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////////////////////////////////////////////////////////////////////////////
// **** DSDPACK **** //
// Lossless DSD (Direct Stream Digital) Audio Compressor //
// Copyright (c) 2013 - 2016 David Bryant. //
// All Rights Reserved. //
// Distributed under the BSD Software License (see license.txt) //
////////////////////////////////////////////////////////////////////////////
// unpack_dsd.c
// This module actually handles the uncompression of the DSD audio data.
#ifdef ENABLE_DSD
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "wavpack_local.h"
///////////////////////////// executable code ////////////////////////////////
// This function initializes the main range-encoded data for DSD audio samples
static int init_dsd_block_fast (WavpackStream *wps, WavpackMetadata *wpmd);
static int init_dsd_block_high (WavpackStream *wps, WavpackMetadata *wpmd);
static int decode_fast (WavpackStream *wps, int32_t *output, int sample_count);
static int decode_high (WavpackStream *wps, int32_t *output, int sample_count);
int init_dsd_block (WavpackContext *wpc, WavpackMetadata *wpmd)
{
WavpackStream *wps = wpc->streams [wpc->current_stream];
if (wpmd->byte_length < 2)
return FALSE;
wps->dsd.byteptr = (unsigned char *)wpmd->data;
wps->dsd.endptr = wps->dsd.byteptr + wpmd->byte_length;
wpc->dsd_multiplier = 1 << *wps->dsd.byteptr++;
wps->dsd.mode = *wps->dsd.byteptr++;
if (!wps->dsd.mode) {
if (wps->dsd.endptr - wps->dsd.byteptr != wps->wphdr.block_samples * (wps->wphdr.flags & MONO_DATA ? 1 : 2)) {
return FALSE;
}
wps->dsd.ready = 1;
return TRUE;
}
if (wps->dsd.mode == 1)
return init_dsd_block_fast (wps, wpmd);
else if (wps->dsd.mode == 3)
return init_dsd_block_high (wps, wpmd);
else
return FALSE;
}
int32_t unpack_dsd_samples (WavpackContext *wpc, int32_t *buffer, uint32_t sample_count)
{
WavpackStream *wps = wpc->streams [wpc->current_stream];
uint32_t flags = wps->wphdr.flags;
// don't attempt to decode past the end of the block, but watch out for overflow!
if (wps->sample_index + sample_count > GET_BLOCK_INDEX (wps->wphdr) + wps->wphdr.block_samples &&
(uint32_t) (GET_BLOCK_INDEX (wps->wphdr) + wps->wphdr.block_samples - wps->sample_index) < sample_count)
sample_count = (uint32_t) (GET_BLOCK_INDEX (wps->wphdr) + wps->wphdr.block_samples - wps->sample_index);
if (GET_BLOCK_INDEX (wps->wphdr) > wps->sample_index || wps->wphdr.block_samples < sample_count)
wps->mute_error = TRUE;
if (!wps->mute_error) {
if (!wps->dsd.mode) {
int total_samples = sample_count * ((flags & MONO_DATA) ? 1 : 2);
int32_t *bptr = buffer;
if (wps->dsd.endptr - wps->dsd.byteptr < total_samples)
total_samples = (int)(wps->dsd.endptr - wps->dsd.byteptr);
while (total_samples--)
wps->crc += (wps->crc << 1) + (*bptr++ = *wps->dsd.byteptr++);
}
else if (wps->dsd.mode == 1) {
if (!decode_fast (wps, buffer, sample_count))
wps->mute_error = TRUE;
}
else if (!decode_high (wps, buffer, sample_count))
wps->mute_error = TRUE;
}
if (wps->mute_error) {
int samples_to_null;
if (wpc->reduced_channels == 1 || wpc->config.num_channels == 1 || (flags & MONO_FLAG))
samples_to_null = sample_count;
else
samples_to_null = sample_count * 2;
while (samples_to_null--)
*buffer++ = 0x55;
wps->sample_index += sample_count;
return sample_count;
}
if (flags & FALSE_STEREO) {
int32_t *dptr = buffer + sample_count * 2;
int32_t *sptr = buffer + sample_count;
int32_t c = sample_count;
while (c--) {
*--dptr = *--sptr;
*--dptr = *sptr;
}
}
wps->sample_index += sample_count;
return sample_count;
}
/*------------------------------------------------------------------------------------------------------------------------*/
// #define DSD_BYTE_READY(low,high) (((low) >> 24) == ((high) >> 24))
// #define DSD_BYTE_READY(low,high) (!(((low) ^ (high)) >> 24))
#define DSD_BYTE_READY(low,high) (!(((low) ^ (high)) & 0xff000000))
static int init_dsd_block_fast (WavpackStream *wps, WavpackMetadata *wpmd)
{
unsigned char history_bits, max_probability, *lb_ptr;
int total_summed_probabilities = 0, bi, i;
if (wps->dsd.byteptr == wps->dsd.endptr)
return FALSE;
history_bits = *wps->dsd.byteptr++;
if (wps->dsd.byteptr == wps->dsd.endptr || history_bits > MAX_HISTORY_BITS)
return FALSE;
wps->dsd.history_bins = 1 << history_bits;
free_dsd_tables (wps);
lb_ptr = wps->dsd.lookup_buffer = (unsigned char *)malloc (wps->dsd.history_bins * MAX_BYTES_PER_BIN);
wps->dsd.value_lookup = (unsigned char **)malloc (sizeof (*wps->dsd.value_lookup) * wps->dsd.history_bins);
memset (wps->dsd.value_lookup, 0, sizeof (*wps->dsd.value_lookup) * wps->dsd.history_bins);
wps->dsd.summed_probabilities = (int16_t (*)[256])malloc (sizeof (*wps->dsd.summed_probabilities) * wps->dsd.history_bins);
wps->dsd.probabilities = (unsigned char (*)[256])malloc (sizeof (*wps->dsd.probabilities) * wps->dsd.history_bins);
max_probability = *wps->dsd.byteptr++;
if (max_probability < 0xff) {
unsigned char *outptr = (unsigned char *) wps->dsd.probabilities;
unsigned char *outend = outptr + sizeof (*wps->dsd.probabilities) * wps->dsd.history_bins;
while (outptr < outend && wps->dsd.byteptr < wps->dsd.endptr) {
int code = *wps->dsd.byteptr++;
if (code > max_probability) {
int zcount = code - max_probability;
while (outptr < outend && zcount--)
*outptr++ = 0;
}
else if (code)
*outptr++ = code;
else
break;
}
if (outptr < outend || (wps->dsd.byteptr < wps->dsd.endptr && *wps->dsd.byteptr++))
return FALSE;
}
else if (wps->dsd.endptr - wps->dsd.byteptr > (int) sizeof (*wps->dsd.probabilities) * wps->dsd.history_bins) {
memcpy (wps->dsd.probabilities, wps->dsd.byteptr, sizeof (*wps->dsd.probabilities) * wps->dsd.history_bins);
wps->dsd.byteptr += sizeof (*wps->dsd.probabilities) * wps->dsd.history_bins;
}
else
return FALSE;
for (bi = 0; bi < wps->dsd.history_bins; ++bi) {
int32_t sum_values;
for (sum_values = i = 0; i < 256; ++i)
wps->dsd.summed_probabilities [bi] [i] = sum_values += wps->dsd.probabilities [bi] [i];
if (sum_values) {
if ((total_summed_probabilities += sum_values) > wps->dsd.history_bins * MAX_BYTES_PER_BIN)
return FALSE;
wps->dsd.value_lookup [bi] = lb_ptr;
for (i = 0; i < 256; i++) {
int c = wps->dsd.probabilities [bi] [i];
while (c--)
*lb_ptr++ = i;
}
}
}
if (wps->dsd.endptr - wps->dsd.byteptr < 4 || total_summed_probabilities > wps->dsd.history_bins * MAX_BYTES_PER_BIN)
return FALSE;
for (i = 4; i--;)
wps->dsd.value = (wps->dsd.value << 8) | *wps->dsd.byteptr++;
wps->dsd.p0 = wps->dsd.p1 = 0;
wps->dsd.low = 0; wps->dsd.high = 0xffffffff;
wps->dsd.ready = 1;
return TRUE;
}
static int decode_fast (WavpackStream *wps, int32_t *output, int sample_count)
{
int total_samples = sample_count;
if (!(wps->wphdr.flags & MONO_DATA))
total_samples *= 2;
while (total_samples--) {
int mult, index, code, i;
if (!wps->dsd.summed_probabilities [wps->dsd.p0] [255])
return 0;
mult = (wps->dsd.high - wps->dsd.low) / wps->dsd.summed_probabilities [wps->dsd.p0] [255];
if (!mult) {
if (wps->dsd.endptr - wps->dsd.byteptr >= 4)
for (i = 4; i--;)
wps->dsd.value = (wps->dsd.value << 8) | *wps->dsd.byteptr++;
wps->dsd.low = 0;
wps->dsd.high = 0xffffffff;
mult = wps->dsd.high / wps->dsd.summed_probabilities [wps->dsd.p0] [255];
if (!mult)
return 0;
}
index = (wps->dsd.value - wps->dsd.low) / mult;
if (index >= wps->dsd.summed_probabilities [wps->dsd.p0] [255])
return 0;
if ((*output++ = code = wps->dsd.value_lookup [wps->dsd.p0] [index]))
wps->dsd.low += wps->dsd.summed_probabilities [wps->dsd.p0] [code-1] * mult;
wps->dsd.high = wps->dsd.low + wps->dsd.probabilities [wps->dsd.p0] [code] * mult - 1;
wps->crc += (wps->crc << 1) + code;
if (wps->wphdr.flags & MONO_DATA)
wps->dsd.p0 = code & (wps->dsd.history_bins-1);
else {
wps->dsd.p0 = wps->dsd.p1;
wps->dsd.p1 = code & (wps->dsd.history_bins-1);
}
while (DSD_BYTE_READY (wps->dsd.high, wps->dsd.low) && wps->dsd.byteptr < wps->dsd.endptr) {
wps->dsd.value = (wps->dsd.value << 8) | *wps->dsd.byteptr++;
wps->dsd.high = (wps->dsd.high << 8) | 0xff;
wps->dsd.low <<= 8;
}
}
return sample_count;
}
/*------------------------------------------------------------------------------------------------------------------------*/
#define PTABLE_BITS 8
#define PTABLE_BINS (1<<PTABLE_BITS)
#define PTABLE_MASK (PTABLE_BINS-1)
#define UP 0x010000fe
#define DOWN 0x00010000
#define DECAY 8
#define PRECISION 20
#define VALUE_ONE (1 << PRECISION)
#define PRECISION_USE 12
#define RATE_S 20
static void init_ptable (int *table, int rate_i, int rate_s)
{
int value = 0x808000, rate = rate_i << 8, c, i;
for (c = (rate + 128) >> 8; c--;)
value += (DOWN - value) >> DECAY;
for (i = 0; i < PTABLE_BINS/2; ++i) {
table [i] = value;
table [PTABLE_BINS-1-i] = 0x100ffff - value;
if (value > 0x010000) {
rate += (rate * rate_s + 128) >> 8;
for (c = (rate + 64) >> 7; c--;)
value += (DOWN - value) >> DECAY;
}
}
}
static int init_dsd_block_high (WavpackStream *wps, WavpackMetadata *wpmd)
{
uint32_t flags = wps->wphdr.flags;
int channel, rate_i, rate_s, i;
if (wps->dsd.endptr - wps->dsd.byteptr < ((flags & MONO_DATA) ? 13 : 20))
return FALSE;
rate_i = *wps->dsd.byteptr++;
rate_s = *wps->dsd.byteptr++;
if (rate_s != RATE_S)
return FALSE;
if (!wps->dsd.ptable)
wps->dsd.ptable = (int32_t *)malloc (PTABLE_BINS * sizeof (*wps->dsd.ptable));
init_ptable (wps->dsd.ptable, rate_i, rate_s);
for (channel = 0; channel < ((flags & MONO_DATA) ? 1 : 2); ++channel) {
DSDfilters *sp = wps->dsd.filters + channel;
sp->filter1 = *wps->dsd.byteptr++ << (PRECISION - 8);
sp->filter2 = *wps->dsd.byteptr++ << (PRECISION - 8);
sp->filter3 = *wps->dsd.byteptr++ << (PRECISION - 8);
sp->filter4 = *wps->dsd.byteptr++ << (PRECISION - 8);
sp->filter5 = *wps->dsd.byteptr++ << (PRECISION - 8);
sp->filter6 = 0;
sp->factor = *wps->dsd.byteptr++ & 0xff;
sp->factor |= (*wps->dsd.byteptr++ << 8) & 0xff00;
sp->factor = (sp->factor << 16) >> 16;
}
wps->dsd.high = 0xffffffff;
wps->dsd.low = 0x0;
for (i = 4; i--;)
wps->dsd.value = (wps->dsd.value << 8) | *wps->dsd.byteptr++;
wps->dsd.ready = 1;
return TRUE;
}
static int decode_high (WavpackStream *wps, int32_t *output, int sample_count)
{
int total_samples = sample_count, stereo = (wps->wphdr.flags & MONO_DATA) ? 0 : 1;
DSDfilters *sp = wps->dsd.filters;
while (total_samples--) {
int bitcount = 8;
sp [0].value = sp [0].filter1 - sp [0].filter5 + ((sp [0].filter6 * sp [0].factor) >> 2);
if (stereo)
sp [1].value = sp [1].filter1 - sp [1].filter5 + ((sp [1].filter6 * sp [1].factor) >> 2);
while (bitcount--) {
int32_t *pp = wps->dsd.ptable + ((sp [0].value >> (PRECISION - PRECISION_USE)) & PTABLE_MASK);
uint32_t split = wps->dsd.low + ((wps->dsd.high - wps->dsd.low) >> 8) * (*pp >> 16);
if (wps->dsd.value <= split) {
wps->dsd.high = split;
*pp += (UP - *pp) >> DECAY;
sp [0].filter0 = -1;
}
else {
wps->dsd.low = split + 1;
*pp += (DOWN - *pp) >> DECAY;
sp [0].filter0 = 0;
}
while (DSD_BYTE_READY (wps->dsd.high, wps->dsd.low) && wps->dsd.byteptr < wps->dsd.endptr) {
wps->dsd.value = (wps->dsd.value << 8) | *wps->dsd.byteptr++;
wps->dsd.high = (wps->dsd.high << 8) | 0xff;
wps->dsd.low <<= 8;
}
sp [0].value += sp [0].filter6 << 3;
sp [0].byte = (sp [0].byte << 1) | (sp [0].filter0 & 1);
sp [0].factor += (((sp [0].value ^ sp [0].filter0) >> 31) | 1) & ((sp [0].value ^ (sp [0].value - (sp [0].filter6 << 4))) >> 31);
sp [0].filter1 += ((sp [0].filter0 & VALUE_ONE) - sp [0].filter1) >> 6;
sp [0].filter2 += ((sp [0].filter0 & VALUE_ONE) - sp [0].filter2) >> 4;
sp [0].filter3 += (sp [0].filter2 - sp [0].filter3) >> 4;
sp [0].filter4 += (sp [0].filter3 - sp [0].filter4) >> 4;
sp [0].value = (sp [0].filter4 - sp [0].filter5) >> 4;
sp [0].filter5 += sp [0].value;
sp [0].filter6 += (sp [0].value - sp [0].filter6) >> 3;
sp [0].value = sp [0].filter1 - sp [0].filter5 + ((sp [0].filter6 * sp [0].factor) >> 2);
if (!stereo)
continue;
pp = wps->dsd.ptable + ((sp [1].value >> (PRECISION - PRECISION_USE)) & PTABLE_MASK);
split = wps->dsd.low + ((wps->dsd.high - wps->dsd.low) >> 8) * (*pp >> 16);
if (wps->dsd.value <= split) {
wps->dsd.high = split;
*pp += (UP - *pp) >> DECAY;
sp [1].filter0 = -1;
}
else {
wps->dsd.low = split + 1;
*pp += (DOWN - *pp) >> DECAY;
sp [1].filter0 = 0;
}
while (DSD_BYTE_READY (wps->dsd.high, wps->dsd.low) && wps->dsd.byteptr < wps->dsd.endptr) {
wps->dsd.value = (wps->dsd.value << 8) | *wps->dsd.byteptr++;
wps->dsd.high = (wps->dsd.high << 8) | 0xff;
wps->dsd.low <<= 8;
}
sp [1].value += sp [1].filter6 << 3;
sp [1].byte = (sp [1].byte << 1) | (sp [1].filter0 & 1);
sp [1].factor += (((sp [1].value ^ sp [1].filter0) >> 31) | 1) & ((sp [1].value ^ (sp [1].value - (sp [1].filter6 << 4))) >> 31);
sp [1].filter1 += ((sp [1].filter0 & VALUE_ONE) - sp [1].filter1) >> 6;
sp [1].filter2 += ((sp [1].filter0 & VALUE_ONE) - sp [1].filter2) >> 4;
sp [1].filter3 += (sp [1].filter2 - sp [1].filter3) >> 4;
sp [1].filter4 += (sp [1].filter3 - sp [1].filter4) >> 4;
sp [1].value = (sp [1].filter4 - sp [1].filter5) >> 4;
sp [1].filter5 += sp [1].value;
sp [1].filter6 += (sp [1].value - sp [1].filter6) >> 3;
sp [1].value = sp [1].filter1 - sp [1].filter5 + ((sp [1].filter6 * sp [1].factor) >> 2);
}
wps->crc += (wps->crc << 1) + (*output++ = sp [0].byte & 0xff);
sp [0].factor -= (sp [0].factor + 512) >> 10;
if (stereo) {
wps->crc += (wps->crc << 1) + (*output++ = wps->dsd.filters [1].byte & 0xff);
wps->dsd.filters [1].factor -= (wps->dsd.filters [1].factor + 512) >> 10;
}
}
return sample_count;
}
/*------------------------------------------------------------------------------------------------------------------------*/
#if 0
// 80 term DSD decimation filter
// < 1 dB down at 20 kHz
// > 108 dB stopband attenuation (fs/16)
static const int32_t decm_filter [] = {
4, 17, 56, 147, 336, 693, 1320, 2359,
4003, 6502, 10170, 15392, 22623, 32389, 45275, 61920,
82994, 109174, 141119, 179431, 224621, 277068, 336983, 404373,
479004, 560384, 647741, 740025, 835917, 933849, 1032042, 1128551,
1221329, 1308290, 1387386, 1456680, 1514425, 1559128, 1589610, 1605059,
1605059, 1589610, 1559128, 1514425, 1456680, 1387386, 1308290, 1221329,
1128551, 1032042, 933849, 835917, 740025, 647741, 560384, 479004,
404373, 336983, 277068, 224621, 179431, 141119, 109174, 82994,
61920, 45275, 32389, 22623, 15392, 10170, 6502, 4003,
2359, 1320, 693, 336, 147, 56, 17, 4,
};
#define NUM_FILTER_TERMS 80
#else
// 56 term decimation filter
// < 0.5 dB down at 20 kHz
// > 100 dB stopband attenuation (fs/12)
static const int32_t decm_filter [] = {
4, 17, 56, 147, 336, 692, 1315, 2337,
3926, 6281, 9631, 14216, 20275, 28021, 37619, 49155,
62616, 77870, 94649, 112551, 131049, 149507, 167220, 183448,
197472, 208636, 216402, 220385, 220385, 216402, 208636, 197472,
183448, 167220, 149507, 131049, 112551, 94649, 77870, 62616,
49155, 37619, 28021, 20275, 14216, 9631, 6281, 3926,
2337, 1315, 692, 336, 147, 56, 17, 4,
};
#define NUM_FILTER_TERMS 56
#endif
#define HISTORY_BYTES ((NUM_FILTER_TERMS+7)/8)
typedef struct {
unsigned char delay [HISTORY_BYTES];
} DecimationChannel;
typedef struct {
int32_t conv_tables [HISTORY_BYTES] [256];
DecimationChannel *chans;
int num_channels;
} DecimationContext;
void *decimate_dsd_init (int num_channels)
{
DecimationContext *context = (DecimationContext *)malloc (sizeof (DecimationContext));
double filter_sum = 0, filter_scale;
int skipped_terms, i, j;
if (!context)
return context;
memset (context, 0, sizeof (*context));
context->num_channels = num_channels;
context->chans = (DecimationChannel *)malloc (num_channels * sizeof (DecimationChannel));
if (!context->chans) {
free (context);
return NULL;
}
for (i = 0; i < NUM_FILTER_TERMS; ++i)
filter_sum += decm_filter [i];
filter_scale = ((1 << 23) - 1) / filter_sum * 16.0;
// fprintf (stderr, "convolution, %d terms, %f sum, %f scale\n", NUM_FILTER_TERMS, filter_sum, filter_scale);
for (skipped_terms = i = 0; i < NUM_FILTER_TERMS; ++i) {
int scaled_term = (int) floor (decm_filter [i] * filter_scale + 0.5);
if (scaled_term) {
for (j = 0; j < 256; ++j)
if (j & (0x80 >> (i & 0x7)))
context->conv_tables [i >> 3] [j] += scaled_term;
else
context->conv_tables [i >> 3] [j] -= scaled_term;
}
else
skipped_terms++;
}
// fprintf (stderr, "%d terms skipped\n", skipped_terms);
decimate_dsd_reset (context);
return context;
}
void decimate_dsd_reset (void *decimate_context)
{
DecimationContext *context = (DecimationContext *) decimate_context;
int chan = 0, i;
if (!context)
return;
for (chan = 0; chan < context->num_channels; ++chan)
for (i = 0; i < HISTORY_BYTES; ++i)
context->chans [chan].delay [i] = 0x55;
}
void decimate_dsd_run (void *decimate_context, int32_t *samples, int num_samples)
{
DecimationContext *context = (DecimationContext *) decimate_context;
int chan = 0;
if (!context)
return;
while (num_samples) {
DecimationChannel *sp = context->chans + chan;
int sum = 0;
#if (HISTORY_BYTES == 10)
sum += context->conv_tables [0] [sp->delay [0] = sp->delay [1]];
sum += context->conv_tables [1] [sp->delay [1] = sp->delay [2]];
sum += context->conv_tables [2] [sp->delay [2] = sp->delay [3]];
sum += context->conv_tables [3] [sp->delay [3] = sp->delay [4]];
sum += context->conv_tables [4] [sp->delay [4] = sp->delay [5]];
sum += context->conv_tables [5] [sp->delay [5] = sp->delay [6]];
sum += context->conv_tables [6] [sp->delay [6] = sp->delay [7]];
sum += context->conv_tables [7] [sp->delay [7] = sp->delay [8]];
sum += context->conv_tables [8] [sp->delay [8] = sp->delay [9]];
sum += context->conv_tables [9] [sp->delay [9] = *samples];
#elif (HISTORY_BYTES == 7)
sum += context->conv_tables [0] [sp->delay [0] = sp->delay [1]];
sum += context->conv_tables [1] [sp->delay [1] = sp->delay [2]];
sum += context->conv_tables [2] [sp->delay [2] = sp->delay [3]];
sum += context->conv_tables [3] [sp->delay [3] = sp->delay [4]];
sum += context->conv_tables [4] [sp->delay [4] = sp->delay [5]];
sum += context->conv_tables [5] [sp->delay [5] = sp->delay [6]];
sum += context->conv_tables [6] [sp->delay [6] = *samples];
#else
int i;
for (i = 0; i < HISTORY_BYTES-1; ++i)
sum += context->conv_tables [i] [sp->delay [i] = sp->delay [i+1]];
sum += context->conv_tables [i] [sp->delay [i] = *samples];
#endif
*samples++ = sum >> 4;
if (++chan == context->num_channels) {
num_samples--;
chan = 0;
}
}
}
void decimate_dsd_destroy (void *decimate_context)
{
DecimationContext *context = (DecimationContext *) decimate_context;
if (!context)
return;
if (context->chans)
free (context->chans);
free (context);
}
#endif // ENABLE_DSD
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