Alexandre Lision | 7c6f4a6 | 2013-09-05 13:27:01 -0400 | [diff] [blame] | 1 | /* |
| 2 | ** Copyright (C) 2001-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| 3 | ** |
| 4 | ** All rights reserved. |
| 5 | ** |
| 6 | ** Redistribution and use in source and binary forms, with or without |
| 7 | ** modification, are permitted provided that the following conditions are |
| 8 | ** met: |
| 9 | ** |
| 10 | ** * Redistributions of source code must retain the above copyright |
| 11 | ** notice, this list of conditions and the following disclaimer. |
| 12 | ** * Redistributions in binary form must reproduce the above copyright |
| 13 | ** notice, this list of conditions and the following disclaimer in |
| 14 | ** the documentation and/or other materials provided with the |
| 15 | ** distribution. |
| 16 | ** * Neither the author nor the names of any contributors may be used |
| 17 | ** to endorse or promote products derived from this software without |
| 18 | ** specific prior written permission. |
| 19 | ** |
| 20 | ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 22 | ** TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 23 | ** PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| 24 | ** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 25 | ** EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 26 | ** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 27 | ** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 28 | ** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 29 | ** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 30 | ** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 31 | */ |
| 32 | |
| 33 | #include <stdio.h> |
| 34 | |
| 35 | /* Include this header file to use functions from libsndfile. */ |
| 36 | #include <sndfile.h> |
| 37 | |
| 38 | /* This will be the length of the buffer used to hold.frames while |
| 39 | ** we process them. |
| 40 | */ |
| 41 | #define BUFFER_LEN 1024 |
| 42 | |
| 43 | /* libsndfile can handle more than 6 channels but we'll restrict it to 6. */ |
| 44 | #define MAX_CHANNELS 6 |
| 45 | |
| 46 | /* Function prototype. */ |
| 47 | static void process_data (double *data, int count, int channels) ; |
| 48 | |
| 49 | |
| 50 | int |
| 51 | main (void) |
| 52 | { /* This is a buffer of double precision floating point values |
| 53 | ** which will hold our data while we process it. |
| 54 | */ |
| 55 | static double data [BUFFER_LEN] ; |
| 56 | |
| 57 | /* A SNDFILE is very much like a FILE in the Standard C library. The |
| 58 | ** sf_open function return an SNDFILE* pointer when they sucessfully |
| 59 | ** open the specified file. |
| 60 | */ |
| 61 | SNDFILE *infile, *outfile ; |
| 62 | |
| 63 | /* A pointer to an SF_INFO stutct is passed to sf_open. |
| 64 | ** On read, the library fills this struct with information about the file. |
| 65 | ** On write, the struct must be filled in before calling sf_open. |
| 66 | */ |
| 67 | SF_INFO sfinfo ; |
| 68 | int readcount ; |
| 69 | const char *infilename = "input.wav" ; |
| 70 | const char *outfilename = "output.wav" ; |
| 71 | |
| 72 | /* Here's where we open the input file. We pass sf_open the file name and |
| 73 | ** a pointer to an SF_INFO struct. |
| 74 | ** On successful open, sf_open returns a SNDFILE* pointer which is used |
| 75 | ** for all subsequent operations on that file. |
| 76 | ** If an error occurs during sf_open, the function returns a NULL pointer. |
| 77 | ** |
| 78 | ** If you are trying to open a raw headerless file you will need to set the |
| 79 | ** format and channels fields of sfinfo before calling sf_open(). For |
| 80 | ** instance to open a raw 16 bit stereo PCM file you would need the following |
| 81 | ** two lines: |
| 82 | ** |
| 83 | ** sfinfo.format = SF_FORMAT_RAW | SF_FORMAT_PCM_16 ; |
| 84 | ** sfinfo.channels = 2 ; |
| 85 | */ |
| 86 | if (! (infile = sf_open (infilename, SFM_READ, &sfinfo))) |
| 87 | { /* Open failed so print an error message. */ |
| 88 | printf ("Not able to open input file %s.\n", infilename) ; |
| 89 | /* Print the error message from libsndfile. */ |
| 90 | puts (sf_strerror (NULL)) ; |
| 91 | return 1 ; |
| 92 | } ; |
| 93 | |
| 94 | if (sfinfo.channels > MAX_CHANNELS) |
| 95 | { printf ("Not able to process more than %d channels\n", MAX_CHANNELS) ; |
| 96 | return 1 ; |
| 97 | } ; |
| 98 | /* Open the output file. */ |
| 99 | if (! (outfile = sf_open (outfilename, SFM_WRITE, &sfinfo))) |
| 100 | { printf ("Not able to open output file %s.\n", outfilename) ; |
| 101 | puts (sf_strerror (NULL)) ; |
| 102 | return 1 ; |
| 103 | } ; |
| 104 | |
| 105 | /* While there are.frames in the input file, read them, process |
| 106 | ** them and write them to the output file. |
| 107 | */ |
| 108 | while ((readcount = sf_read_double (infile, data, BUFFER_LEN))) |
| 109 | { process_data (data, readcount, sfinfo.channels) ; |
| 110 | sf_write_double (outfile, data, readcount) ; |
| 111 | } ; |
| 112 | |
| 113 | /* Close input and output files. */ |
| 114 | sf_close (infile) ; |
| 115 | sf_close (outfile) ; |
| 116 | |
| 117 | return 0 ; |
| 118 | } /* main */ |
| 119 | |
| 120 | static void |
| 121 | process_data (double *data, int count, int channels) |
| 122 | { double channel_gain [MAX_CHANNELS] = { 0.5, 0.8, 0.1, 0.4, 0.4, 0.9 } ; |
| 123 | int k, chan ; |
| 124 | |
| 125 | /* Process the data here. |
| 126 | ** If the soundfile contains more then 1 channel you need to take care of |
| 127 | ** the data interleaving youself. |
| 128 | ** Current we just apply a channel dependant gain. |
| 129 | */ |
| 130 | |
| 131 | for (chan = 0 ; chan < channels ; chan ++) |
| 132 | for (k = chan ; k < count ; k+= channels) |
| 133 | data [k] *= channel_gain [chan] ; |
| 134 | |
| 135 | return ; |
| 136 | } /* process_data */ |
| 137 | |