// rresample.h
#ifndef __RRESAMPLE_H_
#define __RRESAMPLE_H_
int init_PCM_resample(int output_channels, int input_channels, int output_rate, int input_rate);
int start_PCM_resample(short *output, short *input, int in_len);
int uninit_PCM_resample();
int bit_wide_transform(int flag,int in_len,unsigned char* in_buf,unsigned char* out_buf);
int volume_control(short* out_buf,short* in_buf,int in_len, float in_vol);
#endif
//========================================================================
//rresample.c
#include "rresample.h"
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define FRAC_BITS 16
#define FRAC (1 << FRAC_BITS)
#define av_free(p) {if(p) free(p);}
#define av_malloc(size) malloc(size)
#define UINT unsigned int
typedef struct {
/* fractional resampling */
UINT incr; /* fractional increment */
UINT frac;
int last_sample;
/* integer down sample */
int iratio; /* integer divison ratio */
int icount, isum;
int inv;
} ReSampleChannelContext;
typedef struct ReSampleContext {
ReSampleChannelContext channel_ctx[2];
float ratio;
/* channel convert */
int input_channels, output_channels, filter_channels;
} ReSampleContext;
ReSampleContext *m_context;
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void init_mono_resample(ReSampleChannelContext *s, float ratio)
{
ratio = (float)(1.0 / ratio);
s->iratio = (int)floorf(ratio);
if (s->iratio == 0)
s->iratio = 1;
s->incr = (int)((ratio / s->iratio) * FRAC);
s->frac = FRAC;
s->last_sample = 0;
s->icount = s->iratio;
s->isum = 0;
s->inv = (FRAC / s->iratio);
}
/* fractional audio resampling */
int fractional_resample(ReSampleChannelContext *s, short *output, short *input, int nb_samples)
{
unsigned int frac, incr;
int l0, l1;
short *q, *p, *pend;
l0 = s->last_sample;
incr = s->incr;
frac = s->frac;
p = input;
pend = input + nb_samples;
q = output;
l1 = *p++;
for(;;) {
/* interpolate */
*q++ = (l0 * (FRAC - frac) + l1 * frac) >> FRAC_BITS;
frac = frac + s->incr;
while (frac >= FRAC) {
frac -= FRAC;
if (p >= pend)
goto the_end;
l0 = l1;
l1 = *p++;
}
}
the_end:
s->last_sample = l1;
s->frac = frac;
return q - output;
}
int integer_downsample(ReSampleChannelContext *s, short *output, short *input, int nb_samples)
{
short *q, *p, *pend;
int c, sum;
p = input;
pend = input + nb_samples;
q = output;
c = s->icount;
sum = s->isum;
for(;;) {
sum += *p++;
if (--c == 0) {
*q++ = (sum * s->inv) >> FRAC_BITS;
c = s->iratio;
sum = 0;
}
if (p >= pend)
break;
}
s->isum = sum;
s->icount = c;
return q - output;
}
/* n1: number of samples */
void stereo_to_mono(short *output, short *input, int n1)
{
short *p, *q;
int n = n1;
p = input;
q = output;
while (n >= 4) {
q[0] = (p[0] + p[1]) >> 1;
q[1] = (p[2] + p[3]) >> 1;
q[2] = (p[4] + p[5]) >> 1;
q[3] = (p[6] + p[7]) >> 1;
q += 4;
p += 8;
n -= 4;
}
while (n > 0) {
q[0] = (p[0] + p[1]) >> 1;
q++;
p += 2;
n--;
}
}
/* n1: number of samples */
void mono_to_stereo(short *output, short *input, int n1)
{
short *p, *q;
int n = n1;
int v;
p = input;
q = output;
while (n >= 4) {
v = p[0]; q[0] = v; q[1] = v;
v = p[1]; q[2] = v; q[3] = v;
v = p[2]; q[4] = v; q[5] = v;
v = p[3]; q[6] = v; q[7] = v;
q += 8;
p += 4;
n -= 4;
}
while (n > 0) {
v = p[0]; q[0] = v; q[1] = v;
q += 2;
p += 1;
n--;
}
}
/* XXX: should use more abstract 'N' channels system */
void stereo_split(short *output1, short *output2, short *input, int n)
{
int i;
for(i=0;i<n;i++) {
*output1++ = *input++;
*output2++ = *input++;
}
}
void stereo_mux(short *output, short *input1, short *input2, int n)
{
int i;
for(i=0;i<n;i++) {
*output++ = *input1++;
*output++ = *input2++;
}
}
void ac3_5p1_mux(short *output, short *input1, short *input2, int n)
{
int i;
short l,r;
for(i=0;i<n;i++) {
l=*input1++;
r=*input2++;
*output++ = l; /* left */
*output++ = (l/2)+(r/2); /* center */
*output++ = r; /* right */
*output++ = 0; /* left surround */
*output++ = 0; /* right surroud */
*output++ = 0; /* low freq */
}
}
int mono_resample(ReSampleChannelContext *s, short *output, short *input, int nb_samples)
{
short *buf1;
short *buftmp;
buf1= (short*)av_malloc( nb_samples * sizeof(short) );
/* first downsample by an integer factor with averaging filter */
if (s->iratio > 1) {
buftmp = buf1;
nb_samples = integer_downsample(s, buftmp, input, nb_samples);
} else {
buftmp = input;
}
/* then do a fractional resampling with linear interpolation */
if (s->incr != FRAC) {
nb_samples = fractional_resample(s, output, buftmp, nb_samples);
} else {
memcpy(output, buftmp, nb_samples * sizeof(short));
}
av_free(buf1);
return nb_samples;
}
//==========================================================================================================
int init_PCM_resample(int output_channels, int input_channels, int output_rate, int input_rate)
{
int i;
if ( input_channels > 2)
{
printf("Resampling with input channels greater than 2 unsupported.");
return -1;
}
m_context = (ReSampleContext *)malloc(sizeof(ReSampleContext));
memset(m_context, 0, sizeof(ReSampleContext));
m_context->ratio = (float)output_rate / (float)input_rate;
m_context->input_channels = input_channels;
m_context->output_channels = output_channels;
m_context->filter_channels = m_context->input_channels;
if (m_context->output_channels < m_context->filter_channels)
m_context->filter_channels = m_context->output_channels;
/*
* ac3 output is the only case where filter_channels could be greater than 2.
* input channels can't be greater than 2, so resample the 2 channels and then
* expand to 6 channels after the resampling.
*/
if(m_context->filter_channels>2)
m_context->filter_channels = 2;
for(i=0;i<m_context->filter_channels;i++) {
init_mono_resample(&m_context->channel_ctx[i], m_context->ratio);
}
return 0;
}
/* resample audio. 'nb_samples' is the number of input samples */
/* XXX: optimize it ! */
/* XXX: do it with polyphase filters, since the quality here is
HORRIBLE. Return the number of samples available in output */
// 重采样
// output para1:重采样后输出的数据
// input para2:输入数据
// para3:此帧音频的采样点数
// 注:44100的采样点数固定为1024,其他采样率不固定,需要通道此帧长度,通道数,位宽,计算采样点数
int start_PCM_resample(short *output, short *input, int in_len)
{
int i, nb_samples1;
short *bufin[2];
short *bufout[2];
short *buftmp2[2], *buftmp3[2];
int lenout;
int nb_samples = in_len/(m_context->input_channels * sizeof(short));
if (m_context->input_channels == m_context->output_channels && m_context->ratio == 1.0) {
/* nothing to do */
memcpy(output, input, nb_samples * m_context->input_channels * sizeof(short));
return nb_samples;
}
/* XXX: move those malloc to resample init code */
bufin[0]= (short*) av_malloc( nb_samples * sizeof(short) );
bufin[1]= (short*) av_malloc( nb_samples * sizeof(short) );
/* make some zoom to avoid round pb */
lenout= (int)(nb_samples * m_context->ratio) + 16;
bufout[0]= (short*) av_malloc( lenout * sizeof(short) );
bufout[1]= (short*) av_malloc( lenout * sizeof(short) );
if (m_context->input_channels == 2 &&
m_context->output_channels == 1) {
buftmp2[0] = bufin[0];
buftmp3[0] = output;
stereo_to_mono(buftmp2[0], input, nb_samples);
} else if (m_context->output_channels >= 2 && m_context->input_channels == 1) {
buftmp2[0] = input;
buftmp3[0] = bufout[0];
} else if (m_context->output_channels >= 2) {
buftmp2[0] = bufin[0];
buftmp2[1] = bufin[1];
buftmp3[0] = bufout[0];
buftmp3[1] = bufout[1];
stereo_split(buftmp2[0], buftmp2[1], input, nb_samples);
} else {
buftmp2[0] = input;
buftmp3[0] = output;
}
/* resample each channel */
nb_samples1 = 0; /* avoid warning */
for(i=0;i<m_context->filter_channels;i++) {
nb_samples1 = mono_resample(&m_context->channel_ctx[i], buftmp3[i], buftmp2[i], nb_samples);
}
if (m_context->output_channels == 2 && m_context->input_channels == 1) {
mono_to_stereo(output, buftmp3[0], nb_samples1);
} else if (m_context->output_channels == 2) {
stereo_mux(output, buftmp3[0], buftmp3[1], nb_samples1);
} else if (m_context->output_channels == 6) {
ac3_5p1_mux(output, buftmp3[0], buftmp3[1], nb_samples1);
}
av_free(bufin[0]);
av_free(bufin[1]);
av_free(bufout[0]);
av_free(bufout[1]);
return nb_samples1*m_context->output_channels*sizeof(short);
}
// 去初始化
int uninit_PCM_resample()
{
if(NULL == m_context)
{
free(m_context);
m_context = NULL;
}
return 0;
}
// 16bit_to_8bit(注意输出数据是有符号的还是无符号的)
// output: para 1: 8bit的数据
// input: para 2: 16bit数据
// para 3: 要转换数据的次数,为原数据长度的一半,因为一次转换2个字节
int mono_16bit_to_8bit(unsigned char* lp8bits, short* lp16bits, int len)
{
int i=0;
for(i=0; i<len; i++) {
*lp8bits++ = ((*lp16bits++) >> 8) + 128;
}
return i>>1;
}
// 8bit_to_16bit(注意:输出数据是有符号的还是无符号的)
// output: para 1: 16bit的数据
// input: para 2: 8bit数据
// para 3: 要转换数据的次数,为原数据长度,
//注:因为一次转换1个字节变两个字节,所以转换后数据的总长度为8位数据的两倍
int mono_8bit_to_16bit(short* lp16bits, unsigned char* lp8bits, int len)
{
int i=0;
for(i=0; i<len; i++) {
*lp16bits++ = ((*lp8bits++) -128) << 8;
}
return i<<1;
}
// 位宽转换
// input : para1 重采样对象
// para2 flag : [8]--16位转8位 ,[16]--8位转16位
// para3 输入数据长度
// para4 输入数据
// output: para5 输出数据
// return 输出数据长度
int bit_wide_transform(int flag,int in_len,unsigned char* in_buf,unsigned char* out_buf)
{
// 转换次数,转换单位是源数据一次采样,
// 即8位转16位:源数据是一次转换一个字节
// 即16位转8位:源数据是一次转换两个字节
int ns_sample = 0;
if(8 == flag)
{
ns_sample = in_len/2;
mono_16bit_to_8bit(out_buf, (short *)in_buf, ns_sample);
return ns_sample*1;
}
else if(16 == flag)
{
ns_sample = in_len;
mono_8bit_to_16bit((short*)out_buf, in_buf, ns_sample);
return ns_sample*2;
}
}
// 音量控制
// output: para1 输出数据
// input : para2 输入数据
// para3 输入长度
// para4 音量控制参数,有效控制范围[0,100]
int volume_control(short* out_buf,short* in_buf,int in_len, float in_vol)
{
int i,tmp;
// in_vol[0,100]
float vol = in_vol - 98;
if(-98 < vol && vol <0 )
{
vol = 1/(vol*(-1));
}
else if(0 <= vol && vol <= 1)
{
vol = 1;
}
/*else if(1 < vol && vol <= 2)
{
vol = vol;
}*/
else if(vol <= -98)
{
vol = 0;
}
else if(2 <= vol)
{
vol = 2;
}
for(i=0; i<in_len/2; i++)
{
tmp = in_buf[i]*vol;
if(tmp > 32767)
{
tmp = 32767;
}
else if( tmp < -32768)
{
tmp = -32768;
}
out_buf[i] = tmp;
}
return 0;
}
//=========================================================================
=========================================================================
//test.c
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include "rresample.h"
int openFileWrite(FILE** fp,char *name)
{
*fp = fopen(name,"w+");
if(NULL == *fp)
{
return -1;
}
else
{
return 0;
}
}
int openFileRead(FILE** fp,char *name)
{
*fp = fopen(name,"r+");
if(NULL == *fp)
{
return -1;
}
else
{
return 0;
}
}
int overreadFile(FILE *fp, unsigned char *buf,int *len_t)
{
if(NULL == fp || NULL == buf)
{
return -1;
}
int len = 0;
int len1 = 0;
len1 = ftell(fp);
fseek(fp, 0, SEEK_END);
len = ftell(fp);
fseek(fp, 0, SEEK_SET);
printf("len[%d]--len1[%d]\n",len,len1);
*len_t = len;
int i=0;
while(1)
{
if(len < 1024)
{
//printf("66666666666666\n");
if(1!= fread(buf+1024*i, len, 1, fp))
{
perror("read error---111[]\n");
printf("read error---111[i:%d]\n",i);
return -1;
}
}
else
{
//printf("999999999999999\n");
if(1 != fread(buf+1024*i, 1024, 1, fp))
{
perror("read error---222[\n");
printf("read error---222[i:%d]\n",i);
return -1;
}
}
//printf("22223323333333333\n");
i++;
//printf("111111111111\n");
len -= 1024;
//printf("2222222222222\n");
if(len <= 0)
{
break;
}
}
printf("read file successful\n");
printf("1111111111\n");
printf("2222222222222---*len_t[%d]\n",*len_t);
return 0;
}
int writeAllFile(FILE *fp, unsigned char *buf, int len)
{
if(NULL == fp || NULL == buf || 0 == len)
{
printf("NULL == fp || NULL == buf || 0 == len write \n");
return -1;
}
printf("write error---len[%d]\n",len);
int i=0;
while(1)
{
if(len < 1024)
{
if(1!= fwrite(buf+1024*i, len, 1, fp))
{
perror("\n");
printf("write error-len[%d]--111[i:%d]\n",len,i);
return -1;
}
}
else
{
if(1 != fwrite(buf+1024*i, 1024, 1, fp))
{
perror("write error---222[\n");
printf("write error---222[i:%d]\n",i);
return -1;
}
}
i++;
len -= 1024;
if(len <= 0)
{
break;
}
}
printf("write file successful\n");
return 0;
}
#define MAX_BUF_SIZE 1024*1024*120
int main(int argc, char *argv[])
{
#if 1
FILE *fp1 = NULL;
FILE *fp2 = NULL;
FILE *fp3 = NULL;
int len = 0;
unsigned char *read_buf = (unsigned char *)malloc(MAX_BUF_SIZE);
unsigned char *write_buf = (unsigned char *)malloc(MAX_BUF_SIZE);
if(NULL == read_buf || NULL == write_buf)
{
printf("malloc fail\n");
return -1;
}
if(0 != openFileRead(&fp1,argv[1]))
{
printf("open [%s] fail\n",argv[1]);
return -1;
}
if(0 != openFileWrite(&fp2,argv[2]))
{
printf("open [%s] fail\n",argv[2]);
return -1;
}
if(0 != overreadFile(fp1, (unsigned char *)read_buf, &len))
{
printf("overreadFile fail\n");
return -1;
}
int ns_sample = 1024;
int ns_sample1 = 0;
int i = 0;
int len_t = len;
int in_len = 0;
int out_len = 0;
int n =0;
unsigned char *p1 = write_buf;
unsigned char *p2 = read_buf;
int ret =-1;
#if 1
init_PCM_resample(2, 1, 44100, 11025);
while(1)
{
if(len_t > 4096)
{
in_len = 4096;
}
else
{
in_len = len_t;
}
//volume_control((short*)p1,(short*)p2,in_len, 80);
//n = bit_wide_transform(16,in_len, p2, p1);
n = start_PCM_resample((short *)p1, (short *)p2,in_len);
out_len += n;
p2 += in_len;
p1 += n;
len_t -= 4096;
if(len_t <= 0)
{
printf("I break---3233333333---\n");
break;
}
}
#endif
uninit_PCM_resample();
if(0 != writeAllFile(fp2, (unsigned char *)write_buf, out_len))
{
printf("writeAllFile fail\n");
return -1;
}
printf("complete resample================\n");
free(write_buf);
write_buf = NULL;
free(read_buf);
read_buf = NULL;
#endif
return 0;
}