.h>
#include <limits.h>
#include <string.h>
#include "sbc.h"
#include "sbc_math.h"
#include "sbc_tables.h"
#include "sbc_primitives.h"
#include "sbc_primitives_mmx.h"
#include "sbc_primitives_neon.h"
/*
* A reference C code of analysis filter with SIMD-friendly tables
* reordering and code layout. This code can be used to develop platform
* specific SIMD optimizations. Also it may be used as some kind of test
* for compiler autovectorization capabilities (who knows, if the compiler
* is very good at this stuff, hand optimized assembly may be not strictly
* needed for some platform).
*
* Note: It is also possible to make a simple variant of analysis filter,
* which needs only a single constants table without taking care about
* even/odd cases. This simple variant of filter can be implemented without
* input data permutation. The only thing that would be lost is the
* possibility to use pairwise SIMD multiplications. But for some simple
* CPU cores without SIMD extensions it can be useful. If anybody is
* interested in implementing such variant of a filter, sourcecode from
* bluez versions 4.26/4.27 can be used as a reference and the history of
* the changes in git repository done around that time may be worth checking.
*/
static inline void sbc_analyze_four_simd(const int16_t *in, int32_t *out,
const FIXED_T *consts)
{
FIXED_A t1[4];
FIXED_T t2[4];
int hop = 0;
/* rounding coefficient */
t1[0] = t1[1] = t1[2] = t1[3] =
(FIXED_A) 1 << (SBC_PROTO_FIXED4_SCALE - 1);
/* low pass polyphase filter */
for (hop = 0; hop < 40; hop += 8) {
t1[0] += (FIXED_A) in[hop] * consts[hop];
t1[0] += (FIXED_A) in[hop + 1] * consts[hop + 1];
t1[1] += (FIXED_A) in[hop + 2] * consts[hop + 2];
t1[1] += (FIXED_A) in[hop + 3] * consts[hop + 3];
t1[2] += (FIXED_A) in[hop + 4] * consts[hop + 4];
t1[2] += (FIXED_A) in[hop + 5] * consts[hop + 5];
t1[3] += (FIXED_A) in[hop + 6] * consts[hop + 6];
t1[3] += (FIXED_A) in[hop + 7] * consts[hop + 7];
}
/* scaling */
t2[0] = t1[0] >> SBC_PROTO_FIXED4_SCALE;
t2[1] = t1[1] >> SBC_PROTO_FIXED4_SCALE;
t2[2] = t1[2] >> SBC_PROTO_FIXED4_SCALE;
t2[3] = t1[3] >> SBC_PROTO_FIXED4_SCALE;
/* do the cos transform */
t1[0] = (FIXED_A) t2[0] * consts[40 + 0];
t1[0] += (FIXED_A) t2[1] * consts[40 + 1];
t1[1] = (FIXED_A) t2[0] * consts[40 + 2];
t1[1] += (FIXED_A) t2[1] * consts[40 + 3];
t1[2] = (FIXED_A) t2[0] * consts[40 + 4];
t1[2] += (FIXED_A) t2[1] * consts[40 + 5];
t1[3] = (FIXED_A) t2[0] * consts[40 + 6];
t1[3] += (FIXED_A) t2[1] * consts[40 + 7];
t1[0] += (FIXED_A) t2[2] * consts[40 + 8];
t1[0] += (FIXED_A) t2[3] * consts[40 + 9];
t1[1] += (FIXED_A) t2[2] * consts[40 + 10];
t1[1] += (FIXED_A) t2[3] * consts[40 + 11];
t1[2] += (FIXED_A) t2[2] * consts[40 + 12];
t1[2] += (FIXED_A) t2[3] * consts[40 + 13];
t1[3] += (FIXED_A) t2[2] * consts[40 + 14];
t1[3] += (FIXED_A) t2[3] * consts[40 + 15];
out[0] = t1[0] >>
(SBC_COS_TABLE_FIXED4_SCALE - SCALE_OUT_BITS);
out[1] = t1[1] >>
(SBC_COS_TABLE_FIXED4_SCALE - SCALE_OUT_BITS);
out[2] = t1[2] >>
(SBC_COS_TABLE_FIXED4_SCALE - SCALE_OUT_BITS);
out[3] = t1[3] >>
(SBC_COS_TABLE_FIXED4_SCALE - SCALE_OUT_BITS);
}
static inline void sbc_analyze_eight_simd(const int16_t *in, int32_t *out,
const FIXED_T *consts)
{
FIXED_A t1[8];
FIXED_T t2[8];
int i, hop;
/* rounding coefficient */
t1[0] = t1[1] = t1[2] = t1[3] = t1[4] = t1[5] = t1[6] = t1[7] =
(FIXED_A) 1 << (SBC_PROTO_FIXED8_SCALE-1);
/* low pass polyphase filter */
for (hop = 0; hop < 80; hop += 16) {
t1[0] += (FIXED_A) in[hop] * consts[hop];
t1[0] += (FIXED_A) in[hop + 1] * consts[hop + 1];
t1[1] += (FIXED_A) in[hop + 2] * consts[hop + 2];
t1[1] += (FIXED_A) in[hop + 3] * consts[hop + 3];
t1[2] += (FIXED_A) in[hop + 4] * consts[hop + 4];
t1[2] += (FIXED_A) in[hop + 5] * consts[hop + 5];
t1[3] += (FIXED_A) in[hop + 6] * consts[hop + 6];
t1[3] += (FIXED_A) in[hop + 7] * consts[hop + 7];
t1[4] += (FIXED_A) in[hop + 8] * consts[hop + 8];
t1[4] += (FIXED_A) in[hop + 9] * consts[hop + 9];
t1[5] += (FIXED_A) in[hop + 10] * consts[hop + 10];
t1[5] += (FIXED_A) in[hop + 11] * consts[hop + 11];
t1[6] += (FIXED_A) in[hop + 12] * consts[hop + 12];
t1[6] += (FIXED_A) in[hop + 13] * consts[hop + 13];
t1[7] += (FIXED_A) in[hop + 14] * consts[hop + 14];
t1[7] += (FIXED_A) in[hop + 15] * consts[hop + 15];
}
/* scaling */
t2[0] = t1[0] >> SBC_PROTO_FIXED8_SCALE;
t2[1] = t1[1] >> SBC_PROTO_FIXED8_SCALE;
t2[2] = t1[2] >> SBC_PROTO_FIXED8_SCALE;
t2[3] = t1[3] >> SBC_PROTO_FIXED8_SCALE;
t2[4] = t1[4] >> SBC_PROTO_FIXED8_SCALE;
t2[5] = t1[5] >> SBC_PROTO_FIXED8_SCALE;
t2[6] = t1[6] >> SBC_PROTO_FIXED8_SCALE;
t2[7] = t1[7] >> SBC_PROTO_FIXED8_SCALE;
/* do the cos transform */
t1[0] = t1[1] = t1[2] = t1[3] = t1[4] = t1[5] = t1[6] = t1[7] = 0;
for (i = 0; i < 4; i++) {
t1[0] += (FIXED_A) t2[i * 2 + 0] * consts[80 + i * 16 + 0];
t1[0] += (FIXED_A) t2[i * 2 + 1] * consts[80 + i * 16 + 1];
t1[1] += (FIXED_A) t2[i * 2 + 0] * consts[80 + i * 16 + 2];
t1[1] += (FIXED_A) t2[i * 2 + 1] * consts[80 + i * 16 + 3];
t1[2] += (FIXED_A) t2[i * 2 + 0] * consts[80 + i * 16 + 4];
t1[2] += (FIXED_A) t2[i * 2 + 1] * consts[80 + i * 16 + 5];
t1[3] += (FIXED_A) t2[i * 2 + 0] * consts[80 + i * 16 + 6];
t1[3] += (FIXED_A) t2[i * 2 + 1] * consts[80 + i * 16 + 7];
t1[4] += (FIXED_A) t2[i * 2 + 0] * consts[80 + i * 16 + 8];
t1[4] += (FIXED_A) t2[i * 2 + 1] * consts[80 + i * 16 + 9];
t1[5] += (FIXED_A) t2[i * 2 + 0] * consts[80 + i * 16 + 10];
t1[5] += (FIXED_A) t2[i * 2 + 1] * consts[80 + i * 16 + 11];
t1[6] += (FIXED_A) t2[i * 2 + 0] * consts[80 + i * 16 + 12];
t1[6] += (FIXED_A) t2[i * 2 + 1] * consts[80 + i * 16 + 13];
t1[7] += (FIXED_A) t2[i * 2 + 0] * consts[80 + i * 16 + 14];
t1[7] += (FIXED_A) t2[i * 2 + 1] * consts[80 + i * 16 + 15];
}
for (i = 0; i < 8; i++)
out[i] = t1[i] >>
(SBC_COS_TABLE_FIXED8_SCALE - SCALE_OUT_BITS);
}
static inline void sbc_analyze_4b_4s_simd(int16_t *x,
int32_t *out, int out_stride)
{
/* Analyze blocks */
sbc_analyze_four_simd(x + 12, out, analysis_consts_fixed4_simd_odd);
out += out_stride;
sbc_analyze_four_simd(x + 8, out, analysis_consts_fixed4_simd_even);
out += out_stride;
sbc_analyze_four_simd(x + 4, out, analysis_consts_fixed4_simd_odd);
out += out_stride;
sbc_analyze_four_simd(x + 0, out, analysis_consts_fixed4_simd_even);
}
static inline void sbc_analyze_4b_8s_simd(int16_t *x,
int32_t *out, int out_stride)
{
/* Analyze blocks */
sbc_analyze_eight_simd(x + 24, out, analysis_consts_fixed8_simd_odd);
out += out_stride;
sbc_analyze_eight_simd(x + 16, out, analysis_consts_fixed8_simd_even);
out += out_stride;
sbc_analyze_eight_simd(x + 8, out, analysis_consts_fixed8_simd_odd);
out += out_stride;
sbc_analyze_eight_simd(x + 0, out, analysis_consts_fixed8_simd_even);
}
static inline int16_t unaligned16_be(const uint8_t *ptr)
{
return (int16_t) ((ptr[0] << 8) | ptr[1]);
}
static inline int16_t unaligned16_le(const uint8_t *ptr)
{
return (int16_t) (ptr[0] | (ptr[1] << 8));
}
/*
* Internal helper functions for input data processing. In order to get
* optimal performance, it is important to have "nsamples", "nchannels"
* and "big_endian" arguments used with this inline function as compile
* time constants.
*/
static SBC_ALWAYS_INLINE int sbc_encoder_process_input_s4_internal(
int position,
const uint8_t *pcm, int16_t X[2][SBC_X_BUFFER_SIZE],
int nsamples, int nchannels, int big_endian)
{
/* handle X buffer wraparound */
if (position < nsamples) {
if (nchannels > 0)
memcpy(&X[0][SBC_X_BUFFER_SIZE - 40], &X[0][position],
36 * sizeof(int16_t));
if (nchannels > 1)
memcpy(&X[1][SBC_X_BUFFER_SIZE - 40], &X[1][position],
36 * sizeof(int16_t));
position = SBC_X_BUFFER_SIZE - 40;
}
#define PCM(i) (big_endian ? \
unaligned16_be(pcm + (i) * 2) : unaligned16_le(pcm + (i) * 2))
/* copy/permutate audio samples */
while ((nsamples -= 8) >= 0) {
position -= 8;
if (nchannels > 0) {
int16_t *x = &X[0][position];
x[0] = PCM(0 + 7 * nchannels);
x[1] = PCM(0 + 3 * nchannels);
x[2] = PCM(0 + 6 * nchannels);
x[3] = PCM(0 + 4 * nchannels);
x[4] = PCM(0 + 0 * nchannels);
x[5] = PCM(0 + 2 * nchannels);
x[6] = PCM(0 + 1 * nchannels);
x[7] = PCM(0 + 5 * nchannels);
}
if (nchannels > 1) {
int16_t *x = &X[1][position];
x[0] = PCM(1 + 7 * nchannels);
x[1] = PCM(1 + 3 * nchannels);
x[2] = PCM(1 + 6 * nchannels);
x[3] = PCM(1 + 4 * nchannels);
x[4] = PCM(1 + 0 * nchannels);
x[5] = PCM(1 + 2 * nchannels);
x[6] = PCM(1 + 1 * nchannels);
x[7] = PCM(1 + 5 * nchannels);
}
pcm += 16 * nchannels;
}
#undef PCM
return position;
}
static SBC_ALWAYS_INLINE int sbc_encoder_process_input_s8_internal(
int position,
const uint8_t *pcm, int16_t X[2][SBC_X_BUFFER_SIZE],
int nsamples, int nchannels, int big_endian)
{
/* handle X buffer wraparound */
if (position < nsamples) {
if (nchannels > 0)
memcpy(&X[0][SBC_X_BUFFER_SIZE - 72], &X[0][position],
72 * sizeof(int16_t));
if (nchannels > 1)
memcpy(&X[1][SBC_X_BUFFER_SIZE - 72], &X[1][position],
72 * sizeof(int16_t));
position = SBC_X_BUFFER_SIZE - 72;
}
#define PCM(i) (big_endian ? \
unaligned16_be(pcm + (i) * 2) : unaligned16_le(pcm + (i) * 2))
/* copy/permutate audio samples */
while ((nsamples -= 16) >= 0) {
position -= 16;
if (nchannels > 0) {
int16_t *x = &X[0][position];
x[0] = PCM(0 + 15 * nchannels);
x[1] = PCM(0 + 7 * nchannels);
x[2] = PCM(0 + 14 * nchannels);
x[3] = PCM(0 + 8 * nchannels);
x[4] = PCM(0 + 13 * nchannels);
x[5] = PCM(0 + 9 * nchannels);
x[6] = PCM(0 + 12 * nchannels);
x[7] = PCM(0 + 10 * nchannels);
x[8] = PCM(0 + 11 * nchannels);
x[9] = PCM(0 + 3 * nchannels);
x[10] = PCM(0 + 6 * nchannels);
x[11] = PCM(0 + 0 * nchannels);
x[12] = PCM(0 + 5 * nchannels);
x[13] = PCM(0 + 1 * nchannels);
x[14] = PCM(0 + 4 * nchannels);
x[15] = PCM(0 + 2 * nchannels);
}
if (nchannels > 1) {
int16_t *x = &X[1][position];
x[0] = PCM(1 + 15 * nchannels);
x[1] = PCM(1 + 7 * nchannels);
x[2] = PCM(1 + 14 * nchannels);
x[3] = PCM(1 + 8 * nchannels);
x[4] = PCM(1 + 13 * nchannels);
x[5] = PCM(1 + 9 * nchannels);
x[6] = PCM(1 + 12 * nchannels);
x[7] = PCM(1 + 10 * nchannels);
x[8] = PCM(1 + 11 * nchannels);
x[9] = PCM(1 + 3 * nchannels);
x[10] = PCM(1 + 6 * nchannels);
x[11] = PCM(1 + 0 * nchannels);
x[12] = PCM(1 + 5 * nchannels);
x[13] = PCM(1 + 1 * nchannels);
x[14] = PCM(1 + 4 * nchannels);
x[15] = PCM(1 + 2 * nchannels);
}
pcm += 32 * nchannels;
}
#undef PCM
return position;
}
/*
* Input data processing functions. The data is endian converted if needed,
* channels are deintrleaved and audio samples are reordered for use in
* SIMD-friendly analysis filter function. The results are put into "X"
* array, getting appended to the previous data (or it is better to say
* prepended, as the buffer is filled from top to bottom). Old data is
* discarded when neededed, but availability of (10 * nrof_subbands)
* contiguous samples is always guaranteed for the input to the analysis
* filter. This is achieved by copying a sufficient part of old data
* to the top of the buffer on buffer wraparound.
*/
static int sbc_enc_process_input_4s_le(int position,
const uint8_t *pcm, int16_t X[2][SBC_X_BUFFER_SIZE],
int nsamples, int nchannels)
{
if (nchannels > 1)
return sbc_encoder_process_input_s4_internal(
position, pcm, X, nsamples, 2, 0);
else
return sbc_encoder_process_input_s4_internal(
position, pcm, X, nsamples, 1, 0);
}
static int sbc_enc_process_input_4s_be(int position,
const uint8_t *pcm, int16_t X[2][SBC_X_BUFFER_SIZE],
int nsamples, int nchannels)
{
if (nchannels > 1)
return sbc_encoder_process_input_s4_internal(
position, pcm, X, nsamples, 2, 1);
else
return sbc_encoder_process_input_s4_internal(
position, pcm, X, nsamples, 1, 1);
}
static int sbc_enc_process_input_8s_le(int position,
const uint8_t *pcm, int16_t X[2][SBC_X_BUFFER_SIZE],
int nsamples, int nchannels)
{
if (nchannels > 1)
return sbc_encoder_process_input_s8_internal(
position, pcm, X, nsamples, 2, 0);
else
return sbc_encoder_process_input_s8_internal(
position, pcm, X, nsamples, 1, 0);
}
static int sbc_enc_process_input_8s_be(int position,
const uint8_t *pcm, int16_t X[2][SBC_X_BUFFER_SIZE],
int nsamples, int nchannels)
{
if (nchannels > 1)
return sbc_encoder_process_input_s8_internal(
position, pcm, X, nsamples, 2, 1);
else
return sbc_encoder_process_input_s8_internal(
position, pcm, X, nsamples, 1, 1);
}
/* Supplementary function to count the number of leading zeros */
static inline int sbc_clz(uint32_t x)
{
#ifdef __GNUC__
return __builtin_clz(x);
#else
/* TODO: this should be replaced with something better if good
* performance is wanted when using compilers other than gcc */
int cnt = 0;
while (x) {
cnt++;
x >>= 1;
}
return 32 - cnt;
#endif
}
static void sbc_calc_scalefactors(
int32_t sb_sample_f[16][2][8],
uint32_t scale_factor[2][8],
int blocks, int channels, int subbands)
{
int ch, sb, blk;
for (ch = 0; ch < channels; ch++) {
for (sb = 0; sb < subbands; sb++) {
uint32_t x = 1 << SCALE_OUT_BITS;
for (blk = 0; blk < blocks; blk++) {
int32_t tmp = fabs(sb_sample_f[blk][ch][sb]);
if (tmp != 0)
x |= tmp - 1;
}
scale_factor[ch][sb] = (31 - SCALE_OUT_BITS) -
sbc_clz(x);
}
}
}
/*
* Detect CPU features and setup function pointers
*/
void sbc_init_primitives(struct sbc_encoder_state *state)
{
/* Default implementation for analyze functions */
state->sbc_analyze_4b_4s = sbc_analyze_4b_4s_simd;
state->sbc_analyze_4b_8s = sbc_analyze_4b_8s_simd;
/* Default implementation for input reordering / deinterleaving */
state->sbc_enc_process_input_4s_le = sbc_enc_process_input_4s_le;
state->sbc_enc_process_input_4s_be = sbc_enc_process_input_4s_be;
state->sbc_enc_process_input_8s_le = sbc_enc_process_input_8s_le;
state->sbc_enc_process_input_8s_be = sbc_enc_process_input_8s_be;
/* Default implementation for scale factors calculation */
state->sbc_calc_scalefactors = sbc_calc_scalefactors;
state->implementation_info = "Generic C";
/* X86/AMD64 optimizations */
#ifdef SBC_BUILD_WITH_MMX_SUPPORT
sbc_init_primitives_mmx(state);
#endif
/* ARM optimizations */
#ifdef SBC_BUILD_WITH_NEON_SUPPORT
sbc_init_primitives_neon(state);
#endif
}