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 */ 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 self; only valid while codec is active. */ 62 AVBufferRef *self_ref; 63 64 /* reference back to V4L2m2mPriv */ 65 void *priv; 66 } V4L2m2mContext; 67 68 typedef struct V4L2m2mPriv { 69 AVClass *class; 70 71 V4L2m2mContext *context; 72 AVBufferRef *context_ref; 73 74 int num_output_buffers; 75 int num_capture_buffers; 76 } V4L2m2mPriv; 77 78 /** 79 * Allocate a new context and references for a V4L2 M2M instance. 80 * 81 * @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder. 82 * @param[out] ctx The V4L2m2mContext. 83 * 84 * @returns 0 in success, a negative error code otherwise. 85 */ 86 int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, V4L2m2mContext **s); 87 88 89 /** 90 * Probes the video nodes looking for the required codec capabilities. 91 * 92 * @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder. 93 * 94 * @returns 0 if a driver is found, a negative number otherwise. 95 */ 96 int ff_v4l2_m2m_codec_init(V4L2m2mPriv *priv); 97 98 /** 99 * Releases all the codec resources if all AVBufferRefs have been returned to the 100 * ctx. Otherwise keep the driver open. 101 * 102 * @param[in] The V4L2m2mPriv instantiated by the encoder/decoder. 103 * 104 * @returns 0 105 * 106 */ 107 int ff_v4l2_m2m_codec_end(V4L2m2mPriv *priv); 108 109 /** 110 * Reinitializes the V4L2m2mContext when the driver cannot continue processing 111 * with the capture parameters. 112 * 113 * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder. 114 * 115 * @returns 0 in case of success, negative number otherwise 116 */ 117 int ff_v4l2_m2m_codec_reinit(V4L2m2mContext *ctx); 118 119 /** 120 * Reinitializes the V4L2m2mContext when the driver cannot continue processing 121 * with the any of the current V4L2Contexts (ie, changes in output and capture). 122 * 123 * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder. 124 * 125 * @returns 0 in case of success, negative number otherwise 126 */ 127 int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *ctx); 128 129 #endif /* AVCODEC_V4L2_M2M_H */ 130