FFmpeg
v4l2_m2m.h
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1 /*
2  * V4L2 mem2mem helper functions
3  *
4  * Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org>
5  * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #ifndef AVCODEC_V4L2_M2M_H
25 #define AVCODEC_V4L2_M2M_H
26 
27 #include <semaphore.h>
28 #include <unistd.h>
29 #include <dirent.h>
30 #include <linux/videodev2.h>
31 
32 #include "libavcodec/avcodec.h"
33 #include "v4l2_context.h"
34 
35 #define container_of(ptr, type, member) ({ \
36  const __typeof__(((type *)0)->member ) *__mptr = (ptr); \
37  (type *)((char *)__mptr - offsetof(type,member) );})
38 
39 #define V4L_M2M_DEFAULT_OPTS \
40  { "num_output_buffers", "Number of buffers in the output context",\
41  OFFSET(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 6, INT_MAX, FLAGS }
42 
43 typedef struct V4L2m2mContext {
44  char devname[PATH_MAX];
45  int fd;
46 
47  /* the codec context queues */
50 
51  /* dynamic stream reconfig */
55  int reinit;
56 
57  /* null frame/packet received */
58  int draining;
59 
60  /* Reference to self; only valid while codec is active. */
63 
64 typedef struct V4L2m2mPriv
65 {
66  AVClass *class;
67 
70 
73 } V4L2m2mPriv;
74 
75 /**
76  * Allocate a new context and references for a V4L2 M2M instance.
77  *
78  * @param[in] ctx The AVCodecContext instantiated by the encoder/decoder.
79  * @param[out] ctx The V4L2m2mContext.
80  *
81  * @returns 0 in success, a negative error code otherwise.
82  */
84 
85 
86 /**
87  * Probes the video nodes looking for the required codec capabilities.
88  *
89  * @param[in] ctx The AVCodecContext instantiated by the encoder/decoder.
90  *
91  * @returns 0 if a driver is found, a negative number otherwise.
92  */
94 
95 /**
96  * Releases all the codec resources if all AVBufferRefs have been returned to the
97  * ctx. Otherwise keep the driver open.
98  *
99  * @param[in] The AVCodecContext instantiated by the encoder/decoder.
100  *
101  * @returns 0
102  *
103  */
105 
106 /**
107  * Reinitializes the V4L2m2mContext when the driver cannot continue processing
108  * with the capture parameters.
109  *
110  * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder.
111  *
112  * @returns 0 in case of success, negative number otherwise
113  */
115 
116 /**
117  * Reinitializes the V4L2m2mContext when the driver cannot continue processing
118  * with the any of the current V4L2Contexts (ie, changes in output and capture).
119  *
120  * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder.
121  *
122  * @returns 0 in case of success, negative number otherwise
123  */
125 
126 #endif /* AVCODEC_V4L2_M2M_H */
AVCodecContext * avctx
Definition: v4l2_m2m.h:52
#define sem_t
Definition: semaphore.h:25
int ff_v4l2_m2m_codec_end(AVCodecContext *avctx)
Releases all the codec resources if all AVBufferRefs have been returned to the ctx.
Definition: v4l2_m2m.c:319
V4L2m2mContext * context
Definition: v4l2_m2m.h:68
char devname[PATH_MAX]
Definition: v4l2_m2m.h:44
int num_output_buffers
Definition: v4l2_m2m.h:71
AVFormatContext * ctx
Definition: movenc.c:48
#define s(width, name)
Definition: cbs_vp9.c:257
V4L2Context capture
Definition: v4l2_m2m.h:48
Libavcodec external API header.
atomic_uint refcount
Definition: v4l2_m2m.h:54
main external API structure.
Definition: avcodec.h:1565
Describe the class of an AVClass context structure.
Definition: log.h:67
intptr_t atomic_uint
Definition: stdatomic.h:56
V4L2Context output
Definition: v4l2_m2m.h:49
int ff_v4l2_m2m_codec_init(AVCodecContext *avctx)
Probes the video nodes looking for the required codec capabilities.
Definition: v4l2_m2m.c:341
A reference to a data buffer.
Definition: buffer.h:81
int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *ctx)
Reinitializes the V4L2m2mContext when the driver cannot continue processing with the any of the curre...
Definition: v4l2_m2m.c:231
int num_capture_buffers
Definition: v4l2_m2m.h:72
AVBufferRef * self_ref
Definition: v4l2_m2m.h:61
AVBufferRef * context_ref
Definition: v4l2_m2m.h:69
int ff_v4l2_m2m_create_context(AVCodecContext *avctx, V4L2m2mContext **s)
Allocate a new context and references for a V4L2 M2M instance.
Definition: v4l2_m2m.c:382
sem_t refsync
Definition: v4l2_m2m.h:53
int ff_v4l2_m2m_codec_reinit(V4L2m2mContext *ctx)
Reinitializes the V4L2m2mContext when the driver cannot continue processing with the capture paramete...
Definition: v4l2_m2m.c:189