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buffersrc.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,
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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 
36 enum {
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  */
73 typedef 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  */
87  int width, height;
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 secon.
110  */
112 
113  /**
114  * Audio only, the audio channel layout
115  */
116  uint64_t channel_layout;
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 /**
198  * @}
199  */
200 
201 #endif /* AVFILTER_BUFFERSRC_H */
This structure describes decoded (raw) audio or video data.
Definition: frame.h:184
Main libavfilter public API header.
AVRational frame_rate
Video only, the frame rate of the input video.
Definition: buffersrc.h:100
AVRational sample_aspect_ratio
Video only, the sample (pixel) aspect ratio.
Definition: buffersrc.h:92
AVRational time_base
The timebase to be used for the timestamps on the input frames.
Definition: buffersrc.h:82
static AVFrame * frame
static int flags
Definition: log.c:57
int sample_rate
Audio only, the audio sampling rate in samples per secon.
Definition: buffersrc.h:111
uint64_t channel_layout
Audio only, the audio channel layout.
Definition: buffersrc.h:116
int format
video: the pixel format, value corresponds to enum AVPixelFormat audio: the sample format...
Definition: buffersrc.h:78
This structure contains the parameters describing the frames that will be passed to this filter...
Definition: buffersrc.h:73
Do not check for format changes.
Definition: buffersrc.h:41
AVFormatContext * ctx
Definition: movenc.c:48
AVBufferRef * hw_frames_ctx
Video with a hwaccel pixel format only.
Definition: buffersrc.h:106
Rational number (pair of numerator and denominator).
Definition: rational.h:58
unsigned av_buffersrc_get_nb_failed_requests(AVFilterContext *buffer_src)
Get the number of failed requests.
Definition: buffersrc.c:266
#define av_warn_unused_result
Definition: attributes.h:56
Keep a reference to the frame.
Definition: buffersrc.h:53
av_warn_unused_result int av_buffersrc_write_frame(AVFilterContext *ctx, const AVFrame *frame)
Add a frame to the buffer source.
Definition: buffersrc.c:138
A reference to a data buffer.
Definition: buffer.h:81
Immediately push the frame to the output.
Definition: buffersrc.h:46
int av_buffersrc_parameters_set(AVFilterContext *ctx, AVBufferSrcParameters *param)
Initialize the buffersrc or abuffersrc filter with the provided parameters.
Definition: buffersrc.c:93
av_warn_unused_result int av_buffersrc_add_frame_flags(AVFilterContext *buffer_src, AVFrame *frame, int flags)
Add a frame to the buffer source.
Definition: buffersrc.c:152
AVBufferSrcParameters * av_buffersrc_parameters_alloc(void)
Allocate a new AVBufferSrcParameters instance.
Definition: buffersrc.c:82
An instance of a filter.
Definition: avfilter.h:307
int width
Video only, the display dimensions of the input frames.
Definition: buffersrc.h:87
av_warn_unused_result int av_buffersrc_add_frame(AVFilterContext *ctx, AVFrame *frame)
Add a frame to the buffer source.
Definition: buffersrc.c:144