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dr_mp3.h
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dr_mp3.h
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// MP3 audio decoder. Public domain. See "unlicense" statement at the end of this file.
// dr_mp3 - v0.4.1 - 2018-12-30
//
// David Reid - [email protected]
//
// Based off minimp3 (https://github.com/lieff/minimp3) which is where the real work was done. See the bottom of this file for
// differences between minimp3 and dr_mp3.
// USAGE
// =====
// dr_mp3 is a single-file library. To use it, do something like the following in one .c file.
// #define DR_MP3_IMPLEMENTATION
// #include "dr_mp3.h"
//
// You can then #include this file in other parts of the program as you would with any other header file. To decode audio data,
// do something like the following:
//
// drmp3 mp3;
// if (!drmp3_init_file(&mp3, "MySong.mp3", NULL)) {
// // Failed to open file
// }
//
// ...
//
// drmp3_uint64 framesRead = drmp3_read_pcm_frames_f32(pMP3, framesToRead, pFrames);
//
// The drmp3 object is transparent so you can get access to the channel count and sample rate like so:
//
// drmp3_uint32 channels = mp3.channels;
// drmp3_uint32 sampleRate = mp3.sampleRate;
//
// The third parameter of drmp3_init_file() in the example above allows you to control the output channel count and sample rate. It
// is a pointer to a drmp3_config object. Setting any of the variables of this object to 0 will cause dr_mp3 to use defaults.
//
// The example above initializes a decoder from a file, but you can also initialize it from a block of memory and read and seek
// callbacks with drmp3_init_memory() and drmp3_init() respectively.
//
// You do not need to do any annoying memory management when reading PCM frames - this is all managed internally. You can request
// any number of PCM frames in each call to drmp3_read_pcm_frames_f32() and it will return as many PCM frames as it can, up to the
// requested amount.
//
// You can also decode an entire file in one go with drmp3_open_and_read_f32(), drmp3_open_memory_and_read_f32() and
// drmp3_open_file_and_read_f32().
//
//
// OPTIONS
// =======
// #define these options before including this file.
//
// #define DR_MP3_NO_STDIO
// Disable drmp3_init_file(), etc.
//
// #define DR_MP3_NO_SIMD
// Disable SIMD optimizations.
#ifndef dr_mp3_h
#define dr_mp3_h
#ifdef __cplusplus
extern "C" {
#endif
#include <stddef.h>
#if defined(_MSC_VER) && _MSC_VER < 1600
typedef signed char drmp3_int8;
typedef unsigned char drmp3_uint8;
typedef signed short drmp3_int16;
typedef unsigned short drmp3_uint16;
typedef signed int drmp3_int32;
typedef unsigned int drmp3_uint32;
typedef signed __int64 drmp3_int64;
typedef unsigned __int64 drmp3_uint64;
#else
#include <stdint.h>
typedef int8_t drmp3_int8;
typedef uint8_t drmp3_uint8;
typedef int16_t drmp3_int16;
typedef uint16_t drmp3_uint16;
typedef int32_t drmp3_int32;
typedef uint32_t drmp3_uint32;
typedef int64_t drmp3_int64;
typedef uint64_t drmp3_uint64;
#endif
typedef drmp3_uint8 drmp3_bool8;
typedef drmp3_uint32 drmp3_bool32;
#define DRMP3_TRUE 1
#define DRMP3_FALSE 0
#define DRMP3_MAX_PCM_FRAMES_PER_MP3_FRAME 1152
#define DRMP3_MAX_SAMPLES_PER_FRAME (DRMP3_MAX_PCM_FRAMES_PER_MP3_FRAME*2)
// Low Level Push API
// ==================
typedef struct {
int frame_bytes, channels, hz, layer, bitrate_kbps;
} drmp3dec_frame_info;
typedef struct {
float mdct_overlap[2][9 * 32], qmf_state[15 * 2 * 32];
int reserv, free_format_bytes;
unsigned char header[4], reserv_buf[511];
} drmp3dec;
// Initializes a low level decoder.
void drmp3dec_init(drmp3dec *dec);
// Reads a frame from a low level decoder.
int drmp3dec_decode_frame(drmp3dec *dec, const unsigned char *mp3, int mp3_bytes, void *pcm, drmp3dec_frame_info *info);
// Helper for converting between f32 and s16.
void drmp3dec_f32_to_s16(const float *in, drmp3_int16 *out, int num_samples);
// Main API (Pull API)
// ===================
typedef struct drmp3_src drmp3_src;
typedef drmp3_uint64 (*drmp3_src_read_proc)(drmp3_src *pSRC, drmp3_uint64 frameCount, void *pFramesOut,
void *pUserData); // Returns the number of frames that were read.
typedef enum {
drmp3_src_algorithm_none,
drmp3_src_algorithm_linear
} drmp3_src_algorithm;
#define DRMP3_SRC_CACHE_SIZE_IN_FRAMES 512
typedef struct {
drmp3_src *pSRC;
float pCachedFrames[2 * DRMP3_SRC_CACHE_SIZE_IN_FRAMES];
drmp3_uint32 cachedFrameCount;
drmp3_uint32 iNextFrame;
} drmp3_src_cache;
typedef struct {
drmp3_uint32 sampleRateIn;
drmp3_uint32 sampleRateOut;
drmp3_uint32 channels;
drmp3_src_algorithm algorithm;
drmp3_uint32 cacheSizeInFrames; // The number of frames to read from the client at a time.
} drmp3_src_config;
struct drmp3_src {
drmp3_src_config config;
drmp3_src_read_proc onRead;
void *pUserData;
float bin[256];
drmp3_src_cache cache; // <-- For simplifying and optimizing client -> memory reading.
union {
struct {
double alpha;
drmp3_bool32 isPrevFramesLoaded : 1;
drmp3_bool32 isNextFramesLoaded : 1;
} linear;
} algo;
};
typedef enum {
drmp3_seek_origin_start,
drmp3_seek_origin_current
} drmp3_seek_origin;
typedef struct {
drmp3_uint64 seekPosInBytes; // Points to the first byte of an MP3 frame.
drmp3_uint64 pcmFrameIndex; // The index of the PCM frame this seek point targets.
drmp3_uint16 mp3FramesToDiscard; // The number of whole MP3 frames to be discarded before pcmFramesToDiscard.
drmp3_uint16 pcmFramesToDiscard; // The number of leading samples to read and discard. These are discarded after mp3FramesToDiscard.
} drmp3_seek_point;
// Callback for when data is read. Return value is the number of bytes actually read.
//
// pUserData [in] The user data that was passed to drmp3_init(), drmp3_open() and family.
// pBufferOut [out] The output buffer.
// bytesToRead [in] The number of bytes to read.
//
// Returns the number of bytes actually read.
//
// A return value of less than bytesToRead indicates the end of the stream. Do _not_ return from this callback until
// either the entire bytesToRead is filled or you have reached the end of the stream.
typedef size_t (*drmp3_read_proc)(void *pUserData, void *pBufferOut, size_t bytesToRead);
// Callback for when data needs to be seeked.
//
// pUserData [in] The user data that was passed to drmp3_init(), drmp3_open() and family.
// offset [in] The number of bytes to move, relative to the origin. Will never be negative.
// origin [in] The origin of the seek - the current position or the start of the stream.
//
// Returns whether or not the seek was successful.
//
// Whether or not it is relative to the beginning or current position is determined by the "origin" parameter which
// will be either drmp3_seek_origin_start or drmp3_seek_origin_current.
typedef drmp3_bool32 (*drmp3_seek_proc)(void *pUserData, int offset, drmp3_seek_origin origin);
typedef struct {
drmp3_uint32 outputChannels;
drmp3_uint32 outputSampleRate;
} drmp3_config;
typedef struct {
drmp3dec decoder;
drmp3dec_frame_info frameInfo;
drmp3_uint32 channels;
drmp3_uint32 sampleRate;
drmp3_read_proc onRead;
drmp3_seek_proc onSeek;
void *pUserData;
drmp3_uint32 mp3FrameChannels; // The number of channels in the currently loaded MP3 frame. Internal use only.
drmp3_uint32 mp3FrameSampleRate; // The sample rate of the currently loaded MP3 frame. Internal use only.
drmp3_uint32 pcmFramesConsumedInMP3Frame;
drmp3_uint32 pcmFramesRemainingInMP3Frame;
drmp3_uint8 pcmFrames[sizeof(float) *
DRMP3_MAX_SAMPLES_PER_FRAME]; // <-- Multipled by sizeof(float) to ensure there's enough room for DR_MP3_FLOAT_OUTPUT.
drmp3_uint64 currentPCMFrame; // The current PCM frame, globally, based on the output sample rate. Mainly used for seeking.
drmp3_uint64 streamCursor; // The current byte the decoder is sitting on in the raw stream.
drmp3_src src;
drmp3_seek_point *pSeekPoints; // NULL by default. Set with drmp3_bind_seek_table(). Memory is owned by the client. dr_mp3 will never attempt to free this pointer.
drmp3_uint32 seekPointCount; // The number of items in pSeekPoints. When set to 0 assumes to no seek table. Defaults to zero.
size_t dataSize;
size_t dataCapacity;
drmp3_uint8 *pData;
drmp3_bool32 atEnd : 1;
struct {
const drmp3_uint8 *pData;
size_t dataSize;
size_t currentReadPos;
} memory; // Only used for decoders that were opened against a block of memory.
} drmp3;
// Initializes an MP3 decoder.
//
// onRead [in] The function to call when data needs to be read from the client.
// onSeek [in] The function to call when the read position of the client data needs to move.
// pUserData [in, optional] A pointer to application defined data that will be passed to onRead and onSeek.
//
// Returns true if successful; false otherwise.
//
// Close the loader with drmp3_uninit().
//
// See also: drmp3_init_file(), drmp3_init_memory(), drmp3_uninit()
drmp3_bool32
drmp3_init(drmp3 *pMP3, drmp3_read_proc onRead, drmp3_seek_proc onSeek, void *pUserData, const drmp3_config *pConfig);
// Initializes an MP3 decoder from a block of memory.
//
// This does not create a copy of the data. It is up to the application to ensure the buffer remains valid for
// the lifetime of the drmp3 object.
//
// The buffer should contain the contents of the entire MP3 file.
drmp3_bool32 drmp3_init_memory(drmp3 *pMP3, const void *pData, size_t dataSize, const drmp3_config *pConfig);
#ifndef DR_MP3_NO_STDIO
// Initializes an MP3 decoder from a file.
//
// This holds the internal FILE object until drmp3_uninit() is called. Keep this in mind if you're caching drmp3
// objects because the operating system may restrict the number of file handles an application can have open at
// any given time.
drmp3_bool32 drmp3_init_file(drmp3 *pMP3, const char *filePath, const drmp3_config *pConfig);
#endif
// Uninitializes an MP3 decoder.
void drmp3_uninit(drmp3 *pMP3);
// Reads PCM frames as interleaved 32-bit IEEE floating point PCM.
//
// Note that framesToRead specifies the number of PCM frames to read, _not_ the number of MP3 frames.
drmp3_uint64 drmp3_read_pcm_frames_f32(drmp3 *pMP3, drmp3_uint64 framesToRead, float *pBufferOut);
// Seeks to a specific frame.
//
// Note that this is _not_ an MP3 frame, but rather a PCM frame.
drmp3_bool32 drmp3_seek_to_pcm_frame(drmp3 *pMP3, drmp3_uint64 frameIndex);
// Calculates the total number of PCM frames in the MP3 stream. Cannot be used for infinite streams such as internet
// radio. Runs in linear time. Returns 0 on error.
drmp3_uint64 drmp3_get_pcm_frame_count(drmp3 *pMP3);
// Calculates the total number of MP3 frames in the MP3 stream. Cannot be used for infinite streams such as internet
// radio. Runs in linear time. Returns 0 on error.
drmp3_uint64 drmp3_get_mp3_frame_count(drmp3 *pMP3);
// Calculates the seekpoints based on PCM frames. This is slow.
//
// pSeekpoint count is a pointer to a uint32 containing the seekpoint count. On input it contains the desired count.
// On output it contains the actual count. The reason for this design is that the client may request too many
// seekpoints, in which case dr_mp3 will return a corrected count.
//
// Note that seektable seeking is not quite sample exact when the MP3 stream contains inconsistent sample rates.
drmp3_bool32 drmp3_calculate_seek_points(drmp3 *pMP3, drmp3_uint32 *pSeekPointCount, drmp3_seek_point *pSeekPoints);
// Binds a seek table to the decoder.
//
// This does _not_ make a copy of pSeekPoints - it only references it. It is up to the application to ensure this
// remains valid while it is bound to the decoder.
//
// Use drmp3_calculate_seek_points() to calculate the seek points.
drmp3_bool32 drmp3_bind_seek_table(drmp3 *pMP3, drmp3_uint32 seekPointCount, drmp3_seek_point *pSeekPoints);
// Opens an decodes an entire MP3 stream as a single operation.
//
// pConfig is both an input and output. On input it contains what you want. On output it contains what you got.
//
// Free the returned pointer with drmp3_free().
float *drmp3_open_and_read_f32(drmp3_read_proc onRead, drmp3_seek_proc onSeek, void *pUserData, drmp3_config *pConfig,
drmp3_uint64 *pTotalFrameCount);
float *drmp3_open_memory_and_read_f32(const void *pData, size_t dataSize, drmp3_config *pConfig,
drmp3_uint64 *pTotalFrameCount);
#ifndef DR_MP3_NO_STDIO
float *drmp3_open_file_and_read_f32(const char *filePath, drmp3_config *pConfig, drmp3_uint64 *pTotalFrameCount);
#endif
// Frees any memory that was allocated by a public drmp3 API.
void drmp3_free(void *p);
#ifdef __cplusplus
}
#endif
#endif // dr_mp3_h
/////////////////////////////////////////////////////
//
// IMPLEMENTATION
//
/////////////////////////////////////////////////////
#ifdef DR_MP3_IMPLEMENTATION
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <limits.h> // For INT_MAX
// Disable SIMD when compiling with TCC for now.
#if defined(__TINYC__)
#define DR_MP3_NO_SIMD
#endif
#define DRMP3_OFFSET_PTR(p, offset) ((void*)((drmp3_uint8*)(p) + (offset)))
#define DRMP3_MAX_FREE_FORMAT_FRAME_SIZE 2304 /* more than ISO spec's */
#ifndef DRMP3_MAX_FRAME_SYNC_MATCHES
#define DRMP3_MAX_FRAME_SYNC_MATCHES 10
#endif
#define DRMP3_MAX_L3_FRAME_PAYLOAD_BYTES DRMP3_MAX_FREE_FORMAT_FRAME_SIZE /* MUST be >= 320000/8/32000*1152 = 1440 */
#define DRMP3_MAX_BITRESERVOIR_BYTES 511
#define DRMP3_SHORT_BLOCK_TYPE 2
#define DRMP3_STOP_BLOCK_TYPE 3
#define DRMP3_MODE_MONO 3
#define DRMP3_MODE_JOINT_STEREO 1
#define DRMP3_HDR_SIZE 4
#define DRMP3_HDR_IS_MONO(h) (((h[3]) & 0xC0) == 0xC0)
#define DRMP3_HDR_IS_MS_STEREO(h) (((h[3]) & 0xE0) == 0x60)
#define DRMP3_HDR_IS_FREE_FORMAT(h) (((h[2]) & 0xF0) == 0)
#define DRMP3_HDR_IS_CRC(h) (!((h[1]) & 1))
#define DRMP3_HDR_TEST_PADDING(h) ((h[2]) & 0x2)
#define DRMP3_HDR_TEST_MPEG1(h) ((h[1]) & 0x8)
#define DRMP3_HDR_TEST_NOT_MPEG25(h) ((h[1]) & 0x10)
#define DRMP3_HDR_TEST_I_STEREO(h) ((h[3]) & 0x10)
#define DRMP3_HDR_TEST_MS_STEREO(h) ((h[3]) & 0x20)
#define DRMP3_HDR_GET_STEREO_MODE(h) (((h[3]) >> 6) & 3)
#define DRMP3_HDR_GET_STEREO_MODE_EXT(h) (((h[3]) >> 4) & 3)
#define DRMP3_HDR_GET_LAYER(h) (((h[1]) >> 1) & 3)
#define DRMP3_HDR_GET_BITRATE(h) ((h[2]) >> 4)
#define DRMP3_HDR_GET_SAMPLE_RATE(h) (((h[2]) >> 2) & 3)
#define DRMP3_HDR_GET_MY_SAMPLE_RATE(h) (DRMP3_HDR_GET_SAMPLE_RATE(h) + (((h[1] >> 3) & 1) + ((h[1] >> 4) & 1))*3)
#define DRMP3_HDR_IS_FRAME_576(h) ((h[1] & 14) == 2)
#define DRMP3_HDR_IS_LAYER_1(h) ((h[1] & 6) == 6)
#define DRMP3_BITS_DEQUANTIZER_OUT -1
#define DRMP3_MAX_SCF (255 + DRMP3_BITS_DEQUANTIZER_OUT*4 - 210)
#define DRMP3_MAX_SCFI ((DRMP3_MAX_SCF + 3) & ~3)
#define DRMP3_MIN(a, b) ((a) > (b) ? (b) : (a))
#define DRMP3_MAX(a, b) ((a) < (b) ? (b) : (a))
#if !defined(DR_MP3_NO_SIMD)
#if !defined(DR_MP3_ONLY_SIMD) && (defined(_M_X64) || defined(_M_ARM64) || defined(__x86_64__) || defined(__aarch64__))
/* x64 always have SSE2, arm64 always have neon, no need for generic code */
#define DR_MP3_ONLY_SIMD
#endif
#if (defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))) || ((defined(__i386__) || defined(__x86_64__)) && defined(__SSE2__))
#if defined(_MSC_VER)
#include <intrin.h>
#endif
#include <emmintrin.h>
#define DRMP3_HAVE_SSE 1
#define DRMP3_HAVE_SIMD 1
#define DRMP3_VSTORE _mm_storeu_ps
#define DRMP3_VLD _mm_loadu_ps
#define DRMP3_VSET _mm_set1_ps
#define DRMP3_VADD _mm_add_ps
#define DRMP3_VSUB _mm_sub_ps
#define DRMP3_VMUL _mm_mul_ps
#define DRMP3_VMAC(a, x, y) _mm_add_ps(a, _mm_mul_ps(x, y))
#define DRMP3_VMSB(a, x, y) _mm_sub_ps(a, _mm_mul_ps(x, y))
#define DRMP3_VMUL_S(x, s) _mm_mul_ps(x, _mm_set1_ps(s))
#define DRMP3_VREV(x) _mm_shuffle_ps(x, x, _MM_SHUFFLE(0, 1, 2, 3))
typedef __m128 drmp3_f4;
#if defined(_MSC_VER) || defined(DR_MP3_ONLY_SIMD)
#define drmp3_cpuid __cpuid
#else
static __inline__ __attribute__((always_inline)) void drmp3_cpuid(int CPUInfo[], const int InfoType)
{
#if defined(__PIC__)
__asm__ __volatile__(
#if defined(__x86_64__)
"push %%rbx\n"
"cpuid\n"
"xchgl %%ebx, %1\n"
"pop %%rbx\n"
#else
"xchgl %%ebx, %1\n"
"cpuid\n"
"xchgl %%ebx, %1\n"
#endif
: "=a" (CPUInfo[0]), "=r" (CPUInfo[1]), "=c" (CPUInfo[2]), "=d" (CPUInfo[3])
: "a" (InfoType));
#else
__asm__ __volatile__(
"cpuid"
: "=a" (CPUInfo[0]), "=b" (CPUInfo[1]), "=c" (CPUInfo[2]), "=d" (CPUInfo[3])
: "a" (InfoType));
#endif
}
#endif
static int drmp3_have_simd() {
#ifdef DR_MP3_ONLY_SIMD
return 1;
#else
static int g_have_simd;
int CPUInfo[4];
#ifdef MINIMP3_TEST
static int g_counter;
if (g_counter++ > 100)
return 0;
#endif
if (g_have_simd)
goto end;
drmp3_cpuid(CPUInfo, 0);
if (CPUInfo[0] > 0)
{
drmp3_cpuid(CPUInfo, 1);
g_have_simd = (CPUInfo[3] & (1 << 26)) + 1; /* SSE2 */
return g_have_simd - 1;
}
end:
return g_have_simd - 1;
#endif
}
#elif defined(__ARM_NEON) || defined(__aarch64__)
#include <arm_neon.h>
#define DRMP3_HAVE_SIMD 1
#define DRMP3_VSTORE vst1q_f32
#define DRMP3_VLD vld1q_f32
#define DRMP3_VSET vmovq_n_f32
#define DRMP3_VADD vaddq_f32
#define DRMP3_VSUB vsubq_f32
#define DRMP3_VMUL vmulq_f32
#define DRMP3_VMAC(a, x, y) vmlaq_f32(a, x, y)
#define DRMP3_VMSB(a, x, y) vmlsq_f32(a, x, y)
#define DRMP3_VMUL_S(x, s) vmulq_f32(x, vmovq_n_f32(s))
#define DRMP3_VREV(x) vcombine_f32(vget_high_f32(vrev64q_f32(x)), vget_low_f32(vrev64q_f32(x)))
typedef float32x4_t drmp3_f4;
static int drmp3_have_simd()
{ /* TODO: detect neon for !DR_MP3_ONLY_SIMD */
return 1;
}
#else
#define DRMP3_HAVE_SIMD 0
#ifdef DR_MP3_ONLY_SIMD
#error DR_MP3_ONLY_SIMD used, but SSE/NEON not enabled
#endif
#endif
#else
#define DRMP3_HAVE_SIMD 0
#endif
typedef struct {
const drmp3_uint8 *buf;
int pos, limit;
} drmp3_bs;
typedef struct {
float scf[3 * 64];
drmp3_uint8 total_bands, stereo_bands, bitalloc[64], scfcod[64];
} drmp3_L12_scale_info;
typedef struct {
drmp3_uint8 tab_offset, code_tab_width, band_count;
} drmp3_L12_subband_alloc;
typedef struct {
const drmp3_uint8 *sfbtab;
drmp3_uint16 part_23_length, big_values, scalefac_compress;
drmp3_uint8 global_gain, block_type, mixed_block_flag, n_long_sfb, n_short_sfb;
drmp3_uint8 table_select[3], region_count[3], subblock_gain[3];
drmp3_uint8 preflag, scalefac_scale, count1_table, scfsi;
} drmp3_L3_gr_info;
typedef struct {
drmp3_bs bs;
drmp3_uint8 maindata[DRMP3_MAX_BITRESERVOIR_BYTES + DRMP3_MAX_L3_FRAME_PAYLOAD_BYTES];
drmp3_L3_gr_info gr_info[4];
float grbuf[2][576], scf[40], syn[18 + 15][2 * 32];
drmp3_uint8 ist_pos[2][39];
} drmp3dec_scratch;
static void drmp3_bs_init(drmp3_bs *bs, const drmp3_uint8 *data, int bytes) {
bs->buf = data;
bs->pos = 0;
bs->limit = bytes * 8;
}
static drmp3_uint32 drmp3_bs_get_bits(drmp3_bs *bs, int n) {
drmp3_uint32 next, cache = 0, s = bs->pos & 7;
int shl = n + s;
const drmp3_uint8 *p = bs->buf + (bs->pos >> 3);
if ((bs->pos += n) > bs->limit)
return 0;
next = *p++ & (255 >> s);
while ((shl -= 8) > 0) {
cache |= next << shl;
next = *p++;
}
return cache | (next >> -shl);
}
static int drmp3_hdr_valid(const drmp3_uint8 *h) {
return h[0] == 0xff &&
((h[1] & 0xF0) == 0xf0 || (h[1] & 0xFE) == 0xe2) &&
(DRMP3_HDR_GET_LAYER(h) != 0) &&
(DRMP3_HDR_GET_BITRATE(h) != 15) &&
(DRMP3_HDR_GET_SAMPLE_RATE(h) != 3);
}
static int drmp3_hdr_compare(const drmp3_uint8 *h1, const drmp3_uint8 *h2) {
return drmp3_hdr_valid(h2) &&
((h1[1] ^ h2[1]) & 0xFE) == 0 &&
((h1[2] ^ h2[2]) & 0x0C) == 0 &&
!(DRMP3_HDR_IS_FREE_FORMAT(h1) ^ DRMP3_HDR_IS_FREE_FORMAT(h2));
}
static unsigned drmp3_hdr_bitrate_kbps(const drmp3_uint8 *h) {
static const drmp3_uint8 halfrate[2][3][15] = {
{{0, 4, 8, 12, 16, 20, 24, 28, 32, 40, 48, 56, 64, 72, 80}, {0, 4, 8, 12, 16, 20, 24, 28, 32, 40, 48, 56, 64, 72, 80}, {0, 16, 24, 28, 32, 40, 48, 56, 64, 72, 80, 88, 96, 112, 128}},
{{0, 16, 20, 24, 28, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160}, {0, 16, 24, 28, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192}, {0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224}},
};
return 2 * halfrate[!!DRMP3_HDR_TEST_MPEG1(h)][DRMP3_HDR_GET_LAYER(h) - 1][DRMP3_HDR_GET_BITRATE(h)];
}
static unsigned drmp3_hdr_sample_rate_hz(const drmp3_uint8 *h) {
static const unsigned g_hz[3] = {44100, 48000, 32000};
return g_hz[DRMP3_HDR_GET_SAMPLE_RATE(h)] >> (int) !DRMP3_HDR_TEST_MPEG1(h) >> (int) !DRMP3_HDR_TEST_NOT_MPEG25(h);
}
static unsigned drmp3_hdr_frame_samples(const drmp3_uint8 *h) {
return DRMP3_HDR_IS_LAYER_1(h) ? 384 : (1152 >> (int) DRMP3_HDR_IS_FRAME_576(h));
}
static int drmp3_hdr_frame_bytes(const drmp3_uint8 *h, int free_format_size) {
int frame_bytes = drmp3_hdr_frame_samples(h) * drmp3_hdr_bitrate_kbps(h) * 125 / drmp3_hdr_sample_rate_hz(h);
if (DRMP3_HDR_IS_LAYER_1(h)) {
frame_bytes &= ~3; /* slot align */
}
return frame_bytes ? frame_bytes : free_format_size;
}
static int drmp3_hdr_padding(const drmp3_uint8 *h) {
return DRMP3_HDR_TEST_PADDING(h) ? (DRMP3_HDR_IS_LAYER_1(h) ? 4 : 1) : 0;
}
#ifndef DR_MP3_ONLY_MP3
static const drmp3_L12_subband_alloc *drmp3_L12_subband_alloc_table(const drmp3_uint8 *hdr, drmp3_L12_scale_info *sci) {
const drmp3_L12_subband_alloc *alloc;
int mode = DRMP3_HDR_GET_STEREO_MODE(hdr);
int nbands, stereo_bands = (mode == DRMP3_MODE_MONO) ? 0 : (mode == DRMP3_MODE_JOINT_STEREO) ?
(DRMP3_HDR_GET_STEREO_MODE_EXT(hdr) << 2) + 4 : 32;
if (DRMP3_HDR_IS_LAYER_1(hdr)) {
static const drmp3_L12_subband_alloc g_alloc_L1[] = {{76, 4, 32}};
alloc = g_alloc_L1;
nbands = 32;
} else if (!DRMP3_HDR_TEST_MPEG1(hdr)) {
static const drmp3_L12_subband_alloc g_alloc_L2M2[] = {{60, 4, 4},
{44, 3, 7},
{44, 2, 19}};
alloc = g_alloc_L2M2;
nbands = 30;
} else {
static const drmp3_L12_subband_alloc g_alloc_L2M1[] = {{0, 4, 3},
{16, 4, 8},
{32, 3, 12},
{40, 2, 7}};
int sample_rate_idx = DRMP3_HDR_GET_SAMPLE_RATE(hdr);
unsigned kbps = drmp3_hdr_bitrate_kbps(hdr) >> (int) (mode != DRMP3_MODE_MONO);
if (!kbps) /* free-format */
{
kbps = 192;
}
alloc = g_alloc_L2M1;
nbands = 27;
if (kbps < 56) {
static const drmp3_L12_subband_alloc g_alloc_L2M1_lowrate[] = {{44, 4, 2},
{44, 3, 10}};
alloc = g_alloc_L2M1_lowrate;
nbands = sample_rate_idx == 2 ? 12 : 8;
} else if (kbps >= 96 && sample_rate_idx != 1) {
nbands = 30;
}
}
sci->total_bands = (drmp3_uint8) nbands;
sci->stereo_bands = (drmp3_uint8) DRMP3_MIN(stereo_bands, nbands);
return alloc;
}
static void drmp3_L12_read_scalefactors(drmp3_bs *bs, drmp3_uint8 *pba, drmp3_uint8 *scfcod, int bands, float *scf) {
static const float g_deq_L12[18 * 3] = {
#define DRMP3_DQ(x) 9.53674316e-07f/x, 7.56931807e-07f/x, 6.00777173e-07f/x
DRMP3_DQ(3), DRMP3_DQ(7), DRMP3_DQ(15), DRMP3_DQ(31), DRMP3_DQ(63), DRMP3_DQ(127), DRMP3_DQ(255),
DRMP3_DQ(511), DRMP3_DQ(1023), DRMP3_DQ(2047), DRMP3_DQ(4095), DRMP3_DQ(8191), DRMP3_DQ(16383),
DRMP3_DQ(32767), DRMP3_DQ(65535), DRMP3_DQ(3), DRMP3_DQ(5), DRMP3_DQ(9)
};
int i, m;
for (i = 0; i < bands; i++) {
float s = 0;
int ba = *pba++;
int mask = ba ? 4 + ((19 >> scfcod[i]) & 3) : 0;
for (m = 4; m; m >>= 1) {
if (mask & m) {
int b = drmp3_bs_get_bits(bs, 6);
s = g_deq_L12[ba * 3 - 6 + b % 3] * (1 << 21 >> b / 3);
}
*scf++ = s;
}
}
}
static void drmp3_L12_read_scale_info(const drmp3_uint8 *hdr, drmp3_bs *bs, drmp3_L12_scale_info *sci) {
static const drmp3_uint8 g_bitalloc_code_tab[] = {
0, 17, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
0, 17, 18, 3, 19, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 16,
0, 17, 18, 3, 19, 4, 5, 16,
0, 17, 18, 16,
0, 17, 18, 19, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
0, 17, 18, 3, 19, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
};
const drmp3_L12_subband_alloc *subband_alloc = drmp3_L12_subband_alloc_table(hdr, sci);
int i, k = 0, ba_bits = 0;
const drmp3_uint8 *ba_code_tab = g_bitalloc_code_tab;
for (i = 0; i < sci->total_bands; i++) {
drmp3_uint8 ba;
if (i == k) {
k += subband_alloc->band_count;
ba_bits = subband_alloc->code_tab_width;
ba_code_tab = g_bitalloc_code_tab + subband_alloc->tab_offset;
subband_alloc++;
}
ba = ba_code_tab[drmp3_bs_get_bits(bs, ba_bits)];
sci->bitalloc[2 * i] = ba;
if (i < sci->stereo_bands) {
ba = ba_code_tab[drmp3_bs_get_bits(bs, ba_bits)];
}
sci->bitalloc[2 * i + 1] = sci->stereo_bands ? ba : 0;
}
for (i = 0; i < 2 * sci->total_bands; i++) {
sci->scfcod[i] = (drmp3_uint8) (sci->bitalloc[i] ? DRMP3_HDR_IS_LAYER_1(hdr) ? 2 : drmp3_bs_get_bits(bs, 2)
: 6);
}
drmp3_L12_read_scalefactors(bs, sci->bitalloc, sci->scfcod, sci->total_bands * 2, sci->scf);
for (i = sci->stereo_bands; i < sci->total_bands; i++) {
sci->bitalloc[2 * i + 1] = 0;
}
}
static int drmp3_L12_dequantize_granule(float *grbuf, drmp3_bs *bs, drmp3_L12_scale_info *sci, int group_size) {
int i, j, k, choff = 576;
for (j = 0; j < 4; j++) {
float *dst = grbuf + group_size * j;
for (i = 0; i < 2 * sci->total_bands; i++) {
int ba = sci->bitalloc[i];
if (ba != 0) {
if (ba < 17) {
int half = (1 << (ba - 1)) - 1;
for (k = 0; k < group_size; k++) {
dst[k] = (float) ((int) drmp3_bs_get_bits(bs, ba) - half);
}
} else {
unsigned mod = (2 << (ba - 17)) + 1; /* 3, 5, 9 */
unsigned code = drmp3_bs_get_bits(bs, mod + 2 - (mod >> 3)); /* 5, 7, 10 */
for (k = 0; k < group_size; k++, code /= mod) {
dst[k] = (float) ((int) (code % mod - mod / 2));
}
}
}
dst += choff;
choff = 18 - choff;
}
}
return group_size * 4;
}
static void drmp3_L12_apply_scf_384(drmp3_L12_scale_info *sci, const float *scf, float *dst) {
int i, k;
memcpy(dst + 576 + sci->stereo_bands * 18, dst + sci->stereo_bands * 18,
(sci->total_bands - sci->stereo_bands) * 18 * sizeof(float));
for (i = 0; i < sci->total_bands; i++, dst += 18, scf += 6) {
for (k = 0; k < 12; k++) {
dst[k + 0] *= scf[0];
dst[k + 576] *= scf[3];
}
}
}
#endif
static int drmp3_L3_read_side_info(drmp3_bs *bs, drmp3_L3_gr_info *gr, const drmp3_uint8 *hdr) {
static const drmp3_uint8 g_scf_long[8][23] = {
{6, 6, 6, 6, 6, 6, 8, 10, 12, 14, 16, 20, 24, 28, 32, 38, 46, 52, 60, 68, 58, 54, 0},
{12, 12, 12, 12, 12, 12, 16, 20, 24, 28, 32, 40, 48, 56, 64, 76, 90, 2, 2, 2, 2, 2, 0},
{6, 6, 6, 6, 6, 6, 8, 10, 12, 14, 16, 20, 24, 28, 32, 38, 46, 52, 60, 68, 58, 54, 0},
{6, 6, 6, 6, 6, 6, 8, 10, 12, 14, 16, 18, 22, 26, 32, 38, 46, 54, 62, 70, 76, 36, 0},
{6, 6, 6, 6, 6, 6, 8, 10, 12, 14, 16, 20, 24, 28, 32, 38, 46, 52, 60, 68, 58, 54, 0},
{4, 4, 4, 4, 4, 4, 6, 6, 8, 8, 10, 12, 16, 20, 24, 28, 34, 42, 50, 54, 76, 158, 0},
{4, 4, 4, 4, 4, 4, 6, 6, 6, 8, 10, 12, 16, 18, 22, 28, 34, 40, 46, 54, 54, 192, 0},
{4, 4, 4, 4, 4, 4, 6, 6, 8, 10, 12, 16, 20, 24, 30, 38, 46, 56, 68, 84, 102, 26, 0}
};
static const drmp3_uint8 g_scf_short[8][40] = {
{4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 6, 8, 8, 8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18, 18, 24, 24, 24, 30, 30, 30, 40, 40, 40, 18, 18, 18, 0},
{8, 8, 8, 8, 8, 8, 8, 8, 8, 12, 12, 12, 16, 16, 16, 20, 20, 20, 24, 24, 24, 28, 28, 28, 36, 36, 36, 2, 2, 2, 2, 2, 2, 2, 2, 2, 26, 26, 26, 0},
{4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 6, 6, 6, 6, 8, 8, 8, 10, 10, 10, 14, 14, 14, 18, 18, 18, 26, 26, 26, 32, 32, 32, 42, 42, 42, 18, 18, 18, 0},
{4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 6, 8, 8, 8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18, 18, 24, 24, 24, 32, 32, 32, 44, 44, 44, 12, 12, 12, 0},
{4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 6, 8, 8, 8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18, 18, 24, 24, 24, 30, 30, 30, 40, 40, 40, 18, 18, 18, 0},
{4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 6, 8, 8, 8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18, 18, 22, 22, 22, 30, 30, 30, 56, 56, 56, 0},
{4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 6, 6, 6, 6, 10, 10, 10, 12, 12, 12, 14, 14, 14, 16, 16, 16, 20, 20, 20, 26, 26, 26, 66, 66, 66, 0},
{4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 6, 8, 8, 8, 12, 12, 12, 16, 16, 16, 20, 20, 20, 26, 26, 26, 34, 34, 34, 42, 42, 42, 12, 12, 12, 0}
};
static const drmp3_uint8 g_scf_mixed[8][40] = {
{6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18, 18, 24, 24, 24, 30, 30, 30, 40, 40, 40, 18, 18, 18, 0},
{12, 12, 12, 4, 4, 4, 8, 8, 8, 12, 12, 12, 16, 16, 16, 20, 20, 20, 24, 24, 24, 28, 28, 28, 36, 36, 36, 2, 2, 2, 2, 2, 2, 2, 2, 2, 26, 26, 26, 0},
{6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 10, 10, 10, 14, 14, 14, 18, 18, 18, 26, 26, 26, 32, 32, 32, 42, 42, 42, 18, 18, 18, 0},
{6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18, 18, 24, 24, 24, 32, 32, 32, 44, 44, 44, 12, 12, 12, 0},
{6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18, 18, 24, 24, 24, 30, 30, 30, 40, 40, 40, 18, 18, 18, 0},
{4, 4, 4, 4, 4, 4, 6, 6, 4, 4, 4, 6, 6, 6, 8, 8, 8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18, 18, 22, 22, 22, 30, 30, 30, 56, 56, 56, 0},
{4, 4, 4, 4, 4, 4, 6, 6, 4, 4, 4, 6, 6, 6, 6, 6, 6, 10, 10, 10, 12, 12, 12, 14, 14, 14, 16, 16, 16, 20, 20, 20, 26, 26, 26, 66, 66, 66, 0},
{4, 4, 4, 4, 4, 4, 6, 6, 4, 4, 4, 6, 6, 6, 8, 8, 8, 12, 12, 12, 16, 16, 16, 20, 20, 20, 26, 26, 26, 34, 34, 34, 42, 42, 42, 12, 12, 12, 0}
};
unsigned tables, scfsi = 0;
int main_data_begin, part_23_sum = 0;
int sr_idx = DRMP3_HDR_GET_MY_SAMPLE_RATE(hdr);
sr_idx -= (sr_idx != 0);
int gr_count = DRMP3_HDR_IS_MONO(hdr) ? 1 : 2;
if (DRMP3_HDR_TEST_MPEG1(hdr)) {
gr_count *= 2;
main_data_begin = drmp3_bs_get_bits(bs, 9);
scfsi = drmp3_bs_get_bits(bs, 7 + gr_count);
} else {
main_data_begin = drmp3_bs_get_bits(bs, 8 + gr_count) >> gr_count;
}
do {
if (DRMP3_HDR_IS_MONO(hdr)) {
scfsi <<= 4;
}
gr->part_23_length = (drmp3_uint16) drmp3_bs_get_bits(bs, 12);
part_23_sum += gr->part_23_length;
gr->big_values = (drmp3_uint16) drmp3_bs_get_bits(bs, 9);
if (gr->big_values > 288) {
return -1;
}
gr->global_gain = (drmp3_uint8) drmp3_bs_get_bits(bs, 8);
gr->scalefac_compress = (drmp3_uint16) drmp3_bs_get_bits(bs, DRMP3_HDR_TEST_MPEG1(hdr) ? 4 : 9);
gr->sfbtab = g_scf_long[sr_idx];
gr->n_long_sfb = 22;
gr->n_short_sfb = 0;
if (drmp3_bs_get_bits(bs, 1)) {
gr->block_type = (drmp3_uint8) drmp3_bs_get_bits(bs, 2);
if (!gr->block_type) {
return -1;
}
gr->mixed_block_flag = (drmp3_uint8) drmp3_bs_get_bits(bs, 1);
gr->region_count[0] = 7;
gr->region_count[1] = 255;
if (gr->block_type == DRMP3_SHORT_BLOCK_TYPE) {
scfsi &= 0x0F0F;
if (!gr->mixed_block_flag) {
gr->region_count[0] = 8;
gr->sfbtab = g_scf_short[sr_idx];
gr->n_long_sfb = 0;
gr->n_short_sfb = 39;
} else {
gr->sfbtab = g_scf_mixed[sr_idx];
gr->n_long_sfb = DRMP3_HDR_TEST_MPEG1(hdr) ? 8 : 6;
gr->n_short_sfb = 30;
}
}
tables = drmp3_bs_get_bits(bs, 10);
tables <<= 5;
gr->subblock_gain[0] = (drmp3_uint8) drmp3_bs_get_bits(bs, 3);
gr->subblock_gain[1] = (drmp3_uint8) drmp3_bs_get_bits(bs, 3);
gr->subblock_gain[2] = (drmp3_uint8) drmp3_bs_get_bits(bs, 3);
} else {
gr->block_type = 0;
gr->mixed_block_flag = 0;
tables = drmp3_bs_get_bits(bs, 15);
gr->region_count[0] = (drmp3_uint8) drmp3_bs_get_bits(bs, 4);
gr->region_count[1] = (drmp3_uint8) drmp3_bs_get_bits(bs, 3);
gr->region_count[2] = 255;
}
gr->table_select[0] = (drmp3_uint8) (tables >> 10);
gr->table_select[1] = (drmp3_uint8) ((tables >> 5) & 31);
gr->table_select[2] = (drmp3_uint8) ((tables) & 31);
gr->preflag = (drmp3_uint8) (DRMP3_HDR_TEST_MPEG1(hdr) ? drmp3_bs_get_bits(bs, 1) : (gr->scalefac_compress >=
500));
gr->scalefac_scale = (drmp3_uint8) drmp3_bs_get_bits(bs, 1);
gr->count1_table = (drmp3_uint8) drmp3_bs_get_bits(bs, 1);
gr->scfsi = (drmp3_uint8) ((scfsi >> 12) & 15);
scfsi <<= 4;
gr++;
} while (--gr_count);
if (part_23_sum + bs->pos > bs->limit + main_data_begin * 8) {
return -1;
}
return main_data_begin;
}
static void drmp3_L3_read_scalefactors(drmp3_uint8 *scf, drmp3_uint8 *ist_pos, const drmp3_uint8 *scf_size,
const drmp3_uint8 *scf_count, drmp3_bs *bitbuf, int scfsi) {
int i, k;
for (i = 0; i < 4 && scf_count[i]; i++, scfsi *= 2) {
int cnt = scf_count[i];
if (scfsi & 8) {
memcpy(scf, ist_pos, cnt);
} else {
int bits = scf_size[i];
if (!bits) {
memset(scf, 0, cnt);
memset(ist_pos, 0, cnt);
} else {
int max_scf = (scfsi < 0) ? (1 << bits) - 1 : -1;
for (k = 0; k < cnt; k++) {
int s = drmp3_bs_get_bits(bitbuf, bits);
ist_pos[k] = (drmp3_uint8) (s == max_scf ? -1 : s);
scf[k] = (drmp3_uint8) s;
}
}
}
ist_pos += cnt;
scf += cnt;
}
scf[0] = scf[1] = scf[2] = 0;
}
static float drmp3_L3_ldexp_q2(float y, int exp_q2) {
static const float g_expfrac[4] = {9.31322575e-10f, 7.83145814e-10f, 6.58544508e-10f, 5.53767716e-10f};
int e;
do {
e = DRMP3_MIN(30 * 4, exp_q2);
y *= g_expfrac[e & 3] * (1 << 30 >> (e >> 2));
} while ((exp_q2 -= e) > 0);
return y;
}
static void
drmp3_L3_decode_scalefactors(const drmp3_uint8 *hdr, drmp3_uint8 *ist_pos, drmp3_bs *bs, const drmp3_L3_gr_info *gr,
float *scf, int ch) {
static const drmp3_uint8 g_scf_partitions[3][28] = {
{6, 5, 5, 5, 6, 5, 5, 5, 6, 5, 7, 3, 11, 10, 0, 0, 7, 7, 7, 0, 6, 6, 6, 3, 8, 8, 5, 0},
{8, 9, 6, 12, 6, 9, 9, 9, 6, 9, 12, 6, 15, 18, 0, 0, 6, 15, 12, 0, 6, 12, 9, 6, 6, 18, 9, 0},
{9, 9, 6, 12, 9, 9, 9, 9, 9, 9, 12, 6, 18, 18, 0, 0, 12, 12, 12, 0, 12, 9, 9, 6, 15, 12, 9, 0}
};
const drmp3_uint8 *scf_partition = g_scf_partitions[!!gr->n_short_sfb + !gr->n_long_sfb];
drmp3_uint8 scf_size[4], iscf[40];
int i, scf_shift = gr->scalefac_scale + 1, gain_exp, scfsi = gr->scfsi;
float gain;
if (DRMP3_HDR_TEST_MPEG1(hdr)) {
static const drmp3_uint8 g_scfc_decode[16] = {0, 1, 2, 3, 12, 5, 6, 7, 9, 10, 11, 13, 14, 15, 18, 19};
int part = g_scfc_decode[gr->scalefac_compress];
scf_size[1] = scf_size[0] = (drmp3_uint8) (part >> 2);
scf_size[3] = scf_size[2] = (drmp3_uint8) (part & 3);
} else {
static const drmp3_uint8 g_mod[
6 * 4] = {5, 5, 4, 4, 5, 5, 4, 1, 4, 3, 1, 1, 5, 6, 6, 1, 4, 4, 4, 1, 4, 3, 1, 1};
int k, modprod, sfc, ist = DRMP3_HDR_TEST_I_STEREO(hdr) && ch;
sfc = gr->scalefac_compress >> ist;
for (k = ist * 3 * 4; sfc >= 0; sfc -= modprod, k += 4) {
for (modprod = 1, i = 3; i >= 0; i--) {
scf_size[i] = (drmp3_uint8) (sfc / modprod % g_mod[k + i]);
modprod *= g_mod[k + i];
}
}
scf_partition += k;
scfsi = -16;
}
drmp3_L3_read_scalefactors(iscf, ist_pos, scf_size, scf_partition, bs, scfsi);
if (gr->n_short_sfb) {
int sh = 3 - scf_shift;
for (i = 0; i < gr->n_short_sfb; i += 3) {
iscf[gr->n_long_sfb + i + 0] += gr->subblock_gain[0] << sh;
iscf[gr->n_long_sfb + i + 1] += gr->subblock_gain[1] << sh;
iscf[gr->n_long_sfb + i + 2] += gr->subblock_gain[2] << sh;
}
} else if (gr->preflag) {
static const drmp3_uint8 g_preamp[10] = {1, 1, 1, 1, 2, 2, 3, 3, 3, 2};
for (i = 0; i < 10; i++) {
iscf[11 + i] += g_preamp[i];
}
}
gain_exp = gr->global_gain + DRMP3_BITS_DEQUANTIZER_OUT * 4 - 210 - (DRMP3_HDR_IS_MS_STEREO(hdr) ? 2 : 0);
gain = drmp3_L3_ldexp_q2(1 << (DRMP3_MAX_SCFI / 4), DRMP3_MAX_SCFI - gain_exp);
for (i = 0; i < (int) (gr->n_long_sfb + gr->n_short_sfb); i++) {
scf[i] = drmp3_L3_ldexp_q2(gain, iscf[i] << scf_shift);
}
}
static const float g_drmp3_pow43[129 + 16] = {
0, -1, -2.519842f, -4.326749f, -6.349604f, -8.549880f, -10.902724f, -13.390518f, -16.000000f, -18.720754f,
-21.544347f, -24.463781f, -27.473142f, -30.567351f, -33.741992f, -36.993181f,
0, 1, 2.519842f, 4.326749f, 6.349604f, 8.549880f, 10.902724f, 13.390518f, 16.000000f, 18.720754f, 21.544347f,
24.463781f, 27.473142f, 30.567351f, 33.741992f, 36.993181f, 40.317474f, 43.711787f, 47.173345f, 50.699631f,
54.288352f, 57.937408f, 61.644865f, 65.408941f, 69.227979f, 73.100443f, 77.024898f, 81.000000f, 85.024491f,
89.097188f, 93.216975f, 97.382800f, 101.593667f, 105.848633f, 110.146801f, 114.487321f, 118.869381f,
123.292209f, 127.755065f, 132.257246f, 136.798076f, 141.376907f, 145.993119f, 150.646117f, 155.335327f,
160.060199f, 164.820202f, 169.614826f, 174.443577f, 179.305980f, 184.201575f, 189.129918f, 194.090580f,
199.083145f, 204.107210f, 209.162385f, 214.248292f, 219.364564f, 224.510845f, 229.686789f, 234.892058f,
240.126328f, 245.389280f, 250.680604f, 256.000000f, 261.347174f, 266.721841f, 272.123723f, 277.552547f,
283.008049f, 288.489971f, 293.998060f, 299.532071f, 305.091761f, 310.676898f, 316.287249f, 321.922592f,
327.582707f, 333.267377f, 338.976394f, 344.709550f, 350.466646f, 356.247482f, 362.051866f, 367.879608f,
373.730522f, 379.604427f, 385.501143f, 391.420496f, 397.362314f, 403.326427f, 409.312672f, 415.320884f,
421.350905f, 427.402579f, 433.475750f, 439.570269f, 445.685987f, 451.822757f, 457.980436f, 464.158883f,
470.357960f, 476.577530f, 482.817459f, 489.077615f, 495.357868f, 501.658090f, 507.978156f, 514.317941f,
520.677324f, 527.056184f, 533.454404f, 539.871867f, 546.308458f, 552.764065f, 559.238575f, 565.731879f,
572.243870f, 578.774440f, 585.323483f, 591.890898f, 598.476581f, 605.080431f, 611.702349f, 618.342238f,
625.000000f, 631.675540f, 638.368763f, 645.079578f
};
static float drmp3_L3_pow_43(int x) {
float frac;
int sign, mult = 256;
if (x < 129) {
return g_drmp3_pow43[16 + x];
}
if (x < 1024) {
mult = 16;
x <<= 3;
}
sign = 2 * x & 64;
frac = (float) ((x & 63) - sign) / ((x & ~63) + sign);
return g_drmp3_pow43[16 + ((x + sign) >> 6)] * (1.f + frac * ((4.f / 3) + frac * (2.f / 9))) * mult;
}
static void
drmp3_L3_huffman(float *dst, drmp3_bs *bs, const drmp3_L3_gr_info *gr_info, const float *scf, int layer3gr_limit) {
static const drmp3_int16 tabs[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0,
785, 785, 785, 785, 784, 784, 784, 784, 513, 513, 513, 513, 513, 513, 513, 513,
256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256, 256,