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>
6 * This file is part of Libav.
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.
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.
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
25 * Linux framebuffer input device,
26 * inspired by code from fbgrab.c by Gunnar Monell.
27 * @see http://linux-fbdev.sourceforge.net/
32 #include <sys/ioctl.h>
37 #include "libavutil/internal.h"
38 #include "libavutil/log.h"
39 #include "libavutil/mem.h"
40 #include "libavutil/opt.h"
41 #include "libavutil/time.h"
42 #include "libavutil/parseutils.h"
43 #include "libavutil/pixdesc.h"
44 #include "libavformat/avformat.h"
45 #include "libavformat/internal.h"
47 struct rgb_pixfmt_map_entry {
49 int red_offset, green_offset, blue_offset, alpha_offset;
50 enum AVPixelFormat pixfmt;
53 static struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = {
54 // bpp, red_offset, green_offset, blue_offset, alpha_offset, pixfmt
55 { 32, 0, 8, 16, 24, AV_PIX_FMT_RGBA },
56 { 32, 16, 8, 0, 24, AV_PIX_FMT_BGRA },
57 { 32, 8, 16, 24, 0, AV_PIX_FMT_ARGB },
58 { 32, 3, 2, 8, 0, AV_PIX_FMT_ABGR },
59 { 24, 0, 8, 16, 0, AV_PIX_FMT_RGB24 },
60 { 24, 16, 8, 0, 0, AV_PIX_FMT_BGR24 },
63 static enum AVPixelFormat get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
67 for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {
68 struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i];
69 if (entry->bits_per_pixel == varinfo->bits_per_pixel &&
70 entry->red_offset == varinfo->red.offset &&
71 entry->green_offset == varinfo->green.offset &&
72 entry->blue_offset == varinfo->blue.offset)
76 return AV_PIX_FMT_NONE;
79 typedef struct FBDevContext {
80 AVClass *class; ///< class for private options
81 int frame_size; ///< size in bytes of a grabbed frame
82 AVRational framerate_q; ///< framerate
83 char *framerate; ///< framerate string set by a private option
84 int64_t time_frame; ///< time for the next frame to output (in 1/1000000 units)
86 int fd; ///< framebuffer device file descriptor
87 int width, height; ///< assumed frame resolution
88 int frame_linesize; ///< linesize of the output frame, it is assumed to be constant
91 struct fb_var_screeninfo varinfo; ///< variable info;
92 struct fb_fix_screeninfo fixinfo; ///< fixed info;
94 uint8_t *data; ///< framebuffer data
97 static av_cold int fbdev_read_header(AVFormatContext *avctx)
99 FBDevContext *fbdev = avctx->priv_data;
101 enum AVPixelFormat pix_fmt;
102 int ret, flags = O_RDONLY;
105 ret = av_parse_video_rate(&fbdev->framerate_q, fbdev->framerate);
107 av_log(avctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", fbdev->framerate);
111 if (!(st = avformat_new_stream(avctx, NULL)))
112 return AVERROR(ENOMEM);
113 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */
115 /* NONBLOCK is ignored by the fbdev driver, only set for consistency */
116 if (avctx->flags & AVFMT_FLAG_NONBLOCK)
119 if ((fbdev->fd = avpriv_open(avctx->filename, flags)) == -1) {
120 ret = AVERROR(errno);
121 av_strerror(ret, errbuf, sizeof(errbuf));
122 av_log(avctx, AV_LOG_ERROR,
123 "Could not open framebuffer device '%s': %s\n",
124 avctx->filename, errbuf);
128 if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
129 ret = AVERROR(errno);
130 av_strerror(ret, errbuf, sizeof(errbuf));
131 av_log(avctx, AV_LOG_ERROR,
132 "FBIOGET_VSCREENINFO: %s\n", errbuf);
136 if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
137 ret = AVERROR(errno);
138 av_strerror(ret, errbuf, sizeof(errbuf));
139 av_log(avctx, AV_LOG_ERROR,
140 "FBIOGET_FSCREENINFO: %s\n", errbuf);
144 pix_fmt = get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
145 if (pix_fmt == AV_PIX_FMT_NONE) {
146 ret = AVERROR(EINVAL);
147 av_log(avctx, AV_LOG_ERROR,
148 "Framebuffer pixel format not supported.\n");
152 fbdev->width = fbdev->varinfo.xres;
153 fbdev->height = fbdev->varinfo.yres;
154 fbdev->bytes_per_pixel = (fbdev->varinfo.bits_per_pixel + 7) >> 3;
155 fbdev->frame_linesize = fbdev->width * fbdev->bytes_per_pixel;
156 fbdev->frame_size = fbdev->frame_linesize * fbdev->height;
157 fbdev->time_frame = AV_NOPTS_VALUE;
158 fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_READ, MAP_SHARED, fbdev->fd, 0);
159 if (fbdev->data == MAP_FAILED) {
160 ret = AVERROR(errno);
161 av_strerror(ret, errbuf, sizeof(errbuf));
162 av_log(avctx, AV_LOG_ERROR, "Error in mmap(): %s\n", errbuf);
166 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
167 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
168 st->codec->width = fbdev->width;
169 st->codec->height = fbdev->height;
170 st->codec->pix_fmt = pix_fmt;
171 st->codec->time_base = (AVRational){fbdev->framerate_q.den, fbdev->framerate_q.num};
172 st->codec->bit_rate =
173 fbdev->width * fbdev->height * fbdev->bytes_per_pixel * av_q2d(fbdev->framerate_q) * 8;
175 av_log(avctx, AV_LOG_INFO,
176 "w:%d h:%d bpp:%d pixfmt:%s fps:%d/%d bit_rate:%d\n",
177 fbdev->width, fbdev->height, fbdev->varinfo.bits_per_pixel,
178 av_get_pix_fmt_name(pix_fmt),
179 fbdev->framerate_q.num, fbdev->framerate_q.den,
180 st->codec->bit_rate);
188 static int fbdev_read_packet(AVFormatContext *avctx, AVPacket *pkt)
190 FBDevContext *fbdev = avctx->priv_data;
191 int64_t curtime, delay;
196 if (fbdev->time_frame == AV_NOPTS_VALUE)
197 fbdev->time_frame = av_gettime();
199 /* wait based on the frame rate */
200 curtime = av_gettime();
201 delay = fbdev->time_frame - curtime;
203 "time_frame:%"PRId64" curtime:%"PRId64" delay:%"PRId64"\n",
204 fbdev->time_frame, curtime, delay);
206 if (avctx->flags & AVFMT_FLAG_NONBLOCK)
207 return AVERROR(EAGAIN);
208 ts.tv_sec = delay / 1000000;
209 ts.tv_nsec = (delay % 1000000) * 1000;
210 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
212 /* compute the time of the next frame */
213 fbdev->time_frame += INT64_C(1000000) / av_q2d(fbdev->framerate_q);
215 if ((ret = av_new_packet(pkt, fbdev->frame_size)) < 0)
218 /* refresh fbdev->varinfo, visible data position may change at each call */
219 if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
221 av_strerror(AVERROR(errno), errbuf, sizeof(errbuf));
222 av_log(avctx, AV_LOG_WARNING,
223 "Error refreshing variable info: %s\n", errbuf);
228 /* compute visible data offset */
229 pin = fbdev->data + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset +
230 fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
233 // TODO it'd be nice if the lines were aligned
234 for (i = 0; i < fbdev->height; i++) {
235 memcpy(pout, pin, fbdev->frame_linesize);
236 pin += fbdev->fixinfo.line_length;
237 pout += fbdev->frame_linesize;
240 return fbdev->frame_size;
243 static av_cold int fbdev_read_close(AVFormatContext *avctx)
245 FBDevContext *fbdev = avctx->priv_data;
247 munmap(fbdev->data, fbdev->frame_size);
253 #define OFFSET(x) offsetof(FBDevContext, x)
254 #define DEC AV_OPT_FLAG_DECODING_PARAM
255 static const AVOption options[] = {
256 { "framerate","", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC },
260 static const AVClass fbdev_class = {
261 .class_name = "fbdev indev",
262 .item_name = av_default_item_name,
264 .version = LIBAVUTIL_VERSION_INT,
267 AVInputFormat ff_fbdev_demuxer = {
269 .long_name = NULL_IF_CONFIG_SMALL("Linux framebuffer"),
270 .priv_data_size = sizeof(FBDevContext),
271 .read_header = fbdev_read_header,
272 .read_packet = fbdev_read_packet,
273 .read_close = fbdev_read_close,
274 .flags = AVFMT_NOFILE,
275 .priv_class = &fbdev_class,