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Diffstat (limited to 'media/ffvpx/libavutil/fifo.h')
-rw-r--r-- | media/ffvpx/libavutil/fifo.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/fifo.h b/media/ffvpx/libavutil/fifo.h new file mode 100644 index 000000000..dc7bc6f0d --- /dev/null +++ b/media/ffvpx/libavutil/fifo.h @@ -0,0 +1,179 @@ +/* + * 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 + */ + +/** + * @file + * a very simple circular buffer FIFO implementation + */ + +#ifndef AVUTIL_FIFO_H +#define AVUTIL_FIFO_H + +#include <stdint.h> +#include "avutil.h" +#include "attributes.h" + +typedef struct AVFifoBuffer { + uint8_t *buffer; + uint8_t *rptr, *wptr, *end; + uint32_t rndx, wndx; +} AVFifoBuffer; + +/** + * Initialize an AVFifoBuffer. + * @param size of FIFO + * @return AVFifoBuffer or NULL in case of memory allocation failure + */ +AVFifoBuffer *av_fifo_alloc(unsigned int size); + +/** + * Initialize an AVFifoBuffer. + * @param nmemb number of elements + * @param size size of the single element + * @return AVFifoBuffer or NULL in case of memory allocation failure + */ +AVFifoBuffer *av_fifo_alloc_array(size_t nmemb, size_t size); + +/** + * Free an AVFifoBuffer. + * @param f AVFifoBuffer to free + */ +void av_fifo_free(AVFifoBuffer *f); + +/** + * Free an AVFifoBuffer and reset pointer to NULL. + * @param f AVFifoBuffer to free + */ +void av_fifo_freep(AVFifoBuffer **f); + +/** + * Reset the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied. + * @param f AVFifoBuffer to reset + */ +void av_fifo_reset(AVFifoBuffer *f); + +/** + * Return the amount of data in bytes in the AVFifoBuffer, that is the + * amount of data you can read from it. + * @param f AVFifoBuffer to read from + * @return size + */ +int av_fifo_size(const AVFifoBuffer *f); + +/** + * Return the amount of space in bytes in the AVFifoBuffer, that is the + * amount of data you can write into it. + * @param f AVFifoBuffer to write into + * @return size + */ +int av_fifo_space(const AVFifoBuffer *f); + +/** + * Feed data at specific position from an AVFifoBuffer to a user-supplied callback. + * Similar as av_fifo_gereric_read but without discarding data. + * @param f AVFifoBuffer to read from + * @param offset offset from current read position + * @param buf_size number of bytes to read + * @param func generic read function + * @param dest data destination + */ +int av_fifo_generic_peek_at(AVFifoBuffer *f, void *dest, int offset, int buf_size, void (*func)(void*, void*, int)); + +/** + * Feed data from an AVFifoBuffer to a user-supplied callback. + * Similar as av_fifo_gereric_read but without discarding data. + * @param f AVFifoBuffer to read from + * @param buf_size number of bytes to read + * @param func generic read function + * @param dest data destination + */ +int av_fifo_generic_peek(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int)); + +/** + * Feed data from an AVFifoBuffer to a user-supplied callback. + * @param f AVFifoBuffer to read from + * @param buf_size number of bytes to read + * @param func generic read function + * @param dest data destination + */ +int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int)); + +/** + * Feed data from a user-supplied callback to an AVFifoBuffer. + * @param f AVFifoBuffer to write to + * @param src data source; non-const since it may be used as a + * modifiable context by the function defined in func + * @param size number of bytes to write + * @param func generic write function; the first parameter is src, + * the second is dest_buf, the third is dest_buf_size. + * func must return the number of bytes written to dest_buf, or <= 0 to + * indicate no more data available to write. + * If func is NULL, src is interpreted as a simple byte array for source data. + * @return the number of bytes written to the FIFO + */ +int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int)); + +/** + * Resize an AVFifoBuffer. + * In case of reallocation failure, the old FIFO is kept unchanged. + * + * @param f AVFifoBuffer to resize + * @param size new AVFifoBuffer size in bytes + * @return <0 for failure, >=0 otherwise + */ +int av_fifo_realloc2(AVFifoBuffer *f, unsigned int size); + +/** + * Enlarge an AVFifoBuffer. + * In case of reallocation failure, the old FIFO is kept unchanged. + * The new fifo size may be larger than the requested size. + * + * @param f AVFifoBuffer to resize + * @param additional_space the amount of space in bytes to allocate in addition to av_fifo_size() + * @return <0 for failure, >=0 otherwise + */ +int av_fifo_grow(AVFifoBuffer *f, unsigned int additional_space); + +/** + * Read and discard the specified amount of data from an AVFifoBuffer. + * @param f AVFifoBuffer to read from + * @param size amount of data to read in bytes + */ +void av_fifo_drain(AVFifoBuffer *f, int size); + +/** + * Return a pointer to the data stored in a FIFO buffer at a certain offset. + * The FIFO buffer is not modified. + * + * @param f AVFifoBuffer to peek at, f must be non-NULL + * @param offs an offset in bytes, its absolute value must be less + * than the used buffer size or the returned pointer will + * point outside to the buffer data. + * The used buffer size can be checked with av_fifo_size(). + */ +static inline uint8_t *av_fifo_peek2(const AVFifoBuffer *f, int offs) +{ + uint8_t *ptr = f->rptr + offs; + if (ptr >= f->end) + ptr = f->buffer + (ptr - f->end); + else if (ptr < f->buffer) + ptr = f->end - (f->buffer - ptr); + return ptr; +} + +#endif /* AVUTIL_FIFO_H */ |