mirror of https://github.com/FFmpeg/FFmpeg.git
libavformat/utils.c into libavutil Originally committed as revision 6310 to svn://svn.ffmpeg.org/ffmpeg/trunkpull/126/head
Roman Shaposhnik
19 years ago
parent
a1ef006823
commit
f5a478f65d
9 changed files with 212 additions and 219 deletions
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/*
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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 library 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 of the License, or (at your option) any later version. |
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* |
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* This library 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 this library; 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->buffer = av_malloc(size); |
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if (!f->buffer) |
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return -1; |
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f->end = f->buffer + size; |
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f->wptr = f->rptr = f->buffer; |
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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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int len; |
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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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if (size < buf_size) |
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return -1; |
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while (buf_size > 0) { |
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len = FFMIN(f->end - f->rptr, buf_size); |
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memcpy(buf, f->rptr, len); |
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buf += len; |
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f->rptr += len; |
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if (f->rptr >= f->end) |
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f->rptr = f->buffer; |
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buf_size -= len; |
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} |
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return 0; |
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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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uint8_t *old= f->buffer; |
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f->buffer= av_realloc(f->buffer, new_size); |
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f->rptr += f->buffer - old; |
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f->wptr += f->buffer - old; |
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if(f->wptr < f->rptr){ |
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memmove(f->rptr + new_size - old_size, f->rptr, f->buffer + old_size - f->rptr); |
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f->rptr += new_size - old_size; |
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} |
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f->end= f->buffer + new_size; |
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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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int len; |
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while (size > 0) { |
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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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} |
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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 len; |
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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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if (size < buf_size) |
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return -1; |
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while (buf_size > 0) { |
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len = FFMIN(f->end - f->rptr, buf_size); |
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func(dest, f->rptr, len); |
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f->rptr += len; |
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if (f->rptr >= f->end) |
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f->rptr = f->buffer; |
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buf_size -= len; |
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} |
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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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@ -0,0 +1,25 @@ |
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#ifndef FIFO_H |
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#define FIFO_H |
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typedef struct AVFifoBuffer { |
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uint8_t *buffer; |
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uint8_t *rptr, *wptr, *end; |
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} AVFifoBuffer; |
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int av_fifo_init(AVFifoBuffer *f, int size); |
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void av_fifo_free(AVFifoBuffer *f); |
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int av_fifo_size(AVFifoBuffer *f); |
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int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size); |
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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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void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size); |
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void av_fifo_realloc(AVFifoBuffer *f, unsigned int size); |
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void av_fifo_drain(AVFifoBuffer *f, int size); |
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static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs) |
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{ |
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uint8_t *ptr = f->rptr + offs; |
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if (ptr >= f->end) |
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ptr -= f->end - f->buffer; |
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return *ptr; |
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} |
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#endif /* FIFO_H */ |
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