X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Ffifo.h;h=f106239304b29c8c138edaacf9682acd11edc539;hb=6766169c4198031c58a7972604d74947a16b75a7;hp=68ed064c1d5b98197d590cae5554159b3321f80d;hpb=33147993689223956d735e691dca45588a10c28f;p=ffmpeg diff --git a/libavutil/fifo.h b/libavutil/fifo.h index 68ed064c1d5..f106239304b 100644 --- a/libavutil/fifo.h +++ b/libavutil/fifo.h @@ -1,23 +1,23 @@ /* - * This file is part of FFmpeg. + * This file is part of Libav. * - * FFmpeg is free software; you can redistribute it and/or + * Libav 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, + * Libav 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 + * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** - * @file libavutil/fifo.h + * @file * a very simple circular buffer FIFO implementation */ @@ -26,7 +26,6 @@ #include #include "avutil.h" -#include "common.h" typedef struct AVFifoBuffer { uint8_t *buffer; @@ -35,56 +34,56 @@ typedef struct AVFifoBuffer { } AVFifoBuffer; /** - * Initializes an AVFifoBuffer. + * Initialize an AVFifoBuffer. * @param size of FIFO - * @return AVFifoBuffer or NULL if mem allocation failure + * @return AVFifoBuffer or NULL in case of memory allocation failure */ AVFifoBuffer *av_fifo_alloc(unsigned int size); /** - * Frees an AVFifoBuffer. - * @param *f AVFifoBuffer to free + * Free an AVFifoBuffer. + * @param f AVFifoBuffer to free */ void av_fifo_free(AVFifoBuffer *f); /** - * Resets the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied. - * @param *f AVFifoBuffer to reset + * 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); /** - * Returns the amount of data in bytes in the AVFifoBuffer, that is the + * 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 + * @param f AVFifoBuffer to read from * @return size */ int av_fifo_size(AVFifoBuffer *f); /** - * Returns the amount of space in bytes in the AVFifoBuffer, that is the + * 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 + * @param f AVFifoBuffer to write into * @return size */ int av_fifo_space(AVFifoBuffer *f); /** - * Feeds data from an AVFifoBuffer to a user-supplied callback. - * @param *f AVFifoBuffer to read from + * 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 + * @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)); /** - * Feeds 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 + * 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, + * @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. @@ -94,25 +93,49 @@ int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func) int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int)); /** - * Resizes an AVFifoBuffer. - * @param *f AVFifoBuffer to resize + * Resize an AVFifoBuffer. + * @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); /** - * Reads and discards the specified amount of data from an AVFifoBuffer. - * @param *f AVFifoBuffer to read from + * 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); -static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs) +/** + * 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->end - f->buffer; - return *ptr; + ptr = f->buffer + (ptr - f->end); + else if (ptr < f->buffer) + ptr = f->end - (f->buffer - ptr); + return ptr; } + +#if FF_API_AV_FIFO_PEEK +/** + * @deprecated Use av_fifo_peek2() instead. + */ +attribute_deprecated +static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs) +{ + return *av_fifo_peek2(f, offs); +} +#endif + #endif /* AVUTIL_FIFO_H */