/*
  * Copyright (c) 2011 Stefano Sabatini
  * Copyright (c) 2009 Giliard B. de Freitas <giliarde@gmail.com>
  * Copyright (C) 2002 Gunnar Monell <gmo@linux.nu>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/ioctl.h>

 #include <stdlib.h>

 #include "fbdev_common.h"
 #include "libavutil/common.h"

 #include "avdevice.h"

 
 struct rgb_pixfmt_map_entry {
     int bits_per_pixel;
     int red_offset, green_offset, blue_offset, alpha_offset;
     enum AVPixelFormat pixfmt;
 };
 
 static const struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = {
     // bpp, red_offset,  green_offset, blue_offset, alpha_offset, pixfmt
     {  32,       0,           8,          16,           24,   AV_PIX_FMT_RGBA  },
     {  32,      16,           8,           0,           24,   AV_PIX_FMT_BGRA  },
     {  32,       8,          16,          24,            0,   AV_PIX_FMT_ARGB  },
     {  32,       3,           2,           8,            0,   AV_PIX_FMT_ABGR  },
     {  24,       0,           8,          16,            0,   AV_PIX_FMT_RGB24 },
     {  24,      16,           8,           0,            0,   AV_PIX_FMT_BGR24 },

     {  16,      11,           5,           0,            0,   AV_PIX_FMT_RGB565 },

 };
 
 enum AVPixelFormat ff_get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
 {
     int i;
 
     for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {
         const struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i];
         if (entry->bits_per_pixel == varinfo->bits_per_pixel &&
             entry->red_offset     == varinfo->red.offset     &&
             entry->green_offset   == varinfo->green.offset   &&
             entry->blue_offset    == varinfo->blue.offset)
             return entry->pixfmt;
     }
 
     return AV_PIX_FMT_NONE;
 }

 
 const char* ff_fbdev_default_device()
 {
     const char *dev = getenv("FRAMEBUFFER");
     if (!dev)
         dev = "/dev/fb0";
     return dev;
 }
 

 int ff_fbdev_get_device_list(AVDeviceInfoList *device_list)
 {
     struct fb_var_screeninfo varinfo;
     struct fb_fix_screeninfo fixinfo;
     char device_file[12];
     AVDeviceInfo *device = NULL;
     int i, fd, ret = 0;
     const char *default_device = ff_fbdev_default_device();
 
     if (!device_list)
         return AVERROR(EINVAL);
 
     for (i = 0; i <= 31; i++) {
         snprintf(device_file, sizeof(device_file), "/dev/fb%d", i);
 

         if ((fd = avpriv_open(device_file, O_RDWR)) < 0) {
             int err = AVERROR(errno);
             if (err != AVERROR(ENOENT))
                 av_log(NULL, AV_LOG_ERROR, "Could not open framebuffer device '%s': %s\n",
                        device_file, av_err2str(err));

             continue;

         }

         if (ioctl(fd, FBIOGET_VSCREENINFO, &varinfo) == -1)
             goto fail_device;
         if (ioctl(fd, FBIOGET_FSCREENINFO, &fixinfo) == -1)
             goto fail_device;
 
         device = av_mallocz(sizeof(AVDeviceInfo));
         if (!device) {
             ret = AVERROR(ENOMEM);
             goto fail_device;
         }
         device->device_name = av_strdup(device_file);
         device->device_description = av_strdup(fixinfo.id);
         if (!device->device_name || !device->device_description) {
             ret = AVERROR(ENOMEM);
             goto fail_device;
         }
 
         if ((ret = av_dynarray_add_nofree(&device_list->devices,
                                           &device_list->nb_devices, device)) < 0)
             goto fail_device;
 
         if (default_device && !strcmp(device->device_name, default_device)) {
             device_list->default_device = device_list->nb_devices - 1;
             default_device = NULL;
         }
         close(fd);
         continue;
 
       fail_device:
         if (device) {

             av_freep(&device->device_name);
             av_freep(&device->device_description);

             av_freep(&device);
         }
         if (fd >= 0)
             close(fd);
         if (ret < 0)
             return ret;
     }
     return 0;
 }