FFmpeg 4.4.5
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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_channel_layout(),
50 * - av_buffersink_get_sample_rate().
51 *
52 * The format can be constrained by setting options, using av_opt_set() and
53 * related functions with the AV_OPT_SEARCH_CHILDREN flag.
54 * - pix_fmts (int list),
55 * - sample_fmts (int list),
56 * - sample_rates (int list),
57 * - channel_layouts (int64_t),
58 * - channel_counts (int list),
59 * - all_channel_counts (bool).
60 * Most of these options are of type binary, and should be set using
61 * av_opt_set_int_list() or av_opt_set_bin(). If they are not set, all
62 * corresponding formats are accepted.
63 *
64 * As a special case, if neither channel_layouts nor channel_counts is set,
65 * all valid channel layouts are accepted, but channel counts without a
66 * layout are not, unless all_channel_counts is set.
67 * Also, channel_layouts must not contain a channel layout already accepted
68 * by a value in channel_counts; for example, if channel_counts contains 2,
69 * then channel_layouts must not contain stereo.
70 */
71
72/**
73 * Get a frame with filtered data from sink and put it in frame.
74 *
75 * @param ctx pointer to a buffersink or abuffersink filter context.
76 * @param frame pointer to an allocated frame that will be filled with data.
77 * The data must be freed using av_frame_unref() / av_frame_free()
78 * @param flags a combination of AV_BUFFERSINK_FLAG_* flags
79 *
80 * @return >= 0 in for success, a negative AVERROR code for failure.
81 */
83
84/**
85 * Tell av_buffersink_get_buffer_ref() to read video/samples buffer
86 * reference, but not remove it from the buffer. This is useful if you
87 * need only to read a video/samples buffer, without to fetch it.
88 */
89#define AV_BUFFERSINK_FLAG_PEEK 1
90
91/**
92 * Tell av_buffersink_get_buffer_ref() not to request a frame from its input.
93 * If a frame is already buffered, it is read (and removed from the buffer),
94 * but if no frame is present, return AVERROR(EAGAIN).
95 */
96#define AV_BUFFERSINK_FLAG_NO_REQUEST 2
97
98#if FF_API_BUFFERSINK_ALLOC
99/**
100 * Deprecated and unused struct to use for initializing a buffersink context.
101 */
102typedef struct AVBufferSinkParams {
103 const enum AVPixelFormat *pixel_fmts; ///< list of allowed pixel formats, terminated by AV_PIX_FMT_NONE
104} AVBufferSinkParams;
105
106/**
107 * Create an AVBufferSinkParams structure.
108 *
109 * Must be freed with av_free().
110 */
112AVBufferSinkParams *av_buffersink_params_alloc(void);
113
114/**
115 * Deprecated and unused struct to use for initializing an abuffersink context.
116 */
117typedef struct AVABufferSinkParams {
118 const enum AVSampleFormat *sample_fmts; ///< list of allowed sample formats, terminated by AV_SAMPLE_FMT_NONE
119 const int64_t *channel_layouts; ///< list of allowed channel layouts, terminated by -1
120 const int *channel_counts; ///< list of allowed channel counts, terminated by -1
121 int all_channel_counts; ///< if not 0, accept any channel count or layout
122 int *sample_rates; ///< list of allowed sample rates, terminated by -1
123} AVABufferSinkParams;
124
125/**
126 * Create an AVABufferSinkParams structure.
127 *
128 * Must be freed with av_free().
129 */
131AVABufferSinkParams *av_abuffersink_params_alloc(void);
132#endif
133
134/**
135 * Set the frame size for an audio buffer sink.
136 *
137 * All calls to av_buffersink_get_buffer_ref will return a buffer with
138 * exactly the specified number of samples, or AVERROR(EAGAIN) if there is
139 * not enough. The last buffer at EOF will be padded with 0.
140 */
141void av_buffersink_set_frame_size(AVFilterContext *ctx, unsigned frame_size);
142
143/**
144 * @defgroup lavfi_buffersink_accessors Buffer sink accessors
145 * Get the properties of the stream
146 * @{
147 */
148
152
157
161
163
164/** @} */
165
166/**
167 * Get a frame with filtered data from sink and put it in frame.
168 *
169 * @param ctx pointer to a context of a buffersink or abuffersink AVFilter.
170 * @param frame pointer to an allocated frame that will be filled with data.
171 * The data must be freed using av_frame_unref() / av_frame_free()
172 *
173 * @return
174 * - >= 0 if a frame was successfully returned.
175 * - AVERROR(EAGAIN) if no frames are available at this point; more
176 * input frames must be added to the filtergraph to get more output.
177 * - AVERROR_EOF if there will be no more output frames on this sink.
178 * - A different negative AVERROR code in other failure cases.
179 */
181
182/**
183 * Same as av_buffersink_get_frame(), but with the ability to specify the number
184 * of samples read. This function is less efficient than
185 * av_buffersink_get_frame(), because it copies the data around.
186 *
187 * @param ctx pointer to a context of the abuffersink AVFilter.
188 * @param frame pointer to an allocated frame that will be filled with data.
189 * The data must be freed using av_frame_unref() / av_frame_free()
190 * frame will contain exactly nb_samples audio samples, except at
191 * the end of stream, when it can contain less than nb_samples.
192 *
193 * @return The return codes have the same meaning as for
194 * av_buffersink_get_frame().
195 *
196 * @warning do not mix this function with av_buffersink_get_frame(). Use only one or
197 * the other with a single sink, not both.
198 */
200
201/**
202 * @}
203 */
204
205#endif /* AVFILTER_BUFFERSINK_H */
#define attribute_deprecated
Definition attributes.h:100
Main libavfilter public API header.
static AVFrame * frame
AVBufferRef * av_buffersink_get_hw_frames_ctx(const AVFilterContext *ctx)
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)
uint64_t av_buffersink_get_channel_layout(const AVFilterContext *ctx)
int av_buffersink_get_h(const AVFilterContext *ctx)
AVRational av_buffersink_get_sample_aspect_ratio(const AVFilterContext *ctx)
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:58
AVPixelFormat
Pixel format.
Definition pixfmt.h:64
A reference to a data buffer.
Definition buffer.h:84
An instance of a filter.
Definition avfilter.h:341
This structure describes decoded (raw) audio or video data.
Definition frame.h:318
Rational number (pair of numerator and denominator).
Definition rational.h:58