+++ /dev/null
-/*
- * 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_buffer
- * refcounted data buffer API
- */
-
-#ifndef AVUTIL_BUFFER_H
-#define AVUTIL_BUFFER_H
-
-#include <stdint.h>
-
-/**
- * @defgroup lavu_buffer AVBuffer
- * @ingroup lavu_data
- *
- * @{
- * AVBuffer is an API for reference-counted data buffers.
- *
- * There are two core objects in this API -- AVBuffer and AVBufferRef. AVBuffer
- * represents the data buffer itself; it is opaque and not meant to be accessed
- * by the caller directly, but only through AVBufferRef. However, the caller may
- * e.g. compare two AVBuffer pointers to check whether two different references
- * are describing the same data buffer. AVBufferRef represents a single
- * reference to an AVBuffer and it is the object that may be manipulated by the
- * caller directly.
- *
- * There are two functions provided for creating a new AVBuffer with a single
- * reference -- av_buffer_alloc() to just allocate a new buffer, and
- * av_buffer_create() to wrap an existing array in an AVBuffer. From an existing
- * reference, additional references may be created with av_buffer_ref().
- * Use av_buffer_unref() to free a reference (this will automatically free the
- * data once all the references are freed).
- *
- * The convention throughout this API and the rest of FFmpeg is such that the
- * buffer is considered writable if there exists only one reference to it (and
- * it has not been marked as read-only). The av_buffer_is_writable() function is
- * provided to check whether this is true and av_buffer_make_writable() will
- * automatically create a new writable buffer when necessary.
- * Of course nothing prevents the calling code from violating this convention,
- * however that is safe only when all the existing references are under its
- * control.
- *
- * @note Referencing and unreferencing the buffers is thread-safe and thus
- * may be done from multiple threads simultaneously without any need for
- * additional locking.
- *
- * @note Two different references to the same buffer can point to different
- * parts of the buffer (i.e. their AVBufferRef.data will not be equal).
- */
-
-/**
- * A reference counted buffer type. It is opaque and is meant to be used through
- * references (AVBufferRef).
- */
-typedef struct AVBuffer AVBuffer;
-
-/**
- * A reference to a data buffer.
- *
- * The size of this struct is not a part of the public ABI and it is not meant
- * to be allocated directly.
- */
-typedef struct AVBufferRef {
- AVBuffer *buffer;
-
- /**
- * The data buffer. It is considered writable if and only if
- * this is the only reference to the buffer, in which case
- * av_buffer_is_writable() returns 1.
- */
- uint8_t *data;
- /**
- * Size of data in bytes.
- */
- int size;
-} AVBufferRef;
-
-/**
- * Allocate an AVBuffer of the given size using av_malloc().
- *
- * @return an AVBufferRef of given size or NULL when out of memory
- */
-AVBufferRef *av_buffer_alloc(int size);
-
-/**
- * Same as av_buffer_alloc(), except the returned buffer will be initialized
- * to zero.
- */
-AVBufferRef *av_buffer_allocz(int size);
-
-/**
- * Always treat the buffer as read-only, even when it has only one
- * reference.
- */
-#define AV_BUFFER_FLAG_READONLY (1 << 0)
-
-/**
- * Create an AVBuffer from an existing array.
- *
- * If this function is successful, data is owned by the AVBuffer. The caller may
- * only access data through the returned AVBufferRef and references derived from
- * it.
- * If this function fails, data is left untouched.
- * @param data data array
- * @param size size of data in bytes
- * @param free a callback for freeing this buffer's data
- * @param opaque parameter to be got for processing or passed to free
- * @param flags a combination of AV_BUFFER_FLAG_*
- *
- * @return an AVBufferRef referring to data on success, NULL on failure.
- */
-AVBufferRef *av_buffer_create(uint8_t *data, int size,
- void (*free)(void *opaque, uint8_t *data),
- void *opaque, int flags);
-
-/**
- * Default free callback, which calls av_free() on the buffer data.
- * This function is meant to be passed to av_buffer_create(), not called
- * directly.
- */
-void av_buffer_default_free(void *opaque, uint8_t *data);
-
-/**
- * Create a new reference to an AVBuffer.
- *
- * @return a new AVBufferRef referring to the same AVBuffer as buf or NULL on
- * failure.
- */
-AVBufferRef *av_buffer_ref(AVBufferRef *buf);
-
-/**
- * Free a given reference and automatically free the buffer if there are no more
- * references to it.
- *
- * @param buf the reference to be freed. The pointer is set to NULL on return.
- */
-void av_buffer_unref(AVBufferRef **buf);
-
-/**
- * @return 1 if the caller may write to the data referred to by buf (which is
- * true if and only if buf is the only reference to the underlying AVBuffer).
- * Return 0 otherwise.
- * A positive answer is valid until av_buffer_ref() is called on buf.
- */
-int av_buffer_is_writable(const AVBufferRef *buf);
-
-/**
- * @return the opaque parameter set by av_buffer_create.
- */
-void *av_buffer_get_opaque(const AVBufferRef *buf);
-
-int av_buffer_get_ref_count(const AVBufferRef *buf);
-
-/**
- * Create a writable reference from a given buffer reference, avoiding data copy
- * if possible.
- *
- * @param buf buffer reference to make writable. On success, buf is either left
- * untouched, or it is unreferenced and a new writable AVBufferRef is
- * written in its place. On failure, buf is left untouched.
- * @return 0 on success, a negative AVERROR on failure.
- */
-int av_buffer_make_writable(AVBufferRef **buf);
-
-/**
- * Reallocate a given buffer.
- *
- * @param buf a buffer reference to reallocate. On success, buf will be
- * unreferenced and a new reference with the required size will be
- * written in its place. On failure buf will be left untouched. *buf
- * may be NULL, then a new buffer is allocated.
- * @param size required new buffer size.
- * @return 0 on success, a negative AVERROR on failure.
- *
- * @note the buffer is actually reallocated with av_realloc() only if it was
- * initially allocated through av_buffer_realloc(NULL) and there is only one
- * reference to it (i.e. the one passed to this function). In all other cases
- * a new buffer is allocated and the data is copied.
- */
-int av_buffer_realloc(AVBufferRef **buf, int size);
-
-/**
- * @}
- */
-
-/**
- * @defgroup lavu_bufferpool AVBufferPool
- * @ingroup lavu_data
- *
- * @{
- * AVBufferPool is an API for a lock-free thread-safe pool of AVBuffers.
- *
- * Frequently allocating and freeing large buffers may be slow. AVBufferPool is
- * meant to solve this in cases when the caller needs a set of buffers of the
- * same size (the most obvious use case being buffers for raw video or audio
- * frames).
- *
- * At the beginning, the user must call av_buffer_pool_init() to create the
- * buffer pool. Then whenever a buffer is needed, call av_buffer_pool_get() to
- * get a reference to a new buffer, similar to av_buffer_alloc(). This new
- * reference works in all aspects the same way as the one created by
- * av_buffer_alloc(). However, when the last reference to this buffer is
- * unreferenced, it is returned to the pool instead of being freed and will be
- * reused for subsequent av_buffer_pool_get() calls.
- *
- * When the caller is done with the pool and no longer needs to allocate any new
- * buffers, av_buffer_pool_uninit() must be called to mark the pool as freeable.
- * Once all the buffers are released, it will automatically be freed.
- *
- * Allocating and releasing buffers with this API is thread-safe as long as
- * either the default alloc callback is used, or the user-supplied one is
- * thread-safe.
- */
-
-/**
- * The buffer pool. This structure is opaque and not meant to be accessed
- * directly. It is allocated with av_buffer_pool_init() and freed with
- * av_buffer_pool_uninit().
- */
-typedef struct AVBufferPool AVBufferPool;
-
-/**
- * Allocate and initialize a buffer pool.
- *
- * @param size size of each buffer in this pool
- * @param alloc a function that will be used to allocate new buffers when the
- * pool is empty. May be NULL, then the default allocator will be used
- * (av_buffer_alloc()).
- * @return newly created buffer pool on success, NULL on error.
- */
-AVBufferPool *av_buffer_pool_init(int size, AVBufferRef* (*alloc)(int size));
-
-/**
- * Mark the pool as being available for freeing. It will actually be freed only
- * once all the allocated buffers associated with the pool are released. Thus it
- * is safe to call this function while some of the allocated buffers are still
- * in use.
- *
- * @param pool pointer to the pool to be freed. It will be set to NULL.
- * @see av_buffer_pool_can_uninit()
- */
-void av_buffer_pool_uninit(AVBufferPool **pool);
-
-/**
- * Allocate a new AVBuffer, reusing an old buffer from the pool when available.
- * This function may be called simultaneously from multiple threads.
- *
- * @return a reference to the new buffer on success, NULL on error.
- */
-AVBufferRef *av_buffer_pool_get(AVBufferPool *pool);
-
-/**
- * @}
- */
-
-#endif /* AVUTIL_BUFFER_H */
projects / rtmpclient.git / blobdiff