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filters.h
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1 /*
2  * Filters implementation helper functions
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public License
8  * as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public License
17  * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVFILTER_FILTERS_H
22 #define AVFILTER_FILTERS_H
23 
24 /**
25  * Filters implementation helper functions
26  */
27 
28 #include "avfilter.h"
29 #include "internal.h"
30 
31 /**
32  * Special return code when activate() did not do anything.
33  */
34 #define FFERROR_NOT_READY FFERRTAG('N','R','D','Y')
35 
36 /**
37  * Mark a filter ready and schedule it for activation.
38  *
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
44  * events.
45  */
46 void ff_filter_set_ready(AVFilterContext *filter, unsigned priority);
47 
48 /**
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.
52  */
54 
55 /**
56  * Evaluate the timeline expression of the link for the time and properties
57  * of the frame.
58  * @return >0 if enabled, 0 if disabled
59  * @note It does not update link->dst->is_disabled.
60  */
62 
63 /**
64  * Get the number of frames available on the link.
65  * @return the number of frames available in the link fifo.
66  */
68 
69 /**
70  * Test if a frame is available on the link.
71  * @return >0 if a frame is available
72  */
74 
75 
76 /***
77  * Get the number of samples available on the link.
78  * @return the numer of samples available on the link.
79  */
81 
82 /**
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
86  */
88 
89 /**
90  * Take a frame from the link's FIFO and update the link's stats.
91  *
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.
95  *
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,
99  * or AVERROR code
100  */
101 int ff_inlink_consume_frame(AVFilterLink *link, AVFrame **rframe);
102 
103 /**
104  * Take samples from the link's FIFO and update the link's stats.
105  *
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.
109  *
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,
113  * or AVERROR code
114  */
115 int ff_inlink_consume_samples(AVFilterLink *link, unsigned min, unsigned max,
116  AVFrame **rframe);
117 
118 /**
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.
122  */
123 AVFrame *ff_inlink_peek_frame(AVFilterLink *link, size_t idx);
124 
125 /**
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.
129  */
131 
132 /**
133  * Test and acknowledge the change of status on the link.
134  *
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...).
142  *
143  * Filters implementing the activate callback should call this function when
144  * they think it might succeed (usually after checking unsuccessfully for a
145  * queued frame).
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().
148  *
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
152  */
153 int ff_inlink_acknowledge_status(AVFilterLink *link, int *rstatus, int64_t *rpts);
154 
155 /**
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.
160  */
162 
163 /**
164  * Set the status on an input link.
165  * Also discard all frames in the link's FIFO.
166  */
167 void ff_inlink_set_status(AVFilterLink *link, int status);
168 
169 /**
170  * Test if a frame is wanted on an output link.
171  */
172 static inline int ff_outlink_frame_wanted(AVFilterLink *link)
173 {
174  return link->frame_wanted_out;
175 }
176 
177 /**
178  * Get the status on an output link.
179  */
181 
182 /**
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.
188  */
189 static inline void ff_outlink_set_status(AVFilterLink *link, int status, int64_t pts)
190 {
191  ff_avfilter_link_set_in_status(link, status, pts);
192 }
193 
194 /**
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.
198  */
199 #define FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink) do { \
200  int ret = ff_outlink_get_status(outlink); \
201  if (ret) { \
202  ff_inlink_set_status(inlink, ret); \
203  return 0; \
204  } \
205 } while (0)
206 
207 /**
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.
211  */
212 #define FF_FILTER_FORWARD_STATUS_BACK_ALL(outlink, filter) do { \
213  int ret = ff_outlink_get_status(outlink); \
214  if (ret) { \
215  unsigned i; \
216  for (i = 0; i < filter->nb_inputs; i++) \
217  ff_inlink_set_status(filter->inputs[i], ret); \
218  return 0; \
219  } \
220 } while (0)
221 
222 /**
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.
225  */
226 #define FF_FILTER_FORWARD_STATUS(inlink, outlink) do { \
227  int status; \
228  int64_t pts; \
229  if (ff_inlink_acknowledge_status(inlink, &status, &pts)) { \
230  ff_outlink_set_status(outlink, status, pts); \
231  return 0; \
232  } \
233 } while (0)
234 
235 /**
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.
238  */
239 #define FF_FILTER_FORWARD_STATUS_ALL(inlink, filter) do { \
240  int status; \
241  int64_t pts; \
242  if (ff_inlink_acknowledge_status(inlink, &status, &pts)) { \
243  unsigned i; \
244  for (i = 0; i < filter->nb_outputs; i++) \
245  ff_outlink_set_status(filter->outputs[i], status, pts); \
246  return 0; \
247  } \
248 } while (0)
249 
250 /**
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.
253  */
254 #define FF_FILTER_FORWARD_WANTED(outlink, inlink) do { \
255  if (ff_outlink_frame_wanted(outlink)) { \
256  ff_inlink_request_frame(inlink); \
257  return 0; \
258  } \
259 } while (0)
260 
261 #endif /* AVFILTER_FILTERS_H */
This structure describes decoded (raw) audio or video data.
Definition: frame.h:226
Main libavfilter public API header.
int ff_inlink_check_available_samples(AVFilterLink *link, unsigned min)
Test if enough samples are available on the link.
Definition: avfilter.c:1466
void ff_filter_set_ready(AVFilterContext *filter, unsigned priority)
Mark a filter ready and schedule it for activation.
Definition: avfilter.c:193
static void ff_outlink_set_status(AVFilterLink *link, int status, int64_t pts)
Set the status field of a link from the source filter.
Definition: filters.h:189
static int ff_outlink_frame_wanted(AVFilterLink *link)
Test if a frame is wanted on an output link.
Definition: filters.h:172
static void filter(int16_t *output, ptrdiff_t out_stride, int16_t *low, ptrdiff_t low_stride, int16_t *high, ptrdiff_t high_stride, int len, int clip)
Definition: cfhd.c:153
AVFrame * ff_inlink_peek_frame(AVFilterLink *link, size_t idx)
Access a frame in the link fifo without consuming it.
Definition: avfilter.c:1520
static AVFrame * frame
int ff_inlink_queued_samples(AVFilterLink *link)
Definition: avfilter.c:1461
int ff_inlink_consume_frame(AVFilterLink *link, AVFrame **rframe)
Take a frame from the link's FIFO and update the link's stats.
Definition: avfilter.c:1481
int ff_inlink_acknowledge_status(AVFilterLink *link, int *rstatus, int64_t *rpts)
Test and acknowledge the change of status on the link.
Definition: avfilter.c:1436
int ff_outlink_get_status(AVFilterLink *link)
Get the status on an output link.
Definition: avfilter.c:1630
static int64_t pts
int ff_inlink_process_commands(AVFilterLink *link, const AVFrame *frame)
Process the commands queued in the link up to the time of the frame.
Definition: avfilter.c:1574
int ff_inlink_evaluate_timeline_at_frame(AVFilterLink *link, const AVFrame *frame)
Evaluate the timeline expression of the link for the time and properties of the frame.
Definition: avfilter.c:1589
int ff_inlink_make_frame_writable(AVFilterLink *link, AVFrame **rframe)
Make sure a frame is writable.
Definition: avfilter.c:1525
void ff_inlink_request_frame(AVFilterLink *link)
Mark that a frame is wanted on the link.
Definition: avfilter.c:1607
void ff_avfilter_link_set_in_status(AVFilterLink *link, int status, int64_t pts)
Set the status field of a link from the source filter.
Definition: avfilter.c:211
An instance of a filter.
Definition: avfilter.h:338
internal API functions
float min
int ff_inlink_check_available_frame(AVFilterLink *link)
Test if a frame is available on the link.
Definition: avfilter.c:1456
size_t ff_inlink_queued_frames(AVFilterLink *link)
Get the number of frames available on the link.
Definition: avfilter.c:1451
int ff_inlink_consume_samples(AVFilterLink *link, unsigned min, unsigned max, AVFrame **rframe)
Take samples from the link's FIFO and update the link's stats.
Definition: avfilter.c:1500
void ff_inlink_set_status(AVFilterLink *link, int status)
Set the status on an input link.
Definition: avfilter.c:1615