1/* 2 * Copyright (c) 2011 Stefano Sabatini 3 * Copyright (c) 2009 Giliard B. de Freitas <giliarde@gmail.com> 4 * Copyright (C) 2002 Gunnar Monell <gmo@linux.nu> 5 * 6 * This file is part of Libav. 7 * 8 * Libav is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * Libav is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with Libav; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23/** 24 * @file 25 * Linux framebuffer input device, 26 * inspired by code from fbgrab.c by Gunnar Monell. 27 * @see http://linux-fbdev.sourceforge.net/ 28 */ 29 30/* #define DEBUG */ 31 32#include <unistd.h> 33#include <fcntl.h> 34#include <sys/ioctl.h> 35#include <sys/time.h> 36#include <sys/mman.h> 37#include <time.h> 38#include <linux/fb.h> 39 40#include "libavutil/log.h" 41#include "libavutil/mem.h" 42#include "libavutil/opt.h" 43#include "libavutil/parseutils.h" 44#include "libavutil/pixdesc.h" 45#include "libavformat/avformat.h" 46#include "libavformat/internal.h" 47 48struct rgb_pixfmt_map_entry { 49 int bits_per_pixel; 50 int red_offset, green_offset, blue_offset, alpha_offset; 51 enum PixelFormat pixfmt; 52}; 53 54static struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = { 55 // bpp, red_offset, green_offset, blue_offset, alpha_offset, pixfmt 56 { 32, 0, 8, 16, 24, PIX_FMT_RGBA }, 57 { 32, 16, 8, 0, 24, PIX_FMT_BGRA }, 58 { 32, 8, 16, 24, 0, PIX_FMT_ARGB }, 59 { 32, 3, 2, 8, 0, PIX_FMT_ABGR }, 60 { 24, 0, 8, 16, 0, PIX_FMT_RGB24 }, 61 { 24, 16, 8, 0, 0, PIX_FMT_BGR24 }, 62}; 63 64static enum PixelFormat get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo) 65{ 66 int i; 67 68 for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) { 69 struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i]; 70 if (entry->bits_per_pixel == varinfo->bits_per_pixel && 71 entry->red_offset == varinfo->red.offset && 72 entry->green_offset == varinfo->green.offset && 73 entry->blue_offset == varinfo->blue.offset) 74 return entry->pixfmt; 75 } 76 77 return PIX_FMT_NONE; 78} 79 80typedef struct { 81 AVClass *class; ///< class for private options 82 int frame_size; ///< size in bytes of a grabbed frame 83 AVRational framerate_q; ///< framerate 84 char *framerate; ///< framerate string set by a private option 85 int64_t time_frame; ///< time for the next frame to output (in 1/1000000 units) 86 87 int fd; ///< framebuffer device file descriptor 88 int width, height; ///< assumed frame resolution 89 int frame_linesize; ///< linesize of the output frame, it is assumed to be constant 90 int bytes_per_pixel; 91 92 struct fb_var_screeninfo varinfo; ///< variable info; 93 struct fb_fix_screeninfo fixinfo; ///< fixed info; 94 95 uint8_t *data; ///< framebuffer data 96} FBDevContext; 97 98av_cold static int fbdev_read_header(AVFormatContext *avctx, 99 AVFormatParameters *ap) 100{ 101 FBDevContext *fbdev = avctx->priv_data; 102 AVStream *st = NULL; 103 enum PixelFormat pix_fmt; 104 int ret, flags = O_RDONLY; 105 106 ret = av_parse_video_rate(&fbdev->framerate_q, fbdev->framerate); 107 if (ret < 0) { 108 av_log(avctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", fbdev->framerate); 109 return ret; 110 } 111 112 if (!(st = avformat_new_stream(avctx, NULL))) 113 return AVERROR(ENOMEM); 114 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */ 115 116 /* NONBLOCK is ignored by the fbdev driver, only set for consistency */ 117 if (avctx->flags & AVFMT_FLAG_NONBLOCK) 118 flags |= O_NONBLOCK; 119 120 if ((fbdev->fd = open(avctx->filename, flags)) == -1) { 121 ret = AVERROR(errno); 122 av_log(avctx, AV_LOG_ERROR, 123 "Could not open framebuffer device '%s': %s\n", 124 avctx->filename, strerror(ret)); 125 return ret; 126 } 127 128 if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) { 129 ret = AVERROR(errno); 130 av_log(avctx, AV_LOG_ERROR, 131 "FBIOGET_VSCREENINFO: %s\n", strerror(errno)); 132 goto fail; 133 } 134 135 if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) { 136 ret = AVERROR(errno); 137 av_log(avctx, AV_LOG_ERROR, 138 "FBIOGET_FSCREENINFO: %s\n", strerror(errno)); 139 goto fail; 140 } 141 142 pix_fmt = get_pixfmt_from_fb_varinfo(&fbdev->varinfo); 143 if (pix_fmt == PIX_FMT_NONE) { 144 ret = AVERROR(EINVAL); 145 av_log(avctx, AV_LOG_ERROR, 146 "Framebuffer pixel format not supported.\n"); 147 goto fail; 148 } 149 150 fbdev->width = fbdev->varinfo.xres; 151 fbdev->height = fbdev->varinfo.yres; 152 fbdev->bytes_per_pixel = (fbdev->varinfo.bits_per_pixel + 7) >> 3; 153 fbdev->frame_linesize = fbdev->width * fbdev->bytes_per_pixel; 154 fbdev->frame_size = fbdev->frame_linesize * fbdev->height; 155 fbdev->time_frame = AV_NOPTS_VALUE; 156 fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_READ, MAP_SHARED, fbdev->fd, 0); 157 if (fbdev->data == MAP_FAILED) { 158 ret = AVERROR(errno); 159 av_log(avctx, AV_LOG_ERROR, "Error in mmap(): %s\n", strerror(errno)); 160 goto fail; 161 } 162 163 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 164 st->codec->codec_id = CODEC_ID_RAWVIDEO; 165 st->codec->width = fbdev->width; 166 st->codec->height = fbdev->height; 167 st->codec->pix_fmt = pix_fmt; 168 st->codec->time_base = (AVRational){fbdev->framerate_q.den, fbdev->framerate_q.num}; 169 st->codec->bit_rate = 170 fbdev->width * fbdev->height * fbdev->bytes_per_pixel * av_q2d(fbdev->framerate_q) * 8; 171 172 av_log(avctx, AV_LOG_INFO, 173 "w:%d h:%d bpp:%d pixfmt:%s fps:%d/%d bit_rate:%d\n", 174 fbdev->width, fbdev->height, fbdev->varinfo.bits_per_pixel, 175 av_pix_fmt_descriptors[pix_fmt].name, 176 fbdev->framerate_q.num, fbdev->framerate_q.den, 177 st->codec->bit_rate); 178 return 0; 179 180fail: 181 close(fbdev->fd); 182 return ret; 183} 184 185static int fbdev_read_packet(AVFormatContext *avctx, AVPacket *pkt) 186{ 187 FBDevContext *fbdev = avctx->priv_data; 188 int64_t curtime, delay; 189 struct timespec ts; 190 int i, ret; 191 uint8_t *pin, *pout; 192 193 if (fbdev->time_frame == AV_NOPTS_VALUE) 194 fbdev->time_frame = av_gettime(); 195 196 /* wait based on the frame rate */ 197 curtime = av_gettime(); 198 delay = fbdev->time_frame - curtime; 199 av_dlog(avctx, 200 "time_frame:%"PRId64" curtime:%"PRId64" delay:%"PRId64"\n", 201 fbdev->time_frame, curtime, delay); 202 if (delay > 0) { 203 if (avctx->flags & AVFMT_FLAG_NONBLOCK) 204 return AVERROR(EAGAIN); 205 ts.tv_sec = delay / 1000000; 206 ts.tv_nsec = (delay % 1000000) * 1000; 207 while (nanosleep(&ts, &ts) < 0 && errno == EINTR); 208 } 209 /* compute the time of the next frame */ 210 fbdev->time_frame += INT64_C(1000000) / av_q2d(fbdev->framerate_q); 211 212 if ((ret = av_new_packet(pkt, fbdev->frame_size)) < 0) 213 return ret; 214 215 /* refresh fbdev->varinfo, visible data position may change at each call */ 216 if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) 217 av_log(avctx, AV_LOG_WARNING, 218 "Error refreshing variable info: %s\n", strerror(errno)); 219 220 pkt->pts = curtime; 221 222 /* compute visible data offset */ 223 pin = fbdev->data + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset + 224 fbdev->varinfo.yoffset * fbdev->fixinfo.line_length; 225 pout = pkt->data; 226 227 // TODO it'd be nice if the lines were aligned 228 for (i = 0; i < fbdev->height; i++) { 229 memcpy(pout, pin, fbdev->frame_linesize); 230 pin += fbdev->fixinfo.line_length; 231 pout += fbdev->frame_linesize; 232 } 233 234 return fbdev->frame_size; 235} 236 237av_cold static int fbdev_read_close(AVFormatContext *avctx) 238{ 239 FBDevContext *fbdev = avctx->priv_data; 240 241 munmap(fbdev->data, fbdev->frame_size); 242 close(fbdev->fd); 243 244 return 0; 245} 246 247#define OFFSET(x) offsetof(FBDevContext, x) 248#define DEC AV_OPT_FLAG_DECODING_PARAM 249static const AVOption options[] = { 250 { "framerate","", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC }, 251 { NULL }, 252}; 253 254static const AVClass fbdev_class = { 255 .class_name = "fbdev indev", 256 .item_name = av_default_item_name, 257 .option = options, 258 .version = LIBAVUTIL_VERSION_INT, 259}; 260 261AVInputFormat ff_fbdev_demuxer = { 262 .name = "fbdev", 263 .long_name = NULL_IF_CONFIG_SMALL("Linux framebuffer"), 264 .priv_data_size = sizeof(FBDevContext), 265 .read_header = fbdev_read_header, 266 .read_packet = fbdev_read_packet, 267 .read_close = fbdev_read_close, 268 .flags = AVFMT_NOFILE, 269 .priv_class = &fbdev_class, 270}; 271