FFmpeg
buffersink.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_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 
36 /**
37  * Get a frame with filtered data from sink and put it in frame.
38  *
39  * @param ctx pointer to a buffersink or abuffersink filter context.
40  * @param frame pointer to an allocated frame that will be filled with data.
41  * The data must be freed using av_frame_unref() / av_frame_free()
42  * @param flags a combination of AV_BUFFERSINK_FLAG_* flags
43  *
44  * @return >= 0 in for success, a negative AVERROR code for failure.
45  */
47 
48 /**
49  * Tell av_buffersink_get_buffer_ref() to read video/samples buffer
50  * reference, but not remove it from the buffer. This is useful if you
51  * need only to read a video/samples buffer, without to fetch it.
52  */
53 #define AV_BUFFERSINK_FLAG_PEEK 1
54 
55 /**
56  * Tell av_buffersink_get_buffer_ref() not to request a frame from its input.
57  * If a frame is already buffered, it is read (and removed from the buffer),
58  * but if no frame is present, return AVERROR(EAGAIN).
59  */
60 #define AV_BUFFERSINK_FLAG_NO_REQUEST 2
61 
62 #if FF_API_NEXT
63 /**
64  * Struct to use for initializing a buffersink context.
65  */
66 typedef struct AVBufferSinkParams {
67  const enum AVPixelFormat *pixel_fmts; ///< list of allowed pixel formats, terminated by AV_PIX_FMT_NONE
68 } AVBufferSinkParams;
69 
70 /**
71  * Create an AVBufferSinkParams structure.
72  *
73  * Must be freed with av_free().
74  */
76 AVBufferSinkParams *av_buffersink_params_alloc(void);
77 
78 /**
79  * Struct to use for initializing an abuffersink context.
80  */
81 typedef struct AVABufferSinkParams {
82  const enum AVSampleFormat *sample_fmts; ///< list of allowed sample formats, terminated by AV_SAMPLE_FMT_NONE
83  const int64_t *channel_layouts; ///< list of allowed channel layouts, terminated by -1
84  const int *channel_counts; ///< list of allowed channel counts, terminated by -1
85  int all_channel_counts; ///< if not 0, accept any channel count or layout
86  int *sample_rates; ///< list of allowed sample rates, terminated by -1
87 } AVABufferSinkParams;
88 
89 /**
90  * Create an AVABufferSinkParams structure.
91  *
92  * Must be freed with av_free().
93  */
95 AVABufferSinkParams *av_abuffersink_params_alloc(void);
96 #endif
97 
98 /**
99  * Set the frame size for an audio buffer sink.
100  *
101  * All calls to av_buffersink_get_buffer_ref will return a buffer with
102  * exactly the specified number of samples, or AVERROR(EAGAIN) if there is
103  * not enough. The last buffer at EOF will be padded with 0.
104  */
106 
107 /**
108  * @defgroup lavfi_buffersink_accessors Buffer sink accessors
109  * Get the properties of the stream
110  * @{
111  */
112 
116 
118 int av_buffersink_get_w (const AVFilterContext *ctx);
119 int av_buffersink_get_h (const AVFilterContext *ctx);
121 
125 
127 
128 /** @} */
129 
130 /**
131  * Get a frame with filtered data from sink and put it in frame.
132  *
133  * @param ctx pointer to a context of a buffersink or abuffersink AVFilter.
134  * @param frame pointer to an allocated frame that will be filled with data.
135  * The data must be freed using av_frame_unref() / av_frame_free()
136  *
137  * @return
138  * - >= 0 if a frame was successfully returned.
139  * - AVERROR(EAGAIN) if no frames are available at this point; more
140  * input frames must be added to the filtergraph to get more output.
141  * - AVERROR_EOF if there will be no more output frames on this sink.
142  * - A different negative AVERROR code in other failure cases.
143  */
145 
146 /**
147  * Same as av_buffersink_get_frame(), but with the ability to specify the number
148  * of samples read. This function is less efficient than
149  * av_buffersink_get_frame(), because it copies the data around.
150  *
151  * @param ctx pointer to a context of the abuffersink AVFilter.
152  * @param frame pointer to an allocated frame that will be filled with data.
153  * The data must be freed using av_frame_unref() / av_frame_free()
154  * frame will contain exactly nb_samples audio samples, except at
155  * the end of stream, when it can contain less than nb_samples.
156  *
157  * @return The return codes have the same meaning as for
158  * av_buffersink_get_frame().
159  *
160  * @warning do not mix this function with av_buffersink_get_frame(). Use only one or
161  * the other with a single sink, not both.
162  */
163 int av_buffersink_get_samples(AVFilterContext *ctx, AVFrame *frame, int nb_samples);
164 
165 /**
166  * @}
167  */
168 
169 #endif /* AVFILTER_BUFFERSINK_H */
This structure describes decoded (raw) audio or video data.
Definition: frame.h:308
Main libavfilter public API header.
int av_buffersink_get_sample_rate(const AVFilterContext *ctx)
AVBufferSinkParams * av_buffersink_params_alloc(void)
Definition: buffersink.c:129
AVRational av_buffersink_get_frame_rate(const AVFilterContext *ctx)
AVBufferRef * av_buffersink_get_hw_frames_ctx(const AVFilterContext *ctx)
int av_buffersink_get_h(const AVFilterContext *ctx)
int av_buffersink_get_format(const AVFilterContext *ctx)
AVABufferSinkParams * av_abuffersink_params_alloc(void)
Definition: buffersink.c:140
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.
Definition: buffersink.c:117
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...
Definition: buffersink.c:122
AVFormatContext * ctx
Definition: movenc.c:48
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
static const uint8_t channel_counts[7]
Definition: dca_lbr.c:109
AVRational av_buffersink_get_sample_aspect_ratio(const AVFilterContext *ctx)
int frame_size
Definition: mxfenc.c:2139
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
uint64_t av_buffersink_get_channel_layout(const AVFilterContext *ctx)
static const uint16_t channel_layouts[7]
Definition: dca_lbr.c:113
enum AVMediaType av_buffersink_get_type(const AVFilterContext *ctx)
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVMediaType
Definition: avutil.h:199
int av_buffersink_get_w(const AVFilterContext *ctx)
#define flags(name, subs,...)
Definition: cbs_av1.c:560
#define attribute_deprecated
Definition: attributes.h:100
A reference to a data buffer.
Definition: buffer.h:81
sample_rates
void av_buffersink_set_frame_size(AVFilterContext *ctx, unsigned frame_size)
Set the frame size for an audio buffer sink.
Definition: buffersink.c:175
int av_buffersink_get_channels(const AVFilterContext *ctx)
An instance of a filter.
Definition: avfilter.h:338
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:723
int av_buffersink_get_frame(AVFilterContext *ctx, AVFrame *frame)
Get a frame with filtered data from sink and put it in frame.
Definition: buffersink.c:65
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
AVRational av_buffersink_get_time_base(const AVFilterContext *ctx)