Chris@69: /* Copyright (c) 2013 Jean-Marc Valin */
Chris@69: /*
Chris@69:    Redistribution and use in source and binary forms, with or without
Chris@69:    modification, are permitted provided that the following conditions
Chris@69:    are met:
Chris@69: 
Chris@69:    - Redistributions of source code must retain the above copyright
Chris@69:    notice, this list of conditions and the following disclaimer.
Chris@69: 
Chris@69:    - Redistributions in binary form must reproduce the above copyright
Chris@69:    notice, this list of conditions and the following disclaimer in the
Chris@69:    documentation and/or other materials provided with the distribution.
Chris@69: 
Chris@69:    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
Chris@69:    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
Chris@69:    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
Chris@69:    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
Chris@69:    OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
Chris@69:    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
Chris@69:    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
Chris@69:    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
Chris@69:    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
Chris@69:    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
Chris@69:    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Chris@69: */
Chris@69: 
Chris@69: /* This is meant to be a simple example of encoding and decoding audio
Chris@69:    using Opus. It should make it easy to understand how the Opus API
Chris@69:    works. For more information, see the full API documentation at:
Chris@69:    https://www.opus-codec.org/docs/ */
Chris@69: 
Chris@69: #include <stdlib.h>
Chris@69: #include <errno.h>
Chris@69: #include <string.h>
Chris@69: #include <opus.h>
Chris@69: #include <stdio.h>
Chris@69: 
Chris@69: /*The frame size is hardcoded for this sample code but it doesn't have to be*/
Chris@69: #define FRAME_SIZE 960
Chris@69: #define SAMPLE_RATE 48000
Chris@69: #define CHANNELS 2
Chris@69: #define APPLICATION OPUS_APPLICATION_AUDIO
Chris@69: #define BITRATE 64000
Chris@69: 
Chris@69: #define MAX_FRAME_SIZE 6*960
Chris@69: #define MAX_PACKET_SIZE (3*1276)
Chris@69: 
Chris@69: int main(int argc, char **argv)
Chris@69: {
Chris@69:    char *inFile;
Chris@69:    FILE *fin;
Chris@69:    char *outFile;
Chris@69:    FILE *fout;
Chris@69:    opus_int16 in[FRAME_SIZE*CHANNELS];
Chris@69:    opus_int16 out[MAX_FRAME_SIZE*CHANNELS];
Chris@69:    unsigned char cbits[MAX_PACKET_SIZE];
Chris@69:    int nbBytes;
Chris@69:    /*Holds the state of the encoder and decoder */
Chris@69:    OpusEncoder *encoder;
Chris@69:    OpusDecoder *decoder;
Chris@69:    int err;
Chris@69: 
Chris@69:    if (argc != 3)
Chris@69:    {
Chris@69:       fprintf(stderr, "usage: trivial_example input.pcm output.pcm\n");
Chris@69:       fprintf(stderr, "input and output are 16-bit little-endian raw files\n");
Chris@69:       return EXIT_FAILURE;
Chris@69:    }
Chris@69: 
Chris@69:    /*Create a new encoder state */
Chris@69:    encoder = opus_encoder_create(SAMPLE_RATE, CHANNELS, APPLICATION, &err);
Chris@69:    if (err<0)
Chris@69:    {
Chris@69:       fprintf(stderr, "failed to create an encoder: %s\n", opus_strerror(err));
Chris@69:       return EXIT_FAILURE;
Chris@69:    }
Chris@69:    /* Set the desired bit-rate. You can also set other parameters if needed.
Chris@69:       The Opus library is designed to have good defaults, so only set
Chris@69:       parameters you know you need. Doing otherwise is likely to result
Chris@69:       in worse quality, but better. */
Chris@69:    err = opus_encoder_ctl(encoder, OPUS_SET_BITRATE(BITRATE));
Chris@69:    if (err<0)
Chris@69:    {
Chris@69:       fprintf(stderr, "failed to set bitrate: %s\n", opus_strerror(err));
Chris@69:       return EXIT_FAILURE;
Chris@69:    }
Chris@69:    inFile = argv[1];
Chris@69:    fin = fopen(inFile, "r");
Chris@69:    if (fin==NULL)
Chris@69:    {
Chris@69:       fprintf(stderr, "failed to open input file: %s\n", strerror(errno));
Chris@69:       return EXIT_FAILURE;
Chris@69:    }
Chris@69: 
Chris@69: 
Chris@69:    /* Create a new decoder state. */
Chris@69:    decoder = opus_decoder_create(SAMPLE_RATE, CHANNELS, &err);
Chris@69:    if (err<0)
Chris@69:    {
Chris@69:       fprintf(stderr, "failed to create decoder: %s\n", opus_strerror(err));
Chris@69:       return EXIT_FAILURE;
Chris@69:    }
Chris@69:    outFile = argv[2];
Chris@69:    fout = fopen(outFile, "w");
Chris@69:    if (fout==NULL)
Chris@69:    {
Chris@69:       fprintf(stderr, "failed to open output file: %s\n", strerror(errno));
Chris@69:       return EXIT_FAILURE;
Chris@69:    }
Chris@69: 
Chris@69:    while (1)
Chris@69:    {
Chris@69:       int i;
Chris@69:       unsigned char pcm_bytes[MAX_FRAME_SIZE*CHANNELS*2];
Chris@69:       int frame_size;
Chris@69: 
Chris@69:       /* Read a 16 bits/sample audio frame. */
Chris@69:       fread(pcm_bytes, sizeof(short)*CHANNELS, FRAME_SIZE, fin);
Chris@69:       if (feof(fin))
Chris@69:          break;
Chris@69:       /* Convert from little-endian ordering. */
Chris@69:       for (i=0;i<CHANNELS*FRAME_SIZE;i++)
Chris@69:          in[i]=pcm_bytes[2*i+1]<<8|pcm_bytes[2*i];
Chris@69: 
Chris@69:       /* Encode the frame. */
Chris@69:       nbBytes = opus_encode(encoder, in, FRAME_SIZE, cbits, MAX_PACKET_SIZE);
Chris@69:       if (nbBytes<0)
Chris@69:       {
Chris@69:          fprintf(stderr, "encode failed: %s\n", opus_strerror(nbBytes));
Chris@69:          return EXIT_FAILURE;
Chris@69:       }
Chris@69: 
Chris@69: 
Chris@69:       /* Decode the data. In this example, frame_size will be constant because
Chris@69:          the encoder is using a constant frame size. However, that may not
Chris@69:          be the case for all encoders, so the decoder must always check
Chris@69:          the frame size returned. */
Chris@69:       frame_size = opus_decode(decoder, cbits, nbBytes, out, MAX_FRAME_SIZE, 0);
Chris@69:       if (frame_size<0)
Chris@69:       {
Chris@69:          fprintf(stderr, "decoder failed: %s\n", opus_strerror(frame_size));
Chris@69:          return EXIT_FAILURE;
Chris@69:       }
Chris@69: 
Chris@69:       /* Convert to little-endian ordering. */
Chris@69:       for(i=0;i<CHANNELS*frame_size;i++)
Chris@69:       {
Chris@69:          pcm_bytes[2*i]=out[i]&0xFF;
Chris@69:          pcm_bytes[2*i+1]=(out[i]>>8)&0xFF;
Chris@69:       }
Chris@69:       /* Write the decoded audio to file. */
Chris@69:       fwrite(pcm_bytes, sizeof(short), frame_size*CHANNELS, fout);
Chris@69:    }
Chris@69:    /*Destroy the encoder state*/
Chris@69:    opus_encoder_destroy(encoder);
Chris@69:    opus_decoder_destroy(decoder);
Chris@69:    fclose(fin);
Chris@69:    fclose(fout);
Chris@69:    return EXIT_SUCCESS;
Chris@69: }