ffmpeg/libavdevice/fbdev_dec.c

   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
  48 typedef struct FBDevContext {
  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
  65 static 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     const char* device;
  72
  73     if (!(st = avformat_new_stream(avctx, NULL)))
  74         return AVERROR(ENOMEM);
  75     avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */
  76
  77     /* NONBLOCK is ignored by the fbdev driver, only set for consistency */
  78     if (avctx->flags & AVFMT_FLAG_NONBLOCK)
  79         flags |= O_NONBLOCK;
  80
  81     if (avctx->filename[0])
  82         device = avctx->filename;
  83     else
  84         device = ff_fbdev_default_device();
  85
  86     if ((fbdev->fd = avpriv_open(device, flags)) == -1) {
  87         ret = AVERROR(errno);
  88         av_log(avctx, AV_LOG_ERROR,
  89                "Could not open framebuffer device '%s': %s\n",
  90                device, av_err2str(ret));
  91         return ret;
  92     }
  93
  94     if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
  95         ret = AVERROR(errno);
  96         av_log(avctx, AV_LOG_ERROR,
  97                "FBIOGET_VSCREENINFO: %s\n", av_err2str(ret));
  98         goto fail;
  99     }
 100
 101     if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
 102         ret = AVERROR(errno);
 103         av_log(avctx, AV_LOG_ERROR,
 104                "FBIOGET_FSCREENINFO: %s\n", av_err2str(ret));
 105         goto fail;
 106     }
 107
 108     pix_fmt = ff_get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
 109     if (pix_fmt == AV_PIX_FMT_NONE) {
 110         ret = AVERROR(EINVAL);
 111         av_log(avctx, AV_LOG_ERROR,
 112                "Framebuffer pixel format not supported.\n");
 113         goto fail;
 114     }
 115
 116     fbdev->width           = fbdev->varinfo.xres;
 117     fbdev->height          = fbdev->varinfo.yres;
 118     fbdev->bytes_per_pixel = (fbdev->varinfo.bits_per_pixel + 7) >> 3;
 119     fbdev->frame_linesize  = fbdev->width * fbdev->bytes_per_pixel;
 120     fbdev->frame_size      = fbdev->frame_linesize * fbdev->height;
 121     fbdev->time_frame      = AV_NOPTS_VALUE;
 122     fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_READ, MAP_SHARED, fbdev->fd, 0);
 123     if (fbdev->data == MAP_FAILED) {
 124         ret = AVERROR(errno);
 125         av_log(avctx, AV_LOG_ERROR, "Error in mmap(): %s\n", av_err2str(ret));
 126         goto fail;
 127     }
 128
 129     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
 130     st->codec->codec_id   = AV_CODEC_ID_RAWVIDEO;
 131     st->codec->width      = fbdev->width;
 132     st->codec->height     = fbdev->height;
 133     st->codec->pix_fmt    = pix_fmt;
 134     st->codec->time_base  = av_inv_q(fbdev->framerate_q);
 135     st->codec->bit_rate   =
 136         fbdev->width * fbdev->height * fbdev->bytes_per_pixel * av_q2d(fbdev->framerate_q) * 8;
 137
 138     av_log(avctx, AV_LOG_INFO,
 139            "w:%d h:%d bpp:%d pixfmt:%s fps:%d/%d bit_rate:%d\n",
 140            fbdev->width, fbdev->height, fbdev->varinfo.bits_per_pixel,
 141            av_get_pix_fmt_name(pix_fmt),
 142            fbdev->framerate_q.num, fbdev->framerate_q.den,
 143            st->codec->bit_rate);
 144     return 0;
 145
 146 fail:
 147     close(fbdev->fd);
 148     return ret;
 149 }
 150
 151 static int fbdev_read_packet(AVFormatContext *avctx, AVPacket *pkt)
 152 {
 153     FBDevContext *fbdev = avctx->priv_data;
 154     int64_t curtime, delay;
 155     struct timespec ts;
 156     int i, ret;
 157     uint8_t *pin, *pout;
 158
 159     if (fbdev->time_frame == AV_NOPTS_VALUE)
 160         fbdev->time_frame = av_gettime();
 161
 162     /* wait based on the frame rate */
 163     while (1) {
 164         curtime = av_gettime();
 165         delay = fbdev->time_frame - curtime;
 166         av_dlog(avctx,
 167                 "time_frame:%"PRId64" curtime:%"PRId64" delay:%"PRId64"\n",
 168                 fbdev->time_frame, curtime, delay);
 169         if (delay <= 0) {
 170             fbdev->time_frame += INT64_C(1000000) / av_q2d(fbdev->framerate_q);
 171             break;
 172         }
 173         if (avctx->flags & AVFMT_FLAG_NONBLOCK)
 174             return AVERROR(EAGAIN);
 175         ts.tv_sec  =  delay / 1000000;
 176         ts.tv_nsec = (delay % 1000000) * 1000;
 177         while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
 178     }
 179
 180     if ((ret = av_new_packet(pkt, fbdev->frame_size)) < 0)
 181         return ret;
 182
 183     /* refresh fbdev->varinfo, visible data position may change at each call */
 184     if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
 185         av_log(avctx, AV_LOG_WARNING,
 186                "Error refreshing variable info: %s\n", av_err2str(AVERROR(errno)));
 187     }
 188
 189     pkt->pts = curtime;
 190
 191     /* compute visible data offset */
 192     pin = fbdev->data + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset +
 193                         fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
 194     pout = pkt->data;
 195
 196     for (i = 0; i < fbdev->height; i++) {
 197         memcpy(pout, pin, fbdev->frame_linesize);
 198         pin  += fbdev->fixinfo.line_length;
 199         pout += fbdev->frame_linesize;
 200     }
 201
 202     return fbdev->frame_size;
 203 }
 204
 205 static av_cold int fbdev_read_close(AVFormatContext *avctx)
 206 {
 207     FBDevContext *fbdev = avctx->priv_data;
 208
 209     munmap(fbdev->data, fbdev->fixinfo.smem_len);
 210     close(fbdev->fd);
 211
 212     return 0;
 213 }
 214
 215 static int fbdev_get_device_list(AVFormatContext *s, AVDeviceInfoList *device_list)
 216 {
 217     return ff_fbdev_get_device_list(device_list);
 218 }
 219
 220 #define OFFSET(x) offsetof(FBDevContext, x)
 221 #define DEC AV_OPT_FLAG_DECODING_PARAM
 222 static const AVOption options[] = {
 223     { "framerate","", OFFSET(framerate_q), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, DEC },
 224     { NULL },
 225 };
 226
 227 static const AVClass fbdev_class = {
 228     .class_name = "fbdev indev",
 229     .item_name  = av_default_item_name,
 230     .option     = options,
 231     .version    = LIBAVUTIL_VERSION_INT,
 232     .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
 233 };
 234
 235 AVInputFormat ff_fbdev_demuxer = {
 236     .name           = "fbdev",
 237     .long_name      = NULL_IF_CONFIG_SMALL("Linux framebuffer"),
 238     .priv_data_size = sizeof(FBDevContext),
 239     .read_header    = fbdev_read_header,
 240     .read_packet    = fbdev_read_packet,
 241     .read_close     = fbdev_read_close,
 242     .get_device_list = fbdev_get_device_list,
 243     .flags          = AVFMT_NOFILE,
 244     .priv_class     = &fbdev_class,
 245 };