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 /* Global mp .. it's a hack */
  26 struct mpstr *gmp;
  27
  28
  29 BOOL InitMP3(struct mpstr *mp)
  30 {
  31         static int init = 0;
  32
  33         memset(mp,0,sizeof(struct mpstr));
  34
  35         mp->framesize = 0;
  36         mp->fsizeold = -1;
  37         mp->bsize = 0;
  38         mp->head = mp->tail = NULL;
  39         mp->fr.single = -1;
  40         mp->bsnum = 0;
  41         mp->synth_bo = 1;
  42
  43         if(!init) {
  44                 init = 1;
  45                 make_decode_tables(32767);
  46                 init_layer2();
  47                 init_layer3(SBLIMIT);
  48         }
  49
  50         return !0;
  51 }
  52
  53 void ExitMP3(struct mpstr *mp)
  54 {
  55         struct buf *b,*bn;
  56
  57         b = mp->tail;
  58         while(b) {
  59                 free(b->pnt);
  60                 bn = b->next;
  61                 free(b);
  62                 b = bn;
  63         }
  64 }
  65
  66 static struct buf *addbuf(struct mpstr *mp,const unsigned char *buf,int size)
  67 {
  68         struct buf *nbuf;
  69
  70         nbuf = malloc( sizeof(struct buf) );
  71         if(!nbuf) {
  72                 fprintf(stderr,"Out of memory!\n");
  73                 return NULL;
  74         }
  75         nbuf->pnt = malloc(size);
  76         if(!nbuf->pnt) {
  77                 free(nbuf);
  78                 return NULL;
  79         }
  80         nbuf->size = size;
  81         memcpy(nbuf->pnt,buf,size);
  82         nbuf->next = NULL;
  83         nbuf->prev = mp->head;
  84         nbuf->pos = 0;
  85
  86         if(!mp->tail) {
  87                 mp->tail = nbuf;
  88         }
  89         else {
  90           mp->head->next = nbuf;
  91         }
  92
  93         mp->head = nbuf;
  94         mp->bsize += size;
  95
  96         return nbuf;
  97 }
  98
  99 static void remove_buf(struct mpstr *mp)
 100 {
 101   struct buf *buf = mp->tail;
 102
 103   mp->tail = buf->next;
 104   if(mp->tail)
 105     mp->tail->prev = NULL;
 106   else {
 107     mp->tail = mp->head = NULL;
 108   }
 109
 110   free(buf->pnt);
 111   free(buf);
 112
 113 }
 114
 115 static int read_buf_byte(struct mpstr *mp)
 116 {
 117         unsigned int b;
 118
 119         int pos;
 120
 121         pos = mp->tail->pos;
 122         while(pos >= mp->tail->size) {
 123                 remove_buf(mp);
 124                 pos = mp->tail->pos;
 125                 if(!mp->tail) {
 126                         fprintf(stderr,"Fatal error!\n");
 127                         exit(1);
 128                 }
 129         }
 130
 131         b = mp->tail->pnt[pos];
 132         mp->bsize--;
 133         mp->tail->pos++;
 134
 135
 136         return b;
 137 }
 138
 139 static void read_head(struct mpstr *mp)
 140 {
 141         unsigned long head;
 142
 143         head = read_buf_byte(mp);
 144         head <<= 8;
 145         head |= read_buf_byte(mp);
 146         head <<= 8;
 147         head |= read_buf_byte(mp);
 148         head <<= 8;
 149         head |= read_buf_byte(mp);
 150
 151         mp->header = head;
 152 }
 153
 154 int decodeMP3(struct mpstr *mp,const unsigned char *in,int isize,unsigned char *out,
 155                 int osize,int *done)
 156 {
 157         int len;
 158
 159         gmp = mp;
 160
 161         if(osize < 4608) {
 162                 fprintf(stderr,"To less out space\n");
 163                 return MP3_ERR;
 164         }
 165
 166         if(in) {
 167                 if(addbuf(mp,in,isize) == NULL) {
 168                         return MP3_ERR;
 169                 }
 170         }
 171
 172         /* First decode header */
 173         if(mp->framesize == 0) {
 174                 if(mp->bsize < 4) {
 175                         return MP3_NEED_MORE;
 176                 }
 177                 read_head(mp);
 178                 if (decode_header(&mp->fr,mp->header) == 0) {
 179                         return MP3_ERR;
 180                 }
 181                 mp->framesize = mp->fr.framesize;
 182         }
 183
 184         if(mp->fr.framesize > mp->bsize)
 185                 return MP3_NEED_MORE;
 186
 187         wordpointer = mp->bsspace[mp->bsnum] + 512;
 188         mp->bsnum = (mp->bsnum + 1) & 0x1;
 189         bitindex = 0;
 190
 191         len = 0;
 192         while(len < mp->framesize) {
 193                 int nlen;
 194                 int blen = mp->tail->size - mp->tail->pos;
 195                 if( (mp->framesize - len) <= blen) {
 196                   nlen = mp->framesize-len;
 197                 }
 198                 else {
 199                   nlen = blen;
 200                 }
 201                 memcpy(wordpointer+len,mp->tail->pnt+mp->tail->pos,nlen);
 202                 len += nlen;
 203                 mp->tail->pos += nlen;
 204                 mp->bsize -= nlen;
 205                 if(mp->tail->pos == mp->tail->size) {
 206                    remove_buf(mp);
 207                 }
 208         }
 209
 210         *done = 0;
 211         if(mp->fr.error_protection)
 212            getbits(16);
 213         switch(mp->fr.lay) {
 214           case 1:
 215             do_layer1(&mp->fr,(unsigned char *) out,done);
 216             break;
 217           case 2:
 218             do_layer2(&mp->fr,(unsigned char *) out,done);
 219             break;
 220           case 3:
 221             do_layer3(&mp->fr,(unsigned char *) out,done);
 222             break;
 223         }
 224
 225         mp->fsizeold = mp->framesize;
 226         mp->framesize = 0;
 227
 228         return MP3_OK;
 229 }
 230
 231 int set_pointer(long backstep)
 232 {
 233   unsigned char *bsbufold;
 234   if(gmp->fsizeold < 0 && backstep > 0) {
 235     fprintf(stderr,"Can't step back %ld!\n",backstep);
 236     return MP3_ERR;
 237   }
 238   bsbufold = gmp->bsspace[gmp->bsnum] + 512;
 239   wordpointer -= backstep;
 240   if (backstep)
 241     memcpy(wordpointer,bsbufold+gmp->fsizeold-backstep,backstep);
 242   bitindex = 0;
 243   return MP3_OK;
 244 }