diff options
Diffstat (limited to 'src/lib/ffmpeg-2.1/libavutil/buffer.pas')
| -rw-r--r-- | src/lib/ffmpeg-2.1/libavutil/buffer.pas | 423 |
1 files changed, 210 insertions, 213 deletions
diff --git a/src/lib/ffmpeg-2.1/libavutil/buffer.pas b/src/lib/ffmpeg-2.1/libavutil/buffer.pas index e4f40fc9..6eead1dc 100644 --- a/src/lib/ffmpeg-2.1/libavutil/buffer.pas +++ b/src/lib/ffmpeg-2.1/libavutil/buffer.pas @@ -28,59 +28,65 @@ *) const - (** - * Always treat the buffer as read-only, even when it has only one - * reference. - *) +(** + * Always treat the buffer as read-only, even when it has only one + * reference. + *) AV_BUFFER_FLAG_READONLY = (1 << 0); type - (** - * @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). - *) +(** + * @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). - *) +(** + * A reference counted buffer type. It is opaque and is meant to be used through + * references (AVBufferRef). + *) TAVBuffer = record end; +(** + * 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. + *) PPAVBufferRef = ^PAVBufferRef; PAVBufferRef = ^TAVBufferRef; TAVBufferRef = record @@ -89,11 +95,11 @@ type * 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. - *) - data: PByte; + *) + data: PByte; (** * Size of data in bytes. - *) + *) size: cint; end; @@ -101,186 +107,177 @@ type TFree = procedure(opaque: pointer; data: pbyte); TAlloc = function(size: cint): PAVBufferRef; - (** - * 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(). - *) +(** + * 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(). + *) PPAVBufferPool = ^PAVBufferPool; PAVBufferPool = ^TAVBufferPool; TAVBufferPool = record end; +(** + * Allocate an AVBuffer of the given size using av_malloc(). + * + * @return an AVBufferRef of given size or NULL when out of memory + *) +function av_buffer_alloc(size: cint): PAVBufferRef; + cdecl; external av__util; - (** - * Allocate an AVBuffer of the given size using av_malloc(). - * - * @return an AVBufferRef of given size or NULL when out of memory - *) - function av_buffer_alloc(size: cint): PAVBufferRef; - cdecl; external av__util; - - (** - * 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. - *) - - function av_buffer_create(data: PByte; size: cint; - free: TFree; - opaque: pointer; flags: cint): PAVBufferRef; - cdecl; external av__util; - - (** - * 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. - *) - procedure av_buffer_default_free(opaque: pointer; data: pbyte); - cdecl; external av__util; +(** + * 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. + *) - (** - * Create a new reference to an AVBuffer. - * - * @return a new AVBufferRef referring to the same AVBuffer as buf or NULL on - * failure. - *) - function av_buffer_ref(buf: PAVBufferRef): PAVBufferRef; - cdecl; external av__util; +function av_buffer_create(data: PByte; size: cint; + free: TFree; + opaque: pointer; flags: cint): PAVBufferRef; + cdecl; external av__util; - (** - * 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. - *) - procedure av_buffer_unref(buf: PPAVBufferRef); - cdecl; external av__util; +(** + * 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. + *) +procedure av_buffer_default_free(opaque: pointer; data: pbyte); + cdecl; external av__util; - (** - * @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. - *) - function av_buffer_is_writable(buf: {const} PAVBufferRef): cint; - cdecl; external av__util; +(** + * Create a new reference to an AVBuffer. + * + * @return a new AVBufferRef referring to the same AVBuffer as buf or NULL on + * failure. + *) +function av_buffer_ref(buf: PAVBufferRef): PAVBufferRef; + cdecl; external av__util; - (** - * @return the opaque parameter set by av_buffer_create. - *) - procedure av_buffer_get_opaque(buf: {const} PAVBufferRef); - cdecl; external av__util; +(** + * 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. + *) +procedure av_buffer_unref(buf: PPAVBufferRef); + cdecl; external av__util; - function av_buffer_get_ref_count(buf: {const} PAVBufferRef): cint; - cdecl; external av__util; +(** + * @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. + *) +function av_buffer_is_writable(buf: {const} PAVBufferRef): cint; + cdecl; external av__util; - (** - * 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. - *) - function av_buffer_make_writable(buf: PPAVBufferRef): cint; - cdecl; external av__util; +(** + * @return the opaque parameter set by av_buffer_create. + *) +procedure av_buffer_get_opaque(buf: {const} PAVBufferRef); + cdecl; external av__util; - (** - * 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. - *) - function av_buffer_realloc(buf: PPAVBufferRef; size: cint): cint; - cdecl; external av__util; +function av_buffer_get_ref_count(buf: {const} PAVBufferRef): cint; + cdecl; external av__util; - (** - * @} - *) +(** + * 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. + *) +function av_buffer_make_writable(buf: PPAVBufferRef): cint; + cdecl; external av__util; - (** - * @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. - *) +(** + * 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. + *) +function av_buffer_realloc(buf: PPAVBufferRef; size: cint): cint; + cdecl; external av__util; - (** - * 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. - *) - function av_buffer_pool_init(size: cint; alloc: TAlloc): PAVBufferRef; - cdecl; external av__util; +(** + * @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. + *) - (** - * 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() - *) - procedure av_buffer_pool_uninit(pool: PPAVBufferPool); - cdecl; external av__util; +(** + * 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. + *) +function av_buffer_pool_init(size: cint; alloc: TAlloc): PAVBufferRef; + cdecl; external av__util; - (** - * 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. - *) - function av_buffer_pool_get(pool: PAVBufferPool): PAVBufferRef; - cdecl; external av__util; +(** + * 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() + *) +procedure av_buffer_pool_uninit(pool: PPAVBufferPool); + cdecl; external av__util; - (** - * @{ - *) +(** + * 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. + *) +function av_buffer_pool_get(pool: PAVBufferPool): PAVBufferRef; + cdecl; external av__util; |