/*
* play a frame read by read_frame();
* (re)initialize audio if necessary.
*/
static void decode_frame(APEG_LAYER *layer, struct frame *fr, struct mpstr *mp)
{
int clip;
/* do the decoding */
switch(fr->lay)
{
case 1:
clip = do_layer1(mp, fr, layer);
break;
case 2:
clip = do_layer2(mp, fr, layer);
break;
case 3:
clip = do_layer3(mp, fr, layer);
break;
default:
// Shouldn't get here...
clip = 1;
mp->return_later = FALSE;
}
if(clip < 0)
apeg_error_jump("Error decoding audio frame");
}
int MPGLIB_DecodeFrame(PMPSTR mp, const unsigned char* in, void* out)
{
int done;
/* First decode header */
mp->header =
(((unsigned long)in[0]) << 24) |
(((unsigned long)in[1]) << 16) |
(((unsigned long)in[2]) << 8) |
(((unsigned long)in[3]));
decode_header(&mp->fr, mp->header);
mp->framesize = mp->fr.framesize;
mp->wordpointer = mp->bsspace[mp->bsnum] + 512;
mp->bsnum = (mp->bsnum + 1) & 0x1;
mp->bitindex = 0;
memcpy(mp->wordpointer, in+4, mp->framesize);
done = 0;
if(mp->fr.error_protection)
getbits(mp, 16);
switch(mp->fr.lay) {
case 1:
do_layer1(mp,(unsigned char *) out, &done);
break;
case 2:
do_layer2(mp,(unsigned char *) out, &done);
break;
case 3:
do_layer3(mp,(unsigned char *) out, &done, synth_1to1_mono, synth_1to1);
break;
}
mp->fsizeold = mp->framesize;
mp->framesize = 0;
if (done) {
return MP3_OK;
} else {
return MP3_INVALID_BITS;
}
}
int
decodeMP3 (struct mpstr *mp, char *in, int isize, char *out,
int osize, int *done)
{
int len;
gmp = mp;
if (osize < 4608)
{
fprintf (stderr, "To less out space\n");
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;
}
read_head (mp);
decode_header (&mp->fr, mp->header);
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 3:
do_layer3 (&mp->fr, (unsigned char *) out, done);
break;
}
mp->fsizeold = mp->framesize;
mp->framesize = 0;
return MP3_OK;
}
