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/
34 #include <sys/ioctl.h>
39 #include "libavutil/log.h"
40 #include "libavutil/mem.h"
41 #include "libavutil/opt.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 PixelFormat 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, PIX_FMT_RGBA },
56 { 32, 16, 8, 0, 24, PIX_FMT_BGRA },
57 { 32, 8, 16, 24, 0, PIX_FMT_ARGB },
58 { 32, 3, 2, 8, 0, PIX_FMT_ABGR },
59 { 24, 0, 8, 16, 0, PIX_FMT_RGB24 },
60 { 24, 16, 8, 0, 0, PIX_FMT_BGR24 },
63 static enum PixelFormat 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)
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 PixelFormat pix_fmt;
102 int ret, flags = O_RDONLY;
104 ret = av_parse_video_rate(&fbdev->framerate_q, fbdev->framerate);
106 av_log(avctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", fbdev->framerate);
110 if (!(st = avformat_new_stream(avctx, NULL)))
111 return AVERROR(ENOMEM);
112 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */
114 /* NONBLOCK is ignored by the fbdev driver, only set for consistency */
115 if (avctx->flags & AVFMT_FLAG_NONBLOCK)
118 if ((fbdev->fd = open(avctx->filename, flags)) == -1) {
119 ret = AVERROR(errno);
120 av_log(avctx, AV_LOG_ERROR,
121 "Could not open framebuffer device '%s': %s\n",
122 avctx->filename, strerror(ret));
126 if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
127 ret = AVERROR(errno);
128 av_log(avctx, AV_LOG_ERROR,
129 "FBIOGET_VSCREENINFO: %s\n", strerror(errno));
133 if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
134 ret = AVERROR(errno);
135 av_log(avctx, AV_LOG_ERROR,
136 "FBIOGET_FSCREENINFO: %s\n", strerror(errno));
140 pix_fmt = get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
141 if (pix_fmt == PIX_FMT_NONE) {
142 ret = AVERROR(EINVAL);
143 av_log(avctx, AV_LOG_ERROR,
144 "Framebuffer pixel format not supported.\n");
148 fbdev->width = fbdev->varinfo.xres;
149 fbdev->height = fbdev->varinfo.yres;
150 fbdev->bytes_per_pixel = (fbdev->varinfo.bits_per_pixel + 7) >> 3;
151 fbdev->frame_linesize = fbdev->width * fbdev->bytes_per_pixel;
152 fbdev->frame_size = fbdev->frame_linesize * fbdev->height;
153 fbdev->time_frame = AV_NOPTS_VALUE;
154 fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_READ, MAP_SHARED, fbdev->fd, 0);
155 if (fbdev->data == MAP_FAILED) {
156 ret = AVERROR(errno);
157 av_log(avctx, AV_LOG_ERROR, "Error in mmap(): %s\n", strerror(errno));
161 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
162 st->codec->codec_id = CODEC_ID_RAWVIDEO;
163 st->codec->width = fbdev->width;
164 st->codec->height = fbdev->height;
165 st->codec->pix_fmt = pix_fmt;
166 st->codec->time_base = (AVRational){fbdev->framerate_q.den, fbdev->framerate_q.num};
167 st->codec->bit_rate =
168 fbdev->width * fbdev->height * fbdev->bytes_per_pixel * av_q2d(fbdev->framerate_q) * 8;
170 av_log(avctx, AV_LOG_INFO,
171 "w:%d h:%d bpp:%d pixfmt:%s fps:%d/%d bit_rate:%d\n",
172 fbdev->width, fbdev->height, fbdev->varinfo.bits_per_pixel,
173 av_pix_fmt_descriptors[pix_fmt].name,
174 fbdev->framerate_q.num, fbdev->framerate_q.den,
175 st->codec->bit_rate);
183 static int fbdev_read_packet(AVFormatContext *avctx, AVPacket *pkt)
185 FBDevContext *fbdev = avctx->priv_data;
186 int64_t curtime, delay;
191 if (fbdev->time_frame == AV_NOPTS_VALUE)
192 fbdev->time_frame = av_gettime();
194 /* wait based on the frame rate */
195 curtime = av_gettime();
196 delay = fbdev->time_frame - curtime;
198 "time_frame:%"PRId64" curtime:%"PRId64" delay:%"PRId64"\n",
199 fbdev->time_frame, curtime, delay);
201 if (avctx->flags & AVFMT_FLAG_NONBLOCK)
202 return AVERROR(EAGAIN);
203 ts.tv_sec = delay / 1000000;
204 ts.tv_nsec = (delay % 1000000) * 1000;
205 while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
207 /* compute the time of the next frame */
208 fbdev->time_frame += INT64_C(1000000) / av_q2d(fbdev->framerate_q);
210 if ((ret = av_new_packet(pkt, fbdev->frame_size)) < 0)
213 /* refresh fbdev->varinfo, visible data position may change at each call */
214 if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0)
215 av_log(avctx, AV_LOG_WARNING,
216 "Error refreshing variable info: %s\n", strerror(errno));
220 /* compute visible data offset */
221 pin = fbdev->data + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset +
222 fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
225 // TODO it'd be nice if the lines were aligned
226 for (i = 0; i < fbdev->height; i++) {
227 memcpy(pout, pin, fbdev->frame_linesize);
228 pin += fbdev->fixinfo.line_length;
229 pout += fbdev->frame_linesize;
232 return fbdev->frame_size;
235 static av_cold int fbdev_read_close(AVFormatContext *avctx)
237 FBDevContext *fbdev = avctx->priv_data;
239 munmap(fbdev->data, fbdev->frame_size);
245 #define OFFSET(x) offsetof(FBDevContext, x)
246 #define DEC AV_OPT_FLAG_DECODING_PARAM
247 static const AVOption options[] = {
248 { "framerate","", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC },
252 static const AVClass fbdev_class = {
253 .class_name = "fbdev indev",
254 .item_name = av_default_item_name,
256 .version = LIBAVUTIL_VERSION_INT,
259 AVInputFormat ff_fbdev_demuxer = {
261 .long_name = NULL_IF_CONFIG_SMALL("Linux framebuffer"),
262 .priv_data_size = sizeof(FBDevContext),
263 .read_header = fbdev_read_header,
264 .read_packet = fbdev_read_packet,
265 .read_close = fbdev_read_close,
266 .flags = AVFMT_NOFILE,
267 .priv_class = &fbdev_class,