FFmpeg  4.0
fbdev_common.c
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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 
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, 0, 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 
65 {
66  const char *dev = getenv("FRAMEBUFFER");
67  if (!dev)
68  dev = "/dev/fb0";
69  return dev;
70 }
71 
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 }
#define NULL
Definition: coverity.c:32
Structure describes basic parameters of the device.
Definition: avdevice.h:452
int blue_offset
Definition: fbdev_common.c:33
char * device_description
human friendly name
Definition: avdevice.h:454
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:64
int alpha_offset
Definition: fbdev_common.c:33
char * device_name
device name, format depends on device
Definition: avdevice.h:453
const char * ff_fbdev_default_device()
Definition: fbdev_common.c:64
packed ABGR 8:8:8:8, 32bpp, ABGRABGR...
Definition: pixfmt.h:90
int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66
int av_dynarray_add_nofree(void *tab_ptr, int *nb_ptr, void *elem)
Add an element to a dynamic array.
Definition: mem.c:294
Definition: fbdev_common.c:31
#define av_log(a,...)
Main libavdevice API header.
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
packed BGRA 8:8:8:8, 32bpp, BGRABGRA...
Definition: pixfmt.h:91
enum AVPixelFormat pixfmt
Definition: fbdev_common.c:34
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
AVDeviceInfo ** devices
list of autodetected devices
Definition: avdevice.h:461
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:88
int green_offset
Definition: fbdev_common.c:33
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:89
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:119
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:65
#define FF_ARRAY_ELEMS(a)
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:251
static const struct rgb_pixfmt_map_entry rgb_pixfmt_map[]
Definition: fbdev_common.c:37
int ff_fbdev_get_device_list(AVDeviceInfoList *device_list)
Definition: fbdev_common.c:72
#define snprintf
Definition: snprintf.h:34
int default_device
index of default device or -1 if no default
Definition: avdevice.h:463
List of devices.
Definition: avdevice.h:460
common internal and external API header
enum AVPixelFormat ff_get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
Definition: fbdev_common.c:48
int red_offset
Definition: fbdev_common.c:33
#define AV_PIX_FMT_RGB565
Definition: pixfmt.h:355
#define av_freep(p)
int nb_devices
number of autodetected devices
Definition: avdevice.h:462
AVPixelFormat
Pixel format.
Definition: pixfmt.h:60
int bits_per_pixel
Definition: fbdev_common.c:32