opus sample

Opus 是一种开源音频编解码器，适用于音频流传输和储存。以下是 Opus 编码和解码的示例代码：

编码：

#include <opus/opus.h>

int main() {
    int error;
    OpusEncoder *encoder;
    int32_t sample_rate = 48000;
    int channels = 2;
    int application = OPUS_APPLICATION_AUDIO;
    int max_payload_bytes = 4000;

    encoder = opus_encoder_create(sample_rate, channels, application, &error);
    if (error != OPUS_OK) {
        fprintf(stderr, "failed to create encoder: %s\n", opus_strerror(error));
        return -1;
    }

    error = opus_encoder_ctl(encoder, OPUS_SET_MAX_PAYLOAD_BYTES(max_payload_bytes));
    if (error != OPUS_OK) {
        fprintf(stderr, "failed to set max payload bytes: %s\n", opus_strerror(error));
        return -1;
    }

    int16_t pcm_frame[960 * channels];
    uint8_t compressed_frame[max_payload_bytes];
    int compressed_size;

    /* read a frame of audio data from somewhere */
    while (1) {
        /* encode the frame */
        compressed_size = opus_encode(encoder, pcm_frame, 960, compressed_frame, max_payload_bytes);
        if (compressed_size < 0) {
            fprintf(stderr, "opus_encode failed: %s\n", opus_strerror(compressed_size));
            return -1;
        }

        /* send the compressed data over the network */
        send_data_to_network(compressed_frame, compressed_size);
    }

    opus_encoder_destroy(encoder);
}

解码：

#include <opus/opus.h>

int main() {
    int error;
    OpusDecoder *decoder;
    int32_t sample_rate = 48000;
    int channels = 2;
    int max_payload_bytes = 4000;

    decoder = opus_decoder_create(sample_rate, channels, &error);
    if (error != OPUS_OK) {
        fprintf(stderr, "failed to create decoder: %s\n", opus_strerror(error));
        return -1;
    }

    error = opus_decoder_ctl(decoder, OPUS_SET_MAX_PAYLOAD_BYTES(max_payload_bytes));
    if (error != OPUS_OK) {
        fprintf(stderr, "failed to set max payload bytes: %s\n", opus_strerror(error));
        return -1;
    }

    uint8_t compressed_frame[max_payload_bytes];
    int compressed_size;
    int16_t pcm_frame[960 * channels];
    int pcm_size;

    /* receive a compressed frame of audio data from the network */
    while (1) {
        /* decode the frame */
        pcm_size = opus_decode(decoder, compressed_frame, compressed_size, pcm_frame, 960, 0);
        if (pcm_size < 0) {
            fprintf(stderr, "opus_decode failed: %s\n", opus_strerror(pcm_size));
            return -1;
        }

        /* play the decoded audio */
        play_audio(pcm_frame, pcm_size);
    }

    opus_decoder_destroy(decoder);
}