/*
- * Filter layer
+ * filter layer
* copyright (c) 2007 Bobby Bingham
*
* This file is part of FFmpeg.
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#ifndef FFMPEG_AVFILTER_H
-#define FFMPEG_AVFILTER_H
+#ifndef AVFILTER_AVFILTER_H
+#define AVFILTER_AVFILTER_H
-#include "avcodec.h"
+#define LIBAVFILTER_VERSION_MAJOR 0
+#define LIBAVFILTER_VERSION_MINOR 5
+#define LIBAVFILTER_VERSION_MICRO 0
+
+#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
+ LIBAVFILTER_VERSION_MINOR, \
+ LIBAVFILTER_VERSION_MICRO)
+#define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
+ LIBAVFILTER_VERSION_MINOR, \
+ LIBAVFILTER_VERSION_MICRO)
+#define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
+
+#include <stddef.h>
+#include "libavcodec/avcodec.h"
+
+/**
+ * Returns the LIBAVFILTER_VERSION_INT constant.
+ */
+unsigned avfilter_version(void);
typedef struct AVFilterContext AVFilterContext;
typedef struct AVFilterLink AVFilterLink;
/**
* A reference-counted picture data type used by the filter system. Filters
* should not store pointers to this structure directly, but instead use the
- * AVFilterPicRef structure below
+ * AVFilterPicRef structure below.
*/
typedef struct AVFilterPic
{
- uint8_t *data[4];
- int linesize[4]; ///< number of bytes per line
- enum PixelFormat format;
+ uint8_t *data[4]; ///< picture data for each plane
+ int linesize[4]; ///< number of bytes per line
+ enum PixelFormat format; ///< colorspace
- unsigned refcount;
+ unsigned refcount; ///< number of references to this image
+
+ /** private data to be used by a custom free function */
void *priv;
+ /**
+ * A pointer to the function to deallocate this image if the default
+ * function is not sufficient. This could, for example, add the memory
+ * back into a memory pool to be reused later without the overhead of
+ * reallocating it from scratch.
+ */
void (*free)(struct AVFilterPic *pic);
} AVFilterPic;
*/
typedef struct AVFilterPicRef
{
- AVFilterPic *pic;
- uint8_t *data[4];
- int linesize[4];
- int w, h;
+ AVFilterPic *pic; ///< the picture that this is a reference to
+ uint8_t *data[4]; ///< picture data for each plane
+ int linesize[4]; ///< number of bytes per line
+ int w; ///< image width
+ int h; ///< image height
+
+ int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
- int64_t pts; ///< presentation timestamp in milliseconds
+ AVRational pixel_aspect; ///< pixel aspect ratio
int perms; ///< permissions
#define AV_PERM_READ 0x01 ///< can read from the buffer
#define AV_PERM_WRITE 0x02 ///< can write to the buffer
#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
-#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times
+#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
+#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
} AVFilterPicRef;
/**
* Add a new reference to a picture.
- * @param ref An existing reference to the picture
- * @param pmask A bitmask containing the allowable permissions in the new reference
- * @return A new reference to the picture with the same properties as the old
+ * @param ref an existing reference to the picture
+ * @param pmask a bitmask containing the allowable permissions in the new
+ * reference
+ * @return a new reference to the picture with the same properties as the
+ * old, excluding any permissions denied by pmask
*/
AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
/**
* Remove a reference to a picture. If this is the last reference to the
* picture, the picture itself is also automatically freed.
- * @param ref Reference to the picture.
+ * @param ref reference to the picture
*/
void avfilter_unref_pic(AVFilterPicRef *ref);
+/**
+ * A list of supported formats for one end of a filter link. This is used
+ * during the format negotiation process to try to pick the best format to
+ * use to minimize the number of necessary conversions. Each filter gives a
+ * list of the formats supported by each input and output pad. The list
+ * given for each pad need not be distinct - they may be references to the
+ * same list of formats, as is often the case when a filter supports multiple
+ * formats, but will always output the same format as it is given in input.
+ *
+ * In this way, a list of possible input formats and a list of possible
+ * output formats are associated with each link. When a set of formats is
+ * negotiated over a link, the input and output lists are merged to form a
+ * new list containing only the common elements of each list. In the case
+ * that there were no common elements, a format conversion is necessary.
+ * Otherwise, the lists are merged, and all other links which reference
+ * either of the format lists involved in the merge are also affected.
+ *
+ * For example, consider the filter chain:
+ * filter (a) --> (b) filter (b) --> (c) filter
+ *
+ * where the letters in parenthesis indicate a list of formats supported on
+ * the input or output of the link. Suppose the lists are as follows:
+ * (a) = {A, B}
+ * (b) = {A, B, C}
+ * (c) = {B, C}
+ *
+ * First, the first link's lists are merged, yielding:
+ * filter (a) --> (a) filter (a) --> (c) filter
+ *
+ * Notice that format list (b) now refers to the same list as filter list (a).
+ * Next, the lists for the second link are merged, yielding:
+ * filter (a) --> (a) filter (a) --> (a) filter
+ *
+ * where (a) = {B}.
+ *
+ * Unfortunately, when the format lists at the two ends of a link are merged,
+ * we must ensure that all links which reference either pre-merge format list
+ * get updated as well. Therefore, we have the format list structure store a
+ * pointer to each of the pointers to itself.
+ */
+typedef struct AVFilterFormats AVFilterFormats;
+struct AVFilterFormats
+{
+ unsigned format_count; ///< number of formats
+ int *formats; ///< list of formats
+
+ unsigned refcount; ///< number of references to this list
+ AVFilterFormats ***refs; ///< references to this list
+};
+
+/**
+ * Helper function to create a list of supported formats. This is intended
+ * for use in AVFilter->query_formats().
+ * @param len the number of formats supported
+ * @param ... a list of the supported formats
+ * @return the format list, with no existing references
+ */
+AVFilterFormats *avfilter_make_format_list(int len, ...);
+
+/**
+ * Returns a list of all colorspaces supported by FFmpeg.
+ */
+AVFilterFormats *avfilter_all_colorspaces(void);
+
+/**
+ * Returns a format list which contains the intersection of the formats of
+ * a and b. Also, all the references of a, all the references of b, and
+ * a and b themselves will be deallocated.
+ *
+ * If a and b do not share any common formats, neither is modified, and NULL
+ * is returned.
+ */
+AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
+
+/**
+ * Adds *ref as a new reference to formats.
+ * That is the pointers will point like in the ascii art below:
+ * ________
+ * |formats |<--------.
+ * | ____ | ____|___________________
+ * | |refs| | | __|_
+ * | |* * | | | | | | AVFilterLink
+ * | |* *--------->|*ref|
+ * | |____| | | |____|
+ * |________| |________________________
+ */
+void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
+
+/**
+ * Remove *ref as a reference to the format list it currently points to,
+ * deallocate that list if this was the last reference, and set *ref to NULL.
+ *
+ * Before After
+ * ________ ________ NULL
+ * |formats |<--------. |formats | ^
+ * | ____ | ____|________________ | ____ | ____|________________
+ * | |refs| | | __|_ | |refs| | | __|_
+ * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
+ * | |* *--------->|*ref| | |* | | | |*ref|
+ * | |____| | | |____| | |____| | | |____|
+ * |________| |_____________________ |________| |_____________________
+ */
+void avfilter_formats_unref(AVFilterFormats **ref);
+
+/**
+ *
+ * Before After
+ * ________ ________
+ * |formats |<---------. |formats |<---------.
+ * | ____ | ___|___ | ____ | ___|___
+ * | |refs| | | | | | |refs| | | | | NULL
+ * | |* *--------->|*oldref| | |* *--------->|*newref| ^
+ * | |* * | | |_______| | |* * | | |_______| ___|___
+ * | |____| | | |____| | | | |
+ * |________| |________| |*oldref|
+ * |_______|
+ */
+void avfilter_formats_changeref(AVFilterFormats **oldref,
+ AVFilterFormats **newref);
+
+/**
+ * A filter pad used for either input or output.
+ */
struct AVFilterPad
{
/**
- * Pad name. The name is unique among inputs and among oututs, but an
- * input may have the same name as an output.
+ * Pad name. The name is unique among inputs and among outputs, but an
+ * input may have the same name as an output. This may be NULL if this
+ * pad has no need to ever be referenced by name.
*/
- char *name;
+ const char *name;
/**
* AVFilterPad type. Only video supported now, hopefully someone will
* add audio in the future.
*/
- int type;
-#define AV_PAD_VIDEO 0
+ enum CodecType type;
+
+ /**
+ * Minimum required permissions on incoming buffers. Any buffer with
+ * insufficient permissions will be automatically copied by the filter
+ * system to a new buffer which provides the needed access permissions.
+ *
+ * Input pads only.
+ */
+ int min_perms;
/**
- * Callback to get a list of supported formats. The returned list should
- * be terminated by -1. This is used for both input and output pads and
- * is required for both.
+ * Permissions which are not accepted on incoming buffers. Any buffer
+ * which has any of these permissions set will be automatically copied
+ * by the filter system to a new buffer which does not have those
+ * permissions. This can be used to easily disallow buffers with
+ * AV_PERM_REUSE.
+ *
+ * Input pads only.
*/
- int *(*query_formats)(AVFilterLink *link);
+ int rej_perms;
/**
* Callback called before passing the first slice of a new frame. If
* NULL, the filter layer will default to storing a reference to the
* picture inside the link structure.
+ *
+ * Input video pads only.
*/
void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
/**
* Callback function to get a buffer. If NULL, the filter system will
- * handle buffer requests. Only required for input video pads.
+ * handle buffer requests.
+ *
+ * Input video pads only.
*/
AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);
* Callback called after the slices of a frame are completely sent. If
* NULL, the filter layer will default to releasing the reference stored
* in the link structure during start_frame().
+ *
+ * Input video pads only.
*/
void (*end_frame)(AVFilterLink *link);
/**
* Slice drawing callback. This is where a filter receives video data
- * and should do its processing. Only required for input video pads.
+ * and should do its processing.
+ *
+ * Input video pads only.
+ */
+ void (*draw_slice)(AVFilterLink *link, int y, int height);
+
+ /**
+ * Frame poll callback. This returns the number of immediately available
+ * frames. It should return a positive value if the next request_frame()
+ * is guaranteed to return one frame (with no delay).
+ *
+ * Defaults to just calling the source poll_frame() method.
+ *
+ * Output video pads only.
*/
- void (*draw_slice)(AVFilterLink *link, uint8_t *data[4], int y, int height);
+ int (*poll_frame)(AVFilterLink *link);
/**
* Frame request callback. A call to this should result in at least one
- * frame being output over the given link. Video output pads only.
+ * frame being output over the given link. This should return zero on
+ * success, and another value on error.
+ *
+ * Output video pads only.
*/
- void (*request_frame)(AVFilterLink *link);
+ int (*request_frame)(AVFilterLink *link);
/**
- * Link configuration callback. For output pads, this should set the link
- * properties such as width/height. NOTE: this should not set the format
- * property - that is negotiated between filters by the filter system using
- * the query_formats() callback.
+ * Link configuration callback.
+ *
+ * For output pads, this should set the link properties such as
+ * width/height. This should NOT set the format property - that is
+ * negotiated between filters by the filter system using the
+ * query_formats() callback before this function is called.
*
* For input pads, this should check the properties of the link, and update
* the filter's internal state as necessary.
+ *
+ * For both input and output filters, this should return zero on success,
+ * and another value on error.
*/
int (*config_props)(AVFilterLink *link);
};
-/* the default implementations of start_frame() and end_frame() */
+/** default handler for start_frame() for video inputs */
void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
+/** default handler for draw_slice() for video inputs */
+void avfilter_default_draw_slice(AVFilterLink *link, int y, int h);
+/** default handler for end_frame() for video inputs */
void avfilter_default_end_frame(AVFilterLink *link);
+/** default handler for config_props() for video outputs */
+int avfilter_default_config_output_link(AVFilterLink *link);
+/** default handler for config_props() for video inputs */
+int avfilter_default_config_input_link (AVFilterLink *link);
+/** default handler for get_video_buffer() for video inputs */
+AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
+ int perms);
+/**
+ * A helper for query_formats() which sets all links to the same list of
+ * formats. If there are no links hooked to this filter, the list of formats is
+ * freed.
+ */
+void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
+/** Default handler for query_formats() */
+int avfilter_default_query_formats(AVFilterContext *ctx);
+/**
+ * Filter definition. This defines the pads a filter contains, and all the
+ * callback functions used to interact with the filter.
+ */
typedef struct
{
- char *name;
- char *author;
+ const char *name; ///< filter name
- int priv_size;
+ int priv_size; ///< size of private data to allocate for the filter
/**
* Filter initialization function. Args contains the user-supplied
* opaque is data provided by the code requesting creation of the filter,
* and is used to pass data to the filter.
*/
- int (*init)(AVFilterContext *ctx, const char *args, const void *opaque);
+ int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
+
+ /**
+ * Filter uninitialization function. Should deallocate any memory held
+ * by the filter, release any picture references, etc. This does not need
+ * to deallocate the AVFilterContext->priv memory itself.
+ */
void (*uninit)(AVFilterContext *ctx);
- const AVFilterPad *inputs; /// NULL terminated list of inputs. NULL if none
- const AVFilterPad *outputs; /// NULL terminated list of outputs. NULL if none
+ /**
+ * Query formats supported by the filter and its pads. Should set the
+ * in_formats for links connected to its output pads, and out_formats
+ * for links connected to its input pads.
+ *
+ * Should return zero on success.
+ */
+ int (*query_formats)(AVFilterContext *);
+
+ const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
+ const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
} AVFilter;
+/** An instance of a filter */
struct AVFilterContext
{
- AVClass *av_class;
+ const AVClass *av_class; ///< needed for av_log()
- AVFilter *filter;
+ AVFilter *filter; ///< the AVFilter of which this is an instance
- char *name;
+ char *name; ///< name of this filter instance
- AVFilterLink **inputs;
- AVFilterLink **outputs;
+ unsigned input_count; ///< number of input pads
+ AVFilterPad *input_pads; ///< array of input pads
+ AVFilterLink **inputs; ///< array of pointers to input links
- void *priv;
+ unsigned output_count; ///< number of output pads
+ AVFilterPad *output_pads; ///< array of output pads
+ AVFilterLink **outputs; ///< array of pointers to output links
+
+ void *priv; ///< private data for use by the filter
};
+/**
+ * A link between two filters. This contains pointers to the source and
+ * destination filters between which this link exists, and the indexes of
+ * the pads involved. In addition, this link also contains the parameters
+ * which have been negotiated and agreed upon between the filter, such as
+ * image dimensions, format, etc.
+ */
struct AVFilterLink
{
- AVFilterContext *src;
- unsigned int srcpad;
+ AVFilterContext *src; ///< source filter
+ unsigned int srcpad; ///< index of the output pad on the source filter
+
+ AVFilterContext *dst; ///< dest filter
+ unsigned int dstpad; ///< index of the input pad on the dest filter
- AVFilterContext *dst;
- unsigned int dstpad;
+ /** stage of the initialization of the link properties (dimensions, etc) */
+ enum {
+ AVLINK_UNINIT = 0, ///< not started
+ AVLINK_STARTINIT, ///< started, but incomplete
+ AVLINK_INIT ///< complete
+ } init_state;
- int w, h;
- enum PixelFormat format;
+ int w; ///< agreed upon image width
+ int h; ///< agreed upon image height
+ enum PixelFormat format; ///< agreed upon image colorspace
+
+ /**
+ * Lists of formats supported by the input and output filters respectively.
+ * These lists are used for negotiating the format to actually be used,
+ * which will be loaded into the format member, above, when chosen.
+ */
+ AVFilterFormats *in_formats;
+ AVFilterFormats *out_formats;
+
+ /**
+ * The picture reference currently being sent across the link by the source
+ * filter. This is used internally by the filter system to allow
+ * automatic copying of pictures which do not have sufficient permissions
+ * for the destination. This should not be accessed directly by the
+ * filters.
+ */
+ AVFilterPicRef *srcpic;
AVFilterPicRef *cur_pic;
AVFilterPicRef *outpic;
};
-/** Link two filters together */
+/**
+ * Link two filters together.
+ * @param src the source filter
+ * @param srcpad index of the output pad on the source filter
+ * @param dst the destination filter
+ * @param dstpad index of the input pad on the destination filter
+ * @return zero on success
+ */
int avfilter_link(AVFilterContext *src, unsigned srcpad,
AVFilterContext *dst, unsigned dstpad);
+/**
+ * Negotiate the colorspace, dimensions, etc of all inputs to a filter.
+ * @param filter the filter to negotiate the properties for its inputs
+ * @return zero on successful negotiation
+ */
+int avfilter_config_links(AVFilterContext *filter);
+
+/**
+ * Request a picture buffer with a specific set of permissions.
+ * @param link the output link to the filter from which the picture will
+ * be requested
+ * @param perms the required access permissions
+ * @return A reference to the picture. This must be unreferenced with
+ * avfilter_unref_pic when you are finished with it.
+ */
AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
-void avfilter_request_frame(AVFilterLink *link);
+
+/**
+ * Request an input frame from the filter at the other end of the link.
+ * @param link the input link
+ * @return zero on success
+ */
+int avfilter_request_frame(AVFilterLink *link);
+
+/**
+ * Poll a frame from the filter chain.
+ * @param link the input link
+ * @return the number of immediately available frames, a negative
+ * number in case of error
+ */
+int avfilter_poll_frame(AVFilterLink *link);
+
+/**
+ * Notify the next filter of the start of a frame.
+ * @param link the output link the frame will be sent over
+ * @param picref A reference to the frame about to be sent. The data for this
+ * frame need only be valid once draw_slice() is called for that
+ * portion. The receiving filter will free this reference when
+ * it no longer needs it.
+ */
void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
+
+/**
+ * Notify the next filter that the current frame has finished.
+ * @param link the output link the frame was sent over
+ */
void avfilter_end_frame(AVFilterLink *link);
-void avfilter_draw_slice(AVFilterLink *link, uint8_t *data[4], int y, int h);
-void avfilter_init(void);
+/**
+ * Send a slice to the next filter.
+ * @param link the output link over which the frame is being sent
+ * @param y offset in pixels from the top of the image for this slice
+ * @param h height of this slice in pixels
+ */
+void avfilter_draw_slice(AVFilterLink *link, int y, int h);
+
+/** Initialize the filter system. Registers all builtin filters */
+void avfilter_register_all(void);
+
+/** Uninitialize the filter system. Unregisters all filters */
void avfilter_uninit(void);
+
+/**
+ * Register a filter. This is only needed if you plan to use
+ * avfilter_get_by_name later to lookup the AVFilter structure by name. A
+ * filter can still by instantiated with avfilter_open even if it is not
+ * registered.
+ * @param filter the filter to register
+ */
void avfilter_register(AVFilter *filter);
-AVFilter *avfilter_get_by_name(char *name);
-AVFilterContext *avfilter_create(AVFilter *filter, char *inst_name);
-AVFilterContext *avfilter_create_by_name(char *name, char *inst_name);
+/**
+ * Gets a filter definition matching the given name.
+ * @param name the filter name to find
+ * @return the filter definition, if any matching one is registered.
+ * NULL if none found.
+ */
+AVFilter *avfilter_get_by_name(const char *name);
+
+/**
+ * Create a filter instance.
+ * @param filter the filter to create an instance of
+ * @param inst_name Name to give to the new instance. Can be NULL for none.
+ * @return Pointer to the new instance on success. NULL on failure.
+ */
+AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
+
+/**
+ * Initialize a filter.
+ * @param filter the filter to initialize
+ * @param args A string of parameters to use when initializing the filter.
+ * The format and meaning of this string varies by filter.
+ * @param opaque Any extra non-string data needed by the filter. The meaning
+ * of this parameter varies by filter.
+ * @return zero on success
+ */
int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
+
+/**
+ * Destroy a filter.
+ * @param filter the filter to destroy
+ */
void avfilter_destroy(AVFilterContext *filter);
-int *avfilter_make_format_list(int len, ...);
+/**
+ * Insert a filter in the middle of an existing link.
+ * @param link the link into which the filter should be inserted
+ * @param filt the filter to be inserted
+ * @param in the input pad on the filter to connect
+ * @param out the output pad on the filter to connect
+ * @return zero on success
+ */
+int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
+ unsigned in, unsigned out);
+
+/**
+ * Insert a new pad.
+ * @param idx Insertion point. Pad is inserted at the end if this point
+ * is beyond the end of the list of pads.
+ * @param count Pointer to the number of pads in the list
+ * @param padidx_off Offset within an AVFilterLink structure to the element
+ * to increment when inserting a new pad causes link
+ * numbering to change
+ * @param pads Pointer to the pointer to the beginning of the list of pads
+ * @param links Pointer to the pointer to the beginning of the list of links
+ * @param newpad The new pad to add. A copy is made when adding.
+ */
+void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
+ AVFilterPad **pads, AVFilterLink ***links,
+ AVFilterPad *newpad);
+
+/** Insert a new input pad for the filter. */
+static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
+ AVFilterPad *p)
+{
+ avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
+ &f->input_pads, &f->inputs, p);
+}
+
+/** Insert a new output pad for the filter. */
+static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
+ AVFilterPad *p)
+{
+ avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
+ &f->output_pads, &f->outputs, p);
+}
-#endif /* FFMPEG_AVFILTER_H */
+#endif /* AVFILTER_AVFILTER_H */
projects / frescor / ffmpeg.git / blobdiff