diff options
Diffstat (limited to 'libopus/doc/trivial_example.c')
| -rw-r--r-- | libopus/doc/trivial_example.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/libopus/doc/trivial_example.c b/libopus/doc/trivial_example.c new file mode 100644 index 0000000..047ca0a --- /dev/null +++ b/libopus/doc/trivial_example.c @@ -0,0 +1,160 @@ +/* Copyright (c) 2013 Jean-Marc Valin */ +/* + 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. + + 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. +*/ + +/* This is meant to be a simple example of encoding and decoding audio + using Opus. It should make it easy to understand how the Opus API + works. For more information, see the full API documentation at: + https://www.opus-codec.org/docs/ */ + +#include <stdlib.h> +#include <errno.h> +#include <string.h> +#include <opus.h> +#include <stdio.h> + +/*The frame size is hardcoded for this sample code but it doesn't have to be*/ +#define FRAME_SIZE 960 +#define SAMPLE_RATE 48000 +#define CHANNELS 2 +#define APPLICATION OPUS_APPLICATION_AUDIO +#define BITRATE 64000 + +#define MAX_FRAME_SIZE 6*960 +#define MAX_PACKET_SIZE (3*1276) + +int main(int argc, char **argv) +{ + char *inFile; + FILE *fin; + char *outFile; + FILE *fout; + opus_int16 in[FRAME_SIZE*CHANNELS]; + opus_int16 out[MAX_FRAME_SIZE*CHANNELS]; + unsigned char cbits[MAX_PACKET_SIZE]; + int nbBytes; + /*Holds the state of the encoder and decoder */ + OpusEncoder *encoder; + OpusDecoder *decoder; + int err; + + if (argc != 3) + { + fprintf(stderr, "usage: trivial_example input.pcm output.pcm\n"); + fprintf(stderr, "input and output are 16-bit little-endian raw files\n"); + return EXIT_FAILURE; + } + + /*Create a new encoder state */ + encoder = opus_encoder_create(SAMPLE_RATE, CHANNELS, APPLICATION, &err); + if (err<0) + { + fprintf(stderr, "failed to create an encoder: %s\n", opus_strerror(err)); + return EXIT_FAILURE; + } + /* Set the desired bit-rate. You can also set other parameters if needed. + The Opus library is designed to have good defaults, so only set + parameters you know you need. Doing otherwise is likely to result + in worse quality, but better. */ + err = opus_encoder_ctl(encoder, OPUS_SET_BITRATE(BITRATE)); + if (err<0) + { + fprintf(stderr, "failed to set bitrate: %s\n", opus_strerror(err)); + return EXIT_FAILURE; + } + inFile = argv[1]; + fin = fopen(inFile, "r"); + if (fin==NULL) + { + fprintf(stderr, "failed to open input file: %s\n", strerror(errno)); + return EXIT_FAILURE; + } + + + /* Create a new decoder state. */ + decoder = opus_decoder_create(SAMPLE_RATE, CHANNELS, &err); + if (err<0) + { + fprintf(stderr, "failed to create decoder: %s\n", opus_strerror(err)); + return EXIT_FAILURE; + } + outFile = argv[2]; + fout = fopen(outFile, "w"); + if (fout==NULL) + { + fprintf(stderr, "failed to open output file: %s\n", strerror(errno)); + return EXIT_FAILURE; + } + + while (1) + { + int i; + unsigned char pcm_bytes[MAX_FRAME_SIZE*CHANNELS*2]; + int frame_size; + + /* Read a 16 bits/sample audio frame. */ + fread(pcm_bytes, sizeof(short)*CHANNELS, FRAME_SIZE, fin); + if (feof(fin)) + break; + /* Convert from little-endian ordering. */ + for (i=0;i<CHANNELS*FRAME_SIZE;i++) + in[i]=pcm_bytes[2*i+1]<<8|pcm_bytes[2*i]; + + /* Encode the frame. */ + nbBytes = opus_encode(encoder, in, FRAME_SIZE, cbits, MAX_PACKET_SIZE); + if (nbBytes<0) + { + fprintf(stderr, "encode failed: %s\n", opus_strerror(nbBytes)); + return EXIT_FAILURE; + } + + + /* Decode the data. In this example, frame_size will be constant because + the encoder is using a constant frame size. However, that may not + be the case for all encoders, so the decoder must always check + the frame size returned. */ + frame_size = opus_decode(decoder, cbits, nbBytes, out, MAX_FRAME_SIZE, 0); + if (frame_size<0) + { + fprintf(stderr, "decoder failed: %s\n", opus_strerror(frame_size)); + return EXIT_FAILURE; + } + + /* Convert to little-endian ordering. */ + for(i=0;i<CHANNELS*frame_size;i++) + { + pcm_bytes[2*i]=out[i]&0xFF; + pcm_bytes[2*i+1]=(out[i]>>8)&0xFF; + } + /* Write the decoded audio to file. */ + fwrite(pcm_bytes, sizeof(short), frame_size*CHANNELS, fout); + } + /*Destroy the encoder state*/ + opus_encoder_destroy(encoder); + opus_decoder_destroy(decoder); + fclose(fin); + fclose(fout); + return EXIT_SUCCESS; +} |