FFmpeg: libavdevice/fbdev_common.c Source File

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libavdevice

fbdev_common.c

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1 /*

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 */

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 "libavutil/file_open.h"

30 #include "libavutil/mem.h"

31 #include "avdevice.h"

33 struct rgb_pixfmt_map_entry {

34 int bits_per_pixel;

35 int red_offset, green_offset, blue_offset, alpha_offset;

36 enum AVPixelFormat pixfmt;

37 };

39 static const struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = {

40 // bpp, red_offset, green_offset, blue_offset, alpha_offset, pixfmt

41 { 32, 0, 8, 16, 24, AV_PIX_FMT_RGBA },

42 { 32, 16, 8, 0, 24, AV_PIX_FMT_BGRA },

43 { 32, 8, 16, 24, 0, AV_PIX_FMT_ARGB },

44 { 32, 3, 2, 8, 0, AV_PIX_FMT_ABGR },

45 { 24, 0, 8, 16, 0, AV_PIX_FMT_RGB24 },

46 { 24, 16, 8, 0, 0, AV_PIX_FMT_BGR24 },

47 { 16, 11, 5, 0, 0, AV_PIX_FMT_RGB565 },

48 };

50 enum AVPixelFormat ff_get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)

51 {

52 int i;

54 for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {

55 const struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i];

56 if (entry->bits_per_pixel == varinfo->bits_per_pixel &&

57 entry->red_offset == varinfo->red.offset &&

58 entry->green_offset == varinfo->green.offset &&

59 entry->blue_offset == varinfo->blue.offset)

60 return entry->pixfmt;

61 }

63 return AV_PIX_FMT_NONE;

64 }

66 const char *ff_fbdev_default_device(void)

67 {

68 const char *dev = getenv("FRAMEBUFFER");

69 if (!dev)

70 dev = "/dev/fb0";

71 return dev;

72 }

74 int ff_fbdev_get_device_list(AVDeviceInfoList *device_list)

75 {

76 struct fb_var_screeninfo varinfo;

77 struct fb_fix_screeninfo fixinfo;

78 char device_file[12];

79 AVDeviceInfo *device = NULL;

80 int i, fd, ret = 0;

81 const char *default_device = ff_fbdev_default_device();

83 if (!device_list)

84 return AVERROR(EINVAL);

86 for (i = 0; i <= 31; i++) {

87 snprintf(device_file, sizeof(device_file), "/dev/fb%d", i);

89 if ((fd = avpriv_open(device_file, O_RDWR)) < 0) {

90 int err = AVERROR(errno);

91 if (err != AVERROR(ENOENT))

92 av_log(NULL, AV_LOG_ERROR, "Could not open framebuffer device '%s': %s\n",

93 device_file, av_err2str(err));

94 continue;

95 }

96 if (ioctl(fd, FBIOGET_VSCREENINFO, &varinfo) == -1)

97 goto fail_device;

98 if (ioctl(fd, FBIOGET_FSCREENINFO, &fixinfo) == -1)

99 goto fail_device;

100

101 device = av_mallocz(sizeof(AVDeviceInfo));

102 if (!device) {

103 ret = AVERROR(ENOMEM);

104 goto fail_device;

105 }

106 device->device_name = av_strdup(device_file);

107 device->device_description = av_strdup(fixinfo.id);

108 if (!device->device_name || !device->device_description) {

109 ret = AVERROR(ENOMEM);

110 goto fail_device;

111 }

112

113 if ((ret = av_dynarray_add_nofree(&device_list->devices,

114 &device_list->nb_devices, device)) < 0)

115 goto fail_device;

116

117 if (default_device && !strcmp(device->device_name, default_device)) {

118 device_list->default_device = device_list->nb_devices - 1;

119 default_device = NULL;

120 }

121 close(fd);

122 continue;

123

124 fail_device:

125 if (device) {

126 av_freep(&device->device_name);

127 av_freep(&device->device_description);

128 av_freep(&device);

129 }

130 if (fd >= 0)

131 close(fd);

132 if (ret < 0)

133 return ret;

134 }

135 return 0;

136 }

AVPixelFormat

Pixel format.

Definition: pixfmt.h:71

entry

#define entry

Definition: aom_film_grain_template.c:66

AVERROR

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

AVDeviceInfo::device_name

char * device_name

device name, format depends on device

Definition: avdevice.h:334

AVDeviceInfoList::nb_devices

int nb_devices

number of autodetected devices

Definition: avdevice.h:345

rgb_pixfmt_map

static const struct rgb_pixfmt_map_entry rgb_pixfmt_map[]

Definition: fbdev_common.c:39

AV_PIX_FMT_BGR24