FFmpeg 4.4.5
Loading...
Searching...
No Matches
buffersrc.h
Go to the documentation of this file.
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_BUFFERSRC_H
20#define AVFILTER_BUFFERSRC_H
21
22/**
23 * @file
24 * @ingroup lavfi_buffersrc
25 * Memory buffer source API.
26 */
27
28#include "avfilter.h"
29
30/**
31 * @defgroup lavfi_buffersrc Buffer source API
32 * @ingroup lavfi
33 * @{
34 */
35
36enum {
37
38 /**
39 * Do not check for format changes.
40 */
42
43 /**
44 * Immediately push the frame to the output.
45 */
47
48 /**
49 * Keep a reference to the frame.
50 * If the frame if reference-counted, create a new reference; otherwise
51 * copy the frame data.
52 */
54
55};
56
57/**
58 * Get the number of failed requests.
59 *
60 * A failed request is when the request_frame method is called while no
61 * frame is present in the buffer.
62 * The number is reset when a frame is added.
63 */
65
66/**
67 * This structure contains the parameters describing the frames that will be
68 * passed to this filter.
69 *
70 * It should be allocated with av_buffersrc_parameters_alloc() and freed with
71 * av_free(). All the allocated fields in it remain owned by the caller.
72 */
73typedef struct AVBufferSrcParameters {
74 /**
75 * video: the pixel format, value corresponds to enum AVPixelFormat
76 * audio: the sample format, value corresponds to enum AVSampleFormat
77 */
78 int format;
79 /**
80 * The timebase to be used for the timestamps on the input frames.
81 */
83
84 /**
85 * Video only, the display dimensions of the input frames.
86 */
88
89 /**
90 * Video only, the sample (pixel) aspect ratio.
91 */
93
94 /**
95 * Video only, the frame rate of the input video. This field must only be
96 * set to a non-zero value if input stream has a known constant framerate
97 * and should be left at its initial value if the framerate is variable or
98 * unknown.
99 */
101
102 /**
103 * Video with a hwaccel pixel format only. This should be a reference to an
104 * AVHWFramesContext instance describing the input frames.
105 */
107
108 /**
109 * Audio only, the audio sampling rate in samples per second.
110 */
112
113 /**
114 * Audio only, the audio channel layout
115 */
118
119/**
120 * Allocate a new AVBufferSrcParameters instance. It should be freed by the
121 * caller with av_free().
122 */
124
125/**
126 * Initialize the buffersrc or abuffersrc filter with the provided parameters.
127 * This function may be called multiple times, the later calls override the
128 * previous ones. Some of the parameters may also be set through AVOptions, then
129 * whatever method is used last takes precedence.
130 *
131 * @param ctx an instance of the buffersrc or abuffersrc filter
132 * @param param the stream parameters. The frames later passed to this filter
133 * must conform to those parameters. All the allocated fields in
134 * param remain owned by the caller, libavfilter will make internal
135 * copies or references when necessary.
136 * @return 0 on success, a negative AVERROR code on failure.
137 */
139
140/**
141 * Add a frame to the buffer source.
142 *
143 * @param ctx an instance of the buffersrc filter
144 * @param frame frame to be added. If the frame is reference counted, this
145 * function will make a new reference to it. Otherwise the frame data will be
146 * copied.
147 *
148 * @return 0 on success, a negative AVERROR on error
149 *
150 * This function is equivalent to av_buffersrc_add_frame_flags() with the
151 * AV_BUFFERSRC_FLAG_KEEP_REF flag.
152 */
155
156/**
157 * Add a frame to the buffer source.
158 *
159 * @param ctx an instance of the buffersrc filter
160 * @param frame frame to be added. If the frame is reference counted, this
161 * function will take ownership of the reference(s) and reset the frame.
162 * Otherwise the frame data will be copied. If this function returns an error,
163 * the input frame is not touched.
164 *
165 * @return 0 on success, a negative AVERROR on error.
166 *
167 * @note the difference between this function and av_buffersrc_write_frame() is
168 * that av_buffersrc_write_frame() creates a new reference to the input frame,
169 * while this function takes ownership of the reference passed to it.
170 *
171 * This function is equivalent to av_buffersrc_add_frame_flags() without the
172 * AV_BUFFERSRC_FLAG_KEEP_REF flag.
173 */
176
177/**
178 * Add a frame to the buffer source.
179 *
180 * By default, if the frame is reference-counted, this function will take
181 * ownership of the reference(s) and reset the frame. This can be controlled
182 * using the flags.
183 *
184 * If this function returns an error, the input frame is not touched.
185 *
186 * @param buffer_src pointer to a buffer source context
187 * @param frame a frame, or NULL to mark EOF
188 * @param flags a combination of AV_BUFFERSRC_FLAG_*
189 * @return >= 0 in case of success, a negative AVERROR code
190 * in case of failure
191 */
194 AVFrame *frame, int flags);
195
196/**
197 * Close the buffer source after EOF.
198 *
199 * This is similar to passing NULL to av_buffersrc_add_frame_flags()
200 * except it takes the timestamp of the EOF, i.e. the timestamp of the end
201 * of the last frame.
202 */
203int av_buffersrc_close(AVFilterContext *ctx, int64_t pts, unsigned flags);
204
205/**
206 * @}
207 */
208
209#endif /* AVFILTER_BUFFERSRC_H */
#define av_warn_unused_result
Definition attributes.h:62
Main libavfilter public API header.
static AVFrame * frame
int av_buffersrc_parameters_set(AVFilterContext *ctx, AVBufferSrcParameters *param)
Initialize the buffersrc or abuffersrc filter with the provided parameters.
av_warn_unused_result int av_buffersrc_add_frame_flags(AVFilterContext *buffer_src, AVFrame *frame, int flags)
Add a frame to the buffer source.
av_warn_unused_result int av_buffersrc_write_frame(AVFilterContext *ctx, const AVFrame *frame)
Add a frame to the buffer source.
int av_buffersrc_close(AVFilterContext *ctx, int64_t pts, unsigned flags)
Close the buffer source after EOF.
av_warn_unused_result int av_buffersrc_add_frame(AVFilterContext *ctx, AVFrame *frame)
Add a frame to the buffer source.
unsigned av_buffersrc_get_nb_failed_requests(AVFilterContext *buffer_src)
Get the number of failed requests.
AVBufferSrcParameters * av_buffersrc_parameters_alloc(void)
Allocate a new AVBufferSrcParameters instance.
@ AV_BUFFERSRC_FLAG_KEEP_REF
Keep a reference to the frame.
Definition buffersrc.h:53
@ AV_BUFFERSRC_FLAG_PUSH
Immediately push the frame to the output.
Definition buffersrc.h:46
@ AV_BUFFERSRC_FLAG_NO_CHECK_FORMAT
Do not check for format changes.
Definition buffersrc.h:41
A reference to a data buffer.
Definition buffer.h:84
This structure contains the parameters describing the frames that will be passed to this filter.
Definition buffersrc.h:73
AVRational frame_rate
Video only, the frame rate of the input video.
Definition buffersrc.h:100
int sample_rate
Audio only, the audio sampling rate in samples per second.
Definition buffersrc.h:111
int format
video: the pixel format, value corresponds to enum AVPixelFormat audio: the sample format,...
Definition buffersrc.h:78
int width
Video only, the display dimensions of the input frames.
Definition buffersrc.h:87
AVRational time_base
The timebase to be used for the timestamps on the input frames.
Definition buffersrc.h:82
AVBufferRef * hw_frames_ctx
Video with a hwaccel pixel format only.
Definition buffersrc.h:106
AVRational sample_aspect_ratio
Video only, the sample (pixel) aspect ratio.
Definition buffersrc.h:92
uint64_t channel_layout
Audio only, the audio channel layout.
Definition buffersrc.h:116
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
static int64_t pts