1 /* Copyright (c) 2013 Jean-Marc Valin */ 2 /* 3 Redistribution and use in source and binary forms, with or without 4 modification, are permitted provided that the following conditions 5 are met: 6 7 - Redistributions of source code must retain the above copyright 8 notice, this list of conditions and the following disclaimer. 9 10 - Redistributions in binary form must reproduce the above copyright 11 notice, this list of conditions and the following disclaimer in the 12 documentation and/or other materials provided with the distribution. 13 14 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 15 ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 16 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 17 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER 18 OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 19 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 20 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 21 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 22 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 23 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 24 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 /* This is meant to be a simple example of encoding and decoding audio 28 using Opus. It should make it easy to understand how the Opus API 29 works. For more information, see the full API documentation at: 30 http://www.opus-codec.org/docs/ */ 31 32 #include <stdlib.h> 33 #include <errno.h> 34 #include <string.h> 35 #include <opus.h> 36 #include <stdio.h> 37 38 /*The frame size is hardcoded for this sample code but it doesn't have to be*/ 39 #define FRAME_SIZE 960 40 #define SAMPLE_RATE 48000 41 #define CHANNELS 2 42 #define APPLICATION OPUS_APPLICATION_AUDIO 43 #define BITRATE 64000 44 45 #define MAX_FRAME_SIZE 6*960 46 #define MAX_PACKET_SIZE (3*1276) 47 48 int main(int argc, char **argv) 49 { 50 char *inFile; 51 FILE *fin; 52 char *outFile; 53 FILE *fout; 54 opus_int16 in[FRAME_SIZE*CHANNELS]; 55 opus_int16 out[MAX_FRAME_SIZE*CHANNELS]; 56 unsigned char cbits[MAX_PACKET_SIZE]; 57 int nbBytes; 58 /*Holds the state of the encoder and decoder */ 59 OpusEncoder *encoder; 60 OpusDecoder *decoder; 61 int err; 62 63 if (argc != 3) 64 { 65 fprintf(stderr, "usage: trivial_example input.pcm output.pcm\n"); 66 fprintf(stderr, "input and output are 16-bit little-endian raw files\n"); 67 return EXIT_FAILURE; 68 } 69 70 /*Create a new encoder state */ 71 encoder = opus_encoder_create(SAMPLE_RATE, CHANNELS, APPLICATION, &err); 72 if (err<0) 73 { 74 fprintf(stderr, "failed to create an encoder: %s\n", opus_strerror(err)); 75 return EXIT_FAILURE; 76 } 77 /* Set the desired bit-rate. You can also set other parameters if needed. 78 The Opus library is designed to have good defaults, so only set 79 parameters you know you need. Doing otherwise is likely to result 80 in worse quality, but better. */ 81 err = opus_encoder_ctl(encoder, OPUS_SET_BITRATE(BITRATE)); 82 if (err<0) 83 { 84 fprintf(stderr, "failed to set bitrate: %s\n", opus_strerror(err)); 85 return EXIT_FAILURE; 86 } 87 inFile = argv[1]; 88 fin = fopen(inFile, "r"); 89 if (fin==NULL) 90 { 91 fprintf(stderr, "failed to open file: %s\n", strerror(errno)); 92 return EXIT_FAILURE; 93 } 94 95 96 /* Create a new decoder state. */ 97 decoder = opus_decoder_create(SAMPLE_RATE, CHANNELS, &err); 98 if (err<0) 99 { 100 fprintf(stderr, "failed to create decoder: %s\n", opus_strerror(err)); 101 return EXIT_FAILURE; 102 } 103 outFile = argv[2]; 104 fout = fopen(outFile, "w"); 105 if (fout==NULL) 106 { 107 fprintf(stderr, "failed to open file: %s\n", strerror(errno)); 108 return EXIT_FAILURE; 109 } 110 111 while (1) 112 { 113 int i; 114 unsigned char pcm_bytes[MAX_FRAME_SIZE*CHANNELS*2]; 115 int frame_size; 116 117 /* Read a 16 bits/sample audio frame. */ 118 fread(pcm_bytes, sizeof(short)*CHANNELS, FRAME_SIZE, fin); 119 if (feof(fin)) 120 break; 121 /* Convert from little-endian ordering. */ 122 for (i=0;i<CHANNELS*FRAME_SIZE;i++) 123 in[i]=pcm_bytes[2*i+1]<<8|pcm_bytes[2*i]; 124 125 /* Encode the frame. */ 126 nbBytes = opus_encode(encoder, in, FRAME_SIZE, cbits, MAX_PACKET_SIZE); 127 if (nbBytes<0) 128 { 129 fprintf(stderr, "encode failed: %s\n", opus_strerror(nbBytes)); 130 return EXIT_FAILURE; 131 } 132 133 134 /* Decode the data. In this example, frame_size will be constant because 135 the encoder is using a constant frame size. However, that may not 136 be the case for all encoders, so the decoder must always check 137 the frame size returned. */ 138 frame_size = opus_decode(decoder, cbits, nbBytes, out, MAX_FRAME_SIZE, 0); 139 if (frame_size<0) 140 { 141 fprintf(stderr, "decoder failed: %s\n", opus_strerror(err)); 142 return EXIT_FAILURE; 143 } 144 145 /* Convert to little-endian ordering. */ 146 for(i=0;i<CHANNELS*frame_size;i++) 147 { 148 pcm_bytes[2*i]=out[i]&0xFF; 149 pcm_bytes[2*i+1]=(out[i]>>8)&0xFF; 150 } 151 /* Write the decoded audio to file. */ 152 fwrite(pcm_bytes, sizeof(short), frame_size*CHANNELS, fout); 153 } 154 /*Destroy the encoder state*/ 155 opus_encoder_destroy(encoder); 156 opus_decoder_destroy(decoder); 157 fclose(fin); 158 fclose(fout); 159 return EXIT_SUCCESS; 160 } 161
