2 * V4L2 buffer helper functions.
4 * Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org>
5 * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
7 * This file is part of FFmpeg.
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.
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.
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
24 #ifndef AVCODEC_V4L2_BUFFERS_H
25 #define AVCODEC_V4L2_BUFFERS_H
27 #include <stdatomic.h>
28 #include <linux/videodev2.h>
32 enum V4L2Buffer_status {
39 * V4L2Buffer (wrapper for v4l2_buffer management)
41 typedef struct V4L2Buffer {
42 /* each buffer needs to have a reference to its context */
43 struct V4L2Context *context;
45 /* This object is refcounted per-plane, so we need to keep track
46 * of how many context-refs we are holding. */
47 AVBufferRef *context_ref;
48 atomic_uint context_refcount;
50 /* keep track of the mmap address and mmap length */
51 struct V4L2Plane_info {
55 } plane_info[VIDEO_MAX_PLANES];
59 /* the v4l2_buffer buf.m.planes pointer uses the planes[] mem */
60 struct v4l2_buffer buf;
61 struct v4l2_plane planes[VIDEO_MAX_PLANES];
64 enum V4L2Buffer_status status;
69 * Extracts the data from a V4L2Buffer to an AVFrame
71 * @param[in] frame The AVFRame to push the information to
72 * @param[in] buf The V4L2Buffer to get the information from
74 * @returns 0 in case of success, AVERROR(EINVAL) if the number of planes is incorrect,
75 * AVERROR(ENOMEM) if the AVBufferRef can't be created.
77 int ff_v4l2_buffer_buf_to_avframe(AVFrame *frame, V4L2Buffer *buf);
80 * Extracts the data from a V4L2Buffer to an AVPacket
82 * @param[in] pkt The AVPacket to push the information to
83 * @param[in] buf The V4L2Buffer to get the information from
85 * @returns 0 in case of success, AVERROR(EINVAL) if the number of planes is incorrect,
86 * AVERROR(ENOMEM) if the AVBufferRef can't be created.
89 int ff_v4l2_buffer_buf_to_avpkt(AVPacket *pkt, V4L2Buffer *buf);
92 * Extracts the data from an AVPacket to a V4L2Buffer
94 * @param[in] frame AVPacket to get the data from
95 * @param[in] avbuf V4L2Bfuffer to push the information to
97 * @returns 0 in case of success, a negative AVERROR code otherwise
99 int ff_v4l2_buffer_avpkt_to_buf(const AVPacket *pkt, V4L2Buffer *out);
102 * Extracts the data from an AVFrame to a V4L2Buffer
104 * @param[in] frame AVFrame to get the data from
105 * @param[in] avbuf V4L2Bfuffer to push the information to
107 * @returns 0 in case of success, a negative AVERROR code otherwise
109 int ff_v4l2_buffer_avframe_to_buf(const AVFrame *frame, V4L2Buffer *out);
112 * Initializes a V4L2Buffer
114 * @param[in] avbuf V4L2Bfuffer to initialize
115 * @param[in] index v4l2 buffer id
117 * @returns 0 in case of success, a negative AVERROR code otherwise
119 int ff_v4l2_buffer_initialize(V4L2Buffer* avbuf, int index);
122 * Enqueues a V4L2Buffer
124 * @param[in] avbuf V4L2Bfuffer to push to the driver
126 * @returns 0 in case of success, a negative AVERROR code otherwise
128 int ff_v4l2_buffer_enqueue(V4L2Buffer* avbuf);
131 #endif // AVCODEC_V4L2_BUFFERS_H