| /* |
| ** Copyright (C) 1999-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| ** |
| ** This program is free software; you can redistribute it and/or modify |
| ** it under the terms of the GNU Lesser General Public License as published by |
| ** the Free Software Foundation; either version 2.1 of the License, or |
| ** (at your option) any later version. |
| ** |
| ** This program is distributed in the hope that it will be useful, |
| ** but WITHOUT ANY WARRANTY; without even the implied warranty of |
| ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| ** GNU Lesser General Public License for more details. |
| ** |
| ** You should have received a copy of the GNU Lesser General Public License |
| ** along with this program; if not, write to the Free Software |
| ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| |
| #include "sfconfig.h" |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #if HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| |
| #include <string.h> |
| #include <errno.h> |
| |
| #include "common.h" |
| |
| typedef struct |
| { int le_float ; |
| int be_float ; |
| int le_int_24_32 ; |
| int be_int_24_32 ; |
| } VOTE ; |
| |
| |
| static void vote_for_format (VOTE * vote, const unsigned char * data, int datalen) ; |
| |
| int |
| audio_detect (SF_PRIVATE * psf, AUDIO_DETECT *ad, const unsigned char * data, int datalen) |
| { VOTE vote ; |
| |
| if (psf == NULL) |
| return 0 ; |
| |
| if (ad == NULL || datalen < 256) |
| return 0 ; |
| |
| vote_for_format (&vote, data, datalen) ; |
| |
| psf_log_printf (psf, "audio_detect :\n" |
| " le_float : %d\n" |
| " be_float : %d\n" |
| " le_int_24_32 : %d\n" |
| " be_int_24_32 : %d\n", |
| vote.le_float, vote.be_float, vote.le_int_24_32, vote.be_int_24_32) ; |
| |
| if (0) puts (psf->logbuffer) ; |
| |
| if (ad->endianness == SF_ENDIAN_LITTLE && vote.le_float > (3 * datalen) / 4) |
| { /* Almost certainly 32 bit floats. */ |
| return SF_FORMAT_FLOAT ; |
| } ; |
| |
| if (ad->endianness == SF_ENDIAN_LITTLE && vote.le_int_24_32 > (3 * datalen) / 4) |
| { /* Almost certainly 24 bit data stored in 32 bit ints. */ |
| return SF_FORMAT_PCM_32 ; |
| } ; |
| |
| return 0 ; |
| } /* data_detect */ |
| |
| static void |
| vote_for_format (VOTE * vote, const unsigned char * data, int datalen) |
| { |
| int k ; |
| |
| memset (vote, 0, sizeof (VOTE)) ; |
| |
| datalen -= datalen % 4 ; |
| |
| for (k = 0 ; k < datalen ; k ++) |
| { if ((k % 4) == 0) |
| { if (data [k] == 0 && data [k + 1] != 0) |
| vote->le_int_24_32 += 4 ; |
| |
| if (data [2] != 0 && data [3] == 0) |
| vote->le_int_24_32 += 4 ; |
| |
| if (data [0] != 0 && data [3] > 0x43 && data [3] < 0x4B) |
| vote->le_float += 4 ; |
| |
| if (data [3] != 0 && data [0] > 0x43 && data [0] < 0x4B) |
| vote->be_float += 4 ; |
| } ; |
| } ; |
| |
| return ; |
| } /* vote_for_format */ |
| |