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      * Callback function to get a video buffer. If NULL, the filter system will
  48      * use avfilter_default_get_video_buffer().
  49      *
  50      * Input video pads only.
  51      */
  52     AVFrame *(*get_video_buffer)(AVFilterLink *link, int w, int h);
  53
  54     /**
  55      * Callback function to get an audio buffer. If NULL, the filter system will
  56      * use avfilter_default_get_audio_buffer().
  57      *
  58      * Input audio pads only.
  59      */
  60     AVFrame *(*get_audio_buffer)(AVFilterLink *link, int nb_samples);
  61
  62     /**
  63      * Filtering callback. This is where a filter receives a frame with
  64      * audio/video data and should do its processing.
  65      *
  66      * Input pads only.
  67      *
  68      * @return >= 0 on success, a negative AVERROR on error. This function
  69      * must ensure that samplesref is properly unreferenced on error if it
  70      * hasn't been passed on to another filter.
  71      */
  72     int (*filter_frame)(AVFilterLink *link, AVFrame *frame);
  73
  74     /**
  75      * Frame poll callback. This returns the number of immediately available
  76      * samples. It should return a positive value if the next request_frame()
  77      * is guaranteed to return one frame (with no delay).
  78      *
  79      * Defaults to just calling the source poll_frame() method.
  80      *
  81      * Output pads only.
  82      */
  83     int (*poll_frame)(AVFilterLink *link);
  84
  85     /**
  86      * Frame request callback. A call to this should result in at least one
  87      * frame being output over the given link. This should return zero on
  88      * success, and another value on error.
  89      *
  90      * Output pads only.
  91      */
  92     int (*request_frame)(AVFilterLink *link);
  93
  94     /**
  95      * Link configuration callback.
  96      *
  97      * For output pads, this should set the link properties such as
  98      * width/height. This should NOT set the format property - that is
  99      * negotiated between filters by the filter system using the
 100      * query_formats() callback before this function is called.
 101      *
 102      * For input pads, this should check the properties of the link, and update
 103      * the filter's internal state as necessary.
 104      *
 105      * For both input and output filters, this should return zero on success,
 106      * and another value on error.
 107      */
 108     int (*config_props)(AVFilterLink *link);
 109
 110     /**
 111      * The filter expects a fifo to be inserted on its input link,
 112      * typically because it has a delay.
 113      *
 114      * input pads only.
 115      */
 116     int needs_fifo;
 117 };
 118 #endif
 119
 120 /** default handler for freeing audio/video buffer when there are no references left */
 121 void ff_avfilter_default_free_buffer(AVFilterBuffer *buf);
 122
 123 /** Tell is a format is contained in the provided list terminated by -1. */
 124 int ff_fmt_is_in(int fmt, const int *fmts);
 125
 126 #define FF_DPRINTF_START(ctx, func) av_dlog(NULL, "%-16s: ", #func)
 127
 128 void ff_dlog_link(void *ctx, AVFilterLink *link, int end);
 129
 130 /**
 131  * Insert a new pad.
 132  *
 133  * @param idx Insertion point. Pad is inserted at the end if this point
 134  *            is beyond the end of the list of pads.
 135  * @param count Pointer to the number of pads in the list
 136  * @param padidx_off Offset within an AVFilterLink structure to the element
 137  *                   to increment when inserting a new pad causes link
 138  *                   numbering to change
 139  * @param pads Pointer to the pointer to the beginning of the list of pads
 140  * @param links Pointer to the pointer to the beginning of the list of links
 141  * @param newpad The new pad to add. A copy is made when adding.
 142  */
 143 void ff_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
 144                    AVFilterPad **pads, AVFilterLink ***links,
 145                    AVFilterPad *newpad);
 146
 147 /** Insert a new input pad for the filter. */
 148 static inline void ff_insert_inpad(AVFilterContext *f, unsigned index,
 149                                    AVFilterPad *p)
 150 {
 151     ff_insert_pad(index, &f->nb_inputs, offsetof(AVFilterLink, dstpad),
 152                   &f->input_pads, &f->inputs, p);
 153 #if FF_API_FOO_COUNT
 154     f->input_count = f->nb_inputs;
 155 #endif
 156 }
 157
 158 /** Insert a new output pad for the filter. */
 159 static inline void ff_insert_outpad(AVFilterContext *f, unsigned index,
 160                                     AVFilterPad *p)
 161 {
 162     ff_insert_pad(index, &f->nb_outputs, offsetof(AVFilterLink, srcpad),
 163                   &f->output_pads, &f->outputs, p);
 164 #if FF_API_FOO_COUNT
 165     f->output_count = f->nb_outputs;
 166 #endif
 167 }
 168
 169 /**
 170  * Poll a frame from the filter chain.
 171  *
 172  * @param  link the input link
 173  * @return the number of immediately available frames, a negative
 174  * number in case of error
 175  */
 176 int ff_poll_frame(AVFilterLink *link);
 177
 178 /**
 179  * Request an input frame from the filter at the other end of the link.
 180  *
 181  * @param link the input link
 182  * @return     zero on success
 183  */
 184 int ff_request_frame(AVFilterLink *link);
 185
 186 /**
 187  * Send a frame of data to the next filter.
 188  *
 189  * @param link   the output link over which the data is being sent
 190  * @param frame a reference to the buffer of data being sent. The
 191  *              receiving filter will free this reference when it no longer
 192  *              needs it or pass it on to the next filter.
 193  *
 194  * @return >= 0 on success, a negative AVERROR on error. The receiving filter
 195  * is responsible for unreferencing frame in case of error.
 196  */
 197 int ff_filter_frame(AVFilterLink *link, AVFrame *frame);
 198
 199 #endif /* AVFILTER_INTERNAL_H */