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
48int 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