ref: cba86cdff8545ad21f99cbe090677f2fbf54eb20
dir: /minimp3_ex.h/
#ifndef MINIMP3_EXT_H
#define MINIMP3_EXT_H
/*
https://github.com/lieff/minimp3
To the extent possible under law, the author(s) have dedicated all copyright and related and neighboring rights to this software to the public domain worldwide.
This software is distributed without any warranty.
See <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
#include "minimp3.h"
typedef struct
{
int16_t *buffer;
size_t samples;
int channels, hz, layer, avg_bitrate_kbps;
} mp3dec_file_info_t;
typedef int (*MP3D_ITERATE_CB)(void *user_data, const uint8_t *frame, int frame_size, size_t offset, mp3dec_frame_info_t *info);
#ifdef __cplusplus
extern "C" {
#endif
/* decode whole file/buffer block */
int mp3dec_load(mp3dec_t *dec, const char *file_name, mp3dec_file_info_t *info);
void mp3dec_load_buf(mp3dec_t *dec, const uint8_t *buf, size_t buf_size, mp3dec_file_info_t *info);
/* iterate through frames with optional decoding */
int mp3dec_iterate(const char *file_name, MP3D_ITERATE_CB callback, void *user_data);
void mp3dec_iterate_buf(const uint8_t *buf, size_t buf_size, MP3D_ITERATE_CB callback, void *user_data);
#ifdef __cplusplus
}
#endif
#endif /*MINIMP3_EXT_H*/
#ifdef MINIMP3_EXT_IMPLEMENTATION
#if defined(__linux__) || defined(__FreeBSD__)
#include <errno.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#if !defined(MAP_POPULATE) && defined(__linux__)
#define MAP_POPULATE 0x08000
#elif !defined(MAP_POPULATE)
#define MAP_POPULATE 0
#endif
typedef struct
{
uint8_t *buffer;
size_t size;
int file;
} mp3dec_map_info_t;
static void mp3dec_close_file(mp3dec_map_info_t *map_info)
{
if (map_info->buffer && MAP_FAILED != map_info->buffer)
munmap(map_info->buffer, map_info->size);
if (map_info->file)
close(map_info->file);
map_info->buffer = 0;
map_info->file = 0;
}
static int mp3dec_open_file(const char *file_name, mp3dec_map_info_t *map_info)
{
struct stat st;
memset(map_info, 0, sizeof(*map_info));
retry_open:
map_info->file = open(file_name, O_RDONLY);
if (map_info->file < 0 && (errno == EAGAIN || errno == EINTR))
goto retry_open;
if (map_info->file < 0 || fstat(map_info->file, &st) < 0)
{
mp3dec_close_file(map_info);
return -1;
}
map_info->size = st.st_size;
retry_mmap:
map_info->buffer = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE | MAP_POPULATE, map_info->file, 0);
if (MAP_FAILED == map_info->buffer && (errno == EAGAIN || errno == EINTR))
goto retry_mmap;
if (MAP_FAILED == map_info->buffer)
{
mp3dec_close_file(map_info);
return -1;
}
return 0;
}
/*#elif defined(_WIN32)*/
#else
#include <stdio.h>
typedef struct
{
uint8_t *buffer;
FILE *file;
size_t size;
} mp3dec_map_info_t;
static void mp3dec_close_file(mp3dec_map_info_t *map_info)
{
if (map_info->buffer)
free(map_info->buffer);
if (map_info->file)
fclose(map_info->file);
map_info->buffer = 0;
map_info->file = 0;
}
static int mp3dec_open_file(const char *file_name, mp3dec_map_info_t *map_info)
{
memset(map_info, 0, sizeof(*map_info));
map_info->file = fopen(file_name, "rb");
if (!map_info->file)
return -1;
if (fseek(map_info->file, 0, SEEK_END))
goto error;
long size = ftell(map_info->file);
if (size < 0)
goto error;
map_info->size = (size_t)size;
if (fseek(map_info->file, 0, SEEK_SET))
goto error;
map_info->buffer = (uint8_t *)malloc(map_info->size);
if (!map_info->buffer)
goto error;
if (fread(map_info->buffer, 1, map_info->size, map_info->file) != map_info->size)
goto error;
return 0;
error:
mp3dec_close_file(map_info);
return -1;
}
#endif
static size_t mp3dec_skip_id3v2(const uint8_t *buf, size_t buf_size)
{
if (buf_size > 10 && !strncmp((char *)buf, "ID3", 3))
{
return (((buf[6] & 0x7f) << 21) | ((buf[7] & 0x7f) << 14) |
((buf[8] & 0x7f) << 7) | (buf[9] & 0x7f)) + 10;
}
return 0;
}
void mp3dec_load_buf(mp3dec_t *dec, const uint8_t *buf, size_t buf_size, mp3dec_file_info_t *info)
{
short pcm[MINIMP3_MAX_SAMPLES_PER_FRAME];
mp3dec_frame_info_t frame_info;
memset(info, 0, sizeof(*info));
memset(&frame_info, 0, sizeof(frame_info));
/* skip id3v2 */
size_t id3v2size = mp3dec_skip_id3v2(buf, buf_size);
if (id3v2size > buf_size)
return;
buf += id3v2size;
buf_size -= id3v2size;
/* try to make allocation size assumption by first frame */
mp3dec_init(dec);
int samples;
do
{
samples = mp3dec_decode_frame(dec, buf, buf_size, pcm, &frame_info);
buf += frame_info.frame_bytes;
buf_size -= frame_info.frame_bytes;
if (samples)
break;
} while (frame_info.frame_bytes);
if (!samples)
return;
size_t samples_bytes = samples*frame_info.channels*2;
size_t allocated = (buf_size/frame_info.frame_bytes)*samples_bytes + MINIMP3_MAX_SAMPLES_PER_FRAME*2;
info->buffer = malloc(allocated);
memcpy(info->buffer, pcm, samples_bytes);
/* save info */
info->channels = frame_info.channels;
info->hz = frame_info.hz;
info->layer = frame_info.layer;
size_t avg_bitrate_kbps = frame_info.bitrate_kbps;
size_t frames = 1;
/* decode rest frames */
do
{
if ((allocated - samples_bytes) < MINIMP3_MAX_SAMPLES_PER_FRAME*2)
{
allocated *= 2;
info->buffer = realloc(info->buffer, allocated);
}
samples = mp3dec_decode_frame(dec, buf, buf_size, (int16_t*)((int8_t *)info->buffer + samples_bytes), &frame_info);
if (samples)
{
info->samples += samples;
avg_bitrate_kbps += frame_info.bitrate_kbps;
samples_bytes += samples*frame_info.channels*2;
}
buf += frame_info.frame_bytes;
buf_size -= frame_info.frame_bytes;
} while (frame_info.frame_bytes);
/* reallocate to normal buffer size */
if (allocated != samples_bytes)
info->buffer = realloc(info->buffer, samples_bytes);
info->avg_bitrate_kbps = avg_bitrate_kbps/frames;
}
int mp3dec_load(mp3dec_t *dec, const char *file_name, mp3dec_file_info_t *info)
{
int ret;
mp3dec_map_info_t map_info;
if ((ret = mp3dec_open_file(file_name, &map_info)))
return ret;
mp3dec_load_buf(dec, map_info.buffer, map_info.size, info);
mp3dec_close_file(&map_info);
return 0;
}
void mp3dec_iterate_buf(const uint8_t *buf, size_t buf_size, MP3D_ITERATE_CB callback, void *user_data)
{
mp3dec_frame_info_t frame_info;
memset(&frame_info, 0, sizeof(frame_info));
/* skip id3v2 */
size_t id3v2size = mp3dec_skip_id3v2(buf, buf_size);
if (id3v2size > buf_size)
return;
buf += id3v2size;
buf_size -= id3v2size;
do
{
int free_format_bytes = 0, frame_size = 0;
int i = mp3d_find_frame(buf, buf_size, &free_format_bytes, &frame_size);
buf += i;
buf_size -= i;
if (i && !frame_size)
continue;
if (!frame_size)
break;
callback(user_data, buf + i, frame_size, i, &frame_info);
buf += frame_size;
buf_size -= frame_size;
} while (1);
}
int mp3dec_iterate(const char *file_name, MP3D_ITERATE_CB callback, void *user_data)
{
int ret;
mp3dec_map_info_t map_info;
if ((ret = mp3dec_open_file(file_name, &map_info)))
return ret;
mp3dec_iterate_buf(map_info.buffer, map_info.size, callback, user_data);
mp3dec_close_file(&map_info);
return 0;
}
#endif /*MINIMP3_EXT_IMPLEMENTATION*/