FFmpeg
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:68
int alpha_offset
Definition: fbdev_common.c:33
char * device_name
device name, format depends on device
Definition: avdevice.h:453
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
const char * ff_fbdev_default_device()
Definition: fbdev_common.c:64
packed ABGR 8:8:8:8, 32bpp, ABGRABGR...
Definition: pixfmt.h:94
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 i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
packed BGRA 8:8:8:8, 32bpp, BGRABGRA...
Definition: pixfmt.h:95
enum AVPixelFormat pixfmt
Definition: fbdev_common.c:34
AVDeviceInfo ** devices
list of autodetected devices
Definition: avdevice.h:461
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:92
int green_offset
Definition: fbdev_common.c:33
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:93
#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:69
#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:374
#define av_freep(p)
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
int nb_devices
number of autodetected devices
Definition: avdevice.h:462
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
int bits_per_pixel
Definition: fbdev_common.c:32