C++实现将PCM文件转换成MP3文件

Question

找一个C++实现将PCM文件转换成MP3文件的代码，要求转换前后播放效果没有差异，能正常的播放，要能成功转换，使用第三方库或者自己编写代码实现都行，谢谢！

Answer 1

#include <stdio.h>
#include <lame/lame.h>

bool convertPcmToMp3(const char* pcmFilePath, const char* mp3FilePath, int sampleRate, int channels, int bitRate) {
    FILE *pcmFile = fopen(pcmFilePath, "rb");
    if (!pcmFile) {
        return false;
    }

    FILE *mp3File = fopen(mp3FilePath, "wb");
    if (!mp3File) {
        fclose(pcmFile);
        return false;
    }

    const int PCM_SIZE = 8192;
    const int MP3_SIZE = 8192;

    short pcmBuffer[PCM_SIZE * channels];
    unsigned char mp3Buffer[MP3_SIZE];

    lame_t lame = lame_init();
    lame_set_num_channels(lame, channels);
    lame_set_in_samplerate(lame, sampleRate);
    lame_set_out_samplerate(lame, sampleRate);
    lame_set_brate(lame, bitRate);
    lame_set_mode(lame, channels == 1 ? MONO : STEREO);
    lame_set_quality(lame, 2);
    lame_init_params(lame);

    bool success = true;
    int readSize = 0;
    int writeSize = 0;
    do {
        readSize = fread(pcmBuffer, sizeof(short) * channels, PCM_SIZE, pcmFile);
        if (readSize != 0) {
            if (channels == 1) {
                writeSize = lame_encode_buffer(lame, pcmBuffer, NULL, readSize, mp3Buffer, MP3_SIZE);
            } else {
                writeSize = lame_encode_buffer_interleaved(lame, pcmBuffer, readSize, mp3Buffer, MP3_SIZE);
            }
            fwrite(mp3Buffer, sizeof(unsigned char), writeSize, mp3File);
        } else {
            // Flush the last bit of data.
            writeSize = lame_encode_flush(lame, mp3Buffer, MP3_SIZE);
            fwrite(mp3Buffer, sizeof(unsigned char), writeSize, mp3File);
        }
    } while (readSize != 0);

    lame_close(lame);
    fclose(pcmFile);
    fclose(mp3File);

    return success;
}

int main() {
    const char* pcmFilePath = "input.pcm";
    const char* mp3FilePath = "output.mp3";
    int sampleRate = 44100;   // 采样率（Hz）
    int channels = 2;         // 声道数（1：单声道，2：立体声）
    int bitRate = 128;        // 比特率（kbps）

    bool success = convertPcmToMp3(pcmFilePath, mp3FilePath, sampleRate, channels, bitRate);
    if (success) {
        printf("PCM to MP3 conversion completed.\n");
    } else {
        printf("Failed to convert PCM to MP3.\n");
    }

    return 0;
}