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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(output.num_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 6, INT_MAX, FLAGS }
42 
43 typedef struct V4L2m2mContext
44 {
45  AVClass *class;
46  char devname[PATH_MAX];
47  int fd;
48 
49  /* the codec context queues */
52 
53  /* refcount of buffers held by the user */
55 
56  /* dynamic stream reconfig */
59  int reinit;
60 
61  /* null frame/packet received */
62  int draining;
64 
65 /**
66  * Probes the video nodes looking for the required codec capabilities.
67  *
68  * @param[in] ctx The AVCodecContext instantiated by the encoder/decoder.
69  *
70  * @returns 0 if a driver is found, a negative number otherwise.
71  */
73 
74 /**
75  * Releases all the codec resources if all AVBufferRefs have been returned to the
76  * ctx. Otherwise keep the driver open.
77  *
78  * @param[in] The AVCodecContext instantiated by the encoder/decoder.
79  *
80  * @returns 0
81  *
82  */
84 
85 /**
86  * Reinitializes the V4L2m2mContext when the driver cant continue processing
87  * with the capture parameters.
88  *
89  * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder.
90  *
91  * @returns 0 in case of success, negative number otherwise
92  */
94 
95 /**
96  * Reinitializes the V4L2m2mContext when the driver cant continue processing
97  * with the any of the current V4L2Contexts (ie, changes in output and capture).
98  *
99  * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder.
100  *
101  * @returns 0 in case of success, negative number otherwise
102  */
104 
105 #endif /* AVCODEC_V4L2_M2M_H */
AVCodecContext * avctx
Definition: v4l2_m2m.h:57
#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:314
char devname[PATH_MAX]
Definition: v4l2_m2m.h:46
AVFormatContext * ctx
Definition: movenc.c:48
V4L2Context capture
Definition: v4l2_m2m.h:50
Libavcodec external API header.
atomic_uint refcount
Definition: v4l2_m2m.h:54
main external API structure.
Definition: avcodec.h:1761
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:51
int ff_v4l2_m2m_codec_init(AVCodecContext *avctx)
Probes the video nodes looking for the required codec capabilities.
Definition: v4l2_m2m.c:344
int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *ctx)
Reinitializes the V4L2m2mContext when the driver cant continue processing with the any of the current...
Definition: v4l2_m2m.c:233
sem_t refsync
Definition: v4l2_m2m.h:58
int ff_v4l2_m2m_codec_reinit(V4L2m2mContext *ctx)
Reinitializes the V4L2m2mContext when the driver cant continue processing with the capture parameters...
Definition: v4l2_m2m.c:189