| /* |
| ** Copyright (C) 2001-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| ** |
| ** All rights reserved. |
| ** |
| ** Redistribution and use in source and binary forms, with or without |
| ** modification, are permitted provided that the following conditions are |
| ** met: |
| ** |
| ** * Redistributions of source code must retain the above copyright |
| ** notice, this list of conditions and the following disclaimer. |
| ** * Redistributions in binary form must reproduce the above copyright |
| ** notice, this list of conditions and the following disclaimer in |
| ** the documentation and/or other materials provided with the |
| ** distribution. |
| ** * Neither the author nor the names of any contributors may be used |
| ** to endorse or promote products derived from this software without |
| ** specific prior written permission. |
| ** |
| ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| ** TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| ** PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| ** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| ** EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| ** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| ** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| ** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| ** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| ** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include <stdio.h> |
| |
| /* Include this header file to use functions from libsndfile. */ |
| #include <sndfile.h> |
| |
| /* This will be the length of the buffer used to hold.frames while |
| ** we process them. |
| */ |
| #define BUFFER_LEN 1024 |
| |
| /* libsndfile can handle more than 6 channels but we'll restrict it to 6. */ |
| #define MAX_CHANNELS 6 |
| |
| /* Function prototype. */ |
| static void process_data (double *data, int count, int channels) ; |
| |
| |
| int |
| main (void) |
| { /* This is a buffer of double precision floating point values |
| ** which will hold our data while we process it. |
| */ |
| static double data [BUFFER_LEN] ; |
| |
| /* A SNDFILE is very much like a FILE in the Standard C library. The |
| ** sf_open function return an SNDFILE* pointer when they sucessfully |
| ** open the specified file. |
| */ |
| SNDFILE *infile, *outfile ; |
| |
| /* A pointer to an SF_INFO stutct is passed to sf_open. |
| ** On read, the library fills this struct with information about the file. |
| ** On write, the struct must be filled in before calling sf_open. |
| */ |
| SF_INFO sfinfo ; |
| int readcount ; |
| const char *infilename = "input.wav" ; |
| const char *outfilename = "output.wav" ; |
| |
| /* Here's where we open the input file. We pass sf_open the file name and |
| ** a pointer to an SF_INFO struct. |
| ** On successful open, sf_open returns a SNDFILE* pointer which is used |
| ** for all subsequent operations on that file. |
| ** If an error occurs during sf_open, the function returns a NULL pointer. |
| ** |
| ** If you are trying to open a raw headerless file you will need to set the |
| ** format and channels fields of sfinfo before calling sf_open(). For |
| ** instance to open a raw 16 bit stereo PCM file you would need the following |
| ** two lines: |
| ** |
| ** sfinfo.format = SF_FORMAT_RAW | SF_FORMAT_PCM_16 ; |
| ** sfinfo.channels = 2 ; |
| */ |
| if (! (infile = sf_open (infilename, SFM_READ, &sfinfo))) |
| { /* Open failed so print an error message. */ |
| printf ("Not able to open input file %s.\n", infilename) ; |
| /* Print the error message from libsndfile. */ |
| puts (sf_strerror (NULL)) ; |
| return 1 ; |
| } ; |
| |
| if (sfinfo.channels > MAX_CHANNELS) |
| { printf ("Not able to process more than %d channels\n", MAX_CHANNELS) ; |
| return 1 ; |
| } ; |
| /* Open the output file. */ |
| if (! (outfile = sf_open (outfilename, SFM_WRITE, &sfinfo))) |
| { printf ("Not able to open output file %s.\n", outfilename) ; |
| puts (sf_strerror (NULL)) ; |
| return 1 ; |
| } ; |
| |
| /* While there are.frames in the input file, read them, process |
| ** them and write them to the output file. |
| */ |
| while ((readcount = sf_read_double (infile, data, BUFFER_LEN))) |
| { process_data (data, readcount, sfinfo.channels) ; |
| sf_write_double (outfile, data, readcount) ; |
| } ; |
| |
| /* Close input and output files. */ |
| sf_close (infile) ; |
| sf_close (outfile) ; |
| |
| return 0 ; |
| } /* main */ |
| |
| static void |
| process_data (double *data, int count, int channels) |
| { double channel_gain [MAX_CHANNELS] = { 0.5, 0.8, 0.1, 0.4, 0.4, 0.9 } ; |
| int k, chan ; |
| |
| /* Process the data here. |
| ** If the soundfile contains more then 1 channel you need to take care of |
| ** the data interleaving youself. |
| ** Current we just apply a channel dependant gain. |
| */ |
| |
| for (chan = 0 ; chan < channels ; chan ++) |
| for (k = chan ; k < count ; k+= channels) |
| data [k] *= channel_gain [chan] ; |
| |
| return ; |
| } /* process_data */ |
| |