cannam@85: /* cannam@85: ** Copyright (C) 2001-2011 Erik de Castro Lopo cannam@85: ** cannam@85: ** All rights reserved. cannam@85: ** cannam@85: ** Redistribution and use in source and binary forms, with or without cannam@85: ** modification, are permitted provided that the following conditions are cannam@85: ** met: cannam@85: ** cannam@85: ** * Redistributions of source code must retain the above copyright cannam@85: ** notice, this list of conditions and the following disclaimer. cannam@85: ** * Redistributions in binary form must reproduce the above copyright cannam@85: ** notice, this list of conditions and the following disclaimer in cannam@85: ** the documentation and/or other materials provided with the cannam@85: ** distribution. cannam@85: ** * Neither the author nor the names of any contributors may be used cannam@85: ** to endorse or promote products derived from this software without cannam@85: ** specific prior written permission. cannam@85: ** cannam@85: ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS cannam@85: ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED cannam@85: ** TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR cannam@85: ** PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR cannam@85: ** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, cannam@85: ** EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, cannam@85: ** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; cannam@85: ** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, cannam@85: ** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR cannam@85: ** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF cannam@85: ** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. cannam@85: */ cannam@85: cannam@85: #include cannam@85: cannam@85: /* Include this header file to use functions from libsndfile. */ cannam@85: #include cannam@85: cannam@85: /* This will be the length of the buffer used to hold.frames while cannam@85: ** we process them. cannam@85: */ cannam@85: #define BUFFER_LEN 1024 cannam@85: cannam@85: /* libsndfile can handle more than 6 channels but we'll restrict it to 6. */ cannam@85: #define MAX_CHANNELS 6 cannam@85: cannam@85: /* Function prototype. */ cannam@85: static void process_data (double *data, int count, int channels) ; cannam@85: cannam@85: cannam@85: int cannam@85: main (void) cannam@85: { /* This is a buffer of double precision floating point values cannam@85: ** which will hold our data while we process it. cannam@85: */ cannam@85: static double data [BUFFER_LEN] ; cannam@85: cannam@85: /* A SNDFILE is very much like a FILE in the Standard C library. The cannam@85: ** sf_open function return an SNDFILE* pointer when they sucessfully cannam@85: ** open the specified file. cannam@85: */ cannam@85: SNDFILE *infile, *outfile ; cannam@85: cannam@85: /* A pointer to an SF_INFO stutct is passed to sf_open. cannam@85: ** On read, the library fills this struct with information about the file. cannam@85: ** On write, the struct must be filled in before calling sf_open. cannam@85: */ cannam@85: SF_INFO sfinfo ; cannam@85: int readcount ; cannam@85: const char *infilename = "input.wav" ; cannam@85: const char *outfilename = "output.wav" ; cannam@85: cannam@85: /* Here's where we open the input file. We pass sf_open the file name and cannam@85: ** a pointer to an SF_INFO struct. cannam@85: ** On successful open, sf_open returns a SNDFILE* pointer which is used cannam@85: ** for all subsequent operations on that file. cannam@85: ** If an error occurs during sf_open, the function returns a NULL pointer. cannam@85: ** cannam@85: ** If you are trying to open a raw headerless file you will need to set the cannam@85: ** format and channels fields of sfinfo before calling sf_open(). For cannam@85: ** instance to open a raw 16 bit stereo PCM file you would need the following cannam@85: ** two lines: cannam@85: ** cannam@85: ** sfinfo.format = SF_FORMAT_RAW | SF_FORMAT_PCM_16 ; cannam@85: ** sfinfo.channels = 2 ; cannam@85: */ cannam@85: if (! (infile = sf_open (infilename, SFM_READ, &sfinfo))) cannam@85: { /* Open failed so print an error message. */ cannam@85: printf ("Not able to open input file %s.\n", infilename) ; cannam@85: /* Print the error message from libsndfile. */ cannam@85: puts (sf_strerror (NULL)) ; cannam@85: return 1 ; cannam@85: } ; cannam@85: cannam@85: if (sfinfo.channels > MAX_CHANNELS) cannam@85: { printf ("Not able to process more than %d channels\n", MAX_CHANNELS) ; cannam@85: return 1 ; cannam@85: } ; cannam@85: /* Open the output file. */ cannam@85: if (! (outfile = sf_open (outfilename, SFM_WRITE, &sfinfo))) cannam@85: { printf ("Not able to open output file %s.\n", outfilename) ; cannam@85: puts (sf_strerror (NULL)) ; cannam@85: return 1 ; cannam@85: } ; cannam@85: cannam@85: /* While there are.frames in the input file, read them, process cannam@85: ** them and write them to the output file. cannam@85: */ cannam@85: while ((readcount = sf_read_double (infile, data, BUFFER_LEN))) cannam@85: { process_data (data, readcount, sfinfo.channels) ; cannam@85: sf_write_double (outfile, data, readcount) ; cannam@85: } ; cannam@85: cannam@85: /* Close input and output files. */ cannam@85: sf_close (infile) ; cannam@85: sf_close (outfile) ; cannam@85: cannam@85: return 0 ; cannam@85: } /* main */ cannam@85: cannam@85: static void cannam@85: process_data (double *data, int count, int channels) cannam@85: { double channel_gain [MAX_CHANNELS] = { 0.5, 0.8, 0.1, 0.4, 0.4, 0.9 } ; cannam@85: int k, chan ; cannam@85: cannam@85: /* Process the data here. cannam@85: ** If the soundfile contains more then 1 channel you need to take care of cannam@85: ** the data interleaving youself. cannam@85: ** Current we just apply a channel dependant gain. cannam@85: */ cannam@85: cannam@85: for (chan = 0 ; chan < channels ; chan ++) cannam@85: for (k = chan ; k < count ; k+= channels) cannam@85: data [k] *= channel_gain [chan] ; cannam@85: cannam@85: return ; cannam@85: } /* process_data */ cannam@85: