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stb_vorbis.c
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stb_vorbis.c
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// Ogg Vorbis I audio decoder -- version 0.99996
//
// Written in April 2007 by Sean Barrett, sponsored by RAD Game Tools.
//
// Placed in the public domain April 2007 by the author: no copyright is
// claimed, and you may use it for any purpose you like.
//
// No warranty for any purpose is expressed or implied by the author (nor
// by RAD Game Tools). Report bugs and send enhancements to the author.
//
// Get the latest version and other information at:
// http://nothings.org/stb_vorbis/
// Todo:
//
// - seeking (note you can seek yourself using the pushdata API)
//
// Limitations:
//
// - floor 0 not supported (used in old ogg vorbis files)
// - lossless sample-truncation at beginning ignored
// - cannot concatenate multiple vorbis streams
// - sample positions are 32-bit, limiting seekable 192Khz
// files to around 6 hours (Ogg supports 64-bit)
//
// All of these limitations may be removed in future versions.
#include "stb_vorbis.h"
#ifndef STB_VORBIS_HEADER_ONLY
// global configuration settings (e.g. set these in the project/makefile),
// or just set them in this file at the top (although ideally the first few
// should be visible when the header file is compiled too, although it's not
// crucial)
// STB_VORBIS_NO_PUSHDATA_API
// does not compile the code for the various stb_vorbis_*_pushdata()
// functions
// #define STB_VORBIS_NO_PUSHDATA_API
// STB_VORBIS_NO_PULLDATA_API
// does not compile the code for the non-pushdata APIs
// #define STB_VORBIS_NO_PULLDATA_API
// STB_VORBIS_NO_STDIO
// does not compile the code for the APIs that use FILE *s internally
// or externally (implied by STB_VORBIS_NO_PULLDATA_API)
// #define STB_VORBIS_NO_STDIO
// STB_VORBIS_NO_INTEGER_CONVERSION
// does not compile the code for converting audio sample data from
// float to integer (implied by STB_VORBIS_NO_PULLDATA_API)
// #define STB_VORBIS_NO_INTEGER_CONVERSION
// STB_VORBIS_NO_FAST_SCALED_FLOAT
// does not use a fast float-to-int trick to accelerate float-to-int on
// most platforms which requires endianness be defined correctly.
//#define STB_VORBIS_NO_FAST_SCALED_FLOAT
// STB_VORBIS_MAX_CHANNELS [number]
// globally define this to the maximum number of channels you need.
// The spec does not put a restriction on channels except that
// the count is stored in a byte, so 255 is the hard limit.
// Reducing this saves about 16 bytes per value, so using 16 saves
// (255-16)*16 or around 4KB. Plus anything other memory usage
// I forgot to account for. Can probably go as low as 8 (7.1 audio),
// 6 (5.1 audio), or 2 (stereo only).
#ifndef STB_VORBIS_MAX_CHANNELS
#define STB_VORBIS_MAX_CHANNELS 16 // enough for anyone?
#endif
// STB_VORBIS_PUSHDATA_CRC_COUNT [number]
// after a flush_pushdata(), stb_vorbis begins scanning for the
// next valid page, without backtracking. when it finds something
// that looks like a page, it streams through it and verifies its
// CRC32. Should that validation fail, it keeps scanning. But it's
// possible that _while_ streaming through to check the CRC32 of
// one candidate page, it sees another candidate page. This #define
// determines how many "overlapping" candidate pages it can search
// at once. Note that "real" pages are typically ~4KB to ~8KB, whereas
// garbage pages could be as big as 64KB, but probably average ~16KB.
// So don't hose ourselves by scanning an apparent 64KB page and
// missing a ton of real ones in the interim; so minimum of 2
#ifndef STB_VORBIS_PUSHDATA_CRC_COUNT
#define STB_VORBIS_PUSHDATA_CRC_COUNT 4
#endif
// STB_VORBIS_FAST_HUFFMAN_LENGTH [number]
// sets the log size of the huffman-acceleration table. Maximum
// supported value is 24. with larger numbers, more decodings are O(1),
// but the table size is larger so worse cache missing, so you'll have
// to probe (and try multiple ogg vorbis files) to find the sweet spot.
#ifndef STB_VORBIS_FAST_HUFFMAN_LENGTH
#define STB_VORBIS_FAST_HUFFMAN_LENGTH 10
#endif
// STB_VORBIS_FAST_BINARY_LENGTH [number]
// sets the log size of the binary-search acceleration table. this
// is used in similar fashion to the fast-huffman size to set initial
// parameters for the binary search
// STB_VORBIS_FAST_HUFFMAN_INT
// The fast huffman tables are much more efficient if they can be
// stored as 16-bit results instead of 32-bit results. This restricts
// the codebooks to having only 65535 possible outcomes, though.
// (At least, accelerated by the huffman table.)
#ifndef STB_VORBIS_FAST_HUFFMAN_INT
#define STB_VORBIS_FAST_HUFFMAN_SHORT
#endif
// STB_VORBIS_NO_HUFFMAN_BINARY_SEARCH
// If the 'fast huffman' search doesn't succeed, then stb_vorbis falls
// back on binary searching for the correct one. This requires storing
// extra tables with the huffman codes in sorted order. Defining this
// symbol trades off space for speed by forcing a linear search in the
// non-fast case, except for "sparse" codebooks.
// #define STB_VORBIS_NO_HUFFMAN_BINARY_SEARCH
// STB_VORBIS_DIVIDES_IN_RESIDUE
// stb_vorbis precomputes the result of the scalar residue decoding
// that would otherwise require a divide per chunk. you can trade off
// space for time by defining this symbol.
// #define STB_VORBIS_DIVIDES_IN_RESIDUE
// STB_VORBIS_DIVIDES_IN_CODEBOOK
// vorbis VQ codebooks can be encoded two ways: with every case explicitly
// stored, or with all elements being chosen from a small range of values,
// and all values possible in all elements. By default, stb_vorbis expands
// this latter kind out to look like the former kind for ease of decoding,
// because otherwise an integer divide-per-vector-element is required to
// unpack the index. If you define STB_VORBIS_DIVIDES_IN_CODEBOOK, you can
// trade off storage for speed.
//#define STB_VORBIS_DIVIDES_IN_CODEBOOK
// STB_VORBIS_CODEBOOK_SHORTS
// The vorbis file format encodes VQ codebook floats as ax+b where a and
// b are floating point per-codebook constants, and x is a 16-bit int.
// Normally, stb_vorbis decodes them to floats rather than leaving them
// as 16-bit ints and computing ax+b while decoding. This is a speed/space
// tradeoff; you can save space by defining this flag.
#ifndef STB_VORBIS_CODEBOOK_SHORTS
#define STB_VORBIS_CODEBOOK_FLOATS
#endif
// STB_VORBIS_DIVIDE_TABLE
// this replaces small integer divides in the floor decode loop with
// table lookups. made less than 1% difference, so disabled by default.
// STB_VORBIS_NO_INLINE_DECODE
// disables the inlining of the scalar codebook fast-huffman decode.
// might save a little codespace; useful for debugging
// #define STB_VORBIS_NO_INLINE_DECODE
// STB_VORBIS_NO_DEFER_FLOOR
// Normally we only decode the floor without synthesizing the actual
// full curve. We can instead synthesize the curve immediately. This
// requires more memory and is very likely slower, so I don't think
// you'd ever want to do it except for debugging.
// #define STB_VORBIS_NO_DEFER_FLOOR
//////////////////////////////////////////////////////////////////////////////
#ifdef STB_VORBIS_NO_PULLDATA_API
#define STB_VORBIS_NO_INTEGER_CONVERSION
#define STB_VORBIS_NO_STDIO
#endif
#if defined(STB_VORBIS_NO_CRT) && !defined(STB_VORBIS_NO_STDIO)
#define STB_VORBIS_NO_STDIO 1
#endif
#ifndef STB_VORBIS_NO_INTEGER_CONVERSION
#ifndef STB_VORBIS_NO_FAST_SCALED_FLOAT
// only need endianness for fast-float-to-int, which we don't
// use for pushdata
#ifndef STB_VORBIS_BIG_ENDIAN
#define STB_VORBIS_ENDIAN 0
#else
#define STB_VORBIS_ENDIAN 1
#endif
#endif
#endif
#ifndef STB_VORBIS_NO_STDIO
#include <stdio.h>
#endif
#ifndef STB_VORBIS_NO_CRT
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <math.h>
#if !(defined(__APPLE__) || defined(MACOSX) || defined(macintosh) || defined(Macintosh))
#include <malloc.h>
#endif
#else
#define NULL 0
#endif
#ifndef _MSC_VER
#if __GNUC__
#define __forceinline inline
#else
#define __forceinline
#endif
#endif
#if STB_VORBIS_MAX_CHANNELS > 256
#error "Value of STB_VORBIS_MAX_CHANNELS outside of allowed range"
#endif
#if STB_VORBIS_FAST_HUFFMAN_LENGTH > 24
#error "Value of STB_VORBIS_FAST_HUFFMAN_LENGTH outside of allowed range"
#endif
#define MAX_BLOCKSIZE_LOG 13 // from specification
#define MAX_BLOCKSIZE (1 << MAX_BLOCKSIZE_LOG)
typedef unsigned char uint8;
typedef signed char int8;
typedef unsigned short uint16;
typedef signed short int16;
typedef unsigned int uint32;
typedef signed int int32;
#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif
#ifdef STB_VORBIS_CODEBOOK_FLOATS
typedef float codetype;
#else
typedef uint16 codetype;
#endif
// @NOTE
//
// Some arrays below are tagged "//varies", which means it's actually
// a variable-sized piece of data, but rather than malloc I assume it's
// small enough it's better to just allocate it all together with the
// main thing
//
// Most of the variables are specified with the smallest size I could pack
// them into. It might give better performance to make them all full-sized
// integers. It should be safe to freely rearrange the structures or change
// the sizes larger--nothing relies on silently truncating etc., nor the
// order of variables.
#define FAST_HUFFMAN_TABLE_SIZE (1 << STB_VORBIS_FAST_HUFFMAN_LENGTH)
#define FAST_HUFFMAN_TABLE_MASK (FAST_HUFFMAN_TABLE_SIZE - 1)
typedef struct
{
int dimensions, entries;
uint8 *codeword_lengths;
float minimum_value;
float delta_value;
uint8 value_bits;
uint8 lookup_type;
uint8 sequence_p;
uint8 sparse;
uint32 lookup_values;
codetype *multiplicands;
uint32 *codewords;
#ifdef STB_VORBIS_FAST_HUFFMAN_SHORT
int16 fast_huffman[FAST_HUFFMAN_TABLE_SIZE];
#else
int32 fast_huffman[FAST_HUFFMAN_TABLE_SIZE];
#endif
uint32 *sorted_codewords;
int *sorted_values;
int sorted_entries;
} Codebook;
typedef struct
{
uint8 order;
uint16 rate;
uint16 bark_map_size;
uint8 amplitude_bits;
uint8 amplitude_offset;
uint8 number_of_books;
uint8 book_list[16]; // varies
} Floor0;
typedef struct
{
uint8 partitions;
uint8 partition_class_list[32]; // varies
uint8 class_dimensions[16]; // varies
uint8 class_subclasses[16]; // varies
uint8 class_masterbooks[16]; // varies
int16 subclass_books[16][8]; // varies
uint16 Xlist[31*8+2]; // varies
uint8 sorted_order[31*8+2];
uint8 neighbors[31*8+2][2];
uint8 floor1_multiplier;
uint8 rangebits;
int values;
} Floor1;
typedef union
{
Floor0 floor0;
Floor1 floor1;
} Floor;
typedef struct
{
uint32 begin, end;
uint32 part_size;
uint8 classifications;
uint8 classbook;
uint8 **classdata;
int16 (*residue_books)[8];
} Residue;
typedef struct
{
uint8 magnitude;
uint8 angle;
uint8 mux;
} MappingChannel;
typedef struct
{
uint16 coupling_steps;
MappingChannel *chan;
uint8 submaps;
uint8 submap_floor[15]; // varies
uint8 submap_residue[15]; // varies
} Mapping;
typedef struct
{
uint8 blockflag;
uint8 mapping;
uint16 windowtype;
uint16 transformtype;
} Mode;
typedef struct
{
uint32 goal_crc; // expected crc if match
int bytes_left; // bytes left in packet
uint32 crc_so_far; // running crc
int bytes_done; // bytes processed in _current_ chunk
uint32 sample_loc; // granule pos encoded in page
} CRCscan;
typedef struct
{
uint32 page_start, page_end;
uint32 after_previous_page_start;
uint32 first_decoded_sample;
uint32 last_decoded_sample;
} ProbedPage;
struct stb_vorbis
{
// user-accessible info
unsigned int sample_rate;
int channels;
unsigned int setup_memory_required;
unsigned int temp_memory_required;
unsigned int setup_temp_memory_required;
// input config
#ifndef STB_VORBIS_NO_STDIO
FILE *f;
uint32 f_start;
int close_on_free;
#endif
uint8 *stream;
uint8 *stream_start;
uint8 *stream_end;
uint32 stream_len;
uint8 push_mode;
uint32 first_audio_page_offset;
ProbedPage p_first, p_last;
// memory management
stb_vorbis_alloc alloc;
int setup_offset;
int temp_offset;
// run-time results
int eof;
enum STBVorbisError error;
// user-useful data
// header info
int blocksize[2];
int blocksize_0, blocksize_1;
int codebook_count;
Codebook *codebooks;
int floor_count;
uint16 floor_types[64]; // varies
Floor *floor_config;
int residue_count;
uint16 residue_types[64]; // varies
Residue *residue_config;
int mapping_count;
Mapping *mapping;
int mode_count;
Mode mode_config[64]; // varies
uint32 total_samples;
// decode buffer
float *channel_buffers[STB_VORBIS_MAX_CHANNELS];
float *outputs [STB_VORBIS_MAX_CHANNELS];
float *previous_window[STB_VORBIS_MAX_CHANNELS];
int previous_length;
#ifndef STB_VORBIS_NO_DEFER_FLOOR
int16 *finalY[STB_VORBIS_MAX_CHANNELS];
#else
float *floor_buffers[STB_VORBIS_MAX_CHANNELS];
#endif
uint32 current_loc; // sample location of next frame to decode
int current_loc_valid;
// per-blocksize precomputed data
// twiddle factors
float *A[2],*B[2],*C[2];
float *window[2];
uint16 *bit_reverse[2];
// current page/packet/segment streaming info
uint32 serial; // stream serial number for verification
int last_page;
int segment_count;
uint8 segments[255];
uint8 page_flag;
uint8 bytes_in_seg;
uint8 first_decode;
int next_seg;
int last_seg; // flag that we're on the last segment
int last_seg_which; // what was the segment number of the last seg?
uint32 acc;
int valid_bits;
int packet_bytes;
int end_seg_with_known_loc;
uint32 known_loc_for_packet;
int discard_samples_deferred;
uint32 samples_output;
// push mode scanning
int page_crc_tests; // only in push_mode: number of tests active; -1 if not searching
#ifndef STB_VORBIS_NO_PUSHDATA_API
CRCscan scan[STB_VORBIS_PUSHDATA_CRC_COUNT];
#endif
// sample-access
int channel_buffer_start;
int channel_buffer_end;
};
extern int my_prof(int slot);
//#define stb_prof my_prof
#ifndef stb_prof
#define stb_prof(x) 0
#endif
#if defined(STB_VORBIS_NO_PUSHDATA_API)
#define IS_PUSH_MODE(f) FALSE
#elif defined(STB_VORBIS_NO_PULLDATA_API)
#define IS_PUSH_MODE(f) TRUE
#else
#define IS_PUSH_MODE(f) ((f)->push_mode)
#endif
typedef struct stb_vorbis vorb;
static int error(vorb *f, enum STBVorbisError e)
{
f->error = e;
if (!f->eof && e != VORBIS_need_more_data) {
f->error=e; // breakpoint for debugging
}
return 0;
}
// these functions are used for allocating temporary memory
// while decoding. if you can afford the stack space, use
// alloca(); otherwise, provide a temp buffer and it will
// allocate out of those.
#define array_size_required(count,size) (count*(sizeof(void *)+(size)))
#define temp_alloc(f,size) (f->alloc.alloc_buffer ? setup_temp_malloc(f,size) : alloca(size))
#ifdef dealloca
#define temp_free(f,p) (f->alloc.alloc_buffer ? 0 : dealloca(size))
#else
#define temp_free(f,p) 0
#endif
#define temp_alloc_save(f) ((f)->temp_offset)
#define temp_alloc_restore(f,p) ((f)->temp_offset = (p))
#define temp_block_array(f,count,size) make_block_array(temp_alloc(f,array_size_required(count,size)), count, size)
// given a sufficiently large block of memory, make an array of pointers to subblocks of it
static void *make_block_array(void *mem, int count, int size)
{
int i;
void ** p = (void **) mem;
char *q = (char *) (p + count);
for (i=0; i < count; ++i) {
p[i] = q;
q += size;
}
return p;
}
static void *setup_malloc(vorb *f, int sz)
{
sz = (sz+3) & ~3;
f->setup_memory_required += sz;
if (f->alloc.alloc_buffer) {
void *p = (char *) f->alloc.alloc_buffer + f->setup_offset;
if (f->setup_offset + sz > f->temp_offset) return NULL;
f->setup_offset += sz;
return p;
}
return sz ? malloc(sz) : NULL;
}
static void setup_free(vorb *f, void *p)
{
if (f->alloc.alloc_buffer) return; // do nothing; setup mem is not a stack
free(p);
}
static void *setup_temp_malloc(vorb *f, int sz)
{
sz = (sz+3) & ~3;
if (f->alloc.alloc_buffer) {
if (f->temp_offset - sz < f->setup_offset) return NULL;
f->temp_offset -= sz;
return (char *) f->alloc.alloc_buffer + f->temp_offset;
}
return malloc(sz);
}
static void setup_temp_free(vorb *f, void *p, size_t sz)
{
if (f->alloc.alloc_buffer) {
f->temp_offset += (sz+3)&~3;
return;
}
free(p);
}
#define CRC32_POLY 0x04c11db7 // from spec
static uint32 crc_table[256];
static void crc32_init(void)
{
int i,j;
uint32 s;
for(i=0; i < 256; i++) {
for (s=i<<24, j=0; j < 8; ++j)
s = (s << 1) ^ (s >= (1<<31) ? CRC32_POLY : 0);
crc_table[i] = s;
}
}
static __forceinline uint32 crc32_update(uint32 crc, uint8 byte)
{
return (crc << 8) ^ crc_table[byte ^ (crc >> 24)];
}
// used in setup, and for huffman that doesn't go fast path
static unsigned int bit_reverse(unsigned int n)
{
n = ((n & 0xAAAAAAAA) >> 1) | ((n & 0x55555555) << 1);
n = ((n & 0xCCCCCCCC) >> 2) | ((n & 0x33333333) << 2);
n = ((n & 0xF0F0F0F0) >> 4) | ((n & 0x0F0F0F0F) << 4);
n = ((n & 0xFF00FF00) >> 8) | ((n & 0x00FF00FF) << 8);
return (n >> 16) | (n << 16);
}
static float square(float x)
{
return x*x;
}
// this is a weird definition of log2() for which log2(1) = 1, log2(2) = 2, log2(4) = 3
// as required by the specification. fast(?) implementation from stb.h
// @OPTIMIZE: called multiple times per-packet with "constants"; move to setup
static int ilog(int32 n)
{
static signed char log2_4[16] = { 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4 };
// 2 compares if n < 16, 3 compares otherwise (4 if signed or n > 1<<29)
if (n < (1U << 14))
if (n < (1U << 4)) return 0 + log2_4[n ];
else if (n < (1U << 9)) return 5 + log2_4[n >> 5];
else return 10 + log2_4[n >> 10];
else if (n < (1U << 24))
if (n < (1U << 19)) return 15 + log2_4[n >> 15];
else return 20 + log2_4[n >> 20];
else if (n < (1U << 29)) return 25 + log2_4[n >> 25];
else if (n < (1U << 31)) return 30 + log2_4[n >> 30];
else return 0; // signed n returns 0
}
#ifndef M_PI
#define M_PI 3.14159265358979323846264f // from CRC
#endif
// code length assigned to a value with no huffman encoding
#define NO_CODE 255
/////////////////////// LEAF SETUP FUNCTIONS //////////////////////////
//
// these functions are only called at setup, and only a few times
// per file
static float float32_unpack(uint32 x)
{
// from the specification
uint32 mantissa = x & 0x1fffff;
uint32 sign = x & 0x80000000;
uint32 exp = (x & 0x7fe00000) >> 21;
double res = sign ? -(double)mantissa : (double)mantissa;
return (float) ldexp((float)res, exp-788);
}
// zlib & jpeg huffman tables assume that the output symbols
// can either be arbitrarily arranged, or have monotonically
// increasing frequencies--they rely on the lengths being sorted;
// this makes for a very simple generation algorithm.
// vorbis allows a huffman table with non-sorted lengths. This
// requires a more sophisticated construction, since symbols in
// order do not map to huffman codes "in order".
static void add_entry(Codebook *c, uint32 huff_code, int symbol, int count, int len, uint32 *values)
{
if (!c->sparse) {
c->codewords [symbol] = huff_code;
} else {
c->codewords [count] = huff_code;
c->codeword_lengths[count] = len;
values [count] = symbol;
}
}
static int compute_codewords(Codebook *c, uint8 *len, int n, uint32 *values)
{
int i,k,m=0;
uint32 available[32];
memset(available, 0, sizeof(available));
// find the first entry
for (k=0; k < n; ++k) if (len[k] < NO_CODE) break;
if (k == n) { assert(c->sorted_entries == 0); return TRUE; }
// add to the list
add_entry(c, 0, k, m++, len[k], values);
// add all available leaves
for (i=1; i <= len[k]; ++i)
available[i] = 1 << (32-i);
// note that the above code treats the first case specially,
// but it's really the same as the following code, so they
// could probably be combined (except the initial code is 0,
// and I use 0 in available[] to mean 'empty')
for (i=k+1; i < n; ++i) {
uint32 res;
int z = len[i], y;
if (z == NO_CODE) continue;
// find lowest available leaf (should always be earliest,
// which is what the specification calls for)
// note that this property, and the fact we can never have
// more than one free leaf at a given level, isn't totally
// trivial to prove, but it seems true and the assert never
// fires, so!
while (z > 0 && !available[z]) --z;
if (z == 0) { assert(0); return FALSE; }
res = available[z];
available[z] = 0;
add_entry(c, bit_reverse(res), i, m++, len[i], values);
// propogate availability up the tree
if (z != len[i]) {
for (y=len[i]; y > z; --y) {
assert(available[y] == 0);
available[y] = res + (1 << (32-y));
}
}
}
return TRUE;
}
// accelerated huffman table allows fast O(1) match of all symbols
// of length <= STB_VORBIS_FAST_HUFFMAN_LENGTH
static void compute_accelerated_huffman(Codebook *c)
{
int i, len;
for (i=0; i < FAST_HUFFMAN_TABLE_SIZE; ++i)
c->fast_huffman[i] = -1;
len = c->sparse ? c->sorted_entries : c->entries;
#ifdef STB_VORBIS_FAST_HUFFMAN_SHORT
if (len > 32767) len = 32767; // largest possible value we can encode!
#endif
for (i=0; i < len; ++i) {
if (c->codeword_lengths[i] <= STB_VORBIS_FAST_HUFFMAN_LENGTH) {
uint32 z = c->sparse ? bit_reverse(c->sorted_codewords[i]) : c->codewords[i];
// set table entries for all bit combinations in the higher bits
while (z < FAST_HUFFMAN_TABLE_SIZE) {
c->fast_huffman[z] = i;
z += 1 << c->codeword_lengths[i];
}
}
}
}
static int uint32_compare(const void *p, const void *q)
{
uint32 x = * (uint32 *) p;
uint32 y = * (uint32 *) q;
return x < y ? -1 : x > y;
}
static int include_in_sort(Codebook *c, uint8 len)
{
if (c->sparse) { assert(len != NO_CODE); return TRUE; }
if (len == NO_CODE) return FALSE;
if (len > STB_VORBIS_FAST_HUFFMAN_LENGTH) return TRUE;
return FALSE;
}
// if the fast table above doesn't work, we want to binary
// search them... need to reverse the bits
static void compute_sorted_huffman(Codebook *c, uint8 *lengths, uint32 *values)
{
int i, len;
// build a list of all the entries
// OPTIMIZATION: don't include the short ones, since they'll be caught by FAST_HUFFMAN.
// this is kind of a frivolous optimization--I don't see any performance improvement,
// but it's like 4 extra lines of code, so.
if (!c->sparse) {
int k = 0;
for (i=0; i < c->entries; ++i)
if (include_in_sort(c, lengths[i]))
c->sorted_codewords[k++] = bit_reverse(c->codewords[i]);
assert(k == c->sorted_entries);
} else {
for (i=0; i < c->sorted_entries; ++i)
c->sorted_codewords[i] = bit_reverse(c->codewords[i]);
}
qsort(c->sorted_codewords, c->sorted_entries, sizeof(c->sorted_codewords[0]), uint32_compare);
c->sorted_codewords[c->sorted_entries] = 0xffffffff;
len = c->sparse ? c->sorted_entries : c->entries;
// now we need to indicate how they correspond; we could either
// #1: sort a different data structure that says who they correspond to
// #2: for each sorted entry, search the original list to find who corresponds
// #3: for each original entry, find the sorted entry
// #1 requires extra storage, #2 is slow, #3 can use binary search!
for (i=0; i < len; ++i) {
int huff_len = c->sparse ? lengths[values[i]] : lengths[i];
if (include_in_sort(c,huff_len)) {
uint32 code = bit_reverse(c->codewords[i]);
int x=0, n=c->sorted_entries;
while (n > 1) {
// invariant: sc[x] <= code < sc[x+n]
int m = x + (n >> 1);
if (c->sorted_codewords[m] <= code) {
x = m;
n -= (n>>1);
} else {
n >>= 1;
}
}
assert(c->sorted_codewords[x] == code);
if (c->sparse) {
c->sorted_values[x] = values[i];
c->codeword_lengths[x] = huff_len;
} else {
c->sorted_values[x] = i;
}
}
}
}
// only run while parsing the header (3 times)
static int vorbis_validate(uint8 *data)
{
static uint8 vorbis[6] = { 'v', 'o', 'r', 'b', 'i', 's' };
return memcmp(data, vorbis, 6) == 0;
}
// called from setup only, once per code book
// (formula implied by specification)
static int lookup1_values(int entries, int dim)
{
int r = (int) floor(exp((float) log((float) entries) / dim));
if ((int) floor(pow((float) r+1, dim)) <= entries) // (int) cast for MinGW warning;
++r; // floor() to avoid _ftol() when non-CRT
assert(pow((float) r+1, dim) > entries);
assert((int) floor(pow((float) r, dim)) <= entries); // (int),floor() as above
return r;
}
// called twice per file
static void compute_twiddle_factors(int n, float *A, float *B, float *C)
{
int n4 = n >> 2, n8 = n >> 3;
int k,k2;
for (k=k2=0; k < n4; ++k,k2+=2) {
A[k2 ] = (float) cos(4*k*M_PI/n);
A[k2+1] = (float) -sin(4*k*M_PI/n);
B[k2 ] = (float) cos((k2+1)*M_PI/n/2) * 0.5f;
B[k2+1] = (float) sin((k2+1)*M_PI/n/2) * 0.5f;
}
for (k=k2=0; k < n8; ++k,k2+=2) {
C[k2 ] = (float) cos(2*(k2+1)*M_PI/n);
C[k2+1] = (float) -sin(2*(k2+1)*M_PI/n);
}
}
static void compute_window(int n, float *window)
{
int n2 = n >> 1, i;
for (i=0; i < n2; ++i)
window[i] = (float) sin(0.5 * M_PI * square((float) sin((i - 0 + 0.5) / n2 * 0.5 * M_PI)));
}
static void compute_bitreverse(int n, uint16 *rev)
{
int ld = ilog(n) - 1; // ilog is off-by-one from normal definitions
int i, n8 = n >> 3;
for (i=0; i < n8; ++i)
rev[i] = (bit_reverse(i) >> (32-ld+3)) << 2;
}
static int init_blocksize(vorb *f, int b, int n)
{
int n2 = n >> 1, n4 = n >> 2, n8 = n >> 3;
f->A[b] = (float *) setup_malloc(f, sizeof(float) * n2);
f->B[b] = (float *) setup_malloc(f, sizeof(float) * n2);
f->C[b] = (float *) setup_malloc(f, sizeof(float) * n4);
if (!f->A[b] || !f->B[b] || !f->C[b]) return error(f, VORBIS_outofmem);
compute_twiddle_factors(n, f->A[b], f->B[b], f->C[b]);
f->window[b] = (float *) setup_malloc(f, sizeof(float) * n2);
if (!f->window[b]) return error(f, VORBIS_outofmem);
compute_window(n, f->window[b]);
f->bit_reverse[b] = (uint16 *) setup_malloc(f, sizeof(uint16) * n8);
if (!f->bit_reverse[b]) return error(f, VORBIS_outofmem);
compute_bitreverse(n, f->bit_reverse[b]);
return TRUE;
}
static void neighbors(uint16 *x, int n, int *plow, int *phigh)
{
int low = -1;
int high = 65536;
int i;
for (i=0; i < n; ++i) {
if (x[i] > low && x[i] < x[n]) { *plow = i; low = x[i]; }
if (x[i] < high && x[i] > x[n]) { *phigh = i; high = x[i]; }
}
}
// this has been repurposed so y is now the original index instead of y
typedef struct
{
uint16 x,y;
} Point;
int point_compare(const void *p, const void *q)
{
Point *a = (Point *) p;
Point *b = (Point *) q;
return a->x < b->x ? -1 : a->x > b->x;
}
//
/////////////////////// END LEAF SETUP FUNCTIONS //////////////////////////
#if defined(STB_VORBIS_NO_STDIO)
#define USE_MEMORY(z) TRUE
#else
#define USE_MEMORY(z) ((z)->stream)
#endif
static uint8 get8(vorb *z)
{
if (USE_MEMORY(z)) {
if (z->stream >= z->stream_end) { z->eof = TRUE; return 0; }
return *z->stream++;
}
#ifndef STB_VORBIS_NO_STDIO
{
int c = fgetc(z->f);
if (c == EOF) { z->eof = TRUE; return 0; }
return c;
}
#endif
}
static uint32 get32(vorb *f)
{
uint32 x;
x = get8(f);
x += get8(f) << 8;
x += get8(f) << 16;
x += get8(f) << 24;
return x;
}
static int getn(vorb *z, uint8 *data, int n)
{
if (USE_MEMORY(z)) {
if (z->stream+n > z->stream_end) { z->eof = 1; return 0; }
memcpy(data, z->stream, n);
z->stream += n;
return 1;
}
#ifndef STB_VORBIS_NO_STDIO
if (fread(data, n, 1, z->f) == 1)
return 1;
else {
z->eof = 1;
return 0;
}
#endif
}
static void skip(vorb *z, int n)
{
if (USE_MEMORY(z)) {
z->stream += n;
if (z->stream >= z->stream_end) z->eof = 1;
return;
}
#ifndef STB_VORBIS_NO_STDIO
{
long x = ftell(z->f);
fseek(z->f, x+n, SEEK_SET);
}
#endif
}
static int set_file_offset(stb_vorbis *f, unsigned int loc)
{
#ifndef STB_VORBIS_NO_PUSHDATA_API
if (f->push_mode) return 0;
#endif
f->eof = 0;
if (USE_MEMORY(f)) {
if (f->stream_start + loc >= f->stream_end || f->stream_start + loc < f->stream_start) {
f->stream = f->stream_end;
f->eof = 1;
return 0;
} else {
f->stream = f->stream_start + loc;
return 1;
}
}
#ifndef STB_VORBIS_NO_STDIO
if (loc + f->f_start < loc || loc >= 0x80000000) {
loc = 0x7fffffff;
f->eof = 1;
} else {
loc += f->f_start;
}
if (!fseek(f->f, loc, SEEK_SET))