libavfilter/internal.h

   1 /*
   2  * This file is part of Libav.
   3  *
   4  * Libav is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * Libav is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with Libav; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef AVFILTER_INTERNAL_H
  20 #define AVFILTER_INTERNAL_H
  21
  22 /**
  23  * @file
  24  * internal API functions
  25  */
  26
  27 #include "avfilter.h"
  28
  29 #if !FF_API_AVFILTERPAD_PUBLIC
  30 /**
  31  * A filter pad used for either input or output.
  32  */
  33 struct AVFilterPad {
  34     /**
  35      * Pad name. The name is unique among inputs and among outputs, but an
  36      * input may have the same name as an output. This may be NULL if this
  37      * pad has no need to ever be referenced by name.
  38      */
  39     const char *name;
  40
  41     /**
  42      * AVFilterPad type.
  43      */
  44     enum AVMediaType type;
  45
  46     /**
  47      * Minimum required permissions on incoming buffers. Any buffer with
  48      * insufficient permissions will be automatically copied by the filter
  49      * system to a new buffer which provides the needed access permissions.
  50      *
  51      * Input pads only.
  52      */
  53     int min_perms;
  54
  55     /**
  56      * Permissions which are not accepted on incoming buffers. Any buffer
  57      * which has any of these permissions set will be automatically copied
  58      * by the filter system to a new buffer which does not have those
  59      * permissions. This can be used to easily disallow buffers with
  60      * AV_PERM_REUSE.
  61      *
  62      * Input pads only.
  63      */
  64     int rej_perms;
  65
  66     /**
  67      * Callback function to get a video buffer. If NULL, the filter system will
  68      * use avfilter_default_get_video_buffer().
  69      *
  70      * Input video pads only.
  71      */
  72     AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
  73
  74     /**
  75      * Callback function to get an audio buffer. If NULL, the filter system will
  76      * use avfilter_default_get_audio_buffer().
  77      *
  78      * Input audio pads only.
  79      */
  80     AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
  81                                            int nb_samples);
  82
  83     /**
  84      * Filtering callback. This is where a filter receives a frame with
  85      * audio/video data and should do its processing.
  86      *
  87      * Input pads only.
  88      *
  89      * @return >= 0 on success, a negative AVERROR on error. This function
  90      * must ensure that samplesref is properly unreferenced on error if it
  91      * hasn't been passed on to another filter.
  92      */
  93     int (*filter_frame)(AVFilterLink *link, AVFilterBufferRef *frame);
  94
  95     /**
  96      * Frame poll callback. This returns the number of immediately available
  97      * samples. It should return a positive value if the next request_frame()
  98      * is guaranteed to return one frame (with no delay).
  99      *
 100      * Defaults to just calling the source poll_frame() method.
 101      *
 102      * Output pads only.
 103      */
 104     int (*poll_frame)(AVFilterLink *link);
 105
 106     /**
 107      * Frame request callback. A call to this should result in at least one
 108      * frame being output over the given link. This should return zero on
 109      * success, and another value on error.
 110      *
 111      * Output pads only.
 112      */
 113     int (*request_frame)(AVFilterLink *link);
 114
 115     /**
 116      * Link configuration callback.
 117      *
 118      * For output pads, this should set the link properties such as
 119      * width/height. This should NOT set the format property - that is
 120      * negotiated between filters by the filter system using the
 121      * query_formats() callback before this function is called.
 122      *
 123      * For input pads, this should check the properties of the link, and update
 124      * the filter's internal state as necessary.
 125      *
 126      * For both input and output filters, this should return zero on success,
 127      * and another value on error.
 128      */
 129     int (*config_props)(AVFilterLink *link);
 130
 131     /**
 132      * The filter expects a fifo to be inserted on its input link,
 133      * typically because it has a delay.
 134      *
 135      * input pads only.
 136      */
 137     int needs_fifo;
 138 };
 139 #endif
 140
 141 /** default handler for freeing audio/video buffer when there are no references left */
 142 void ff_avfilter_default_free_buffer(AVFilterBuffer *buf);
 143
 144 /** Tell is a format is contained in the provided list terminated by -1. */
 145 int ff_fmt_is_in(int fmt, const int *fmts);
 146
 147 #define FF_DPRINTF_START(ctx, func) av_dlog(NULL, "%-16s: ", #func)
 148
 149 void ff_dlog_link(void *ctx, AVFilterLink *link, int end);
 150
 151 /**
 152  * Insert a new pad.
 153  *
 154  * @param idx Insertion point. Pad is inserted at the end if this point
 155  *            is beyond the end of the list of pads.
 156  * @param count Pointer to the number of pads in the list
 157  * @param padidx_off Offset within an AVFilterLink structure to the element
 158  *                   to increment when inserting a new pad causes link
 159  *                   numbering to change
 160  * @param pads Pointer to the pointer to the beginning of the list of pads
 161  * @param links Pointer to the pointer to the beginning of the list of links
 162  * @param newpad The new pad to add. A copy is made when adding.
 163  */
 164 void ff_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
 165                    AVFilterPad **pads, AVFilterLink ***links,
 166                    AVFilterPad *newpad);
 167
 168 /** Insert a new input pad for the filter. */
 169 static inline void ff_insert_inpad(AVFilterContext *f, unsigned index,
 170                                    AVFilterPad *p)
 171 {
 172     ff_insert_pad(index, &f->nb_inputs, offsetof(AVFilterLink, dstpad),
 173                   &f->input_pads, &f->inputs, p);
 174 #if FF_API_FOO_COUNT
 175     f->input_count = f->nb_inputs;
 176 #endif
 177 }
 178
 179 /** Insert a new output pad for the filter. */
 180 static inline void ff_insert_outpad(AVFilterContext *f, unsigned index,
 181                                     AVFilterPad *p)
 182 {
 183     ff_insert_pad(index, &f->nb_outputs, offsetof(AVFilterLink, srcpad),
 184                   &f->output_pads, &f->outputs, p);
 185 #if FF_API_FOO_COUNT
 186     f->output_count = f->nb_outputs;
 187 #endif
 188 }
 189
 190 /**
 191  * Poll a frame from the filter chain.
 192  *
 193  * @param  link the input link
 194  * @return the number of immediately available frames, a negative
 195  * number in case of error
 196  */
 197 int ff_poll_frame(AVFilterLink *link);
 198
 199 /**
 200  * Request an input frame from the filter at the other end of the link.
 201  *
 202  * @param link the input link
 203  * @return     zero on success
 204  */
 205 int ff_request_frame(AVFilterLink *link);
 206
 207 /**
 208  * Send a frame of data to the next filter.
 209  *
 210  * @param link   the output link over which the data is being sent
 211  * @param frame a reference to the buffer of data being sent. The
 212  *              receiving filter will free this reference when it no longer
 213  *              needs it or pass it on to the next filter.
 214  *
 215  * @return >= 0 on success, a negative AVERROR on error. The receiving filter
 216  * is responsible for unreferencing frame in case of error.
 217  */
 218 int ff_filter_frame(AVFilterLink *link, AVFilterBufferRef *frame);
 219
 220 #endif /* AVFILTER_INTERNAL_H */