1011 lines
31 KiB
C
1011 lines
31 KiB
C
/*
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* ALAC (Apple Lossless Audio Codec) decoder
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* Copyright (c) 2005 David Hammerton
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* All rights reserved.
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*
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* This is the actual decoder.
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*
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* http://crazney.net/programs/itunes/alac.html
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use,
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* copy, modify, merge, publish, distribute, sublicense, and/or
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* sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*
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*/
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static const int host_bigendian = 0;
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#ifdef _WIN32
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#include "stdint_win.h"
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#else
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#include <stdint.h>
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#endif
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#include "alac.h"
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#define _Swap32(v) \
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do { \
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v = (((v)&0x000000FF) << 0x18) | (((v)&0x0000FF00) << 0x08) | (((v)&0x00FF0000) >> 0x08) | \
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(((v)&0xFF000000) >> 0x18); \
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} while (0)
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#define _Swap16(v) \
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do { \
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v = (((v)&0x00FF) << 0x08) | (((v)&0xFF00) >> 0x08); \
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} while (0)
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struct {
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signed int x : 24;
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} se_struct_24;
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#define SignExtend24(val) (se_struct_24.x = val)
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void alac_free(alac_file *alac) {
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if (alac->predicterror_buffer_a)
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free(alac->predicterror_buffer_a);
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if (alac->predicterror_buffer_b)
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free(alac->predicterror_buffer_b);
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if (alac->outputsamples_buffer_a)
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free(alac->outputsamples_buffer_a);
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if (alac->outputsamples_buffer_b)
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free(alac->outputsamples_buffer_b);
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if (alac->uncompressed_bytes_buffer_a)
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free(alac->uncompressed_bytes_buffer_a);
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if (alac->uncompressed_bytes_buffer_b)
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free(alac->uncompressed_bytes_buffer_b);
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free(alac);
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}
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void alac_allocate_buffers(alac_file *alac) {
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alac->predicterror_buffer_a = malloc(alac->setinfo_max_samples_per_frame * 4);
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alac->predicterror_buffer_b = malloc(alac->setinfo_max_samples_per_frame * 4);
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alac->outputsamples_buffer_a = malloc(alac->setinfo_max_samples_per_frame * 4);
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alac->outputsamples_buffer_b = malloc(alac->setinfo_max_samples_per_frame * 4);
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alac->uncompressed_bytes_buffer_a = malloc(alac->setinfo_max_samples_per_frame * 4);
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alac->uncompressed_bytes_buffer_b = malloc(alac->setinfo_max_samples_per_frame * 4);
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}
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void alac_set_info(alac_file *alac, char *inputbuffer) {
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char *ptr = inputbuffer;
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ptr += 4; /* size */
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ptr += 4; /* frma */
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ptr += 4; /* alac */
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ptr += 4; /* size */
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ptr += 4; /* alac */
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ptr += 4; /* 0 ? */
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alac->setinfo_max_samples_per_frame = *(uint32_t *)ptr; /* buffer size / 2 ? */
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if (!host_bigendian)
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_Swap32(alac->setinfo_max_samples_per_frame);
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ptr += 4;
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alac->setinfo_7a = *(uint8_t *)ptr;
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ptr += 1;
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alac->setinfo_sample_size = *(uint8_t *)ptr;
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ptr += 1;
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alac->setinfo_rice_historymult = *(uint8_t *)ptr;
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ptr += 1;
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alac->setinfo_rice_initialhistory = *(uint8_t *)ptr;
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ptr += 1;
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alac->setinfo_rice_kmodifier = *(uint8_t *)ptr;
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ptr += 1;
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alac->setinfo_7f = *(uint8_t *)ptr;
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ptr += 1;
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alac->setinfo_80 = *(uint16_t *)ptr;
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if (!host_bigendian)
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_Swap16(alac->setinfo_80);
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ptr += 2;
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alac->setinfo_82 = *(uint32_t *)ptr;
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if (!host_bigendian)
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_Swap32(alac->setinfo_82);
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ptr += 4;
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alac->setinfo_86 = *(uint32_t *)ptr;
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if (!host_bigendian)
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_Swap32(alac->setinfo_86);
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ptr += 4;
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alac->setinfo_8a_rate = *(uint32_t *)ptr;
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if (!host_bigendian)
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_Swap32(alac->setinfo_8a_rate);
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alac_allocate_buffers(alac);
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}
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/* stream reading */
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/* supports reading 1 to 16 bits, in big endian format */
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static uint32_t readbits_16(alac_file *alac, int bits) {
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uint32_t result;
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int new_accumulator;
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result = (alac->input_buffer[0] << 16) | (alac->input_buffer[1] << 8) | (alac->input_buffer[2]);
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/* shift left by the number of bits we've already read,
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* so that the top 'n' bits of the 24 bits we read will
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* be the return bits */
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result = result << alac->input_buffer_bitaccumulator;
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result = result & 0x00ffffff;
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/* and then only want the top 'n' bits from that, where
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* n is 'bits' */
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result = result >> (24 - bits);
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new_accumulator = (alac->input_buffer_bitaccumulator + bits);
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/* increase the buffer pointer if we've read over n bytes. */
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alac->input_buffer += (new_accumulator >> 3);
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/* and the remainder goes back into the bit accumulator */
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alac->input_buffer_bitaccumulator = (new_accumulator & 7);
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return result;
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}
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/* supports reading 1 to 32 bits, in big endian format */
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static uint32_t readbits(alac_file *alac, int bits) {
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int32_t result = 0;
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if (bits > 16) {
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bits -= 16;
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result = readbits_16(alac, 16) << bits;
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}
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result |= readbits_16(alac, bits);
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return result;
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}
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/* reads a single bit */
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static int readbit(alac_file *alac) {
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int result;
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int new_accumulator;
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result = alac->input_buffer[0];
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result = result << alac->input_buffer_bitaccumulator;
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result = result >> 7 & 1;
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new_accumulator = (alac->input_buffer_bitaccumulator + 1);
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alac->input_buffer += (new_accumulator / 8);
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alac->input_buffer_bitaccumulator = (new_accumulator % 8);
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return result;
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}
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static void unreadbits(alac_file *alac, int bits) {
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int new_accumulator = (alac->input_buffer_bitaccumulator - bits);
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alac->input_buffer += (new_accumulator >> 3);
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alac->input_buffer_bitaccumulator = (new_accumulator & 7);
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if (alac->input_buffer_bitaccumulator < 0)
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alac->input_buffer_bitaccumulator *= -1;
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}
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/* various implementations of count_leading_zero:
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* the first one is the original one, the simplest and most
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* obvious for what it's doing. never use this.
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* then there are the asm ones. fill in as necessary
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* and finally an unrolled and optimised c version
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* to fall back to
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*/
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#if 0
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/* hideously inefficient. could use a bitmask search,
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* alternatively bsr on x86,
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*/
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static int count_leading_zeros(int32_t input)
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{
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int i = 0;
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while (!(0x80000000 & input) && i < 32)
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{
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i++;
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input = input << 1;
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}
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return i;
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}
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#elif defined(__GNUC__)
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/* for some reason the unrolled version (below) is
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* actually faster than this. yay intel!
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*/
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static int count_leading_zeros(int input) { return __builtin_clz(input); }
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#elif defined(_MSC_VER) && defined(_M_IX86)
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static int count_leading_zeros(int input) {
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int output = 0;
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if (!input)
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return 32;
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__asm
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{
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mov eax, input;
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mov edx, 0x1f;
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bsr ecx, eax;
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sub edx, ecx;
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mov output, edx;
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}
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return output;
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}
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#else
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#warning using generic count leading zeroes. You may wish to write one for your CPU / compiler
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static int count_leading_zeros(int input) {
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int output = 0;
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int curbyte = 0;
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curbyte = input >> 24;
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if (curbyte)
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goto found;
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output += 8;
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curbyte = input >> 16;
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if (curbyte & 0xff)
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goto found;
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output += 8;
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curbyte = input >> 8;
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if (curbyte & 0xff)
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goto found;
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output += 8;
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curbyte = input;
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if (curbyte & 0xff)
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goto found;
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output += 8;
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return output;
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found:
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if (!(curbyte & 0xf0)) {
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output += 4;
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} else
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curbyte >>= 4;
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if (curbyte & 0x8)
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return output;
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if (curbyte & 0x4)
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return output + 1;
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if (curbyte & 0x2)
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return output + 2;
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if (curbyte & 0x1)
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return output + 3;
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/* shouldn't get here: */
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return output + 4;
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}
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#endif
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#define RICE_THRESHOLD 8 // maximum number of bits for a rice prefix.
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static int32_t entropy_decode_value(alac_file *alac, int readSampleSize, int k,
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int rice_kmodifier_mask) {
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int32_t x = 0; // decoded value
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// read x, number of 1s before 0 represent the rice value.
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while (x <= RICE_THRESHOLD && readbit(alac)) {
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x++;
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}
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if (x > RICE_THRESHOLD) {
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// read the number from the bit stream (raw value)
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int32_t value;
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value = readbits(alac, readSampleSize);
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// mask value
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value &= (((uint32_t)0xffffffff) >> (32 - readSampleSize));
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x = value;
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} else {
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if (k != 1) {
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int extraBits = readbits(alac, k);
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// x = x * (2^k - 1)
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x *= (((1 << k) - 1) & rice_kmodifier_mask);
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if (extraBits > 1)
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x += extraBits - 1;
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else
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unreadbits(alac, 1);
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}
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}
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return x;
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}
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static void entropy_rice_decode(alac_file *alac, int32_t *outputBuffer, int outputSize,
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int readSampleSize, int rice_initialhistory, int rice_kmodifier,
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int rice_historymult, int rice_kmodifier_mask) {
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int outputCount;
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int history = rice_initialhistory;
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int signModifier = 0;
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for (outputCount = 0; outputCount < outputSize; outputCount++) {
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int32_t decodedValue;
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int32_t finalValue;
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int32_t k;
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k = 31 - rice_kmodifier - count_leading_zeros((history >> 9) + 3);
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if (k < 0)
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k += rice_kmodifier;
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else
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k = rice_kmodifier;
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// note: don't use rice_kmodifier_mask here (set mask to 0xFFFFFFFF)
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decodedValue = entropy_decode_value(alac, readSampleSize, k, 0xFFFFFFFF);
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decodedValue += signModifier;
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finalValue = (decodedValue + 1) / 2; // inc by 1 and shift out sign bit
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if (decodedValue & 1) // the sign is stored in the low bit
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finalValue *= -1;
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outputBuffer[outputCount] = finalValue;
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signModifier = 0;
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// update history
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history += (decodedValue * rice_historymult) - ((history * rice_historymult) >> 9);
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if (decodedValue > 0xFFFF)
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history = 0xFFFF;
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// special case, for compressed blocks of 0
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if ((history < 128) && (outputCount + 1 < outputSize)) {
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int32_t blockSize;
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signModifier = 1;
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k = count_leading_zeros(history) + ((history + 16) / 64) - 24;
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// note: blockSize is always 16bit
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blockSize = entropy_decode_value(alac, 16, k, rice_kmodifier_mask);
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// got blockSize 0s
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if (blockSize > 0) {
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memset(&outputBuffer[outputCount + 1], 0, blockSize * sizeof(*outputBuffer));
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outputCount += blockSize;
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}
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if (blockSize > 0xFFFF)
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signModifier = 0;
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history = 0;
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}
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}
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}
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#define SIGN_EXTENDED32(val, bits) ((val << (32 - bits)) >> (32 - bits))
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#define SIGN_ONLY(v) ((v < 0) ? (-1) : ((v > 0) ? (1) : (0)))
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static void predictor_decompress_fir_adapt(int32_t *error_buffer, int32_t *buffer_out,
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int output_size, int readsamplesize,
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int16_t *predictor_coef_table, int predictor_coef_num,
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int predictor_quantitization) {
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int i;
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/* first sample always copies */
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*buffer_out = *error_buffer;
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if (!predictor_coef_num) {
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if (output_size <= 1)
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return;
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memcpy(buffer_out + 1, error_buffer + 1, (output_size - 1) * 4);
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return;
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}
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if (predictor_coef_num == 0x1f) /* 11111 - max value of predictor_coef_num */
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{ /* second-best case scenario for fir decompression,
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* error describes a small difference from the previous sample only
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*/
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if (output_size <= 1)
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return;
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for (i = 0; i < output_size - 1; i++) {
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int32_t prev_value;
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int32_t error_value;
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prev_value = buffer_out[i];
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error_value = error_buffer[i + 1];
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buffer_out[i + 1] = SIGN_EXTENDED32((prev_value + error_value), readsamplesize);
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}
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return;
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}
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/* read warm-up samples */
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if (predictor_coef_num > 0) {
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int i;
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for (i = 0; i < predictor_coef_num; i++) {
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int32_t val;
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val = buffer_out[i] + error_buffer[i + 1];
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val = SIGN_EXTENDED32(val, readsamplesize);
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buffer_out[i + 1] = val;
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}
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}
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#if 0
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/* 4 and 8 are very common cases (the only ones i've seen). these
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* should be unrolled and optimised
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*/
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if (predictor_coef_num == 4)
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{
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/* FIXME: optimised general case */
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return;
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}
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if (predictor_coef_table == 8)
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{
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/* FIXME: optimised general case */
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return;
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}
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#endif
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/* general case */
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if (predictor_coef_num > 0) {
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for (i = predictor_coef_num + 1; i < output_size; i++) {
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int j;
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int sum = 0;
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int outval;
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int error_val = error_buffer[i];
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for (j = 0; j < predictor_coef_num; j++) {
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sum += (buffer_out[predictor_coef_num - j] - buffer_out[0]) * predictor_coef_table[j];
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}
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outval = (1 << (predictor_quantitization - 1)) + sum;
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outval = outval >> predictor_quantitization;
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outval = outval + buffer_out[0] + error_val;
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outval = SIGN_EXTENDED32(outval, readsamplesize);
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buffer_out[predictor_coef_num + 1] = outval;
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|
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if (error_val > 0) {
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int predictor_num = predictor_coef_num - 1;
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while (predictor_num >= 0 && error_val > 0) {
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int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
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int sign = SIGN_ONLY(val);
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predictor_coef_table[predictor_num] -= sign;
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val *= sign; /* absolute value */
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error_val -= ((val >> predictor_quantitization) * (predictor_coef_num - predictor_num));
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predictor_num--;
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}
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} else if (error_val < 0) {
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int predictor_num = predictor_coef_num - 1;
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|
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while (predictor_num >= 0 && error_val < 0) {
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int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
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int sign = -SIGN_ONLY(val);
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predictor_coef_table[predictor_num] -= sign;
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val *= sign; /* neg value */
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error_val -= ((val >> predictor_quantitization) * (predictor_coef_num - predictor_num));
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predictor_num--;
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}
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}
|
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|
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buffer_out++;
|
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}
|
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}
|
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}
|
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|
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static void deinterlace_16(int32_t *buffer_a, int32_t *buffer_b, int16_t *buffer_out,
|
|
int numchannels, int numsamples, uint8_t interlacing_shift,
|
|
uint8_t interlacing_leftweight) {
|
|
int i;
|
|
if (numsamples <= 0)
|
|
return;
|
|
|
|
/* weighted interlacing */
|
|
if (interlacing_leftweight) {
|
|
for (i = 0; i < numsamples; i++) {
|
|
int32_t difference, midright;
|
|
int16_t left;
|
|
int16_t right;
|
|
|
|
midright = buffer_a[i];
|
|
difference = buffer_b[i];
|
|
|
|
right = midright - ((difference * interlacing_leftweight) >> interlacing_shift);
|
|
left = right + difference;
|
|
|
|
/* output is always little endian */
|
|
if (host_bigendian) {
|
|
_Swap16(left);
|
|
_Swap16(right);
|
|
}
|
|
|
|
buffer_out[i * numchannels] = left;
|
|
buffer_out[i * numchannels + 1] = right;
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/* otherwise basic interlacing took place */
|
|
for (i = 0; i < numsamples; i++) {
|
|
int16_t left, right;
|
|
|
|
left = buffer_a[i];
|
|
right = buffer_b[i];
|
|
|
|
/* output is always little endian */
|
|
if (host_bigendian) {
|
|
_Swap16(left);
|
|
_Swap16(right);
|
|
}
|
|
|
|
buffer_out[i * numchannels] = left;
|
|
buffer_out[i * numchannels + 1] = right;
|
|
}
|
|
}
|
|
|
|
static void deinterlace_24(int32_t *buffer_a, int32_t *buffer_b, int uncompressed_bytes,
|
|
int32_t *uncompressed_bytes_buffer_a,
|
|
int32_t *uncompressed_bytes_buffer_b, void *buffer_out, int numchannels,
|
|
int numsamples, uint8_t interlacing_shift,
|
|
uint8_t interlacing_leftweight) {
|
|
int i;
|
|
if (numsamples <= 0)
|
|
return;
|
|
|
|
/* weighted interlacing */
|
|
if (interlacing_leftweight) {
|
|
for (i = 0; i < numsamples; i++) {
|
|
int32_t difference, midright;
|
|
int32_t left;
|
|
int32_t right;
|
|
|
|
midright = buffer_a[i];
|
|
difference = buffer_b[i];
|
|
|
|
right = midright - ((difference * interlacing_leftweight) >> interlacing_shift);
|
|
left = right + difference;
|
|
|
|
if (uncompressed_bytes) {
|
|
uint32_t mask = ~(0xFFFFFFFF << (uncompressed_bytes * 8));
|
|
left <<= (uncompressed_bytes * 8);
|
|
right <<= (uncompressed_bytes * 8);
|
|
|
|
left |= uncompressed_bytes_buffer_a[i] & mask;
|
|
right |= uncompressed_bytes_buffer_b[i] & mask;
|
|
}
|
|
|
|
((uint8_t *)buffer_out)[i * numchannels * 3] = (left)&0xFF;
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 1] = (left >> 8) & 0xFF;
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 2] = (left >> 16) & 0xFF;
|
|
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 3] = (right)&0xFF;
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 4] = (right >> 8) & 0xFF;
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 5] = (right >> 16) & 0xFF;
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/* otherwise basic interlacing took place */
|
|
for (i = 0; i < numsamples; i++) {
|
|
int32_t left, right;
|
|
|
|
left = buffer_a[i];
|
|
right = buffer_b[i];
|
|
|
|
if (uncompressed_bytes) {
|
|
uint32_t mask = ~(0xFFFFFFFF << (uncompressed_bytes * 8));
|
|
left <<= (uncompressed_bytes * 8);
|
|
right <<= (uncompressed_bytes * 8);
|
|
|
|
left |= uncompressed_bytes_buffer_a[i] & mask;
|
|
right |= uncompressed_bytes_buffer_b[i] & mask;
|
|
}
|
|
|
|
((uint8_t *)buffer_out)[i * numchannels * 3] = (left)&0xFF;
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 1] = (left >> 8) & 0xFF;
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 2] = (left >> 16) & 0xFF;
|
|
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 3] = (right)&0xFF;
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 4] = (right >> 8) & 0xFF;
|
|
((uint8_t *)buffer_out)[i * numchannels * 3 + 5] = (right >> 16) & 0xFF;
|
|
}
|
|
}
|
|
|
|
void alac_decode_frame(alac_file *alac, unsigned char *inbuffer, void *outbuffer, int *outputsize) {
|
|
int outbuffer_allocation_size = *outputsize; // initial value
|
|
int channels;
|
|
int32_t outputsamples = alac->setinfo_max_samples_per_frame;
|
|
|
|
/* setup the stream */
|
|
alac->input_buffer = inbuffer;
|
|
alac->input_buffer_bitaccumulator = 0;
|
|
|
|
channels = readbits(alac, 3);
|
|
|
|
*outputsize = outputsamples * alac->bytespersample;
|
|
if (*outputsize > outbuffer_allocation_size) {
|
|
fprintf(stderr, "FIXME: Not enough space if the output buffer for audio frame - E1.\n");
|
|
*outputsize = 0;
|
|
return;
|
|
}
|
|
|
|
switch (channels) {
|
|
case 0: /* 1 channel */
|
|
{
|
|
int hassize;
|
|
int isnotcompressed;
|
|
int readsamplesize;
|
|
|
|
int uncompressed_bytes;
|
|
int ricemodifier;
|
|
|
|
/* 2^result = something to do with output waiting.
|
|
* perhaps matters if we read > 1 frame in a pass?
|
|
*/
|
|
readbits(alac, 4);
|
|
|
|
readbits(alac, 12); /* unknown, skip 12 bits */
|
|
|
|
hassize = readbits(alac, 1); /* the output sample size is stored soon */
|
|
|
|
uncompressed_bytes =
|
|
readbits(alac, 2); /* number of bytes in the (compressed) stream that are not compressed */
|
|
|
|
isnotcompressed = readbits(alac, 1); /* whether the frame is compressed */
|
|
|
|
if (hassize) {
|
|
/* now read the number of samples,
|
|
* as a 32bit integer */
|
|
outputsamples = readbits(alac, 32);
|
|
*outputsize = outputsamples * alac->bytespersample;
|
|
if (*outputsize > outbuffer_allocation_size) {
|
|
fprintf(stderr, "FIXME: Not enough space if the output buffer for audio frame - E2.\n");
|
|
*outputsize = 0;
|
|
return;
|
|
}
|
|
}
|
|
|
|
readsamplesize = alac->setinfo_sample_size - (uncompressed_bytes * 8);
|
|
|
|
if (!isnotcompressed) { /* so it is compressed */
|
|
int16_t predictor_coef_table[32];
|
|
int predictor_coef_num;
|
|
int prediction_type;
|
|
int prediction_quantitization;
|
|
int i;
|
|
|
|
/* skip 16 bits, not sure what they are. seem to be used in
|
|
* two channel case */
|
|
readbits(alac, 8);
|
|
readbits(alac, 8);
|
|
|
|
prediction_type = readbits(alac, 4);
|
|
prediction_quantitization = readbits(alac, 4);
|
|
|
|
ricemodifier = readbits(alac, 3);
|
|
predictor_coef_num = readbits(alac, 5);
|
|
|
|
/* read the predictor table */
|
|
for (i = 0; i < predictor_coef_num; i++) {
|
|
predictor_coef_table[i] = (int16_t)readbits(alac, 16);
|
|
}
|
|
|
|
if (uncompressed_bytes) {
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
alac->uncompressed_bytes_buffer_a[i] = readbits(alac, uncompressed_bytes * 8);
|
|
}
|
|
}
|
|
|
|
entropy_rice_decode(alac, alac->predicterror_buffer_a, outputsamples, readsamplesize,
|
|
alac->setinfo_rice_initialhistory, alac->setinfo_rice_kmodifier,
|
|
ricemodifier * alac->setinfo_rice_historymult / 4,
|
|
(1 << alac->setinfo_rice_kmodifier) - 1);
|
|
|
|
if (prediction_type == 0) { /* adaptive fir */
|
|
predictor_decompress_fir_adapt(alac->predicterror_buffer_a, alac->outputsamples_buffer_a,
|
|
outputsamples, readsamplesize, predictor_coef_table,
|
|
predictor_coef_num, prediction_quantitization);
|
|
} else {
|
|
fprintf(stderr, "FIXME: unhandled prediction type for compressed case: %i\n",
|
|
prediction_type);
|
|
/* i think the only other prediction type (or perhaps this is just a
|
|
* boolean?) runs adaptive fir twice.. like:
|
|
* predictor_decompress_fir_adapt(predictor_error, tempout, ...)
|
|
* predictor_decompress_fir_adapt(predictor_error, outputsamples ...)
|
|
* little strange..
|
|
*/
|
|
}
|
|
|
|
} else { /* not compressed, easy case */
|
|
if (alac->setinfo_sample_size <= 16) {
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int32_t audiobits = readbits(alac, alac->setinfo_sample_size);
|
|
|
|
audiobits = SIGN_EXTENDED32(audiobits, alac->setinfo_sample_size);
|
|
|
|
alac->outputsamples_buffer_a[i] = audiobits;
|
|
}
|
|
} else {
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int32_t audiobits;
|
|
|
|
audiobits = readbits(alac, 16);
|
|
/* special case of sign extension..
|
|
* as we'll be ORing the low 16bits into this */
|
|
audiobits = audiobits << (alac->setinfo_sample_size - 16);
|
|
audiobits |= readbits(alac, alac->setinfo_sample_size - 16);
|
|
audiobits = SignExtend24(audiobits);
|
|
|
|
alac->outputsamples_buffer_a[i] = audiobits;
|
|
}
|
|
}
|
|
uncompressed_bytes = 0; // always 0 for uncompressed
|
|
}
|
|
|
|
switch (alac->setinfo_sample_size) {
|
|
case 16: {
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int16_t sample = alac->outputsamples_buffer_a[i];
|
|
if (host_bigendian)
|
|
_Swap16(sample);
|
|
((int16_t *)outbuffer)[i * alac->numchannels] = sample;
|
|
}
|
|
break;
|
|
}
|
|
case 24: {
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int32_t sample = alac->outputsamples_buffer_a[i];
|
|
|
|
if (uncompressed_bytes) {
|
|
uint32_t mask;
|
|
sample = sample << (uncompressed_bytes * 8);
|
|
mask = ~(0xFFFFFFFF << (uncompressed_bytes * 8));
|
|
sample |= alac->uncompressed_bytes_buffer_a[i] & mask;
|
|
}
|
|
|
|
((uint8_t *)outbuffer)[i * alac->numchannels * 3] = (sample)&0xFF;
|
|
((uint8_t *)outbuffer)[i * alac->numchannels * 3 + 1] = (sample >> 8) & 0xFF;
|
|
((uint8_t *)outbuffer)[i * alac->numchannels * 3 + 2] = (sample >> 16) & 0xFF;
|
|
}
|
|
break;
|
|
}
|
|
case 20:
|
|
case 32:
|
|
fprintf(stderr, "FIXME: unimplemented sample size %i\n", alac->setinfo_sample_size);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
case 1: /* 2 channels */
|
|
{
|
|
int hassize;
|
|
int isnotcompressed;
|
|
int readsamplesize;
|
|
|
|
int uncompressed_bytes;
|
|
|
|
uint8_t interlacing_shift;
|
|
uint8_t interlacing_leftweight;
|
|
|
|
/* 2^result = something to do with output waiting.
|
|
* perhaps matters if we read > 1 frame in a pass?
|
|
*/
|
|
readbits(alac, 4);
|
|
|
|
readbits(alac, 12); /* unknown, skip 12 bits */
|
|
|
|
hassize = readbits(alac, 1); /* the output sample size is stored soon */
|
|
|
|
uncompressed_bytes = readbits(
|
|
alac, 2); /* the number of bytes in the (compressed) stream that are not compressed */
|
|
|
|
isnotcompressed = readbits(alac, 1); /* whether the frame is compressed */
|
|
|
|
if (hassize) {
|
|
/* now read the number of samples,
|
|
* as a 32bit integer */
|
|
outputsamples = readbits(alac, 32);
|
|
*outputsize = outputsamples * alac->bytespersample;
|
|
if (*outputsize > outbuffer_allocation_size) {
|
|
fprintf(stderr, "FIXME: Not enough space if the output buffer for audio frame - E3.\n");
|
|
*outputsize = 0;
|
|
return;
|
|
}
|
|
}
|
|
|
|
readsamplesize = alac->setinfo_sample_size - (uncompressed_bytes * 8) + 1;
|
|
|
|
if (!isnotcompressed) { /* compressed */
|
|
int16_t predictor_coef_table_a[32];
|
|
int predictor_coef_num_a;
|
|
int prediction_type_a;
|
|
int prediction_quantitization_a;
|
|
int ricemodifier_a;
|
|
|
|
int16_t predictor_coef_table_b[32];
|
|
int predictor_coef_num_b;
|
|
int prediction_type_b;
|
|
int prediction_quantitization_b;
|
|
int ricemodifier_b;
|
|
|
|
int i;
|
|
|
|
interlacing_shift = readbits(alac, 8);
|
|
interlacing_leftweight = readbits(alac, 8);
|
|
|
|
/******** channel 1 ***********/
|
|
prediction_type_a = readbits(alac, 4);
|
|
prediction_quantitization_a = readbits(alac, 4);
|
|
|
|
ricemodifier_a = readbits(alac, 3);
|
|
predictor_coef_num_a = readbits(alac, 5);
|
|
|
|
/* read the predictor table */
|
|
for (i = 0; i < predictor_coef_num_a; i++) {
|
|
predictor_coef_table_a[i] = (int16_t)readbits(alac, 16);
|
|
}
|
|
|
|
/******** channel 2 *********/
|
|
prediction_type_b = readbits(alac, 4);
|
|
prediction_quantitization_b = readbits(alac, 4);
|
|
|
|
ricemodifier_b = readbits(alac, 3);
|
|
predictor_coef_num_b = readbits(alac, 5);
|
|
|
|
/* read the predictor table */
|
|
for (i = 0; i < predictor_coef_num_b; i++) {
|
|
predictor_coef_table_b[i] = (int16_t)readbits(alac, 16);
|
|
}
|
|
|
|
/*********************/
|
|
if (uncompressed_bytes) { /* see mono case */
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
alac->uncompressed_bytes_buffer_a[i] = readbits(alac, uncompressed_bytes * 8);
|
|
alac->uncompressed_bytes_buffer_b[i] = readbits(alac, uncompressed_bytes * 8);
|
|
}
|
|
}
|
|
|
|
/* channel 1 */
|
|
entropy_rice_decode(alac, alac->predicterror_buffer_a, outputsamples, readsamplesize,
|
|
alac->setinfo_rice_initialhistory, alac->setinfo_rice_kmodifier,
|
|
ricemodifier_a * alac->setinfo_rice_historymult / 4,
|
|
(1 << alac->setinfo_rice_kmodifier) - 1);
|
|
|
|
if (prediction_type_a == 0) { /* adaptive fir */
|
|
predictor_decompress_fir_adapt(alac->predicterror_buffer_a, alac->outputsamples_buffer_a,
|
|
outputsamples, readsamplesize, predictor_coef_table_a,
|
|
predictor_coef_num_a, prediction_quantitization_a);
|
|
} else { /* see mono case */
|
|
fprintf(stderr, "FIXME: unhandled prediction type on channel 1: %i\n", prediction_type_a);
|
|
}
|
|
|
|
/* channel 2 */
|
|
entropy_rice_decode(alac, alac->predicterror_buffer_b, outputsamples, readsamplesize,
|
|
alac->setinfo_rice_initialhistory, alac->setinfo_rice_kmodifier,
|
|
ricemodifier_b * alac->setinfo_rice_historymult / 4,
|
|
(1 << alac->setinfo_rice_kmodifier) - 1);
|
|
|
|
if (prediction_type_b == 0) { /* adaptive fir */
|
|
predictor_decompress_fir_adapt(alac->predicterror_buffer_b, alac->outputsamples_buffer_b,
|
|
outputsamples, readsamplesize, predictor_coef_table_b,
|
|
predictor_coef_num_b, prediction_quantitization_b);
|
|
} else {
|
|
fprintf(stderr, "FIXME: unhandled prediction type on channel 2: %i\n", prediction_type_b);
|
|
}
|
|
} else { /* not compressed, easy case */
|
|
if (alac->setinfo_sample_size <= 16) {
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int32_t audiobits_a, audiobits_b;
|
|
|
|
audiobits_a = readbits(alac, alac->setinfo_sample_size);
|
|
audiobits_b = readbits(alac, alac->setinfo_sample_size);
|
|
|
|
audiobits_a = SIGN_EXTENDED32(audiobits_a, alac->setinfo_sample_size);
|
|
audiobits_b = SIGN_EXTENDED32(audiobits_b, alac->setinfo_sample_size);
|
|
|
|
alac->outputsamples_buffer_a[i] = audiobits_a;
|
|
alac->outputsamples_buffer_b[i] = audiobits_b;
|
|
}
|
|
} else {
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int32_t audiobits_a, audiobits_b;
|
|
|
|
audiobits_a = readbits(alac, 16);
|
|
audiobits_a = audiobits_a << (alac->setinfo_sample_size - 16);
|
|
audiobits_a |= readbits(alac, alac->setinfo_sample_size - 16);
|
|
audiobits_a = SignExtend24(audiobits_a);
|
|
|
|
audiobits_b = readbits(alac, 16);
|
|
audiobits_b = audiobits_b << (alac->setinfo_sample_size - 16);
|
|
audiobits_b |= readbits(alac, alac->setinfo_sample_size - 16);
|
|
audiobits_b = SignExtend24(audiobits_b);
|
|
|
|
alac->outputsamples_buffer_a[i] = audiobits_a;
|
|
alac->outputsamples_buffer_b[i] = audiobits_b;
|
|
}
|
|
}
|
|
uncompressed_bytes = 0; // always 0 for uncompressed
|
|
interlacing_shift = 0;
|
|
interlacing_leftweight = 0;
|
|
}
|
|
|
|
switch (alac->setinfo_sample_size) {
|
|
case 16: {
|
|
deinterlace_16(alac->outputsamples_buffer_a, alac->outputsamples_buffer_b,
|
|
(int16_t *)outbuffer, alac->numchannels, outputsamples, interlacing_shift,
|
|
interlacing_leftweight);
|
|
break;
|
|
}
|
|
case 24: {
|
|
deinterlace_24(alac->outputsamples_buffer_a, alac->outputsamples_buffer_b, uncompressed_bytes,
|
|
alac->uncompressed_bytes_buffer_a, alac->uncompressed_bytes_buffer_b,
|
|
(int16_t *)outbuffer, alac->numchannels, outputsamples, interlacing_shift,
|
|
interlacing_leftweight);
|
|
break;
|
|
}
|
|
case 20:
|
|
case 32:
|
|
fprintf(stderr, "FIXME: unimplemented sample size %i\n", alac->setinfo_sample_size);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
alac_file *alac_create(int samplesize, int numchannels) {
|
|
alac_file *newfile = malloc(sizeof(alac_file));
|
|
if (newfile) {
|
|
memset(newfile, 0, sizeof(alac_file));
|
|
newfile->samplesize = samplesize;
|
|
newfile->numchannels = numchannels;
|
|
newfile->bytespersample = (samplesize / 8) * numchannels;
|
|
} else {
|
|
fprintf(stderr, "FIXME: can not allocate memory for a new file in alac_cxreate.");
|
|
}
|
|
return newfile;
|
|
}
|