/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
// Use Safefree for libid3tag free calls on Windows
#ifdef _MSC_VER
#define free(ptr) Safefree(ptr)
#endif
#define MP3_BLOCK_SIZE 4096
#define XING_FRAMES 0x01
#define XING_BYTES 0x02
#define XING_TOC 0x04
#define XING_QUALITY 0x08
#define CBR 1
#define ABR 2
#define VBR 3
struct mp3_frameinfo {
short mpeg_version;
unsigned char layer;
unsigned short bitrate;
unsigned int samplerate;
unsigned char stereo;
unsigned char vbr;
unsigned short frame_length;
unsigned char crc_protected;
unsigned short samples_per_frame;
unsigned char padding;
// Xing header
unsigned int xing_offset;
unsigned int xing_frames;
unsigned int xing_bytes;
unsigned short xing_quality;
unsigned char xing_has_toc;
unsigned char xing_toc[100];
// LAME header
char lame_encoder_version[9];
unsigned char lame_tag_revision;
unsigned char lame_vbr_method;
unsigned int lame_lowpass;
float lame_replay_gain[2];
unsigned short lame_abr_rate;
short lame_encoder_delay;
short lame_encoder_padding;
unsigned char lame_noise_shaping;
unsigned char lame_stereo_mode;
unsigned char lame_unwise;
unsigned char lame_source_freq;
int lame_mp3gain;
float lame_mp3gain_db;
unsigned char lame_surround;
unsigned short lame_preset;
unsigned int lame_music_length;
// VBRI header
unsigned short vbri_delay;
unsigned short vbri_quality;
unsigned int vbri_bytes;
unsigned int vbri_frames;
};
typedef struct mp3info {
PerlIO *infile;
char *file;
Buffer *buf;
HV *info;
} mp3info;
// LAME lookup tables
const char *stereo_modes[] = {
"Mono",
"Stereo",
"Dual",
"Joint",
"Force",
"Auto",
"Intensity",
"Undefined"
};
const char *source_freqs[] = {
"<= 32 kHz",
"44.1 kHz",
"48 kHz",
"> 48 kHz"
};
const char *surround[] = {
"None",
"DPL encoding",
"DPL2 encoding",
"Ambisonic encoding",
"Reserved"
};
const char *vbr_methods[] = {
"Unknown",
"Constant Bitrate",
"Average Bitrate",
"Variable Bitrate method1 (old/rh)",
"Variable Bitrate method2 (mtrh)",
"Variable Bitrate method3 (mt)",
"Variable Bitrate method4",
NULL,
"Constant Bitrate (2 pass)",
"Average Bitrate (2 pass)",
NULL,
NULL,
NULL,
NULL,
NULL,
"Reserved"
};
const char *presets_v[] = {
"V9",
"V8",
"V7",
"V6",
"V5",
"V4",
"V3",
"V2",
"V1",
"V0"
};
const char *presets_old[] = {
"r3mix",
"standard",
"extreme",
"insane",
"standard/fast",
"extreme/fast",
"medium",
"medium/fast"
};
static int get_mp3tags(PerlIO *infile, char *file, HV *info, HV *tags);
static int get_mp3fileinfo(PerlIO *infile, char *file, HV *info);
static int _decode_mp3_frame(unsigned char *frame, struct mp3_frameinfo *pfi);
static int mp3_find_frame(PerlIO *infile, char *file, int offset);
static int _has_ape(PerlIO *infile, off_t file_size);
// bitrate_tbl[layer_index][bitrate_index]
static int bitrate_tbl[5][16] = {
{ 0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,0 }, /* MPEG1, L1 */
{ 0,32,48,56,64,80,96,112,128,160,192,224,256,320,384,0 }, /* MPEG1, L2 */
{ 0,32,40,48,56,64,80,96,112,128,160,192,224,256,320,0 }, /* MPEG1, L3 */
{ 0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,0 }, /* MPEG2/2.5, L1 */
{ 0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,0 } /* MPEG2/2.5, L2/L3 */
};
// sample_rate[sample_index][samplerate_index]
static int sample_rate_tbl[3][4] = {
{ 44100, 48000, 32000, 0 }, /* MPEG 1 */
{ 22050, 24000, 16000, 0 }, /* MPEG 2 */
{ 11025, 12000, 8000, 0 } /* MPEG 2.5 */
};