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Diffstat (limited to 'media/ffvpx/libavutil/fifo.h')
| -rw-r--r-- | media/ffvpx/libavutil/fifo.h | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/fifo.h b/media/ffvpx/libavutil/fifo.h new file mode 100644 index 0000000000..70f9376d97 --- /dev/null +++ b/media/ffvpx/libavutil/fifo.h @@ -0,0 +1,448 @@ +/* + * 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 + * @ingroup lavu_fifo + * A generic FIFO API + */ + +#ifndef AVUTIL_FIFO_H +#define AVUTIL_FIFO_H + +#include <stddef.h> +#include <stdint.h> + +#include "attributes.h" +#include "version.h" + +/** + * @defgroup lavu_fifo AVFifo + * @ingroup lavu_data + * + * @{ + * A generic FIFO API + */ + +typedef struct AVFifo AVFifo; + +/** + * Callback for writing or reading from a FIFO, passed to (and invoked from) the + * av_fifo_*_cb() functions. It may be invoked multiple times from a single + * av_fifo_*_cb() call and may process less data than the maximum size indicated + * by nb_elems. + * + * @param opaque the opaque pointer provided to the av_fifo_*_cb() function + * @param buf the buffer for reading or writing the data, depending on which + * av_fifo_*_cb function is called + * @param nb_elems On entry contains the maximum number of elements that can be + * read from / written into buf. On success, the callback should + * update it to contain the number of elements actually written. + * + * @return 0 on success, a negative error code on failure (will be returned from + * the invoking av_fifo_*_cb() function) + */ +typedef int AVFifoCB(void *opaque, void *buf, size_t *nb_elems); + +/** + * Automatically resize the FIFO on writes, so that the data fits. This + * automatic resizing happens up to a limit that can be modified with + * av_fifo_auto_grow_limit(). + */ +#define AV_FIFO_FLAG_AUTO_GROW (1 << 0) + +/** + * Allocate and initialize an AVFifo with a given element size. + * + * @param elems initial number of elements that can be stored in the FIFO + * @param elem_size Size in bytes of a single element. Further operations on + * the returned FIFO will implicitly use this element size. + * @param flags a combination of AV_FIFO_FLAG_* + * + * @return newly-allocated AVFifo on success, a negative error code on failure + */ +AVFifo *av_fifo_alloc2(size_t elems, size_t elem_size, + unsigned int flags); + +/** + * @return Element size for FIFO operations. This element size is set at + * FIFO allocation and remains constant during its lifetime + */ +size_t av_fifo_elem_size(const AVFifo *f); + +/** + * Set the maximum size (in elements) to which the FIFO can be resized + * automatically. Has no effect unless AV_FIFO_FLAG_AUTO_GROW is used. + */ +void av_fifo_auto_grow_limit(AVFifo *f, size_t max_elems); + +/** + * @return number of elements available for reading from the given FIFO. + */ +size_t av_fifo_can_read(const AVFifo *f); + +/** + * @return Number of elements that can be written into the given FIFO without + * growing it. + * + * In other words, this number of elements or less is guaranteed to fit + * into the FIFO. More data may be written when the + * AV_FIFO_FLAG_AUTO_GROW flag was specified at FIFO creation, but this + * may involve memory allocation, which can fail. + */ +size_t av_fifo_can_write(const AVFifo *f); + +/** + * Enlarge an AVFifo. + * + * On success, the FIFO will be large enough to hold exactly + * inc + av_fifo_can_read() + av_fifo_can_write() + * elements. In case of failure, the old FIFO is kept unchanged. + * + * @param f AVFifo to resize + * @param inc number of elements to allocate for, in addition to the current + * allocated size + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_grow2(AVFifo *f, size_t inc); + +/** + * Write data into a FIFO. + * + * In case nb_elems > av_fifo_can_write(f) and the AV_FIFO_FLAG_AUTO_GROW flag + * was not specified at FIFO creation, nothing is written and an error + * is returned. + * + * Calling function is guaranteed to succeed if nb_elems <= av_fifo_can_write(f). + * + * @param f the FIFO buffer + * @param buf Data to be written. nb_elems * av_fifo_elem_size(f) bytes will be + * read from buf on success. + * @param nb_elems number of elements to write into FIFO + * + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_write(AVFifo *f, const void *buf, size_t nb_elems); + +/** + * Write data from a user-provided callback into a FIFO. + * + * @param f the FIFO buffer + * @param read_cb Callback supplying the data to the FIFO. May be called + * multiple times. + * @param opaque opaque user data to be provided to read_cb + * @param nb_elems Should point to the maximum number of elements that can be + * written. Will be updated to contain the number of elements + * actually written. + * + * @return non-negative number on success, a negative error code on failure + */ +int av_fifo_write_from_cb(AVFifo *f, AVFifoCB read_cb, + void *opaque, size_t *nb_elems); + +/** + * Read data from a FIFO. + * + * In case nb_elems > av_fifo_can_read(f), nothing is read and an error + * is returned. + * + * @param f the FIFO buffer + * @param buf Buffer to store the data. nb_elems * av_fifo_elem_size(f) bytes + * will be written into buf on success. + * @param nb_elems number of elements to read from FIFO + * + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_read(AVFifo *f, void *buf, size_t nb_elems); + +/** + * Feed data from a FIFO into a user-provided callback. + * + * @param f the FIFO buffer + * @param write_cb Callback the data will be supplied to. May be called + * multiple times. + * @param opaque opaque user data to be provided to write_cb + * @param nb_elems Should point to the maximum number of elements that can be + * read. Will be updated to contain the total number of elements + * actually sent to the callback. + * + * @return non-negative number on success, a negative error code on failure + */ +int av_fifo_read_to_cb(AVFifo *f, AVFifoCB write_cb, + void *opaque, size_t *nb_elems); + +/** + * Read data from a FIFO without modifying FIFO state. + * + * Returns an error if an attempt is made to peek to nonexistent elements + * (i.e. if offset + nb_elems is larger than av_fifo_can_read(f)). + * + * @param f the FIFO buffer + * @param buf Buffer to store the data. nb_elems * av_fifo_elem_size(f) bytes + * will be written into buf. + * @param nb_elems number of elements to read from FIFO + * @param offset number of initial elements to skip. + * + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_peek(AVFifo *f, void *buf, size_t nb_elems, size_t offset); + +/** + * Feed data from a FIFO into a user-provided callback. + * + * @param f the FIFO buffer + * @param write_cb Callback the data will be supplied to. May be called + * multiple times. + * @param opaque opaque user data to be provided to write_cb + * @param nb_elems Should point to the maximum number of elements that can be + * read. Will be updated to contain the total number of elements + * actually sent to the callback. + * @param offset number of initial elements to skip; offset + *nb_elems must not + * be larger than av_fifo_can_read(f). + * + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_peek_to_cb(AVFifo *f, AVFifoCB write_cb, void *opaque, + size_t *nb_elems, size_t offset); + +/** + * Discard the specified amount of data from an AVFifo. + * @param size number of elements to discard, MUST NOT be larger than + * av_fifo_can_read(f) + */ +void av_fifo_drain2(AVFifo *f, size_t size); + +/* + * Empty the AVFifo. + * @param f AVFifo to reset + */ +void av_fifo_reset2(AVFifo *f); + +/** + * Free an AVFifo and reset pointer to NULL. + * @param f Pointer to an AVFifo to free. *f == NULL is allowed. + */ +void av_fifo_freep2(AVFifo **f); + + +#if FF_API_FIFO_OLD_API +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 + * @deprecated use av_fifo_alloc2() + */ +attribute_deprecated +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 + * @deprecated use av_fifo_alloc2() + */ +attribute_deprecated +AVFifoBuffer *av_fifo_alloc_array(size_t nmemb, size_t size); + +/** + * Free an AVFifoBuffer. + * @param f AVFifoBuffer to free + * @deprecated use the AVFifo API with av_fifo_freep2() + */ +attribute_deprecated +void av_fifo_free(AVFifoBuffer *f); + +/** + * Free an AVFifoBuffer and reset pointer to NULL. + * @param f AVFifoBuffer to free + * @deprecated use the AVFifo API with av_fifo_freep2() + */ +attribute_deprecated +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 + * @deprecated use av_fifo_reset2() with the new AVFifo-API + */ +attribute_deprecated +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 + * @deprecated use av_fifo_can_read() with the new AVFifo-API + */ +attribute_deprecated +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 + * @deprecated use av_fifo_can_write() with the new AVFifo-API + */ +attribute_deprecated +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 + * + * @return a non-negative number on success, a negative error code on failure + * + * @deprecated use the new AVFifo-API with av_fifo_peek() when func == NULL, + * av_fifo_peek_to_cb() otherwise + */ +attribute_deprecated +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 + * + * @return a non-negative number on success, a negative error code on failure + * + * @deprecated use the new AVFifo-API with av_fifo_peek() when func == NULL, + * av_fifo_peek_to_cb() otherwise + */ +attribute_deprecated +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 + * + * @return a non-negative number on success, a negative error code on failure + * + * @deprecated use the new AVFifo-API with av_fifo_read() when func == NULL, + * av_fifo_read_to_cb() otherwise + */ +attribute_deprecated +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 or a negative error code on failure + * + * @deprecated use the new AVFifo-API with av_fifo_write() when func == NULL, + * av_fifo_write_from_cb() otherwise + */ +attribute_deprecated +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 + * + * @deprecated use the new AVFifo-API with av_fifo_grow2() to increase FIFO size, + * decreasing FIFO size is not supported + */ +attribute_deprecated +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 + * + * @deprecated use the new AVFifo-API with av_fifo_grow2(); note that unlike + * this function it adds to the allocated size, rather than to the used size + */ +attribute_deprecated +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 + * + * @deprecated use the new AVFifo-API with av_fifo_drain2() + */ +attribute_deprecated +void av_fifo_drain(AVFifoBuffer *f, int size); + +#if FF_API_FIFO_PEEK2 +/** + * 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(). + * @deprecated use the new AVFifo-API with av_fifo_peek() or av_fifo_peek_to_cb() + */ +attribute_deprecated +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 +#endif + +/** + * @} + */ + +#endif /* AVUTIL_FIFO_H */ |