History

Rewrite colorspace negotiation.

Commited in SoC by Bobby Bingham on 2007-12-20 19:36:26 Originally committed as revision 12105 to svn://svn.ffmpeg.org/ffmpeg/trunk

Vitor Sessak committed 18 years ago

Commit 35f3fdf1 parent 2621f4a1 file · +118 −21Browse files

Unified · Split

libavfilter/avfilter.h+118−21
@@ -101,6 +101,91 @@ AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask); · 100 unmodified lines
101101 */
102102 void avfilter_unref_pic(AVFilterPicRef *ref);
103103
104+/**
105+ * A list of supported formats for one end of a filter link. This is used
106+ * during the format negotiation process to try to pick the best format to
107+ * use to minimize the number of necessary conversions. Each filter gives a
108+ * list of the formats supported by each input and output pad. The list
109+ * given for each pad need not be distinct - they may be references to the
110+ * same list of formats, as is often the case when a filter supports multiple
111+ * formats, but will always outut the same format as it is given in input.
112+ *
113+ * In this way, a list of possible input formats and a list of possible
114+ * output formats are associated with each link. When a set of formats is
115+ * negotiated over a link, the input and output lists are merged to form a
116+ * new list containing only the common elements of each list. In the case
117+ * that there were no common elements, a format conversion is necessary.
118+ * Otherwise, the lists are merged, and all other links which reference
119+ * either of the format lists involved in the merge are also affected.
120+ *
121+ * For example, consider the filter chain:
122+ * filter (a) --> (b) filter (b) --> (c) filter
123+ *
124+ * where the letters in parenthesis indicate a list of formats supported on
125+ * the input or output of the link. Suppose the lists are as follows:
126+ * (a) = {A, B}
127+ * (b) = {A, B, C}
128+ * (c) = {B, C}
129+ *
130+ * First, the first link's lists are merged, yielding:
131+ * filter (a) --> (a) filter (a) --> (c) filter
132+ *
133+ * Notice that format list (b) now refers to the same list as filter list (a).
134+ * Next, the lists for the second link are merged, yielding:
135+ * filter (a) --> (a) filter (a) --> (a) filter
136+ *
137+ * where (a) = {B}.
138+ *
139+ * Unfortunately, when the format lists at the two ends of a link are merged,
140+ * we must ensure that all links which reference either pre-merge format list
141+ * get updated as well. Therefore, we have the format list structure store a
142+ * pointer to each of the pointers to itself.
143+ */
144+typedef struct AVFilterFormats AVFilterFormats;
145+struct AVFilterFormats
146+{
147+ unsigned format_count; ///< number of formats
148+ int *formats; ///< list of formats
149+
150+ unsigned refcount; ///< number of references to this list
151+ AVFilterFormats ***refs; ///< references to this list
152+};
153+
154+/**
155+ * Helper function to create a list of supported formats. This is intended
156+ * for use in AVFilter->query_formats().
157+ * @param len The number of formats supported
158+ * @param ... A list of the supported formats
159+ * @return The format list, with no existing references
160+ */
161+AVFilterFormats *avfilter_make_format_list(int len, ...);
162+
163+/**
164+ * Returns a fairly comprehensive list of colorspaces which are supported by
165+ * many of the included filters. This is not truly "all" the colorspaces, but
166+ * it is most of them, and it is the most commonly supported large subset.
167+ */
168+AVFilterFormats *avfilter_all_colorspaces(void);
169+
170+/**
171+ * If a and b share at least one common format, they are merged into a new
172+ * format list which is returned. All the references to a and b are updated
173+ * to point to this new list, and a and b are deallocated.
174+ *
175+ * If a and b do not share any common formats, neither is modified, and NULL
176+ * is returned.
177+ */
178+AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
179+
180+/** Adds *ref as a new reference to f */
181+void avfilter_formats_ref(AVFilterFormats *f, AVFilterFormats **ref);
182+
183+/**
184+ * Remove *ref as a reference to the format list it currently points to,
185+ * deallocate that list if this was the last reference, and set *ref to NULL
186+ */
187+void avfilter_formats_unref(AVFilterFormats **ref);
188+
104189 /**
105190 * A filter pad used for either input or output
106191 */
@@ -139,18 +224,6 @@ struct AVFilterPad · 32 unmodified lines
139224 */
140225 int rej_perms;
141226
142− /**
143− * Callback to get a list of supported formats. The returned list should
144− * be terminated by -1 (see avfilter_make_format_list for an easy way to
145− * create such a list).
146− *
147− * This is used for both input and output pads. If ommitted from an output
148− * pad, it is assumed that the only format supported is the same format
149− * that is being used for the filter's first input. If the filter has no
150− * inputs, then this may not be ommitted for its output pads.
151− */
152− int *(*query_formats)(AVFilterLink *link);
153−
154227 /**
155228 * Callback called before passing the first slice of a new frame. If
156229 * NULL, the filter layer will default to storing a reference to the
@@ -219,11 +292,17 @@ void avfilter_default_end_frame(AVFilterLink *link); · 62 unmodified lines
219292 int avfilter_default_config_output_link(AVFilterLink *link);
220293 /** Default handler for config_props() for video inputs */
221294 int avfilter_default_config_input_link (AVFilterLink *link);
222−/** Default handler for query_formats() for video outputs */
223−int *avfilter_default_query_output_formats(AVFilterLink *link);
224295 /** Default handler for get_video_buffer() for video inputs */
225296 AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
226297 int perms);
298+/**
299+ * A helper for query_formats() which sets all links to the same list of
300+ * formats. If there are no links hooked to this filter, the list of formats is
301+ * freed.
302+ */
303+void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
304+/** Default handler for query_formats() */
305+int avfilter_default_query_formats(AVFilterContext *ctx);
227306
228307 /**
229308 * Filter definition. This defines the pads a filter contains, and all the
@@ -251,6 +330,15 @@ typedef struct · 21 unmodified lines
251330 */
252331 void (*uninit)(AVFilterContext *ctx);
253332
333+ /**
334+ * Query formats supported by the filter and its pads. Should set the
335+ * in_formats for links connected to its output pads, and out_formats
336+ * for links connected to its input pads.
337+ *
338+ * Should return zero on success.
339+ */
340+ int (*query_formats)(AVFilterContext *);
341+
254342 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
255343 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
256344 } AVFilter;
@@ -294,6 +382,14 @@ struct AVFilterLink · 37 unmodified lines
294382 int h; ///< agreed upon image height
295383 enum PixelFormat format; ///< agreed upon image colorspace
296384
385+ /**
386+ * Lists of formats supported by the input and output filters respectively.
387+ * These lists are used for negotiating the format to actually be used,
388+ * which will be loaded into the format member, above, when chosen.
389+ */
390+ AVFilterFormats *in_formats;
391+ AVFilterFormats *out_formats;
392+
297393 /**
298394 * The picture reference currently being sent across the link by the source
299395 * filter. This is used internally by the filter system to allow
@@ -415,14 +511,15 @@ int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque · 115 unmodified lines
415511 void avfilter_destroy(AVFilterContext *filter);
416512
417513 /**
418− * Helper function to create a list of supported formats. This is intended
419− * for use in AVFilterPad->query_formats().
420− * @param len The number of formats supported
421− * @param ... A list of the supported formats
422− * @return The format list in a form suitable for returning from
423− * AVFilterPad->query_formats()
514+ * Insert a filter in the middle of an existing link.
515+ * @param link The link into which the filter should be inserted
516+ * @param filt The filter to be inserted
517+ * @param in The input pad on the filter to connect
518+ * @param out The output pad on the filter to connect
519+ * @return Zero on success
424520 */
425−int *avfilter_make_format_list(int len, ...);
521+int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
522+ unsigned in, unsigned out);
426523
427524 /**
428525 * Insert a new pad

Keyboard shortcuts

General

Show keyboard shortcuts
?
Focus the current search
/

Issues and pull requests

Open filters
f

Issues, pull requests and Inbox

Select next item
j↓
Select previous item
k↑
Open selected item
Enter
Dismiss filters or clear selection
Esc

Repository code

Go to file
t