Alexandre Lision | 7c6f4a6 | 2013-09-05 13:27:01 -0400 | [diff] [blame] | 1 | /* |
| 2 | ** Copyright (C) 1999-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| 3 | ** |
| 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. |
| 8 | ** |
| 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. |
| 13 | ** |
| 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. |
| 17 | */ |
| 18 | |
| 19 | |
| 20 | #include "sfconfig.h" |
| 21 | |
| 22 | #include <stdio.h> |
| 23 | #include <stdlib.h> |
| 24 | |
| 25 | #if HAVE_UNISTD_H |
| 26 | #include <unistd.h> |
| 27 | #endif |
| 28 | |
| 29 | #include <string.h> |
| 30 | #include <errno.h> |
| 31 | |
| 32 | #include "common.h" |
| 33 | |
| 34 | typedef struct |
| 35 | { int le_float ; |
| 36 | int be_float ; |
| 37 | int le_int_24_32 ; |
| 38 | int be_int_24_32 ; |
| 39 | } VOTE ; |
| 40 | |
| 41 | |
| 42 | static void vote_for_format (VOTE * vote, const unsigned char * data, int datalen) ; |
| 43 | |
| 44 | int |
| 45 | audio_detect (SF_PRIVATE * psf, AUDIO_DETECT *ad, const unsigned char * data, int datalen) |
| 46 | { VOTE vote ; |
| 47 | |
| 48 | if (psf == NULL) |
| 49 | return 0 ; |
| 50 | |
| 51 | if (ad == NULL || datalen < 256) |
| 52 | return 0 ; |
| 53 | |
| 54 | vote_for_format (&vote, data, datalen) ; |
| 55 | |
| 56 | psf_log_printf (psf, "audio_detect :\n" |
| 57 | " le_float : %d\n" |
| 58 | " be_float : %d\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) ; |
| 62 | |
| 63 | if (0) puts (psf->logbuffer) ; |
| 64 | |
| 65 | if (ad->endianness == SF_ENDIAN_LITTLE && vote.le_float > (3 * datalen) / 4) |
| 66 | { /* Almost certainly 32 bit floats. */ |
| 67 | return SF_FORMAT_FLOAT ; |
| 68 | } ; |
| 69 | |
| 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 ; |
| 73 | } ; |
| 74 | |
| 75 | return 0 ; |
| 76 | } /* data_detect */ |
| 77 | |
| 78 | static void |
| 79 | vote_for_format (VOTE * vote, const unsigned char * data, int datalen) |
| 80 | { |
| 81 | int k ; |
| 82 | |
| 83 | memset (vote, 0, sizeof (VOTE)) ; |
| 84 | |
| 85 | datalen -= datalen % 4 ; |
| 86 | |
| 87 | for (k = 0 ; k < datalen ; k ++) |
| 88 | { if ((k % 4) == 0) |
| 89 | { if (data [k] == 0 && data [k + 1] != 0) |
| 90 | vote->le_int_24_32 += 4 ; |
| 91 | |
| 92 | if (data [2] != 0 && data [3] == 0) |
| 93 | vote->le_int_24_32 += 4 ; |
| 94 | |
| 95 | if (data [0] != 0 && data [3] > 0x43 && data [3] < 0x4B) |
| 96 | vote->le_float += 4 ; |
| 97 | |
| 98 | if (data [3] != 0 && data [0] > 0x43 && data [0] < 0x4B) |
| 99 | vote->be_float += 4 ; |
| 100 | } ; |
| 101 | } ; |
| 102 | |
| 103 | return ; |
| 104 | } /* vote_for_format */ |
| 105 | |