mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-29 10:52:20 +00:00
130 lines
3.4 KiB
C
130 lines
3.4 KiB
C
/*
|
|
* a very simple circular buffer FIFO implementation
|
|
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
|
|
* Copyright (c) 2006 Roman Shaposhnik
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
#include "common.h"
|
|
#include "fifo.h"
|
|
|
|
AVFifoBuffer *av_fifo_alloc(unsigned int size)
|
|
{
|
|
AVFifoBuffer *f= av_mallocz(sizeof(AVFifoBuffer));
|
|
if(!f)
|
|
return NULL;
|
|
f->buffer = av_malloc(size);
|
|
f->end = f->buffer + size;
|
|
av_fifo_reset(f);
|
|
if (!f->buffer)
|
|
av_freep(&f);
|
|
return f;
|
|
}
|
|
|
|
void av_fifo_free(AVFifoBuffer *f)
|
|
{
|
|
if(f){
|
|
av_free(f->buffer);
|
|
av_free(f);
|
|
}
|
|
}
|
|
|
|
void av_fifo_reset(AVFifoBuffer *f)
|
|
{
|
|
f->wptr = f->rptr = f->buffer;
|
|
f->wndx = f->rndx = 0;
|
|
}
|
|
|
|
int av_fifo_size(AVFifoBuffer *f)
|
|
{
|
|
return (uint32_t)(f->wndx - f->rndx);
|
|
}
|
|
|
|
int av_fifo_space(AVFifoBuffer *f)
|
|
{
|
|
return f->end - f->buffer - av_fifo_size(f);
|
|
}
|
|
|
|
int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) {
|
|
unsigned int old_size= f->end - f->buffer;
|
|
|
|
if(old_size < new_size){
|
|
int len= av_fifo_size(f);
|
|
AVFifoBuffer *f2= av_fifo_alloc(new_size);
|
|
|
|
if (!f2)
|
|
return -1;
|
|
av_fifo_generic_read(f, f2->buffer, len, NULL);
|
|
f2->wptr += len;
|
|
f2->wndx += len;
|
|
av_free(f->buffer);
|
|
*f= *f2;
|
|
av_free(f2);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
// src must NOT be const as it can be a context for func that may need updating (like a pointer or byte counter)
|
|
int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int))
|
|
{
|
|
int total = size;
|
|
do {
|
|
int len = FFMIN(f->end - f->wptr, size);
|
|
if(func) {
|
|
if(func(src, f->wptr, len) <= 0)
|
|
break;
|
|
} else {
|
|
memcpy(f->wptr, src, len);
|
|
src = (uint8_t*)src + len;
|
|
}
|
|
// Write memory barrier needed for SMP here in theory
|
|
f->wptr += len;
|
|
if (f->wptr >= f->end)
|
|
f->wptr = f->buffer;
|
|
f->wndx += len;
|
|
size -= len;
|
|
} while (size > 0);
|
|
return total - size;
|
|
}
|
|
|
|
|
|
int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int))
|
|
{
|
|
// Read memory barrier needed for SMP here in theory
|
|
do {
|
|
int len = FFMIN(f->end - f->rptr, buf_size);
|
|
if(func) func(dest, f->rptr, len);
|
|
else{
|
|
memcpy(dest, f->rptr, len);
|
|
dest = (uint8_t*)dest + len;
|
|
}
|
|
// memory barrier needed for SMP here in theory
|
|
av_fifo_drain(f, len);
|
|
buf_size -= len;
|
|
} while (buf_size > 0);
|
|
return 0;
|
|
}
|
|
|
|
/** Discard data from the FIFO. */
|
|
void av_fifo_drain(AVFifoBuffer *f, int size)
|
|
{
|
|
f->rptr += size;
|
|
if (f->rptr >= f->end)
|
|
f->rptr -= f->end - f->buffer;
|
|
f->rndx += size;
|
|
}
|