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 43typedef struct V4L2m2mContext { 44 char devname[PATH_MAX]; 45 int fd; 46 47 /* the codec context queues */ 48 V4L2Context capture; 49 V4L2Context output; 50 51 /* dynamic stream reconfig */ 52 AVCodecContext *avctx; 53 sem_t refsync; 54 atomic_uint refcount; 55 int reinit; 56 57 /* null frame/packet received */ 58 int draining; 59 AVPacket buf_pkt; 60 61 /* Reference to a frame. Only used during encoding */ 62 AVFrame *frame; 63 64 /* Reference to self; only valid while codec is active. */ 65 AVBufferRef *self_ref; 66 67 /* reference back to V4L2m2mPriv */ 68 void *priv; 69} V4L2m2mContext; 70 71typedef struct V4L2m2mPriv { 72 AVClass *class; 73 74 V4L2m2mContext *context; 75 AVBufferRef *context_ref; 76 77 int num_output_buffers; 78 int num_capture_buffers; 79} V4L2m2mPriv; 80 81/** 82 * Allocate a new context and references for a V4L2 M2M instance. 83 * 84 * @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder. 85 * @param[out] ctx The V4L2m2mContext. 86 * 87 * @returns 0 in success, a negative error code otherwise. 88 */ 89int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, V4L2m2mContext **s); 90 91 92/** 93 * Probes the video nodes looking for the required codec capabilities. 94 * 95 * @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder. 96 * 97 * @returns 0 if a driver is found, a negative number otherwise. 98 */ 99int ff_v4l2_m2m_codec_init(V4L2m2mPriv *priv); 100 101/** 102 * Releases all the codec resources if all AVBufferRefs have been returned to the 103 * ctx. Otherwise keep the driver open. 104 * 105 * @param[in] The V4L2m2mPriv instantiated by the encoder/decoder. 106 * 107 * @returns 0 108 * 109 */ 110int ff_v4l2_m2m_codec_end(V4L2m2mPriv *priv); 111 112/** 113 * Reinitializes the V4L2m2mContext when the driver cannot continue processing 114 * with the capture parameters. 115 * 116 * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder. 117 * 118 * @returns 0 in case of success, negative number otherwise 119 */ 120int ff_v4l2_m2m_codec_reinit(V4L2m2mContext *ctx); 121 122/** 123 * Reinitializes the V4L2m2mContext when the driver cannot continue processing 124 * with the any of the current V4L2Contexts (ie, changes in output and capture). 125 * 126 * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder. 127 * 128 * @returns 0 in case of success, negative number otherwise 129 */ 130int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *ctx); 131 132#endif /* AVCODEC_V4L2_M2M_H */ 133