ref: cba86cdff8545ad21f99cbe090677f2fbf54eb20
parent: ee2a684e3952abc9363171c286a974d573fa08b9
author: lieff <lieff@users.noreply.github.com>
date: Fri Aug 3 15:01:19 EDT 2018
Rough high-level API implementation
--- a/minimp3_ex.h
+++ b/minimp3_ex.h
@@ -6,16 +6,16 @@
This software is distributed without any warranty.
See <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
-#include <minimp3.h>
+#include "minimp3.h"
typedef struct
{- short *buffer;
+ int16_t *buffer;
size_t samples;
int channels, hz, layer, avg_bitrate_kbps;
} mp3dec_file_info_t;
-typedef int (*MP3D_ITERATE_CB)(mp3dec_t *dec, void *user, const void *frame, int frame_size, mp3dec_frame_info_t *info);
+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" {@@ -23,10 +23,10 @@
/* decode whole file/buffer block */
int mp3dec_load(mp3dec_t *dec, const char *file_name, mp3dec_file_info_t *info);
-int mp3dec_load_buf(mp3dec_t *dec, const void *buf, size_t buf_size, 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(mp3dec_t *dec, const char *file_name, MP3D_ITERATE_CB *cb, void *user);
-int mp3dec_iterate_buf(mp3dec_t *dec, const void *buf, size_t buf_size, MP3D_ITERATE_CB *cb, void *user);
+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
}
@@ -35,23 +35,223 @@
#ifdef MINIMP3_EXT_IMPLEMENTATION
-int mp3dec_load(mp3dec_t *dec, const char *file_name, mp3dec_file_info_t *info)
+#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;
-int mp3dec_load_buf(mp3dec_t *dec, const void *buf, size_t buf_size, mp3dec_file_info_t *info)
+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
-int mp3dec_iterate(mp3dec_t *dec, const char *file_name, MP3D_ITERATE_CB *cb)
+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;
}
-int mp3dec_iterate_buf(mp3dec_t *dec, const void *buf, size_t buf_size, MP3D_ITERATE_CB *cb)
+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;
}