FFmpeg  5.1
buffersink.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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_BUFFERSINK_H
20 #define AVFILTER_BUFFERSINK_H
21 
22 /**
23  * @file
24  * @ingroup lavfi_buffersink
25  * memory buffer sink API for audio and video
26  */
27 
28 #include "avfilter.h"
29 
30 /**
31  * @defgroup lavfi_buffersink Buffer sink API
32  * @ingroup lavfi
33  * @{
34  *
35  * The buffersink and abuffersink filters are there to connect filter graphs
36  * to applications. They have a single input, connected to the graph, and no
37  * output. Frames must be extracted using av_buffersink_get_frame() or
38  * av_buffersink_get_samples().
39  *
40  * The format negotiated by the graph during configuration can be obtained
41  * using the accessor functions:
42  * - av_buffersink_get_time_base(),
43  * - av_buffersink_get_format(),
44  * - av_buffersink_get_frame_rate(),
45  * - av_buffersink_get_w(),
46  * - av_buffersink_get_h(),
47  * - av_buffersink_get_sample_aspect_ratio(),
48  * - av_buffersink_get_channels(),
49  * - av_buffersink_get_ch_layout(),
50  * - av_buffersink_get_sample_rate().
51  *
52  * The layout returned by av_buffersink_get_ch_layout() must de uninitialized
53  * by the caller.
54  *
55  * The format can be constrained by setting options, using av_opt_set() and
56  * related functions with the AV_OPT_SEARCH_CHILDREN flag.
57  * - pix_fmts (int list),
58  * - sample_fmts (int list),
59  * - sample_rates (int list),
60  * - ch_layouts (string),
61  * - channel_counts (int list),
62  * - all_channel_counts (bool).
63  * Most of these options are of type binary, and should be set using
64  * av_opt_set_int_list() or av_opt_set_bin(). If they are not set, all
65  * corresponding formats are accepted.
66  *
67  * As a special case, if ch_layouts is not set, all valid channel layouts are
68  * accepted except for UNSPEC layouts, unless all_channel_counts is set.
69  */
70 
71 /**
72  * Get a frame with filtered data from sink and put it in frame.
73  *
74  * @param ctx pointer to a buffersink or abuffersink filter context.
75  * @param frame pointer to an allocated frame that will be filled with data.
76  * The data must be freed using av_frame_unref() / av_frame_free()
77  * @param flags a combination of AV_BUFFERSINK_FLAG_* flags
78  *
79  * @return >= 0 in for success, a negative AVERROR code for failure.
80  */
82 
83 /**
84  * Tell av_buffersink_get_buffer_ref() to read video/samples buffer
85  * reference, but not remove it from the buffer. This is useful if you
86  * need only to read a video/samples buffer, without to fetch it.
87  */
88 #define AV_BUFFERSINK_FLAG_PEEK 1
89 
90 /**
91  * Tell av_buffersink_get_buffer_ref() not to request a frame from its input.
92  * If a frame is already buffered, it is read (and removed from the buffer),
93  * but if no frame is present, return AVERROR(EAGAIN).
94  */
95 #define AV_BUFFERSINK_FLAG_NO_REQUEST 2
96 
97 #if FF_API_BUFFERSINK_ALLOC
98 /**
99  * Deprecated and unused struct to use for initializing a buffersink context.
100  */
101 typedef struct AVBufferSinkParams {
102  const enum AVPixelFormat *pixel_fmts; ///< list of allowed pixel formats, terminated by AV_PIX_FMT_NONE
103 } AVBufferSinkParams;
104 
105 /**
106  * Create an AVBufferSinkParams structure.
107  *
108  * Must be freed with av_free().
109  */
111 AVBufferSinkParams *av_buffersink_params_alloc(void);
112 
113 /**
114  * Deprecated and unused struct to use for initializing an abuffersink context.
115  */
116 typedef struct AVABufferSinkParams {
117  const enum AVSampleFormat *sample_fmts; ///< list of allowed sample formats, terminated by AV_SAMPLE_FMT_NONE
118  const int64_t *channel_layouts; ///< list of allowed channel layouts, terminated by -1
119  const int *channel_counts; ///< list of allowed channel counts, terminated by -1
120  int all_channel_counts; ///< if not 0, accept any channel count or layout
121  int *sample_rates; ///< list of allowed sample rates, terminated by -1
122 } AVABufferSinkParams;
123 
124 /**
125  * Create an AVABufferSinkParams structure.
126  *
127  * Must be freed with av_free().
128  */
130 AVABufferSinkParams *av_abuffersink_params_alloc(void);
131 #endif
132 
133 /**
134  * Set the frame size for an audio buffer sink.
135  *
136  * All calls to av_buffersink_get_buffer_ref will return a buffer with
137  * exactly the specified number of samples, or AVERROR(EAGAIN) if there is
138  * not enough. The last buffer at EOF will be padded with 0.
139  */
140 void av_buffersink_set_frame_size(AVFilterContext *ctx, unsigned frame_size);
141 
142 /**
143  * @defgroup lavfi_buffersink_accessors Buffer sink accessors
144  * Get the properties of the stream
145  * @{
146  */
147 
151 
156 
158 #if FF_API_OLD_CHANNEL_LAYOUT
160 uint64_t av_buffersink_get_channel_layout (const AVFilterContext *ctx);
161 #endif
163  AVChannelLayout *ch_layout);
165 
167 
168 /** @} */
169 
170 /**
171  * Get a frame with filtered data from sink and put it in frame.
172  *
173  * @param ctx pointer to a context of a buffersink or abuffersink AVFilter.
174  * @param frame pointer to an allocated frame that will be filled with data.
175  * The data must be freed using av_frame_unref() / av_frame_free()
176  *
177  * @return
178  * - >= 0 if a frame was successfully returned.
179  * - AVERROR(EAGAIN) if no frames are available at this point; more
180  * input frames must be added to the filtergraph to get more output.
181  * - AVERROR_EOF if there will be no more output frames on this sink.
182  * - A different negative AVERROR code in other failure cases.
183  */
185 
186 /**
187  * Same as av_buffersink_get_frame(), but with the ability to specify the number
188  * of samples read. This function is less efficient than
189  * av_buffersink_get_frame(), because it copies the data around.
190  *
191  * @param ctx pointer to a context of the abuffersink AVFilter.
192  * @param frame pointer to an allocated frame that will be filled with data.
193  * The data must be freed using av_frame_unref() / av_frame_free()
194  * frame will contain exactly nb_samples audio samples, except at
195  * the end of stream, when it can contain less than nb_samples.
196  *
197  * @return The return codes have the same meaning as for
198  * av_buffersink_get_frame().
199  *
200  * @warning do not mix this function with av_buffersink_get_frame(). Use only one or
201  * the other with a single sink, not both.
202  */
204 
205 /**
206  * @}
207  */
208 
209 #endif /* AVFILTER_BUFFERSINK_H */
#define attribute_deprecated
Definition: attributes.h:100
Main libavfilter public API header.
static AVFrame * frame
enum AVMediaType av_buffersink_get_type(const AVFilterContext *ctx)
int av_buffersink_get_sample_rate(const AVFilterContext *ctx)
int av_buffersink_get_format(const AVFilterContext *ctx)
AVRational av_buffersink_get_frame_rate(const AVFilterContext *ctx)
int av_buffersink_get_h(const AVFilterContext *ctx)
AVBufferRef * av_buffersink_get_hw_frames_ctx(const AVFilterContext *ctx)
AVRational av_buffersink_get_sample_aspect_ratio(const AVFilterContext *ctx)
int av_buffersink_get_ch_layout(const AVFilterContext *ctx, AVChannelLayout *ch_layout)
AVRational av_buffersink_get_time_base(const AVFilterContext *ctx)
int av_buffersink_get_w(const AVFilterContext *ctx)
int av_buffersink_get_channels(const AVFilterContext *ctx)
void av_buffersink_set_frame_size(AVFilterContext *ctx, unsigned frame_size)
Set the frame size for an audio buffer sink.
int av_buffersink_get_frame(AVFilterContext *ctx, AVFrame *frame)
Get a frame with filtered data from sink and put it in frame.
int av_buffersink_get_frame_flags(AVFilterContext *ctx, AVFrame *frame, int flags)
Get a frame with filtered data from sink and put it in frame.
int av_buffersink_get_samples(AVFilterContext *ctx, AVFrame *frame, int nb_samples)
Same as av_buffersink_get_frame(), but with the ability to specify the number of samples read.
AVMediaType
Definition: avutil.h:199
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
A reference to a data buffer.
Definition: buffer.h:82
An AVChannelLayout holds information about the channel layout of audio data.
An instance of a filter.
Definition: avfilter.h:408
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
Rational number (pair of numerator and denominator).
Definition: rational.h:58