ffmpeg/libavdevice/fbdev_common.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 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <sys/ioctl.h>
  26 #include <stdlib.h>
  27 #include "fbdev_common.h"
  28 #include "libavutil/common.h"
  29 #include "avdevice.h"
  30
  31 struct rgb_pixfmt_map_entry {
  32     int bits_per_pixel;
  33     int red_offset, green_offset, blue_offset, alpha_offset;
  34     enum AVPixelFormat pixfmt;
  35 };
  36
  37 static const struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = {
  38     // bpp, red_offset,  green_offset, blue_offset, alpha_offset, pixfmt
  39     {  32,       0,           8,          16,           24,   AV_PIX_FMT_RGBA  },
  40     {  32,      16,           8,           0,           24,   AV_PIX_FMT_BGRA  },
  41     {  32,       8,          16,          24,            0,   AV_PIX_FMT_ARGB  },
  42     {  32,       3,           2,           8,            0,   AV_PIX_FMT_ABGR  },
  43     {  24,       0,           8,          16,            0,   AV_PIX_FMT_RGB24 },
  44     {  24,      16,           8,           0,            0,   AV_PIX_FMT_BGR24 },
  45     {  16,      11,           5,           0,           16,   AV_PIX_FMT_RGB565 },
  46 };
  47
  48 enum AVPixelFormat ff_get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
  49 {
  50     int i;
  51
  52     for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {
  53         const struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i];
  54         if (entry->bits_per_pixel == varinfo->bits_per_pixel &&
  55             entry->red_offset     == varinfo->red.offset     &&
  56             entry->green_offset   == varinfo->green.offset   &&
  57             entry->blue_offset    == varinfo->blue.offset)
  58             return entry->pixfmt;
  59     }
  60
  61     return AV_PIX_FMT_NONE;
  62 }
  63
  64 const char* ff_fbdev_default_device()
  65 {
  66     const char *dev = getenv("FRAMEBUFFER");
  67     if (!dev)
  68         dev = "/dev/fb0";
  69     return dev;
  70 }
  71
  72 int ff_fbdev_get_device_list(AVDeviceInfoList *device_list)
  73 {
  74     struct fb_var_screeninfo varinfo;
  75     struct fb_fix_screeninfo fixinfo;
  76     char device_file[12];
  77     AVDeviceInfo *device = NULL;
  78     int i, fd, ret = 0;
  79     const char *default_device = ff_fbdev_default_device();
  80
  81     if (!device_list)
  82         return AVERROR(EINVAL);
  83
  84     for (i = 0; i <= 31; i++) {
  85         snprintf(device_file, sizeof(device_file), "/dev/fb%d", i);
  86
  87         if ((fd = avpriv_open(device_file, O_RDWR)) < 0) {
  88             int err = AVERROR(errno);
  89             if (err != AVERROR(ENOENT))
  90                 av_log(NULL, AV_LOG_ERROR, "Could not open framebuffer device '%s': %s\n",
  91                        device_file, av_err2str(err));
  92             continue;
  93         }
  94         if (ioctl(fd, FBIOGET_VSCREENINFO, &varinfo) == -1)
  95             goto fail_device;
  96         if (ioctl(fd, FBIOGET_FSCREENINFO, &fixinfo) == -1)
  97             goto fail_device;
  98
  99         device = av_mallocz(sizeof(AVDeviceInfo));
 100         if (!device) {
 101             ret = AVERROR(ENOMEM);
 102             goto fail_device;
 103         }
 104         device->device_name = av_strdup(device_file);
 105         device->device_description = av_strdup(fixinfo.id);
 106         if (!device->device_name || !device->device_description) {
 107             ret = AVERROR(ENOMEM);
 108             goto fail_device;
 109         }
 110
 111         if ((ret = av_dynarray_add_nofree(&device_list->devices,
 112                                           &device_list->nb_devices, device)) < 0)
 113             goto fail_device;
 114
 115         if (default_device && !strcmp(device->device_name, default_device)) {
 116             device_list->default_device = device_list->nb_devices - 1;
 117             default_device = NULL;
 118         }
 119         close(fd);
 120         continue;
 121
 122       fail_device:
 123         if (device) {
 124             av_freep(&device->device_name);
 125             av_freep(&device->device_description);
 126             av_freep(&device);
 127         }
 128         if (fd >= 0)
 129             close(fd);
 130         if (ret < 0)
 131             return ret;
 132     }
 133     return 0;
 134 }