2 ** Copyright (C) 1999-2009 Erik de Castro Lopo <erikd@mega-nerd.com>
4 ** This program is free software; you can redistribute it and/or modify
5 ** it under the terms of the GNU Lesser General Public License as published by
6 ** the Free Software Foundation; either version 2.1 of the License, or
7 ** (at your option) any later version.
9 ** This program 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
12 ** GNU Lesser General Public License for more details.
14 ** You should have received a copy of the GNU Lesser General Public License
15 ** along with this program; if not, write to the Free Software
16 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
42 static void vote_for_format (VOTE * vote, const unsigned char * data, int datalen) ;
45 audio_detect (SF_PRIVATE * psf, AUDIO_DETECT *ad, const unsigned char * data, int datalen)
51 if (ad == NULL || datalen < 256)
54 vote_for_format (&vote, data, datalen) ;
56 psf_log_printf (psf, "audio_detect :\n"
59 " le_int_24_32 : %d\n"
60 " be_int_24_32 : %d\n",
61 vote.le_float, vote.be_float, vote.le_int_24_32, vote.be_int_24_32) ;
63 if (0) puts (psf->logbuffer) ;
65 if (ad->endianness == SF_ENDIAN_LITTLE && vote.le_float > (3 * datalen) / 4)
66 { /* Almost certainly 32 bit floats. */
67 return SF_FORMAT_FLOAT ;
70 if (ad->endianness == SF_ENDIAN_LITTLE && vote.le_int_24_32 > (3 * datalen) / 4)
71 { /* Almost certainly 24 bit data stored in 32 bit ints. */
72 return SF_FORMAT_PCM_32 ;
79 vote_for_format (VOTE * vote, const unsigned char * data, int datalen)
83 memset (vote, 0, sizeof (VOTE)) ;
85 datalen -= datalen % 4 ;
87 for (k = 0 ; k < datalen ; k ++)
89 { if (data [k] == 0 && data [k + 1] != 0)
90 vote->le_int_24_32 += 4 ;
92 if (data [2] != 0 && data [3] == 0)
93 vote->le_int_24_32 += 4 ;
95 if (data [0] != 0 && data [3] > 0x43 && data [3] < 0x4B)
98 if (data [3] != 0 && data [0] > 0x43 && data [0] < 0x4B)
104 } /* vote_for_format */