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 FFmpeg.
7 *
8 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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#include <unistd.h>
31#include <fcntl.h>
32#include <sys/ioctl.h>
33#include <sys/mman.h>
34#include <time.h>
35#include <linux/fb.h>
36
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/internal.h"
45#include "avdevice.h"
46#include "fbdev_common.h"
47
48typedef struct {
49    AVClass *class;          ///< class for private options
50    int frame_size;          ///< size in bytes of a grabbed frame
51    AVRational framerate_q;  ///< framerate
52    int64_t time_frame;      ///< time for the next frame to output (in 1/1000000 units)
53
54    int fd;                  ///< framebuffer device file descriptor
55    int width, height;       ///< assumed frame resolution
56    int frame_linesize;      ///< linesize of the output frame, it is assumed to be constant
57    int bytes_per_pixel;
58
59    struct fb_var_screeninfo varinfo; ///< variable info;
60    struct fb_fix_screeninfo fixinfo; ///< fixed    info;
61
62    uint8_t *data;           ///< framebuffer data
63} FBDevContext;
64
65static av_cold int fbdev_read_header(AVFormatContext *avctx)
66{
67    FBDevContext *fbdev = avctx->priv_data;
68    AVStream *st = NULL;
69    enum AVPixelFormat pix_fmt;
70    int ret, flags = O_RDONLY;
71
72    if (!(st = avformat_new_stream(avctx, NULL)))
73        return AVERROR(ENOMEM);
74    avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */
75
76    /* NONBLOCK is ignored by the fbdev driver, only set for consistency */
77    if (avctx->flags & AVFMT_FLAG_NONBLOCK)
78        flags |= O_NONBLOCK;
79
80    if ((fbdev->fd = avpriv_open(avctx->filename, flags)) == -1) {
81        ret = AVERROR(errno);
82        av_log(avctx, AV_LOG_ERROR,
83               "Could not open framebuffer device '%s': %s\n",
84               avctx->filename, av_err2str(ret));
85        return ret;
86    }
87
88    if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
89        ret = AVERROR(errno);
90        av_log(avctx, AV_LOG_ERROR,
91               "FBIOGET_VSCREENINFO: %s\n", av_err2str(ret));
92        goto fail;
93    }
94
95    if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
96        ret = AVERROR(errno);
97        av_log(avctx, AV_LOG_ERROR,
98               "FBIOGET_FSCREENINFO: %s\n", av_err2str(ret));
99        goto fail;
100    }
101
102    pix_fmt = ff_get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
103    if (pix_fmt == AV_PIX_FMT_NONE) {
104        ret = AVERROR(EINVAL);
105        av_log(avctx, AV_LOG_ERROR,
106               "Framebuffer pixel format not supported.\n");
107        goto fail;
108    }
109
110    fbdev->width           = fbdev->varinfo.xres;
111    fbdev->height          = fbdev->varinfo.yres;
112    fbdev->bytes_per_pixel = (fbdev->varinfo.bits_per_pixel + 7) >> 3;
113    fbdev->frame_linesize  = fbdev->width * fbdev->bytes_per_pixel;
114    fbdev->frame_size      = fbdev->frame_linesize * fbdev->height;
115    fbdev->time_frame      = AV_NOPTS_VALUE;
116    fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_READ, MAP_SHARED, fbdev->fd, 0);
117    if (fbdev->data == MAP_FAILED) {
118        ret = AVERROR(errno);
119        av_log(avctx, AV_LOG_ERROR, "Error in mmap(): %s\n", av_err2str(ret));
120        goto fail;
121    }
122
123    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
124    st->codec->codec_id   = AV_CODEC_ID_RAWVIDEO;
125    st->codec->width      = fbdev->width;
126    st->codec->height     = fbdev->height;
127    st->codec->pix_fmt    = pix_fmt;
128    st->codec->time_base  = av_inv_q(fbdev->framerate_q);
129    st->codec->bit_rate   =
130        fbdev->width * fbdev->height * fbdev->bytes_per_pixel * av_q2d(fbdev->framerate_q) * 8;
131
132    av_log(avctx, AV_LOG_INFO,
133           "w:%d h:%d bpp:%d pixfmt:%s fps:%d/%d bit_rate:%d\n",
134           fbdev->width, fbdev->height, fbdev->varinfo.bits_per_pixel,
135           av_get_pix_fmt_name(pix_fmt),
136           fbdev->framerate_q.num, fbdev->framerate_q.den,
137           st->codec->bit_rate);
138    return 0;
139
140fail:
141    close(fbdev->fd);
142    return ret;
143}
144
145static int fbdev_read_packet(AVFormatContext *avctx, AVPacket *pkt)
146{
147    FBDevContext *fbdev = avctx->priv_data;
148    int64_t curtime, delay;
149    struct timespec ts;
150    int i, ret;
151    uint8_t *pin, *pout;
152
153    if (fbdev->time_frame == AV_NOPTS_VALUE)
154        fbdev->time_frame = av_gettime();
155
156    /* wait based on the frame rate */
157    while (1) {
158        curtime = av_gettime();
159        delay = fbdev->time_frame - curtime;
160        av_dlog(avctx,
161                "time_frame:%"PRId64" curtime:%"PRId64" delay:%"PRId64"\n",
162                fbdev->time_frame, curtime, delay);
163        if (delay <= 0) {
164            fbdev->time_frame += INT64_C(1000000) / av_q2d(fbdev->framerate_q);
165            break;
166        }
167        if (avctx->flags & AVFMT_FLAG_NONBLOCK)
168            return AVERROR(EAGAIN);
169        ts.tv_sec  =  delay / 1000000;
170        ts.tv_nsec = (delay % 1000000) * 1000;
171        while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
172    }
173
174    if ((ret = av_new_packet(pkt, fbdev->frame_size)) < 0)
175        return ret;
176
177    /* refresh fbdev->varinfo, visible data position may change at each call */
178    if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0)
179        av_log(avctx, AV_LOG_WARNING,
180               "Error refreshing variable info: %s\n", av_err2str(ret));
181
182    pkt->pts = curtime;
183
184    /* compute visible data offset */
185    pin = fbdev->data + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset +
186                        fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
187    pout = pkt->data;
188
189    for (i = 0; i < fbdev->height; i++) {
190        memcpy(pout, pin, fbdev->frame_linesize);
191        pin  += fbdev->fixinfo.line_length;
192        pout += fbdev->frame_linesize;
193    }
194
195    return fbdev->frame_size;
196}
197
198static av_cold int fbdev_read_close(AVFormatContext *avctx)
199{
200    FBDevContext *fbdev = avctx->priv_data;
201
202    munmap(fbdev->data, fbdev->fixinfo.smem_len);
203    close(fbdev->fd);
204
205    return 0;
206}
207
208static int fbdev_get_device_list(AVFormatContext *s, AVDeviceInfoList *device_list)
209{
210    return ff_fbdev_get_device_list(device_list);
211}
212
213#define OFFSET(x) offsetof(FBDevContext, x)
214#define DEC AV_OPT_FLAG_DECODING_PARAM
215static const AVOption options[] = {
216    { "framerate","", OFFSET(framerate_q), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, DEC },
217    { NULL },
218};
219
220static const AVClass fbdev_class = {
221    .class_name = "fbdev indev",
222    .item_name  = av_default_item_name,
223    .option     = options,
224    .version    = LIBAVUTIL_VERSION_INT,
225    .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
226};
227
228AVInputFormat ff_fbdev_demuxer = {
229    .name           = "fbdev",
230    .long_name      = NULL_IF_CONFIG_SMALL("Linux framebuffer"),
231    .priv_data_size = sizeof(FBDevContext),
232    .read_header    = fbdev_read_header,
233    .read_packet    = fbdev_read_packet,
234    .read_close     = fbdev_read_close,
235    .get_device_list = fbdev_get_device_list,
236    .flags          = AVFMT_NOFILE,
237    .priv_class     = &fbdev_class,
238};
239