プログラマ専用SNS ミクプラ

コード:

#include<stdio.h>



char *m;

struct {
	unsigned bit7 : 7;
}b;

void Write(int size)
{
	FILE *fp;

	fp=fopen("bit7.pcm","wb");
	for(int i=0;i<size;i++)
	{
		b.bit7=m[i];
		fwrite(b.bit7,b.bit7,1,fp);
	}
	fclose(fp);
}

void Load(char fn[],int *size)
{
	FILE *fp;

	fp=fopen(fn,"rb");
		fseek(fp,0x28,SEEK_SET);
		fseek(fp,0x28,SEEK_END);
		*size=ftell(fp);
		fseek(fp,0x28,SEEK_SET);
		m=new char[*size];
		fread(m,*size,1,fp);
		printf("sizeは、%dです。\n",size);
	fclose(fp);

}

int main(void)
{
	char fn[128];
	int size;
	printf("ファイル名を入力してください。->");
	scanf("%s",fn);
	Load(fn,&size);
	Write(size);

	delete []m;

	return 0;
}

コード:

fseek(fp,0x28,SEEK_SET);
fseek(fp,0x28,SEEK_END);
 *size=ftell(fp);

コード:

for(int j=1;j<size*7/8+1;j++)
{
	m[j-1] <<= 1;
	char tmp=m[j]&128;
	m[j-1]=m[j-1]|tmp;
}

コード:

#include<stdio.h>

int main()
{
	unsigned char number=128;
	int i;
	int tmp[8]={0};
	
	for(i=0;i<8;i++)
	{
		
		tmp[7-i]=number%2;
		number/=2;
	}

	for(i=0;i<8;i++)
	{
		printf("%d",tmp[i]);
	}
	printf("\n");

	return 0;
}

コード:

printf("サイズは%dです。",*size);

コード:

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

#define SRC_LENGTH (16u)

uint8_t read7bits(const uint8_t *buf, size_t pos_in_bits)
{
    uint16_t tmp = buf[pos_in_bits / 8] | (buf[pos_in_bits / 8 + 1] << 8);
    return (uint8_t)((tmp >> (pos_in_bits % 8)) & 0x007fu);
}

void write7bits(uint8_t *buf, size_t pos_in_bits, uint8_t val)
{
    const unsigned int shift_width = (pos_in_bits % 8);
    uint16_t tmp = buf[pos_in_bits / 8] | (buf[pos_in_bits / 8 + 1] << 8);
    tmp &= ~(0x7fu << shift_width);
    tmp |= (val << shift_width);
    buf[pos_in_bits / 8] = (tmp & 0xffu);
    buf[pos_in_bits / 8 + 1] = ((tmp >> 8) & 0xffu);
}

/* return the number of written bits. */
size_t compress(uint8_t *dst, const uint8_t *src, size_t len)
{
    size_t si, di_in_bits = 0;
    for (si = 0; si < len; ++si)
    {
        write7bits(dst, di_in_bits, src[si]);
        di_in_bits += 7;
    }
    return di_in_bits;
}

/* return the number of written bytes. */
size_t decompress(uint8_t *dst, const uint8_t *src, size_t len)
{
    size_t si_in_bits, di = 0;
    for (si_in_bits = 0; si_in_bits + 7 - 1 < len * 8; si_in_bits += 7)
    {
        dst[di] = read7bits(src, si_in_bits);
        di++;
    }
    return di;
}

void print_binary(unsigned char *buf, size_t len)
{
    size_t i;

    for (i = 0; i < len; ++i)
    {
        printf("%02x", buf[i]);
        if (i < len - 1)
        {
            printf(" ");
        }
    }
}

int main(void)
{
    uint8_t src[SRC_LENGTH];
    uint8_t buf[(SRC_LENGTH * 7 + 7) / 8];
    int i;
    size_t buf_len/*, src_len*/;

    /* set to src */
    for (i = 0; i < sizeof(src); ++i)
    {
        src[i] = 0x10 + i;
    }

    printf("compressing src -> buf\n");
    buf_len = compress(buf, src, sizeof(src)) / 8;

    printf("src: ");
    print_binary(src, sizeof(src));
    printf("\nbuf: ");
    print_binary(buf, buf_len);
    printf("\n");

    /* src_len = decompress(src, buf, buf_len); */

    return 0;
}

コード:

struct {
    unsigned bit7 : 7;
}b;