FFmpeg
decode.h
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1 /*
2  * generic decoding-related code
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_DECODE_H
22 #define AVCODEC_DECODE_H
23 
24 #include "libavutil/frame.h"
25 #include "libavutil/hwcontext.h"
26 
27 #include "avcodec.h"
28 
29 /**
30  * This struct stores per-frame lavc-internal data and is attached to it via
31  * private_ref.
32  */
33 typedef struct FrameDecodeData {
34  /**
35  * The callback to perform some delayed processing on the frame right
36  * before it is returned to the caller.
37  *
38  * @note This code is called at some unspecified point after the frame is
39  * returned from the decoder's decode/receive_frame call. Therefore it cannot rely
40  * on AVCodecContext being in any specific state, so it does not get to
41  * access AVCodecContext directly at all. All the state it needs must be
42  * stored in the post_process_opaque object.
43  */
44  int (*post_process)(void *logctx, AVFrame *frame);
46  void (*post_process_opaque_free)(void *opaque);
47 
48  /**
49  * Per-frame private data for hwaccels.
50  */
51  void *hwaccel_priv;
52  void (*hwaccel_priv_free)(void *priv);
54 
55 /**
56  * Called by decoders to get the next packet for decoding.
57  *
58  * @param pkt An empty packet to be filled with data.
59  * @return 0 if a new reference has been successfully written to pkt
60  * AVERROR(EAGAIN) if no data is currently available
61  * AVERROR_EOF if and end of stream has been reached, so no more data
62  * will be available
63  */
65 
66 /**
67  * Set various frame properties from the provided packet.
68  */
70  AVFrame *frame, const AVPacket *pkt);
71 
72 /**
73  * Set various frame properties from the codec context / packet data.
74  */
76 
77 /**
78  * Make sure avctx.hw_frames_ctx is set. If it's not set, the function will
79  * try to allocate it from hw_device_ctx. If that is not possible, an error
80  * message is printed, and an error code is returned.
81  */
83  enum AVHWDeviceType dev_type);
84 
86 
87 /**
88  * Check whether the side-data of src contains a palette of
89  * size AVPALETTE_SIZE; if so, copy it to dst and return 1;
90  * else return 0.
91  * Also emit an error message upon encountering a palette
92  * with invalid size.
93  */
94 int ff_copy_palette(void *dst, const AVPacket *src, void *logctx);
95 
96 /**
97  * Check that the provided frame dimensions are valid and set them on the codec
98  * context.
99  */
101 
102 /**
103  * Check that the provided sample aspect ratio is valid and set it on the codec
104  * context.
105  */
106 int ff_set_sar(AVCodecContext *avctx, AVRational sar);
107 
108 /**
109  * Select the (possibly hardware accelerated) pixel format.
110  * This is a wrapper around AVCodecContext.get_format() and should be used
111  * instead of calling get_format() directly.
112  *
113  * The list of pixel formats must contain at least one valid entry, and is
114  * terminated with AV_PIX_FMT_NONE. If it is possible to decode to software,
115  * the last entry in the list must be the most accurate software format.
116  * If it is not possible to decode to software, AVCodecContext.sw_pix_fmt
117  * must be set before calling this function.
118  */
119 int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt);
120 
121 /**
122  * Get a buffer for a frame. This is a wrapper around
123  * AVCodecContext.get_buffer() and should be used instead calling get_buffer()
124  * directly.
125  */
126 int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags);
127 
128 #define FF_REGET_BUFFER_FLAG_READONLY 1 ///< the returned buffer does not need to be writable
129 /**
130  * Identical in function to ff_get_buffer(), except it reuses the existing buffer
131  * if available.
132  */
134 
135 /**
136  * Add or update AV_FRAME_DATA_MATRIXENCODING side data.
137  */
139  enum AVMatrixEncoding matrix_encoding);
140 
141 /**
142  * Allocate a hwaccel frame private data if the provided avctx
143  * uses a hwaccel method that needs it. The returned data is
144  * a RefStruct reference (if allocated).
145  *
146  * @param avctx The codec context
147  * @param hwaccel_picture_private Pointer to return hwaccel_picture_private
148  * @return 0 on success, < 0 on error
149  */
150 int ff_hwaccel_frame_priv_alloc(AVCodecContext *avctx, void **hwaccel_picture_private);
151 
152 /**
153  * Get side data of the given type from a decoding context.
154  */
157 
158 #endif /* AVCODEC_DECODE_H */
ff_get_format
int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
Select the (possibly hardware accelerated) pixel format.
Definition: decode.c:1264
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:71
ff_hwaccel_frame_priv_alloc
int ff_hwaccel_frame_priv_alloc(AVCodecContext *avctx, void **hwaccel_picture_private)
Allocate a hwaccel frame private data if the provided avctx uses a hwaccel method that needs it.
Definition: decode.c:1839
FrameDecodeData
This struct stores per-frame lavc-internal data and is attached to it via private_ref.
Definition: decode.h:33
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
AVPacketSideData
This structure stores auxiliary information for decoding, presenting, or otherwise processing the cod...
Definition: packet.h:373
FrameDecodeData::hwaccel_priv_free
void(* hwaccel_priv_free)(void *priv)
Definition: decode.h:52
ff_set_dimensions
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:94
FrameDecodeData::post_process_opaque_free
void(* post_process_opaque_free)(void *opaque)
Definition: decode.h:46
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
ff_decode_frame_props
int ff_decode_frame_props(AVCodecContext *avctx, AVFrame *frame)
Set various frame properties from the codec context / packet data.
Definition: decode.c:1505
pkt
AVPacket * pkt
Definition: movenc.c:59
ff_side_data_update_matrix_encoding
int ff_side_data_update_matrix_encoding(AVFrame *frame, enum AVMatrixEncoding matrix_encoding)
Add or update AV_FRAME_DATA_MATRIXENCODING side data.
Definition: utils.c:124
width
#define width
s
#define s(width, name)
Definition: cbs_vp9.c:198
FrameDecodeData::post_process_opaque
void * post_process_opaque
Definition: decode.h:45
AVHWDeviceType
AVHWDeviceType
Definition: hwcontext.h:27
ff_attach_decode_data
int ff_attach_decode_data(AVFrame *frame)
Definition: decode.c:1594
ff_decode_frame_props_from_pkt
int ff_decode_frame_props_from_pkt(const AVCodecContext *avctx, AVFrame *frame, const AVPacket *pkt)
Set various frame properties from the provided packet.
Definition: decode.c:1440
frame
static AVFrame * frame
Definition: demux_decode.c:54
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1618
AVMatrixEncoding
AVMatrixEncoding
Definition: channel_layout.h:254
ff_decode_get_hw_frames_ctx
int ff_decode_get_hw_frames_ctx(AVCodecContext *avctx, enum AVHWDeviceType dev_type)
Make sure avctx.hw_frames_ctx is set.
Definition: decode.c:1108
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
ff_set_sar
int ff_set_sar(AVCodecContext *avctx, AVRational sar)
Check that the provided sample aspect ratio is valid and set it on the codec context.
Definition: utils.c:109
ff_decode_get_packet
int ff_decode_get_packet(AVCodecContext *avctx, AVPacket *pkt)
Called by decoders to get the next packet for decoding.
Definition: decode.c:241
FrameDecodeData::post_process
int(* post_process)(void *logctx, AVFrame *frame)
The callback to perform some delayed processing on the frame right before it is returned to the calle...
Definition: decode.h:44
frame.h
height
#define height
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1736
ff_copy_palette
int ff_copy_palette(void *dst, const AVPacket *src, void *logctx)
Check whether the side-data of src contains a palette of size AVPALETTE_SIZE; if so,...
Definition: decode.c:1824
ff_get_coded_side_data
const AVPacketSideData * ff_get_coded_side_data(const AVCodecContext *avctx, enum AVPacketSideDataType type)
Get side data of the given type from a decoding context.
Definition: decode.c:1402
avcodec.h
AVCodecContext
main external API structure.
Definition: avcodec.h:445
AVPacketSideDataType
AVPacketSideDataType
Definition: packet.h:41
AVPacket
This structure stores compressed data.
Definition: packet.h:499
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
FrameDecodeData::hwaccel_priv
void * hwaccel_priv
Per-frame private data for hwaccels.
Definition: decode.h:51
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
hwcontext.h
int
int
Definition: ffmpeg_filter.c:424