提供c++代码的opus解码字符串的代码

以下是使用 Opus 库在 C++ 中解码字符串的代码示例：

#include <opus/opus.h>
#include <string>

std::string decodeOpus(const uint8_t* compressedData, size_t dataSize) {
    OpusDecoder* decoder = opus_decoder_create(48000, 2, nullptr);
    if (!decoder) {
        throw std::runtime_error("Failed to create Opus decoder");
    }

    const int OPUS_FRAME_SIZE = 960;
    const int MAX_SAMPLES_PER_FRAME = OPUS_FRAME_SIZE * 2; // 2 channels
    const int MAX_SAMPLES_PER_PACKET = MAX_SAMPLES_PER_FRAME * 60; // 60 frames per packet
    const int MAX_OUTPUT_SAMPLES = MAX_SAMPLES_PER_PACKET * 2; // 2 channels
    int outputBuffer[MAX_OUTPUT_SAMPLES];

    int frameSize = opus_decoder_get_size(2);
    if (frameSize < 0) {
        opus_decoder_destroy(decoder);
        throw std::runtime_error("Failed to get Opus decoder frame size");
    }

    int decodedSamples = opus_decode(decoder, compressedData, dataSize, outputBuffer, MAX_OUTPUT_SAMPLES, 0);
    if (decodedSamples < 0) {
        opus_decoder_destroy(decoder);
        throw std::runtime_error("Failed to decode Opus data");
    }

    std::string decodedString(reinterpret_cast<const char*>(outputBuffer), decodedSamples * sizeof(int16_t));
    opus_decoder_destroy(decoder);

    return decodedString;
}

解码过程中的关键步骤：

1. 创建 Opus 解码器实例：`OpusDecoder* decoder = opus_decoder_create(48000, 2, nullptr);`
2. 定义解码缓冲区：`int outputBuffer[MAX_OUTPUT_SAMPLES];`
3. 调用 `opus_decode` 函数解码：`int decodedSamples = opus_decode(decoder, compressedData, dataSize, outputBuffer, MAX_OUTPUT_SAMPLES, 0);`
4. 将解码后的数据转换成字符串：`std::string decodedString(reinterpret_cast<const char*>(outputBuffer), decodedSamples * sizeof(int16_t));`

其中，`compressedData` 是包含 Opus 压缩数据的指针，`dataSize` 是数据大小。函数返回解码后的字符串。