mpv/TOOLS/buffer.c

74 lines
1.5 KiB
C

// General purpose Ring-buffering routines
#define BUFFSIZE (1024)
#define NUM_BUFS (64)
static unsigned char *buffer[NUM_BUFS];
static unsigned int buf_read=0;
static unsigned int buf_write=0;
static unsigned int buf_read_pos=0;
static unsigned int buf_write_pos=0;
static int full_buffers=0;
static int buffered_bytes=0;
static int write_buffer(unsigned char* data,int len){
int len2=0;
int x;
while(len>0){
if(full_buffers==NUM_BUFS) break;
x=BUFFSIZE-buf_write_pos;
if(x>len) x=len;
memcpy(buffer[buf_write]+buf_write_pos,data+len2,x);
len2+=x; len-=x;
buffered_bytes+=x; buf_write_pos+=x;
if(buf_write_pos>=BUFFSIZE){
// block is full, find next!
buf_write=(buf_write+1)%NUM_BUFS;
++full_buffers;
buf_write_pos=0;
}
}
return len2;
}
static int read_buffer(unsigned char* data,int len){
int len2=0;
int x;
while(len>0){
if(full_buffers==0) break; // no more data buffered!
x=BUFFSIZE-buf_read_pos;
if(x>len) x=len;
memcpy(data+len2,buffer[buf_read]+buf_read_pos,x);
len2+=x; len-=x;
buffered_bytes-=x; buf_read_pos+=x;
if(buf_read_pos>=BUFFSIZE){
// block is empty, find next!
buf_read=(buf_read+1)%NUM_BUFS;
--full_buffers;
buf_read_pos=0;
}
}
return len2;
}
static int get_space(){
return (NUM_BUFS-full_buffers)*BUFFSIZE - buf_write_pos;
}
static int get_delay(){
return buffered_bytes;
}
int main(int argc,char* argv[]){
int i;
for(i=0;i<NUM_BUFS;i++) buffer[i]=malloc(BUFFSIZE);
return 0;
}