C语言将音频文件拆分成四个wav文件的代码怎么写

在C语言中直接操作音频文件通常会比较复杂，因为C语言本身并不提供处理音频文件的内置库。不过，你可以使用一些外部库如FFMPEG或者libavcodec来读取和转换音频文件。以下是一个简化的示例，展示了如何使用FFMPEG库将一个大WAV文件拆分成四个等份的小文件。请注意，这个示例需要先安装FFmpeg库，并且假设你知道每个小文件的开始位置。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char *argv[]) {
    if (argc != 4) {
        printf("Usage: %s <input_wav_file> <output_prefix> <chunk_size_in_seconds>\n", argv[0]);
        return 1;
    }

    const char *input_file = argv[1];
    char output_prefix[64] = {0};
    strncpy(output_prefix, argv[2], sizeof(output_prefix));
    size_t chunk_size = atoi(argv[3]) * 1000; // Convert seconds to milliseconds

    av_register_all();
    avformat_network_init();

    AVFormatContext *ifmt_ctx = NULL;
    if (avformat_open_input(&ifmt_ctx, input_file, NULL, NULL) < 0) {
        perror("Failed to open input file");
        exit(1);
    }
    
    if (!avformat_find_stream_info(ifmt_ctx, NULL)) {
        perror("Failed to find stream info");
        exit(1);
    }

    int audio_stream_index = -1;
    for (int i = 0; i < ifmt_ctx->nb_streams; i++) {
        if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
            audio_stream_index = i;
            break;
        }
    }

    if (audio_stream_index == -1) {
        printf("No audio stream found in the input file.\n");
        exit(1);
    }

    AVStream *audio_stm = ifmt_ctx->streams[audio_stream_index];
    AVRational time_base = audio_stm->time_base;
    uint64_t duration = av_rescale_q(audio_stm->duration, time_base, AV_TIME_BASE);

    int split_points[] = {duration / 4, duration * 3 / 4}; // Split points at quarter and three-quarters of total duration
    for (size_t i = 0; i < sizeof(split_points) / sizeof(split_points[0]); i++) {
        int start_time_ms = av_rescale_q(split_points[i], time_base, AV_TIME_BASE);
        int end_time_ms = start_time_ms + chunk_size;

        FILE *ofp = fopen((output_prefix "_part" + itoa(i+1)).c_str(), "wb");
        if (!ofp) {
            perror("Failed to create output file");
            continue;
        }

        int frame_index = 0;
        AVPacket packet;
        while (frame_index < audio_stm->nb_frames && av_read_frame(ifmt_ctx, &packet) >= 0) {
            int packet_start_time_ms = av_rescale_q(packet.duration, time_base, AV_TIME_BASE);
            if (packet_start_time_ms >= start_time_ms && packet_start_time_ms < end_time_ms) {
                fwrite(packet.data, 1, packet.size, ofp);
            }
            av_packet_unref(&packet);
        }
        fclose(ofp);
    }

    avformat_close_input(&ifmt_ctx);
    return 0;
}