#include <stdio.h>

/**
 * wav2pcm ***.wav **.pcm
 * @param argc 命令列引數的長度
 * @param argv 命令列引數，argv[0]是程式名稱
 * @return
 */
int main(int argc, char *argv[]) {
    FILE *wavfile;
    FILE *pcmfile;
    char buf[1024];
    int read_len;

    if (argc != 3) {
        printf("usage:\n"
               "\t wav2pcm ***.wav **.pcm\n");
    }
    wavfile = fopen(argv[1], "rb");
    if (wavfile == NULL) {
        printf("!Error: Can't open wavfile.\n");
        return 1;
    }
    pcmfile = fopen(argv[2], "wb");
    if (pcmfile == NULL) {
        printf("!Error: Can't open pcmfile.\n");
        return 1;
    }

    fseek(wavfile, 44, SEEK_SET);        // 將檔案指標移動到檔案開頭，後移44位元組

    while ((read_len = fread(buf, 1, sizeof(buf), wavfile)) != 0) {
        fwrite(buf, 1, read_len, pcmfile);
    }

    fclose(pcmfile);
    fclose(wavfile);

    return 0;
}

dd if=1.wav of=1.pcm bs=1 skip=44

def wav2pcm(wavfile, pcmfile, data_type=np.int16):
    f = open(wavfile, "rb")
    f.seek(0)
    f.read(44)
    data = np.fromfile(f, dtype=data_type)
    data.tofile(pcmfile)

#include <stdio.h>


int main() {
    FILE *pcmfile;
    int frame_len = 480;     // 幀長
    short buf[frame_len];   // 每個取樣點2位元組
    int read_len;
    char pcmpath[]="../p225_001.pcm";

    pcmfile = fopen(pcmpath, "rb");
    if (pcmfile == NULL) {
        printf("!Error: Can't open wavfile.\n");
        return 1;
    }

    while (feof(pcmfile)==0){
        read_len = fread(buf, sizeof(short), frame_len, pcmfile);
        for (int i = 0; i < read_len; i++) {
            printf("%d ", buf[i]);
        }
    }

    fclose(pcmfile);
    return 0;
}

/**
 * https://github.com/pliu6/pcm2wav
 */
#include <stdlib.h>
#include <string.h>
#include <stdio.h>


typedef struct {
    unsigned char chunk_id[4];     /*{'R', 'I', 'F', 'F'}*/
    unsigned int chunk_size;
    unsigned char format[4];
} FIFFChunk;

typedef struct {
    unsigned char chunk_id[4];  /* {'f', 'm', 't', ' '} */
    unsigned int chunk_size;
    unsigned short audio_format;            // 2位元組
    unsigned short channels;             // 4位元組
    unsigned int sample_rate;       // 4位元組
    unsigned int byte_rate;      // 4位元組
    unsigned short block_align;           // 2位元組
    unsigned short bits_per_sample;        // 2位元組
} FormatChunk;

typedef struct {
    unsigned char chunk_id[4];  /* {'d', 'a', 't', 'a'}  */
    unsigned int chunk_size;
} DataChunk;


// pcm2wav ***.pcm ***.wav 通道 取樣率 量化位數
int main(int argc, char *argv[]) {
    FILE *pcmfile, *wavfile;
    long pcmfile_size;
    FIFFChunk fiffchunk;
    FormatChunk formatchunk;
    DataChunk datachunk;
    int read_len;
    char buf[1024];

    if (argc != 6) {
        printf("usage:\n"
               "\t%s pcmfile wavfile channel samplerate bitspersample\n", argv[0]);
        return 1;
    }

    pcmfile = fopen(argv[1], "rb");
    if (pcmfile == NULL) {
        printf("!Error: Can't open pcmfile.\n");
        return 1;
    }
    fseek(pcmfile, 0, SEEK_END);        // 將檔案指標移動到檔案最後
    pcmfile_size = ftell(pcmfile);          // 返回給定流 stream 的當前檔案位置(位元組)
    fseek(pcmfile, 0, SEEK_SET);        // 將檔案指標移動到檔案開頭

    wavfile = fopen(argv[2], "wb");
    if (wavfile == NULL) {
        printf("!Error: Can't create wavfile.\n");
        return 1;
    }
    /* *********** RIFF區塊  ********************* */
    strncpy(fiffchunk.chunk_id,"RIFF", 4);
    fiffchunk.chunk_size = pcmfile_size+36;
    strncpy(fiffchunk.format,"WAVE",4);
    fwrite(&fiffchunk, sizeof(fiffchunk), 1, wavfile);

    /* *********** FORMAT區塊  ********************* */
    strncpy(formatchunk.chunk_id,"fmt ", 4);
    formatchunk.chunk_size = sizeof(FormatChunk) - 8;       // 不包含該區塊ID和Size的長度
    formatchunk.audio_format = 1;   /* 未壓縮的 */
    formatchunk.channels = atoi(argv[3]);          // 通道數，字串轉換成整型
    formatchunk.sample_rate = atoi(argv[4]);    // 取樣率
    formatchunk.bits_per_sample = atoi(argv[5]);     // 量化位數
    formatchunk.byte_rate = formatchunk.sample_rate * formatchunk.channels * (formatchunk.bits_per_sample >> 3);   // 每秒資料位元組數=SampleRate * NumChannels * BitsPerSample/8
    formatchunk.block_align = formatchunk.channels * (formatchunk.bits_per_sample >> 3);    // 每個樣本需要的位元組數
    fwrite(&formatchunk, 1, sizeof(formatchunk), wavfile);

    /* *********** DATA區塊  ********************* */
    strncpy(datachunk.chunk_id, "data",4);
    datachunk.chunk_size = pcmfile_size;
    fwrite(&datachunk, 1, sizeof(datachunk.chunk_id) + sizeof(datachunk.chunk_size), wavfile);

    while ((read_len = fread(buf, 1, sizeof(buf), pcmfile)) != 0) {
        fwrite(buf, 1, read_len, wavfile);
    }

    fclose(pcmfile);
    fclose(wavfile);
}

/**
* https://github.com/jwhu1024/pcm-to-wav
*/

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

typedef struct {
    unsigned char chunk_id[4];        // RIFF string
    unsigned int chunk_size;         // overall size of file in bytes (36 + data_size)
    unsigned char sub_chunk1_id[8];   // WAVEfmt string with trailing null char
    unsigned int sub_chunk1_size;    // 16 for PCM.  This is the size of the rest of the Subchunk which follows this number.
    unsigned short audio_format;       // format type. 1-PCM, 3- IEEE float, 6 - 8bit A law, 7 - 8bit mu law
    unsigned short num_channels;       // Mono = 1, Stereo = 2
    unsigned int sample_rate;        // 8000, 16000, 44100, etc. (blocks per second)
    unsigned int byte_rate;          // SampleRate * NumChannels * BitsPerSample/8
    unsigned short block_align;        // NumChannels * BitsPerSample/8
    unsigned short bits_per_sample;    // bits per sample, 8- 8bits, 16- 16 bits etc
    unsigned char sub_chunk2_id[4];   // Contains the letters "data"
    unsigned int sub_chunk2_size;    // NumSamples * NumChannels * BitsPerSample/8 - size of the next chunk that will be read
} wav_header_t;

char *dummy_get_raw_pcm(char *p, int *bytes_read) {
    long lSize;
    char *pcm_buf;
    size_t result;
    FILE *fp_pcm;

    fp_pcm = fopen(p, "rb");
    if (fp_pcm == NULL) {
        printf("File error");
        exit(1);
    }

    // obtain file size:
    fseek(fp_pcm, 0, SEEK_END);     // 將檔案指標移動到檔案最後
    lSize = ftell(fp_pcm);              // 返回給定流 stream 的當前檔案位置(位元組)
    rewind(fp_pcm);                     // 將檔案指標移動到檔案開頭

    // 分配記憶體來包含整個檔案
    pcm_buf = (char *) malloc(sizeof(char) * lSize);
    if (pcm_buf == NULL) {
        printf("Memory error");
        exit(2);
    }

    // 將檔案複製到pcm_buf中:
    result = fread(pcm_buf, 1, lSize, fp_pcm);
    if (result != lSize) {
        printf("Reading error");
        exit(3);
    }

    *bytes_read = (int) lSize;
    return pcm_buf;
}

void get_wav_header(int raw_sz, wav_header_t *wh) {
    // RIFF chunk
    strcpy(wh->chunk_id, "RIFF");
    wh->chunk_size = 36 + raw_sz;

    // fmt sub-chunk (to be optimized)
    strncpy(wh->sub_chunk1_id, "WAVEfmt ", strlen("WAVEfmt "));
    wh->sub_chunk1_size = 16;
    wh->audio_format = 1;
    wh->num_channels = 1;
    wh->sample_rate = 16000;
    wh->bits_per_sample = 16;
    wh->block_align = wh->num_channels * wh->bits_per_sample / 8;
    wh->byte_rate = wh->sample_rate * wh->num_channels * wh->bits_per_sample / 8;

    // data sub-chunk
    strncpy(wh->sub_chunk2_id, "data", strlen("data"));
    wh->sub_chunk2_size = raw_sz;
}

void dump_wav_header(wav_header_t *wh) {
    printf("=========================================\n");
    printf("chunk_id:\t\t\t%s\n", wh->chunk_id);
    printf("chunk_size:\t\t\t%d\n", wh->chunk_size);
    printf("sub_chunk1_id:\t\t\t%s\n", wh->sub_chunk1_id);
    printf("sub_chunk1_size:\t\t%d\n", wh->sub_chunk1_size);
    printf("audio_format:\t\t\t%d\n", wh->audio_format);
    printf("num_channels:\t\t\t%d\n", wh->num_channels);
    printf("sample_rate:\t\t\t%d\n", wh->sample_rate);
    printf("bits_per_sample:\t\t%d\n", wh->bits_per_sample);
    printf("block_align:\t\t\t%d\n", wh->block_align);
    printf("byte_rate:\t\t\t%d\n", wh->byte_rate);
    printf("sub_chunk2_id:\t\t\t%s\n", wh->sub_chunk2_id);
    printf("sub_chunk2_size:\t\t%d\n", wh->sub_chunk2_size);
    printf("=========================================\n");
}

// pcm-to-wav ./time.pcm ./***.wav
int main(int argc, char *argv[]) {
    int raw_sz = 0;
    FILE *fwav;
    wav_header_t wheader;           // 檔案頭 結構體變數宣告

    memset(&wheader, '\0', sizeof(wav_header_t));       // 清除記憶體位置

    // check argument
    if (argc != 2)
        return -1;

    // dummy raw pcm data
    char *pcm_buf = dummy_get_raw_pcm("./time.pcm", &raw_sz);

    // construct wav header
    get_wav_header(raw_sz, &wheader);       // 給檔案頭賦 初值
    dump_wav_header(&wheader);              // 列印檔案頭 資訊

    // write out the .wav file
    fwav = fopen(argv[1], "wb");
    fwrite(&wheader, 1, sizeof(wheader), fwav);
    fwrite(pcm_buf, 1, raw_sz, fwav);
    fclose(fwav);

    if (pcm_buf)
        free(pcm_buf);

    return 0;
}

def pcm2wav(pcm_file, wav_file, channels=1, bits=16, sample_rate=16000):
    pcmf = open(pcm_file, 'rb')
    pcmdata = pcmf.read()
    pcmf.close()

    if bits % 8 != 0:
        raise ValueError("bits % 8 must == 0. now bits:" + str(bits))

    wavfile = wave.open(wav_file, 'wb')
    wavfile.setnchannels(channels)
    wavfile.setsampwidth(bits // 8)
    wavfile.setframerate(sample_rate)
    wavfile.writeframes(pcmdata)
    wavfile.close()