rockbox/apps/metadata/asap.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2008 Dominik Wenger
 *
 * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <inttypes.h>

#include "system.h"
#include "metadata.h"
#include "metadata_common.h"
#include "metadata_parsers.h"
#include "rbunicode.h"
#include "debug.h"

#define MAX_SONGS  32

static bool parse_dec(int *retval, const char *p, int minval, int maxval)
{
    int r = 0;
    do {
        char c = *p;
        if (c >= '0' && c <= '9')
            r = 10 * r + c - '0';
        else
            return false;
        if (r > maxval)
            return false;
    } while (*++p != '\0');
    if (r < minval)
        return false;
    *retval = r;
    return true;
}

static bool parse_text(char *retval, const char *p)
{
    int i;
    if (*p != '"')
        return false;
    p++;
    if (p[0] == '<' && p[1] == '?' && p[2] == '>' && p[3] == '"')
        return true;
    i = 0;
    while (*p != '"') {
        if (i >= 127)
            return false;
        if (*p == '\0')
            return false;
        retval[i++] = *p++;
    }
    retval[i] = '\0';
    return true;
}

static int ASAP_ParseDuration(const char *s)
{
    int r;
    if (*s < '0' || *s > '9')
        return -1;
    r = *s++ - '0';
    if (*s >= '0' && *s <= '9')
        r = 10 * r + *s++ - '0';
    if (*s == ':') {
        s++;
        if (*s < '0' || *s > '5')
            return -1;
        r = 60 * r + (*s++ - '0') * 10;
        if (*s < '0' || *s > '9')
            return -1;
        r += *s++ - '0';
    }
    r *= 1000;
    if (*s != '.')
        return r;
    s++;
    if (*s < '0' || *s > '9')
        return r;
    r += 100 * (*s++ - '0');
    if (*s < '0' || *s > '9')
        return r;
    r += 10 * (*s++ - '0');
    if (*s < '0' || *s > '9')
        return r;
    r += *s - '0';
    return r;
}

static bool read_asap_string(char* source,char** buf,char** buffer_end,char** dest)
{
    if(parse_text(*buf,source) == false) return false;
  
    /* set dest pointer */
    *dest = *buf;
    
    /* move buf ptr */
    *buf += strlen(*buf)+1;
       
    /* check size */
    if(*buf >= *buffer_end)
    {
        DEBUGF("Buffer full\n");
        return false;
    }
    return true;
}

static bool parse_sap_header(int fd,struct mp3entry* id3,int file_len)
{
    int module_index = 0;
    int sap_signature = -1;
    int duration_index = 0;
    unsigned char cur_char = 0; 
    int i;
    
    /* set defaults */
    int numSongs=1;
    int defSong=0;
    int numChannels=1;
    int durations[MAX_SONGS];
    int loops[MAX_SONGS];
    for (i = 0; i < MAX_SONGS; i++) {
        durations[i] = -1;
        loops[i] = 0;
    }
    
    /* use id3v2 buffer for our strings */
    char* buffer = id3->id3v2buf;
    char* buffer_end = id3->id3v2buf + ID3V2_BUF_SIZE;
    
    /* parse file */
    while (1)
    {
        char line[256];
        char *p;
        
        if (module_index + 8 >= file_len)
            return false;
        /* read a char */
        read(fd,&cur_char,1);
        /* end of header */
        if (cur_char == 0xff)
            break;
            
        i = 0;
        while (cur_char != 0x0d) 
        {
            line[i++] = cur_char; 
            module_index++;
            if (module_index >= file_len || (unsigned)i >= sizeof(line) - 1)
                return false;
            /* read a char */
            read(fd,&cur_char,1);
        }
        if (++module_index >= file_len )
            return false;
        /* read a char */
        read(fd,&cur_char,1);
        if ( cur_char != 0x0a)    
            return false;    
            
        line[i] = '\0';
        for (p = line; *p != '\0'; p++) {
            if (*p == ' ') {
                *p++ = '\0';
                break;
            }
        }
        
        /* parse tags */
        if(strcmp(line, "SAP") == 0)
            sap_signature = 1;
        if (sap_signature == -1)
            return false;
        if (strcmp(line,"AUTHOR") == 0)
        {
            if(read_asap_string(p,&buffer,&buffer_end,&id3->artist) == false)
                return false;
        }
        else if(strcmp(line,"NAME")==0)
        {
            if(read_asap_string(p,&buffer,&buffer_end,&id3->title) == false)
                return false;
        }
        else if(strcmp(line,"DATE")==0)
        {
            if(read_asap_string(p,&buffer,&buffer_end,&id3->year_string) == false)
                return false;          
        }
        else if (strcmp(line,"SONGS")==0)
        {
            if (parse_dec(&numSongs, p,1,MAX_SONGS) == false )
                return false; 
        }
        else if (strcmp(line,"DEFSONG")==0)
        {
            if (parse_dec(&defSong, p,0,MAX_SONGS) == false)
                return false; 
        }
        else if (strcmp(line,"STEREO")==0)
        {
            numChannels = 2;
        }       
        else if (strcmp(line,"TIME") == 0) 
        {
            int durationTemp = ASAP_ParseDuration(p);
            if (durationTemp < 0 || duration_index >= MAX_SONGS)
                return false;
            durations[duration_index] = durationTemp;
            if (strstr(p, "LOOP") != NULL)
                loops[duration_index] = 1;
            duration_index++;
        }
    }    
    
    /* set length: */
    int length =  durations[defSong];
    if (length < 0)
        length = 180 * 1000;
    id3->length = length;
    
    lseek(fd,0,SEEK_SET);
    return true;
}


bool get_asap_metadata(int fd, struct mp3entry* id3)
{  

    int filelength = filesize(fd);
 
    if(parse_sap_header(fd,id3,filelength) == false)
    {
        DEBUGF("parse sap header failed.\n");
        return false;
    }   
        
    id3->bitrate = 706;
    id3->frequency = 44100;

    id3->vbr = false;
    id3->filesize = filelength;
    
    return true;
}