2 * Filters implementation helper functions
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21 #ifndef AVFILTER_FILTERS_H
22 #define AVFILTER_FILTERS_H
25 * Filters implementation helper functions
32 * Special return code when activate() did not do anything.
34 #define FFERROR_NOT_READY FFERRTAG('N','R','D','Y')
37 * Mark a filter ready and schedule it for activation.
39 * This is automatically done when something happens to the filter (queued
40 * frame, status change, request on output).
41 * Filters implementing the activate callback can call it directly to
42 * perform one more round of processing later.
43 * It is also useful for filters reacting to external or asynchronous
46 void ff_filter_set_ready(AVFilterContext *filter, unsigned priority);
49 * Process the commands queued in the link up to the time of the frame.
50 * Commands will trigger the process_command() callback.
51 * @return >= 0 or AVERROR code.
53 int ff_inlink_process_commands(AVFilterLink *link, const AVFrame *frame);
56 * Evaluate the timeline expression of the link for the time and properties
58 * @return >0 if enabled, 0 if disabled
59 * @note It does not update link->dst->is_disabled.
61 int ff_inlink_evaluate_timeline_at_frame(AVFilterLink *link, const AVFrame *frame);
64 * Get the number of frames available on the link.
65 * @return the number of frames available in the link fifo.
67 size_t ff_inlink_queued_frames(AVFilterLink *link);
70 * Test if a frame is available on the link.
71 * @return >0 if a frame is available
73 int ff_inlink_check_available_frame(AVFilterLink *link);
77 * Get the number of samples available on the link.
78 * @return the numer of samples available on the link.
80 int ff_inlink_queued_samples(AVFilterLink *link);
83 * Test if enough samples are available on the link.
84 * @return >0 if enough samples are available
85 * @note on EOF and error, min becomes 1
87 int ff_inlink_check_available_samples(AVFilterLink *link, unsigned min);
90 * Take a frame from the link's FIFO and update the link's stats.
92 * If ff_inlink_check_available_frame() was previously called, the
93 * preferred way of expressing it is "av_assert1(ret);" immediately after
94 * ff_inlink_consume_frame(). Negative error codes must still be checked.
96 * @note May trigger process_command() and/or update is_disabled.
97 * @return >0 if a frame is available,
98 * 0 and set rframe to NULL if no frame available,
101 int ff_inlink_consume_frame(AVFilterLink *link, AVFrame **rframe);
104 * Take samples from the link's FIFO and update the link's stats.
106 * If ff_inlink_check_available_samples() was previously called, the
107 * preferred way of expressing it is "av_assert1(ret);" immediately after
108 * ff_inlink_consume_samples(). Negative error codes must still be checked.
110 * @note May trigger process_command() and/or update is_disabled.
111 * @return >0 if a frame is available,
112 * 0 and set rframe to NULL if no frame available,
115 int ff_inlink_consume_samples(AVFilterLink *link, unsigned min, unsigned max,
119 * Access a frame in the link fifo without consuming it.
120 * The first frame is numbered 0; the designated frame must exist.
121 * @return the frame at idx position in the link fifo.
123 AVFrame *ff_inlink_peek_frame(AVFilterLink *link, size_t idx);
126 * Make sure a frame is writable.
127 * This is similar to av_frame_make_writable() except it uses the link's
128 * buffer allocation callback, and therefore allows direct rendering.
130 int ff_inlink_make_frame_writable(AVFilterLink *link, AVFrame **rframe);
133 * Test and acknowledge the change of status on the link.
135 * Status means EOF or an error condition; a change from the normal (0)
136 * status to a non-zero status can be queued in a filter's input link, it
137 * becomes relevant after the frames queued in the link's FIFO are
138 * processed. This function tests if frames are still queued and if a queued
139 * status change has not yet been processed. In that case it performs basic
140 * treatment (updating the link's timestamp) and returns a positive value to
141 * let the filter do its own treatments (flushing...).
143 * Filters implementing the activate callback should call this function when
144 * they think it might succeed (usually after checking unsuccessfully for a
146 * Filters implementing the filter_frame and request_frame callbacks do not
147 * need to call that since the same treatment happens in ff_filter_frame().
149 * @param[out] rstatus new or current status
150 * @param[out] rpts current timestamp of the link in link time base
151 * @return >0 if status changed, <0 if status already acked, 0 otherwise
153 int ff_inlink_acknowledge_status(AVFilterLink *link, int *rstatus, int64_t *rpts);
156 * Mark that a frame is wanted on the link.
157 * Unlike ff_filter_frame(), it must not be called when the link has a
158 * non-zero status, and thus does not acknowledge it.
159 * Also it cannot fail.
161 void ff_inlink_request_frame(AVFilterLink *link);
164 * Set the status on an input link.
165 * Also discard all frames in the link's FIFO.
167 void ff_inlink_set_status(AVFilterLink *link, int status);
170 * Test if a frame is wanted on an output link.
172 static inline int ff_outlink_frame_wanted(AVFilterLink *link)
174 return link->frame_wanted_out;
178 * Get the status on an output link.
180 int ff_outlink_get_status(AVFilterLink *link);
183 * Set the status field of a link from the source filter.
184 * The pts should reflect the timestamp of the status change,
185 * in link time base and relative to the frames timeline.
186 * In particular, for AVERROR_EOF, it should reflect the
187 * end time of the last frame.
189 static inline void ff_outlink_set_status(AVFilterLink *link, int status, int64_t pts)
191 ff_avfilter_link_set_in_status(link, status, pts);
195 * Forward the status on an output link to an input link.
196 * If the status is set, it will discard all queued frames and this macro
197 * will return immediately.
199 #define FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink) do { \
200 int ret = ff_outlink_get_status(outlink); \
202 ff_inlink_set_status(inlink, ret); \
208 * Forward the status on an output link to all input links.
209 * If the status is set, it will discard all queued frames and this macro
210 * will return immediately.
212 #define FF_FILTER_FORWARD_STATUS_BACK_ALL(outlink, filter) do { \
213 int ret = ff_outlink_get_status(outlink); \
216 for (i = 0; i < filter->nb_inputs; i++) \
217 ff_inlink_set_status(filter->inputs[i], ret); \
223 * Acknowledge the status on an input link and forward it to an output link.
224 * If the status is set, this macro will return immediately.
226 #define FF_FILTER_FORWARD_STATUS(inlink, outlink) do { \
229 if (ff_inlink_acknowledge_status(inlink, &status, &pts)) { \
230 ff_outlink_set_status(outlink, status, pts); \
236 * Acknowledge the status on an input link and forward it to an output link.
237 * If the status is set, this macro will return immediately.
239 #define FF_FILTER_FORWARD_STATUS_ALL(inlink, filter) do { \
242 if (ff_inlink_acknowledge_status(inlink, &status, &pts)) { \
244 for (i = 0; i < filter->nb_outputs; i++) \
245 ff_outlink_set_status(filter->outputs[i], status, pts); \
251 * Forward the frame_wanted_out flag from an output link to an input link.
252 * If the flag is set, this macro will return immediately.
254 #define FF_FILTER_FORWARD_WANTED(outlink, inlink) do { \
255 if (ff_outlink_frame_wanted(outlink)) { \
256 ff_inlink_request_frame(inlink); \
261 #endif /* AVFILTER_FILTERS_H */