owntone-server/src/scan-mp3.c
2006-02-27 22:48:42 +00:00

985 lines
30 KiB
C

/*
* $Id$
*
* Copyright (C) 2003 Ron Pedde (ron@pedde.com)
*
* 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
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <id3tag.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "conf.h"
#include "daapd.h"
#include "err.h"
#include "mp3-scanner.h"
#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
# define _PACKED __attribute((packed))
#else
# define _PACKED
#endif
/**
* Struct to keep info about the information gleaned from
* the mp3 frame header.
*/
typedef struct tag_scan_frameinfo {
int layer; /**< 1, 2, or 3, representing Layer I, II, and III */
int bitrate; /**< Bitrate in kbps (128, 64, etc) */
int samplerate; /**< Samplerate (e.g. 44100) */
int stereo; /**< Any kind of stereo.. joint, dual mono, etc */
int frame_length; /**< Frame length in bytes - calculated */
int crc_protected; /**< Is the frame crc protected? */
int samples_per_frame; /**< Samples per frame - calculated field */
int padding; /**< Whether or not there is a padding sample */
int xing_offset; /**< Where the xing header should be relative to end of hdr */
int number_of_frames; /**< Number of frames in the song */
int frame_offset; /**< Where this frame was found */
double version; /**< MPEG version (e.g. 2.0, 2.5, 1.0) */
int is_valid;
} SCAN_FRAMEINFO;
/* This should take take of win32 and gcc, any others? */
#pragma pack(1)
typedef struct tag_scan_id3header {
unsigned char id[3];
unsigned char version[2];
unsigned char flags;
unsigned char size[4];
} _PACKED SCAN_ID3HEADER;
#pragma pack()
/*
* Globals
*/
int scan_br_table[5][16] = {
{ 0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,0 }, /* MPEG1, Layer 1 */
{ 0,32,48,56,64,80,96,112,128,160,192,224,256,320,384,0 }, /* MPEG1, Layer 2 */
{ 0,32,40,48,56,64,80,96,112,128,160,192,224,256,320,0 }, /* MPEG1, Layer 3 */
{ 0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,0 }, /* MPEG2/2.5, Layer 1 */
{ 0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,0 } /* MPEG2/2.5, Layer 2/3 */
};
int scan_sample_table[3][4] = {
{ 44100, 48000, 32000, 0 }, /* MPEG 1 */
{ 22050, 24000, 16000, 0 }, /* MPEG 2 */
{ 11025, 12000, 8000, 0 } /* MPEG 2.5 */
};
char *scan_winamp_genre[] = {
"Blues", // 0
"Classic Rock",
"Country",
"Dance",
"Disco",
"Funk", // 5
"Grunge",
"Hip-Hop",
"Jazz",
"Metal",
"New Age", // 10
"Oldies",
"Other",
"Pop",
"R&B",
"Rap", // 15
"Reggae",
"Rock",
"Techno",
"Industrial",
"Alternative", // 20
"Ska",
"Death Metal",
"Pranks",
"Soundtrack",
"Euro-Techno", // 25
"Ambient",
"Trip-Hop",
"Vocal",
"Jazz+Funk",
"Fusion", // 30
"Trance",
"Classical",
"Instrumental",
"Acid",
"House", // 35
"Game",
"Sound Clip",
"Gospel",
"Noise",
"AlternRock", // 40
"Bass",
"Soul",
"Punk",
"Space",
"Meditative", // 45
"Instrumental Pop",
"Instrumental Rock",
"Ethnic",
"Gothic",
"Darkwave", // 50
"Techno-Industrial",
"Electronic",
"Pop-Folk",
"Eurodance",
"Dream", // 55
"Southern Rock",
"Comedy",
"Cult",
"Gangsta",
"Top 40", // 60
"Christian Rap",
"Pop/Funk",
"Jungle",
"Native American",
"Cabaret", // 65
"New Wave",
"Psychadelic",
"Rave",
"Showtunes",
"Trailer", // 70
"Lo-Fi",
"Tribal",
"Acid Punk",
"Acid Jazz",
"Polka", // 75
"Retro",
"Musical",
"Rock & Roll",
"Hard Rock",
"Folk", // 80
"Folk/Rock",
"National folk",
"Swing",
"Fast-fusion",
"Bebob", // 85
"Latin",
"Revival",
"Celtic",
"Bluegrass",
"Avantgarde", // 90
"Gothic Rock",
"Progressive Rock",
"Psychedelic Rock",
"Symphonic Rock",
"Slow Rock", // 95
"Big Band",
"Chorus",
"Easy Listening",
"Acoustic",
"Humour", // 100
"Speech",
"Chanson",
"Opera",
"Chamber Music",
"Sonata", // 105
"Symphony",
"Booty Bass",
"Primus",
"Porn Groove",
"Satire", // 110
"Slow Jam",
"Club",
"Tango",
"Samba",
"Folklore", // 115
"Ballad",
"Powder Ballad",
"Rhythmic Soul",
"Freestyle",
"Duet", // 120
"Punk Rock",
"Drum Solo",
"A Capella",
"Euro-House",
"Dance Hall", // 125
"Goa",
"Drum & Bass",
"Club House",
"Hardcore",
"Terror", // 130
"Indie",
"BritPop",
"NegerPunk",
"Polsk Punk",
"Beat", // 135
"Christian Gangsta",
"Heavy Metal",
"Black Metal",
"Crossover",
"Contemporary C", // 140
"Christian Rock",
"Merengue",
"Salsa",
"Thrash Metal",
"Anime", // 145
"JPop",
"SynthPop",
"Unknown"
};
/* Forwards */
static int scan_mp3_get_mp3tags(char *file, MP3FILE *pmp3);
static int scan_mp3_get_mp3fileinfo(char *file, MP3FILE *pmp3);
static int scan_mp3_decode_mp3_frame(unsigned char *frame,SCAN_FRAMEINFO *pfi);
static void scan_mp3_get_average_bitrate(FILE *infile, SCAN_FRAMEINFO *pfi);
static int scan_mp3_is_numeric(char *str);
static void scan_mp3_get_frame_count(FILE *infile, SCAN_FRAMEINFO *pfi);
/**
* main entrypoint for the scanner
*
* @param filename file to scan
* @param pmp3 MP3FILE structure to fill
* @returns TRUE if file should be added to DB, FALSE otherwise
*/
int scan_get_mp3info(char *filename, MP3FILE *pmp3) {
if(scan_mp3_get_mp3tags(filename, pmp3))
return scan_mp3_get_mp3fileinfo(filename,pmp3);
return FALSE;
}
/**
* decide if a string is numeric or not...
*
* @param str string to evaluate
* @returns 1 if number, 0 otherwise
*/
int scan_mp3_is_numeric(char *str) {
char *ptr=str;
while(*ptr) {
if(!isdigit(*ptr))
return 0;
ptr++;
}
return 1;
}
int scan_mp3_get_mp3tags(char *file, MP3FILE *pmp3) {
struct id3_file *pid3file;
struct id3_tag *pid3tag;
struct id3_frame *pid3frame;
int err;
int index;
int used;
char *utf8_text;
int genre=WINAMP_GENRE_UNKNOWN;
int have_utf8;
int have_text;
id3_ucs4_t const *native_text;
char *tmp;
int got_numeric_genre;
pid3file=id3_file_open(file,ID3_FILE_MODE_READONLY);
if(!pid3file) {
DPRINTF(E_WARN,L_SCAN,"Cannot open %s\n",file);
return FALSE;
}
pid3tag=id3_file_tag(pid3file);
if(!pid3tag) {
err=errno;
id3_file_close(pid3file);
errno=err;
DPRINTF(E_WARN,L_SCAN,"Cannot get ID3 tag for %s\n",file);
return FALSE;
}
DPRINTF(E_SPAM,L_SCAN,"Starting mp3 tag scan\n");
index=0;
while((pid3frame=id3_tag_findframe(pid3tag,"",index))) {
used=0;
utf8_text=NULL;
native_text=NULL;
have_utf8=0;
have_text=0;
DPRINTF(E_SPAM,L_SCAN,"Found tag %s\n",pid3frame->id);
if(!strcmp(pid3frame->id,"YTCP")) { /* for id3v2.2 */
pmp3->compilation = 1;
DPRINTF(E_DBG,L_SCAN,"Compilation: %d\n", pmp3->compilation);
}
if(((pid3frame->id[0] == 'T')||(strcmp(pid3frame->id,"COMM")==0)) &&
(id3_field_getnstrings(&pid3frame->fields[1])))
have_text=1;
if(have_text) {
native_text=id3_field_getstrings(&pid3frame->fields[1],0);
if(native_text) {
/* FIXME: I didn't understand what was happening here.
* this should really be a switch to evaluate latin1
* tags as native codepage. Not only is this hackish,
* it's just plain wrong.
*/
have_utf8=1;
if(conf_get_int("general","latin1_tags",0)) {
utf8_text=(char *)id3_ucs4_latin1duplicate(native_text);
} else {
utf8_text=(char *)id3_ucs4_utf8duplicate(native_text);
}
if(!strcmp(pid3frame->id,"TIT2")) { /* Title */
used=1;
pmp3->title = utf8_text;
DPRINTF(E_DBG,L_SCAN," Title: %s\n",utf8_text);
} else if(!strcmp(pid3frame->id,"TPE1")) {
used=1;
pmp3->artist = utf8_text;
DPRINTF(E_DBG,L_SCAN," Artist: %s\n",utf8_text);
} else if(!strcmp(pid3frame->id,"TALB")) {
used=1;
pmp3->album = utf8_text;
DPRINTF(E_DBG,L_SCAN," Album: %s\n",utf8_text);
} else if(!strcmp(pid3frame->id,"TCOM")) {
used=1;
pmp3->composer = utf8_text;
DPRINTF(E_DBG,L_SCAN," Composer: %s\n",utf8_text);
} else if(!strcmp(pid3frame->id,"TIT1")) {
used=1;
pmp3->grouping = utf8_text;
DPRINTF(E_DBG,L_SCAN," Grouping: %s\n",utf8_text);
} else if(!strcmp(pid3frame->id,"TPE2")) {
used=1;
pmp3->orchestra = utf8_text;
DPRINTF(E_DBG,L_SCAN," Orchestra: %s\n",utf8_text);
} else if(!strcmp(pid3frame->id,"TPE3")) {
used=1;
pmp3->conductor = utf8_text;
DPRINTF(E_DBG,L_SCAN," Conductor: %s\n",utf8_text);
} else if(!strcmp(pid3frame->id,"TCON")) {
used=1;
pmp3->genre = utf8_text;
got_numeric_genre=0;
DPRINTF(E_DBG,L_SCAN," Genre: %s\n",utf8_text);
if(pmp3->genre) {
if(!strlen(pmp3->genre)) {
genre=WINAMP_GENRE_UNKNOWN;
got_numeric_genre=1;
} else if (scan_mp3_is_numeric(pmp3->genre)) {
genre=atoi(pmp3->genre);
got_numeric_genre=1;
} else if ((pmp3->genre[0] == '(') && (isdigit(pmp3->genre[1]))) {
genre=atoi((char*)&pmp3->genre[1]);
got_numeric_genre=1;
}
if(got_numeric_genre) {
if((genre < 0) || (genre > WINAMP_GENRE_UNKNOWN))
genre=WINAMP_GENRE_UNKNOWN;
free(pmp3->genre);
pmp3->genre=strdup(scan_winamp_genre[genre]);
}
}
} else if(!strcmp(pid3frame->id,"COMM")) {
used=1;
pmp3->comment = utf8_text;
DPRINTF(E_DBG,L_SCAN," Comment: %s\n",pmp3->comment);
} else if(!strcmp(pid3frame->id,"TPOS")) {
tmp=utf8_text;
strsep(&tmp,"/");
if(tmp) {
pmp3->total_discs=atoi(tmp);
}
pmp3->disc=atoi(utf8_text);
DPRINTF(E_DBG,L_SCAN," Disc %d of %d\n",pmp3->disc,pmp3->total_discs);
} else if(!strcmp(pid3frame->id,"TRCK")) {
tmp=utf8_text;
strsep(&tmp,"/");
if(tmp) {
pmp3->total_tracks=atoi(tmp);
}
pmp3->track=atoi(utf8_text);
DPRINTF(E_DBG,L_SCAN," Track %d of %d\n",pmp3->track,pmp3->total_tracks);
} else if(!strcmp(pid3frame->id,"TDRC")) {
pmp3->year = atoi(utf8_text);
DPRINTF(E_DBG,L_SCAN," Year: %d\n",pmp3->year);
} else if(!strcmp(pid3frame->id,"TLEN")) {
pmp3->song_length = atoi(utf8_text); /* now in ms */
DPRINTF(E_DBG,L_SCAN," Length: %d\n", pmp3->song_length);
} else if(!strcmp(pid3frame->id,"TBPM")) {
pmp3->bpm = atoi(utf8_text);
DPRINTF(E_DBG,L_SCAN,"BPM: %d\n", pmp3->bpm);
} else if(!strcmp(pid3frame->id,"TCMP")) { /* for id3v2.3 */
pmp3->compilation = (char)atoi(utf8_text);
DPRINTF(E_DBG,L_SCAN,"Compilation: %d\n", pmp3->compilation);
}
}
}
/* can check for non-text tags here */
if((!used) && (have_utf8) && (utf8_text))
free(utf8_text);
/* v2 COMM tags are a bit different than v1 */
if((!strcmp(pid3frame->id,"COMM")) && (pid3frame->nfields == 4)) {
/* Make sure it isn't a application-specific comment...
* This currently includes the following:
*
* iTunes_CDDB_IDs
* iTunNORM
*
* If other apps stuff crap into comment fields, then we'll ignore them
* here.
*/
native_text=id3_field_getstring(&pid3frame->fields[2]);
if(native_text) {
utf8_text=(char*)id3_ucs4_utf8duplicate(native_text);
if((utf8_text) && (strncasecmp(utf8_text,"iTun",4) != 0)) {
/* it's a real comment */
if(utf8_text)
free(utf8_text);
native_text=id3_field_getfullstring(&pid3frame->fields[3]);
if(native_text) {
if(pmp3->comment)
free(pmp3->comment);
utf8_text=(char*)id3_ucs4_utf8duplicate(native_text);
if(utf8_text) {
pmp3->comment=utf8_text;
}
}
} else {
if(utf8_text)
free(utf8_text);
}
}
}
index++;
}
id3_file_close(pid3file);
DPRINTF(E_DBG,L_SCAN,"Got id3 tag successfully\n");
return TRUE;
}
/**
* Decode an mp3 frame header. Determine layer, bitrate,
* samplerate, etc, and fill in the passed structure.
*
* @param frame 4 byte mp3 frame header
* @param pfi pointer to an allocated SCAN_FRAMEINFO struct
* @return 0 on success (valid frame), -1 otherwise
*/
int scan_mp3_decode_mp3_frame(unsigned char *frame, SCAN_FRAMEINFO *pfi) {
int ver;
int layer_index;
int sample_index;
int bitrate_index;
int samplerate_index;
if((frame[0] != 0xFF) || (frame[1] < 224)) {
pfi->is_valid=0;
return -1;
}
ver=(frame[1] & 0x18) >> 3;
pfi->layer = 4 - ((frame[1] & 0x6) >> 1);
layer_index=-1;
sample_index=-1;
switch(ver) {
case 0:
pfi->version = 2.5;
sample_index=2;
if(pfi->layer == 1)
layer_index = 3;
if((pfi->layer == 2) || (pfi->layer == 3))
layer_index = 4;
break;
case 2:
pfi->version = 2.0;
sample_index=1;
if(pfi->layer == 1)
layer_index=3;
if((pfi->layer == 2) || (pfi->layer == 3))
layer_index=4;
break;
case 3:
pfi->version = 1.0;
sample_index=0;
if(pfi->layer == 1)
layer_index = 0;
if(pfi->layer == 2)
layer_index = 1;
if(pfi->layer == 3)
layer_index = 2;
break;
}
if((layer_index < 0) || (layer_index > 4)) {
pfi->is_valid=0;
return -1;
}
if((sample_index < 0) || (sample_index > 2)) {
pfi->is_valid=0;
return -1;
}
if(pfi->layer==1) pfi->samples_per_frame=384;
if(pfi->layer==2) pfi->samples_per_frame=1152;
if(pfi->layer==3) {
if(pfi->version == 1.0) {
pfi->samples_per_frame=1152;
} else {
pfi->samples_per_frame=576;
}
}
bitrate_index=(frame[2] & 0xF0) >> 4;
samplerate_index=(frame[2] & 0x0C) >> 2;
if((bitrate_index == 0xF) || (bitrate_index==0x0)) {
pfi->is_valid=0;
return -1;
}
if(samplerate_index == 3) {
pfi->is_valid=0;
return -1;
}
pfi->bitrate = scan_br_table[layer_index][bitrate_index];
pfi->samplerate = scan_sample_table[sample_index][samplerate_index];
if((frame[3] & 0xC0 >> 6) == 3)
pfi->stereo = 0;
else
pfi->stereo = 1;
if(frame[2] & 0x02) { /* Padding bit set */
pfi->padding=1;
} else {
pfi->padding=0;
}
if(pfi->version == 1.0) {
if(pfi->stereo) {
pfi->xing_offset=32;
} else {
pfi->xing_offset=17;
}
} else {
if(pfi->stereo) {
pfi->xing_offset=17;
} else {
pfi->xing_offset=9;
}
}
pfi->crc_protected=(frame[1] & 0xFE);
if(pfi->layer == 1) {
pfi->frame_length = (12 * pfi->bitrate * 1000 / pfi->samplerate + pfi->padding) * 4;
} else {
pfi->frame_length = 144 * pfi->bitrate * 1000 / pfi->samplerate + pfi->padding;
}
if((pfi->frame_length > 2880) || (pfi->frame_length <= 0)) {
pfi->is_valid=0;
return -1;
}
pfi->is_valid=1;
return 0;
}
/**
* Scan 10 frames from the middle of the file and determine an
* average bitrate from that. It might not be as accurate as a full
* frame count, but it's probably Close Enough (tm)
*
* @param infile file to scan for average bitrate
* @param pfi pointer to frame info struct to put the bitrate into
*/
void scan_mp3_get_average_bitrate(FILE *infile, SCAN_FRAMEINFO *pfi) {
off_t file_size;
unsigned char frame_buffer[2900];
unsigned char header[4];
int index=0;
int found=0;
off_t pos;
SCAN_FRAMEINFO fi;
int frame_count=0;
int bitrate_total=0;
DPRINTF(E_DBG,L_SCAN,"Starting averaging bitrate\n");
fseek(infile,0,SEEK_END);
file_size=ftell(infile);
pos=file_size/2;
/* now, find the first frame */
fseek(infile,pos,SEEK_SET);
if(fread(frame_buffer,1,sizeof(frame_buffer),infile) != sizeof(frame_buffer))
return;
while(!found) {
while((frame_buffer[index] != 0xFF) && (index < (sizeof(frame_buffer)-4)))
index++;
if(index >= (sizeof(frame_buffer)-4)) { /* largest mp3 frame is 2880 bytes */
DPRINTF(E_DBG,L_SCAN,"Could not find frame... quitting\n");
return;
}
if(!scan_mp3_decode_mp3_frame(&frame_buffer[index],&fi)) {
/* see if next frame is valid */
fseek(infile,pos + index + fi.frame_length,SEEK_SET);
if(fread(header,1,sizeof(header),infile) != sizeof(header)) {
DPRINTF(E_DBG,L_SCAN,"Could not read frame header\n");
return;
}
if(!scan_mp3_decode_mp3_frame(header,&fi))
found=1;
}
if(!found)
index++;
}
pos += index;
/* found first frame. Let's move */
while(frame_count < 10) {
fseek(infile,pos,SEEK_SET);
if(fread(header,1,sizeof(header),infile) != sizeof(header)) {
DPRINTF(E_DBG,L_SCAN,"Could not read frame header\n");
return;
}
if(scan_mp3_decode_mp3_frame(header,&fi)) {
DPRINTF(E_DBG,L_SCAN,"Invalid frame header while averaging\n");
return;
}
bitrate_total += fi.bitrate;
frame_count++;
pos += fi.frame_length;
}
DPRINTF(E_DBG,L_SCAN,"Old bitrate: %d\n",pfi->bitrate);
pfi->bitrate = bitrate_total/frame_count;
DPRINTF(E_DBG,L_SCAN,"New bitrate: %d\n",pfi->bitrate);
return;
}
/**
* do a full frame-by-frame scan of the file, counting frames
* as we go to try and get a more accurate song length estimate.
* If the song turns out to be CBR, then we'll not set the frame
* length. Instead we'll use the file size estimate, since it is
* more consistent with iTunes.
*
* @param infile file to scan for frame count
* @param pfi pointer to frame info struct to put framecount into
*/
void scan_mp3_get_frame_count(FILE *infile, SCAN_FRAMEINFO *pfi) {
int pos;
int frames=0;
unsigned char frame_buffer[4];
SCAN_FRAMEINFO fi;
off_t file_size;
int err=0;
int cbr=1;
int last_bitrate=0;
DPRINTF(E_DBG,L_SCAN,"Starting frame count\n");
fseek(infile,0,SEEK_END);
file_size=ftell(infile);
pos=pfi->frame_offset;
while(1) {
err=1;
DPRINTF(E_SPAM,L_SCAN,"Seeking to %d\n",pos);
fseek(infile,pos,SEEK_SET);
if(fread(frame_buffer,1,sizeof(frame_buffer),infile) == sizeof(frame_buffer)) {
/* check for valid frame */
if(!scan_mp3_decode_mp3_frame(frame_buffer,&fi)) {
frames++;
pos += fi.frame_length;
err=0;
if((last_bitrate) && (fi.bitrate != last_bitrate))
cbr=0;
last_bitrate=fi.bitrate;
/* no point in brute scan of a cbr file... */
if(cbr && (frames > 100)) {
DPRINTF(E_DBG,L_SCAN,"File appears to be CBR... quitting frame count\n");
return;
}
}
}
if(err) {
if(pos > (file_size - 4096)) { /* probably good enough */
pfi->number_of_frames=frames;
DPRINTF(E_DBG,L_SCAN,"Estimated frame count: %d\n",frames);
return;
} else {
DPRINTF(E_DBG,L_SCAN,"Frame count aborted on error. Pos=%d, Count=%d\n",
pos, frames);
return;
}
}
}
}
/**
* Get information from the file headers itself -- like
* song length, bit rate, etc.
*
* @param file File to get info for
* @param pmp3 where to put the found information
*/
int scan_mp3_get_mp3fileinfo(char *file, MP3FILE *pmp3) {
FILE *infile;
SCAN_ID3HEADER *pid3;
SCAN_FRAMEINFO fi;
unsigned int size=0;
off_t fp_size=0;
off_t file_size;
unsigned char buffer[1024];
int index;
int xing_flags;
int found;
int first_check=0;
char frame_buffer[4];
if(!(infile=fopen(file,"rb"))) {
DPRINTF(E_WARN,L_SCAN,"Could not open %s for reading\n",file);
return FALSE;
}
memset((void*)&fi,0x00,sizeof(fi));
fseek(infile,0,SEEK_END);
file_size=ftell(infile);
fseek(infile,0,SEEK_SET);
pmp3->file_size=file_size;
if(fread(buffer,1,sizeof(buffer),infile) != sizeof(buffer)) {
if(ferror(infile)) {
DPRINTF(E_LOG,L_SCAN,"Error reading: %s\n",strerror(errno));
} else {
DPRINTF(E_LOG,L_SCAN,"Short file: %s\n",file);
}
fclose(infile);
return FALSE;
}
pid3=(SCAN_ID3HEADER*)buffer;
found=0;
fp_size=0;
if(strncmp((char*)pid3->id,"ID3",3)==0) {
/* found an ID3 header... */
DPRINTF(E_DBG,L_SCAN,"Found ID3 header\n");
size = (pid3->size[0] << 21 | pid3->size[1] << 14 |
pid3->size[2] << 7 | pid3->size[3]);
fp_size=size + sizeof(SCAN_ID3HEADER);
first_check=1;
DPRINTF(E_DBG,L_SCAN,"Header length: %d\n",size);
}
index = 0;
/* Here we start the brute-force header seeking. Sure wish there
* weren't so many crappy mp3 files out there
*/
while(!found) {
fseek(infile,fp_size,SEEK_SET);
DPRINTF(E_DBG,L_SCAN,"Reading in new block at %d\n",(int)fp_size);
if(fread(buffer,1,sizeof(buffer),infile) < sizeof(buffer)) {
DPRINTF(E_LOG,L_SCAN,"Short read: %s\n",file);
fclose(infile);
return TRUE;
}
index=0;
while(!found) {
while((buffer[index] != 0xFF) && (index < (sizeof(buffer)-50)))
index++;
if((first_check) && (index)) {
fp_size=0;
DPRINTF(E_DBG,L_SCAN,"Bad header... dropping back for full frame search\n");
first_check=0;
break;
}
if(index > sizeof(buffer) - 50) {
fp_size += index;
DPRINTF(E_DBG,L_SCAN,"Block exhausted\n");
break;
}
if(!scan_mp3_decode_mp3_frame(&buffer[index],&fi)) {
DPRINTF(E_DBG,L_SCAN,"valid header at %d\n",index);
if(strncasecmp((char*)&buffer[index+fi.xing_offset+4],"XING",4) == 0) {
/* no need to check further... if there is a xing header there,
* this is definately a valid frame */
found=1;
fp_size += index;
} else {
/* No Xing... check for next frame */
DPRINTF(E_DBG,L_SCAN,"Found valid frame at %04x\n",(int)fp_size+index);
DPRINTF(E_DBG,L_SCAN,"Checking at %04x\n",(int)fp_size+index+fi.frame_length);
fseek(infile,fp_size + index + fi.frame_length,SEEK_SET);
if(fread(frame_buffer,1,sizeof(frame_buffer),infile) == sizeof(frame_buffer)) {
if(!scan_mp3_decode_mp3_frame((u_char*)frame_buffer,&fi)) {
found=1;
fp_size += index;
}
} else {
DPRINTF(E_LOG,L_SCAN,"Could not read frame header: %s\n",file);
fclose(infile);
return 0;
}
if(!found) {
DPRINTF(E_DBG,L_SCAN,"Didn't pan out.\n");
}
}
}
if(!found) {
index++;
if (first_check) {
/* if the header info was wrong about where the data started,
* then start a brute-force scan from the beginning of the file.
* don't want to just scan forward, because we might have already
* missed the xing header
*/
DPRINTF(E_DBG,L_SCAN,"Bad header... dropping back for full frame search\n");
first_check=0;
fp_size=0;
break;
}
}
}
}
file_size -= fp_size;
fi.frame_offset=fp_size;
if(scan_mp3_decode_mp3_frame(&buffer[index],&fi)) {
fclose(infile);
DPRINTF(E_LOG,L_SCAN,"Could not find sync frame: %s\n",file);
DPRINTF(E_LOG,L_SCAN,"If this is a valid mp3 file that plays in "
"other applications, please email me at rpedde@users.sourceforge.net "
"and tell me you got this error. Thanks");
return TRUE;
}
DPRINTF(E_DBG,L_SCAN," MPEG Version: %0.1g\n",fi.version);
DPRINTF(E_DBG,L_SCAN," Layer: %d\n",fi.layer);
DPRINTF(E_DBG,L_SCAN," Sample Rate: %d\n",fi.samplerate);
DPRINTF(E_DBG,L_SCAN," Bit Rate: %d\n",fi.bitrate);
/* now check for an XING header */
if(strncasecmp((char*)&buffer[index+fi.xing_offset+4],"XING",4) == 0) {
DPRINTF(E_DBG,L_SCAN,"Found Xing header\n");
xing_flags = buffer[index+fi.xing_offset+4+4] << 24 |
buffer[index+fi.xing_offset+4+5] << 16 |
buffer[index+fi.xing_offset+4+6] << 8 |
buffer[index+fi.xing_offset+4+7];
DPRINTF(E_DBG,L_SCAN,"Xing Flags: %02X\n",xing_flags);
if(xing_flags & 0x1) {
/* Frames field is valid... */
fi.number_of_frames=buffer[index+fi.xing_offset+4+8] << 24 |
buffer[index+fi.xing_offset+4+9] << 16 |
buffer[index+fi.xing_offset+4+10] << 8 |
buffer[index+fi.xing_offset+4+11];
}
}
if((conf_get_int("general","scan_type",0) != 0) &&
(fi.number_of_frames == 0) &&
(!pmp3->song_length)) {
/* We have no good estimate of song time, and we want more
* aggressive scanning */
DPRINTF(E_DBG,L_SCAN,"Starting aggressive file length scan\n");
if(conf_get_int("general","scan_type",0) == 1) {
/* get average bitrate */
scan_mp3_get_average_bitrate(infile, &fi);
} else {
/* get full frame count */
scan_mp3_get_frame_count(infile, &fi);
}
}
pmp3->bitrate=fi.bitrate;
pmp3->samplerate=fi.samplerate;
/* guesstimate the file length */
if(!pmp3->song_length) { /* could have gotten it from the tag */
/* DWB: use ms time instead of seconds, use doubles to
avoid overflow */
if(!fi.number_of_frames) { /* not vbr */
pmp3->song_length = (int) ((double) file_size * 8. /
(double) fi.bitrate);
} else {
pmp3->song_length = (int) ((double)(fi.number_of_frames*fi.samples_per_frame*1000.)/
(double) fi.samplerate);
}
}
DPRINTF(E_DBG,L_SCAN," Song Length: %d\n",pmp3->song_length);
fclose(infile);
return TRUE;
}