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https://git.ffmpeg.org/ffmpeg.git
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115 lines
2.9 KiB
C
115 lines
2.9 KiB
C
/*
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* A very simple circular buffer FIFO implementation
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* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
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* Copyright (c) 2006 Roman Shaposhnik
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "common.h"
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#include "fifo.h"
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int av_fifo_init(AVFifoBuffer *f, int size)
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{
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f->wptr = f->rptr =
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f->buffer = av_malloc(size);
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f->end = f->buffer + size;
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if (!f->buffer)
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return -1;
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return 0;
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}
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void av_fifo_free(AVFifoBuffer *f)
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{
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av_free(f->buffer);
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}
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int av_fifo_size(AVFifoBuffer *f)
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{
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int size = f->wptr - f->rptr;
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if (size < 0)
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size += f->end - f->buffer;
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return size;
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}
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/**
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* Get data from the fifo (returns -1 if not enough data).
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*/
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int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
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{
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return av_fifo_generic_read(f, buf_size, NULL, buf);
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}
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/**
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* Resizes a FIFO.
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*/
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void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
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unsigned int old_size= f->end - f->buffer;
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if(old_size < new_size){
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int len= av_fifo_size(f);
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AVFifoBuffer f2;
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av_fifo_init(&f2, new_size);
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av_fifo_read(f, f2.buffer, len);
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f2.wptr += len;
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av_free(f->buffer);
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*f= f2;
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}
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}
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void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
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{
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do {
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int len = FFMIN(f->end - f->wptr, size);
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memcpy(f->wptr, buf, len);
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f->wptr += len;
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if (f->wptr >= f->end)
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f->wptr = f->buffer;
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buf += len;
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size -= len;
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} while (size > 0);
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}
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/** get data from the fifo (return -1 if not enough data) */
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int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
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{
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int size = av_fifo_size(f);
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if (size < buf_size)
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return -1;
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do {
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int len = FFMIN(f->end - f->rptr, buf_size);
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if(func) func(dest, f->rptr, len);
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else{
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memcpy(dest, f->rptr, len);
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dest = (uint8_t*)dest + len;
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}
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av_fifo_drain(f, len);
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buf_size -= len;
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} while (buf_size > 0);
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return 0;
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}
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/** discard data from the fifo */
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void av_fifo_drain(AVFifoBuffer *f, int size)
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{
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f->rptr += size;
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if (f->rptr >= f->end)
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f->rptr -= f->end - f->buffer;
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}
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