dlls/winemp3.acm/interface.c

   1 /*
   2  * Copyright (c) Michael Hipp and other authors of the mpglib project.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21
  22 #include "mpg123.h"
  23 #include "mpglib.h"
  24
  25
  26 BOOL InitMP3(struct mpstr *mp)
  27 {
  28         static int init = 0;
  29
  30         memset(mp,0,sizeof(struct mpstr));
  31
  32         mp->framesize = 0;
  33         mp->fsizeold = -1;
  34         mp->bsize = 0;
  35         mp->head = mp->tail = NULL;
  36         mp->fr.single = -1;
  37         mp->bsnum = 0;
  38         mp->synth_bo = 1;
  39         mp->fr.mp = mp;
  40
  41         if(!init) {
  42                 init = 1;
  43                 make_decode_tables(32767);
  44                 init_layer2();
  45                 init_layer3(SBLIMIT);
  46         }
  47
  48         return !0;
  49 }
  50
  51 void ClearMP3Buffer(struct mpstr *mp)
  52 {
  53         struct buf *b,*bn;
  54
  55         b = mp->tail;
  56         while(b) {
  57                 free(b->pnt);
  58                 bn = b->next;
  59                 free(b);
  60                 b = bn;
  61         }
  62         mp->tail = NULL;
  63         mp->head = NULL;
  64         mp->bsize = 0;
  65 }
  66
  67 static struct buf *addbuf(struct mpstr *mp,const unsigned char *buf,int size)
  68 {
  69         struct buf *nbuf;
  70
  71         nbuf = malloc( sizeof(struct buf) );
  72         if(!nbuf) {
  73                 fprintf(stderr,"Out of memory!\n");
  74                 return NULL;
  75         }
  76         nbuf->pnt = malloc(size);
  77         if(!nbuf->pnt) {
  78                 free(nbuf);
  79                 return NULL;
  80         }
  81         nbuf->size = size;
  82         memcpy(nbuf->pnt,buf,size);
  83         nbuf->next = NULL;
  84         nbuf->prev = mp->head;
  85         nbuf->pos = 0;
  86
  87         if(!mp->tail) {
  88                 mp->tail = nbuf;
  89         }
  90         else {
  91           mp->head->next = nbuf;
  92         }
  93
  94         mp->head = nbuf;
  95         mp->bsize += size;
  96
  97         return nbuf;
  98 }
  99
 100 static void remove_buf(struct mpstr *mp)
 101 {
 102   struct buf *buf = mp->tail;
 103
 104   mp->tail = buf->next;
 105   if(mp->tail)
 106     mp->tail->prev = NULL;
 107   else {
 108     mp->tail = mp->head = NULL;
 109   }
 110
 111   free(buf->pnt);
 112   free(buf);
 113
 114 }
 115
 116 static int read_buf_byte(struct mpstr *mp)
 117 {
 118         unsigned int b;
 119
 120         int pos;
 121
 122         pos = mp->tail->pos;
 123         while(pos >= mp->tail->size) {
 124                 remove_buf(mp);
 125                 pos = mp->tail->pos;
 126         }
 127
 128         b = mp->tail->pnt[pos];
 129         mp->bsize--;
 130         mp->tail->pos++;
 131
 132
 133         return b;
 134 }
 135
 136 static void read_head(struct mpstr *mp)
 137 {
 138         unsigned long head;
 139
 140         head = read_buf_byte(mp);
 141         head <<= 8;
 142         head |= read_buf_byte(mp);
 143         head <<= 8;
 144         head |= read_buf_byte(mp);
 145         head <<= 8;
 146         head |= read_buf_byte(mp);
 147
 148         mp->header = head;
 149 }
 150
 151 int decodeMP3(struct mpstr *mp,const unsigned char *in,int isize,unsigned char *out,
 152                 int osize,int *done)
 153 {
 154         int len;
 155
 156         if(osize < 4608) {
 157                 fprintf(stderr,"To less out space\n");
 158                 return MP3_ERR;
 159         }
 160
 161         if(in) {
 162                 if(addbuf(mp,in,isize) == NULL) {
 163                         return MP3_ERR;
 164                 }
 165         }
 166
 167         /* First decode header */
 168         if(mp->framesize == 0) {
 169                 if(mp->bsize < 4) {
 170                         return MP3_NEED_MORE;
 171                 }
 172                 read_head(mp);
 173                 if (decode_header(&mp->fr,mp->header) == 0) {
 174                         return MP3_ERR;
 175                 }
 176                 mp->framesize = mp->fr.framesize;
 177         }
 178
 179         if(mp->fr.framesize > mp->bsize)
 180                 return MP3_NEED_MORE;
 181
 182         wordpointer = mp->bsspace[mp->bsnum] + 512;
 183         mp->bsnum = (mp->bsnum + 1) & 0x1;
 184         bitindex = 0;
 185
 186         len = 0;
 187         while(len < mp->framesize) {
 188                 int nlen;
 189                 int blen = mp->tail->size - mp->tail->pos;
 190                 if( (mp->framesize - len) <= blen) {
 191                   nlen = mp->framesize-len;
 192                 }
 193                 else {
 194                   nlen = blen;
 195                 }
 196                 memcpy(wordpointer+len,mp->tail->pnt+mp->tail->pos,nlen);
 197                 len += nlen;
 198                 mp->tail->pos += nlen;
 199                 mp->bsize -= nlen;
 200                 if(mp->tail->pos == mp->tail->size) {
 201                    remove_buf(mp);
 202                 }
 203         }
 204
 205         *done = 0;
 206         if(mp->fr.error_protection)
 207            getbits(16);
 208         switch(mp->fr.lay) {
 209           case 1:
 210             do_layer1(&mp->fr,out,done);
 211             break;
 212           case 2:
 213             do_layer2(&mp->fr,out,done);
 214             break;
 215           case 3:
 216             do_layer3(&mp->fr,out,done);
 217             break;
 218         }
 219
 220         mp->fsizeold = mp->framesize;
 221         mp->framesize = 0;
 222
 223         return MP3_OK;
 224 }
 225
 226 int set_pointer(struct mpstr *mp, long backstep)
 227 {
 228   unsigned char *bsbufold;
 229   if(mp->fsizeold < 0 && backstep > 0) {
 230     fprintf(stderr,"Can't step back %ld!\n",backstep);
 231     return MP3_ERR;
 232   }
 233   bsbufold = mp->bsspace[mp->bsnum] + 512;
 234   wordpointer -= backstep;
 235   if (backstep)
 236     memcpy(wordpointer,bsbufold+mp->fsizeold-backstep,backstep);
 237   bitindex = 0;
 238   return MP3_OK;
 239 }