Mercurial > SDL_sound_CoreAudio
view decoders/mpglib/interface.c @ 341:3466dde3a846
Removed a FIXME.
author | Ryan C. Gordon <icculus@icculus.org> |
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date | Wed, 22 May 2002 09:27:12 +0000 |
parents | ad4c8f34136a |
children | fb519e6028e3 |
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#include <stdlib.h> #include <stdio.h> #include "SDL_sound.h" #define __SDL_SOUND_INTERNAL__ #include "SDL_sound_internal.h" #include "mpg123_sdlsound.h" #include "mpglib_sdlsound.h" BOOL InitMP3(struct mpstr *mp) { static int init = 0; memset(mp,0,sizeof(struct mpstr)); mp->framesize = 0; mp->fsizeold = -1; mp->bsize = 0; mp->head = mp->tail = NULL; mp->fr.single = -1; mp->bsnum = 0; mp->synth_bo = 1; if(!init) { init = 1; make_decode_tables(32767); init_layer2(); init_layer3(SBLIMIT); } return !0; } void ExitMP3(struct mpstr *mp) { struct buf *b,*bn; b = mp->tail; while(b) { free(b->pnt); bn = b->next; free(b); b = bn; } } static struct buf *addbuf(struct mpstr *mp,char *buf,int size) { struct buf *nbuf; nbuf = malloc( sizeof(struct buf) ); if(!nbuf) { Sound_SetError("MPGLIB: Out of memory!"); return NULL; } nbuf->pnt = malloc(size); if(!nbuf->pnt) { free(nbuf); return NULL; } nbuf->size = size; memcpy(nbuf->pnt,buf,size); nbuf->next = NULL; nbuf->prev = mp->head; nbuf->pos = 0; if(!mp->tail) { mp->tail = nbuf; } else { mp->head->next = nbuf; } mp->head = nbuf; mp->bsize += size; return nbuf; } static void remove_buf(struct mpstr *mp) { struct buf *buf = mp->tail; mp->tail = buf->next; if(mp->tail) mp->tail->prev = NULL; else { mp->tail = mp->head = NULL; } free(buf->pnt); free(buf); } static int read_buf_byte(struct mpstr *mp, unsigned long *retval) { int pos; pos = mp->tail->pos; while(pos >= mp->tail->size) { remove_buf(mp); pos = mp->tail->pos; if(!mp->tail) { Sound_SetError("MPGLIB: Fatal error! Short read in read_buf_byte()!"); return 0; } } if (retval != NULL) *retval = mp->tail->pnt[pos]; mp->bsize--; mp->tail->pos++; return 1; } static int read_head(struct mpstr *mp) { unsigned long val; unsigned long head; if (!read_buf_byte(mp, &val)) return 0; head = val << 8; if (!read_buf_byte(mp, &val)) return 0; head |= val; head <<= 8; if (!read_buf_byte(mp, &val)) return 0; head |= val; head <<= 8; if (!read_buf_byte(mp, &val)) return 0; head |= val; mp->header = head; return 1; } int decodeMP3(struct mpstr *mp,char *in,int isize,char *out, int osize,int *done) { int len; if(osize < 4608) { Sound_SetError("MPGLIB: Not enough output space for decoding!"); return MP3_ERR; } if(in) { if(addbuf(mp,in,isize) == NULL) { return MP3_ERR; } } /* First decode header */ if(mp->framesize == 0) { if(mp->bsize < 4) { return MP3_NEED_MORE; } if (!read_head(mp)) return MP3_ERR; if (!decode_header(&mp->fr,mp->header)) return MP3_ERR; mp->framesize = mp->fr.framesize; } if(mp->fr.framesize > mp->bsize) return MP3_NEED_MORE; wordpointer = mp->bsspace[mp->bsnum] + 512; mp->bsnum = (mp->bsnum + 1) & 0x1; bitindex = 0; len = 0; while(len < mp->framesize) { int nlen; int blen = mp->tail->size - mp->tail->pos; if( (mp->framesize - len) <= blen) { nlen = mp->framesize-len; } else { nlen = blen; } memcpy(wordpointer+len,mp->tail->pnt+mp->tail->pos,nlen); len += nlen; mp->tail->pos += nlen; mp->bsize -= nlen; if(mp->tail->pos == mp->tail->size) { remove_buf(mp); } } *done = 0; if(mp->fr.error_protection) getbits(16); switch(mp->fr.lay) { case 1: do_layer1(&mp->fr,(unsigned char *) out,done,mp); break; case 2: do_layer2(&mp->fr,(unsigned char *) out,done,mp); break; case 3: do_layer3(&mp->fr,(unsigned char *) out,done,mp); break; } mp->fsizeold = mp->framesize; mp->framesize = 0; return MP3_OK; } int set_pointer(long backstep, struct mpstr *mp) { unsigned char *bsbufold; if(mp->fsizeold < 0 && backstep > 0) { Sound_SetError("MPGLIB: Can't step back!"); /* FIXME: need formatting: %ld!\n",backstep); */ return MP3_ERR; } bsbufold = mp->bsspace[mp->bsnum] + 512; wordpointer -= backstep; if (backstep) memcpy(wordpointer,bsbufold+mp->fsizeold-backstep,backstep); bitindex = 0; return MP3_OK; }