/*
- * Filter layer
+ * filter layer
* copyright (c) 2007 Bobby Bingham
*
* This file is part of FFmpeg.
#ifndef FFMPEG_AVFILTER_H
#define FFMPEG_AVFILTER_H
+#define LIBAVFILTER_VERSION_MAJOR 0
+#define LIBAVFILTER_VERSION_MINOR 0
+#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 "avcodec.h"
/**
* 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
{
int w; ///< image width
int h; ///< image height
- int64_t pts; ///< presentation timestamp in milliseconds
+ int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
+
+ 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
+ * @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
+ * @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 filter pad used for either input or output
+ * 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 outut 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. And all the references of a and b, and a and b 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 f.
+ * That is the pointers will point like in the ascii art below:
+ * ________
+ * | f |<--------.
+ * | ____ | |
+ * | |refs| | __|_
+ * | |* * | | | | |
+ * | |* *--------->|*ref|
+ * | |____| | |____|
+ * |________|
+ */
+void avfilter_formats_ref(AVFilterFormats *f, 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.
+ */
+void avfilter_formats_unref(AVFilterFormats **ref);
+
+/**
+ *
+ * Before After
+ * ________ ________
+ * | f |<---------. | f |<---------.
+ * | ____ | ___|___ | ____ | ___|___
+ * | |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
{
* 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 ///< video pad
+ enum CodecType type;
/**
* Minimum required permissions on incoming buffers. Any buffers with
*/
int rej_perms;
- /**
- * Callback to get a list of supported formats. The returned list should
- * be terminated by -1 (see avfilter_make_format_list for an easy way to
- * create such a list).
- *
- * This is used for both input and output pads. If ommitted from an output
- * pad, it is assumed that the only format supported is the same format
- * that is being used for the filter's first input. If the filter has no
- * inputs, then this may not be ommitted for its output pads.
- */
- int *(*query_formats)(AVFilterLink *link);
-
/**
* Callback called before passing the first slice of a new frame. If
* NULL, the filter layer will default to storing a reference to the
*/
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.
+ */
+ 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. This should return zero on
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 query_formats() for video outputs */
-int *avfilter_default_query_output_formats(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
*/
typedef struct
{
- char *name; ///< filter name
- char *author; ///< filter author
+ const char *name; ///< filter name
int priv_size; ///< size of private data to allocate for the filter
*/
void (*uninit)(AVFilterContext *ctx);
+ /**
+ * 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; ///< Needed for av_log()
+ const AVClass *av_class; ///< needed for av_log()
- AVFilter *filter; ///< The AVFilter of which this is an instance
+ AVFilter *filter; ///< the AVFilter of which this is an instance
char *name; ///< name of this filter instance
};
/**
- * A links between two filters. This contains pointers to the source and
+ * A link between two filters. This contains pointers to the source and
* destination filters between which this link exists, and the indices of
* the pads involved. In addition, this link also contains the parameters
* which have been negotiated and agreed upon between the filter, such as
AVFilterContext *dst; ///< dest filter
unsigned int dstpad; ///< index of the input pad on the dest filter
+ /** 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; ///< 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 d not have sufficient permissions
+ * automatic copying of pictures which do not have sufficient permissions
* for the destination. This should not be accessed directly by the
* filters.
*/
};
/**
- * 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
+ * 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 a link
- * @param link The link to negotiate the properties of
- * @return Zero on successful negotiation
+ * 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_link(AVFilterLink *link);
+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
+ * @param link the output link to the filter from which the picture will
* be requested
- * @param perms The required access permissions
+ * @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.
*/
/**
* Request an input frame from the filter at the other end of the link.
- * @param link The input link
- * @return Zero on success
+ * @param link the input link
+ * @return zero on success
*/
-int avfilter_request_frame(AVFilterLink *link);
+int avfilter_request_frame(AVFilterLink *link);
+
+/**
+ * Poll a frame from the filter chain.
+ * @param link the input link
+ * @return the number of imediately available frames
+ */
+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 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
/**
* Notify the next filter that the current frame has finished
- * @param link The output link the frame was sent over
+ * @param link the output link the frame was sent over
*/
void avfilter_end_frame(AVFilterLink *link);
/**
- * 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
+ * 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_init(void);
+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 create an instance of
- * this filter by name later with avfilter_create_by_name. A filter can still
- * by created with acfilter_create even if it is not registered.
- * @param filter The filter to register
+ * 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);
/**
- * 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.
+ * 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(char *name);
+AVFilter *avfilter_get_by_name(const char *name);
/**
- * Create a filter instance
- * @param filter The filter to create an instance of
+ * 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_create(AVFilter *filter, char *inst_name);
-
-/**
- * Creates a filter instace
- * @param name The name of the filter type which is to be instantiated
- * @param inst_name Name to give to the new instance. Can be NULL for none.
- * @return Pointer to the new instance on success. NULL in failure.
- */
-AVFilterContext *avfilter_create_by_name(char *name, char *inst_name);
+AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
/**
- * Initialize a filter
- * @param filter The filter to initialize
+ * 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
+ * @return zero on success
*/
int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
/**
- * Destroy a filter
- * @param filter The filter to destroy
+ * Destroy a filter.
+ * @param filter the filter to destroy
*/
void avfilter_destroy(AVFilterContext *filter);
/**
- * Helper function to create a list of supported formats. This is intended
- * for use in AVFilterPad->query_formats().
- * @param len The number of formats supported
- * @param ... A list of the supported formats
- * @return The format list in a form suitable for returning from
- * AVFilterPad->query_formats()
+ * 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_make_format_list(int len, ...);
+int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
+ unsigned in, unsigned out);
/**
- * Insert a new pad
+ * 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