Libav
fbdev.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 Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
30 #include <unistd.h>
31 #include <fcntl.h>
32 #include <sys/ioctl.h>
33 #include <sys/mman.h>
34 #include <time.h>
35 #include <linux/fb.h>
36 
37 #include "libavutil/internal.h"
38 #include "libavutil/log.h"
39 #include "libavutil/mem.h"
40 #include "libavutil/opt.h"
41 #include "libavutil/time.h"
42 #include "libavutil/parseutils.h"
43 #include "libavutil/pixdesc.h"
44 #include "libavformat/avformat.h"
45 #include "libavformat/internal.h"
46 
51 };
52 
54  // bpp, red_offset, green_offset, blue_offset, alpha_offset, pixfmt
55  { 32, 0, 8, 16, 24, AV_PIX_FMT_RGBA },
56  { 32, 16, 8, 0, 24, AV_PIX_FMT_BGRA },
57  { 32, 8, 16, 24, 0, AV_PIX_FMT_ARGB },
58  { 32, 3, 2, 8, 0, AV_PIX_FMT_ABGR },
59  { 24, 0, 8, 16, 0, AV_PIX_FMT_RGB24 },
60  { 24, 16, 8, 0, 0, AV_PIX_FMT_BGR24 },
61  { 16, 11, 5, 0, 0, AV_PIX_FMT_RGB565 },
62 };
63 
64 static enum AVPixelFormat get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
65 {
66  int i;
67 
68  for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {
69  struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i];
70  if (entry->bits_per_pixel == varinfo->bits_per_pixel &&
71  entry->red_offset == varinfo->red.offset &&
72  entry->green_offset == varinfo->green.offset &&
73  entry->blue_offset == varinfo->blue.offset)
74  return entry->pixfmt;
75  }
76 
77  return AV_PIX_FMT_NONE;
78 }
79 
80 typedef struct FBDevContext {
81  AVClass *class;
82  int frame_size;
84  char *framerate;
85  int64_t time_frame;
86 
87  int fd;
88  int width, height;
91 
92  struct fb_var_screeninfo varinfo;
93  struct fb_fix_screeninfo fixinfo;
94 
96 } FBDevContext;
97 
99 {
100  FBDevContext *fbdev = avctx->priv_data;
101  AVStream *st = NULL;
102  enum AVPixelFormat pix_fmt;
103  int ret, flags = O_RDONLY;
104  char errbuf[128];
105 
106  ret = av_parse_video_rate(&fbdev->framerate_q, fbdev->framerate);
107  if (ret < 0) {
108  av_log(avctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", fbdev->framerate);
109  return ret;
110  }
111 
112  if (!(st = avformat_new_stream(avctx, NULL)))
113  return AVERROR(ENOMEM);
114  avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in microseconds */
115 
116  /* NONBLOCK is ignored by the fbdev driver, only set for consistency */
117  if (avctx->flags & AVFMT_FLAG_NONBLOCK)
118  flags |= O_NONBLOCK;
119 
120  if ((fbdev->fd = avpriv_open(avctx->filename, flags)) == -1) {
121  ret = AVERROR(errno);
122  av_strerror(ret, errbuf, sizeof(errbuf));
123  av_log(avctx, AV_LOG_ERROR,
124  "Could not open framebuffer device '%s': %s\n",
125  avctx->filename, errbuf);
126  return ret;
127  }
128 
129  if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
130  ret = AVERROR(errno);
131  av_strerror(ret, errbuf, sizeof(errbuf));
132  av_log(avctx, AV_LOG_ERROR,
133  "FBIOGET_VSCREENINFO: %s\n", errbuf);
134  goto fail;
135  }
136 
137  if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
138  ret = AVERROR(errno);
139  av_strerror(ret, errbuf, sizeof(errbuf));
140  av_log(avctx, AV_LOG_ERROR,
141  "FBIOGET_FSCREENINFO: %s\n", errbuf);
142  goto fail;
143  }
144 
145  pix_fmt = get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
146  if (pix_fmt == AV_PIX_FMT_NONE) {
147  ret = AVERROR(EINVAL);
148  av_log(avctx, AV_LOG_ERROR,
149  "Framebuffer pixel format not supported.\n");
150  goto fail;
151  }
152 
153  fbdev->width = fbdev->varinfo.xres;
154  fbdev->height = fbdev->varinfo.yres;
155  fbdev->bytes_per_pixel = (fbdev->varinfo.bits_per_pixel + 7) >> 3;
156  fbdev->frame_linesize = fbdev->width * fbdev->bytes_per_pixel;
157  fbdev->frame_size = fbdev->frame_linesize * fbdev->height;
158  fbdev->time_frame = AV_NOPTS_VALUE;
159  fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_READ, MAP_SHARED, fbdev->fd, 0);
160  if (fbdev->data == MAP_FAILED) {
161  ret = AVERROR(errno);
162  av_strerror(ret, errbuf, sizeof(errbuf));
163  av_log(avctx, AV_LOG_ERROR, "Error in mmap(): %s\n", errbuf);
164  goto fail;
165  }
166 
169  st->codecpar->width = fbdev->width;
170  st->codecpar->height = fbdev->height;
171  st->codecpar->format = pix_fmt;
172  st->codecpar->bit_rate =
173  fbdev->width * fbdev->height * fbdev->bytes_per_pixel * av_q2d(fbdev->framerate_q) * 8;
174  st->avg_frame_rate = fbdev->framerate_q;
175 
176  av_log(avctx, AV_LOG_INFO,
177  "w:%d h:%d bpp:%d pixfmt:%s fps:%d/%d bit_rate:%d\n",
178  fbdev->width, fbdev->height, fbdev->varinfo.bits_per_pixel,
179  av_get_pix_fmt_name(pix_fmt),
180  fbdev->framerate_q.num, fbdev->framerate_q.den,
181  st->codecpar->bit_rate);
182  return 0;
183 
184 fail:
185  close(fbdev->fd);
186  return ret;
187 }
188 
190 {
191  FBDevContext *fbdev = avctx->priv_data;
192  int64_t curtime, delay;
193  struct timespec ts;
194  int i, ret;
195  uint8_t *pin, *pout;
196 
197  if (fbdev->time_frame == AV_NOPTS_VALUE)
198  fbdev->time_frame = av_gettime();
199 
200  /* wait based on the frame rate */
201  curtime = av_gettime();
202  delay = fbdev->time_frame - curtime;
203  av_log(avctx, AV_LOG_TRACE,
204  "time_frame:%"PRId64" curtime:%"PRId64" delay:%"PRId64"\n",
205  fbdev->time_frame, curtime, delay);
206  if (delay > 0) {
207  if (avctx->flags & AVFMT_FLAG_NONBLOCK)
208  return AVERROR(EAGAIN);
209  ts.tv_sec = delay / 1000000;
210  ts.tv_nsec = (delay % 1000000) * 1000;
211  while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
212  }
213  /* compute the time of the next frame */
214  fbdev->time_frame += INT64_C(1000000) / av_q2d(fbdev->framerate_q);
215 
216  if ((ret = av_new_packet(pkt, fbdev->frame_size)) < 0)
217  return ret;
218 
219  /* refresh fbdev->varinfo, visible data position may change at each call */
220  if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
221  char errbuf[128];
222  av_strerror(AVERROR(errno), errbuf, sizeof(errbuf));
223  av_log(avctx, AV_LOG_WARNING,
224  "Error refreshing variable info: %s\n", errbuf);
225  }
226 
227  pkt->pts = curtime;
228 
229  /* compute visible data offset */
230  pin = fbdev->data + fbdev->bytes_per_pixel * fbdev->varinfo.xoffset +
231  fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
232  pout = pkt->data;
233 
234  // TODO it'd be nice if the lines were aligned
235  for (i = 0; i < fbdev->height; i++) {
236  memcpy(pout, pin, fbdev->frame_linesize);
237  pin += fbdev->fixinfo.line_length;
238  pout += fbdev->frame_linesize;
239  }
240 
241  return fbdev->frame_size;
242 }
243 
245 {
246  FBDevContext *fbdev = avctx->priv_data;
247 
248  munmap(fbdev->data, fbdev->frame_size);
249  close(fbdev->fd);
250 
251  return 0;
252 }
253 
254 #define OFFSET(x) offsetof(FBDevContext, x)
255 #define DEC AV_OPT_FLAG_DECODING_PARAM
256 static const AVOption options[] = {
257  { "framerate","", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC },
258  { NULL },
259 };
260 
261 static const AVClass fbdev_class = {
262  .class_name = "fbdev indev",
263  .item_name = av_default_item_name,
264  .option = options,
265  .version = LIBAVUTIL_VERSION_INT,
266 };
267 
269  .name = "fbdev",
270  .long_name = NULL_IF_CONFIG_SMALL("Linux framebuffer"),
271  .priv_data_size = sizeof(FBDevContext),
275  .flags = AVFMT_NOFILE,
276  .priv_class = &fbdev_class,
277 };
#define DEC
Definition: fbdev.c:255
int height
assumed frame resolution
Definition: fbdev.c:88
int av_parse_video_rate(AVRational *rate, const char *arg)
Parse str and store the detected values in *rate.
Definition: parseutils.c:127
AVOption.
Definition: opt.h:234
int blue_offset
Definition: fbdev.c:49
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:130
char * framerate
framerate string set by a private option
Definition: fbdev.c:84
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:61
memory handling functions
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:2986
int alpha_offset
Definition: fbdev.c:49
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3483
int num
numerator
Definition: rational.h:44
av_log(ac->avr, AV_LOG_TRACE, "%d samples - audio_convert: %s to %s (%s)\, len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt), use_generic ? ac->func_descr_generic :ac->func_descr)
AVInputFormat ff_fbdev_demuxer
Definition: fbdev.c:268
#define FF_ARRAY_ELEMS(a)
int frame_linesize
linesize of the output frame, it is assumed to be constant
Definition: fbdev.c:89
int frame_size
size in bytes of a grabbed frame
Definition: fbdev.c:82
Format I/O context.
Definition: avformat.h:940
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:39
#define AVFMT_FLAG_NONBLOCK
Do not block when reading packets from input.
Definition: avformat.h:1054
uint8_t
#define av_cold
Definition: attributes.h:66
int width
Video only.
Definition: avcodec.h:3525
AVOptions.
#define AV_LOG_TRACE
Extremely verbose debugging, useful for libav* development.
Definition: log.h:150
struct fb_var_screeninfo varinfo
variable info;
Definition: fbdev.c:92
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2648
packed ABGR 8:8:8:8, 32bpp, ABGRABGR...
Definition: pixfmt.h:91
int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66
int64_t time_frame
time for the next frame to output (in 1/1000000 units)
Definition: fbdev.c:85
static double av_q2d(AVRational a)
Convert rational to double.
Definition: rational.h:69
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1051
uint8_t * data
Definition: avcodec.h:1346
static int flags
Definition: log.c:50
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
Definition: fbdev.c:47
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:84
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:124
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:148
packed BGRA 8:8:8:8, 32bpp, BGRABGRA...
Definition: pixfmt.h:92
enum AVPixelFormat pixfmt
Definition: fbdev.c:50
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3479
AVRational avg_frame_rate
Average framerate.
Definition: avformat.h:781
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:89
#define fail()
Definition: checkasm.h:80
int green_offset
Definition: fbdev.c:49
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:90
struct fb_fix_screeninfo fixinfo
fixed info;
Definition: fbdev.c:93
int bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3512
common internal API header
char filename[1024]
input or output filename
Definition: avformat.h:1016
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:62
enum AVPixelFormat pix_fmt
Definition: movenc.c:853
AVRational framerate_q
framerate
Definition: fbdev.c:83
LIBAVUTIL_VERSION_INT
Definition: eval.c:55
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:546
int64_t av_gettime(void)
Get the current time in microseconds.
Definition: time.c:40
Stream structure.
Definition: avformat.h:705
NULL
Definition: eval.c:55
#define AV_LOG_INFO
Standard information.
Definition: log.h:135
static av_cold int fbdev_read_header(AVFormatContext *avctx)
Definition: fbdev.c:98
static int fbdev_read_packet(AVFormatContext *avctx, AVPacket *pkt)
Definition: fbdev.c:189
av_default_item_name
Definition: dnxhdenc.c:55
int width
Definition: fbdev.c:88
int bytes_per_pixel
Definition: fbdev.c:90
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
static av_cold int fbdev_read_close(AVFormatContext *avctx)
Definition: fbdev.c:244
Describe the class of an AVClass context structure.
Definition: log.h:34
rational number numerator/denominator
Definition: rational.h:43
misc parsing utilities
int av_strerror(int errnum, char *errbuf, size_t errbuf_size)
Put a description of the AVERROR code errnum in errbuf.
Definition: error.c:23
int height
Definition: gxfenc.c:72
Main libavformat public API header.
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:412
uint8_t * data
framebuffer data
Definition: fbdev.c:95
static enum AVPixelFormat get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
Definition: fbdev.c:64
int den
denominator
Definition: rational.h:45
int red_offset
Definition: fbdev.c:49
static struct rgb_pixfmt_map_entry rgb_pixfmt_map[]
Definition: fbdev.c:53
void * priv_data
Format private data.
Definition: avformat.h:968
static const AVClass fbdev_class
Definition: fbdev.c:261
#define AV_PIX_FMT_RGB565
Definition: pixfmt.h:250
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:529
AVCodecParameters * codecpar
Definition: avformat.h:831
static const AVOption options[]
Definition: fbdev.c:256
#define OFFSET(x)
Definition: fbdev.c:254
const char * av_get_pix_fmt_name(enum AVPixelFormat pix_fmt)
Return the short name for a pixel format, NULL in case pix_fmt is unknown.
Definition: pixdesc.c:1704
AVPixelFormat
Pixel format.
Definition: pixfmt.h:57
This structure stores compressed data.
Definition: avcodec.h:1323
int fd
framebuffer device file descriptor
Definition: fbdev.c:87
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1339
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:235
int bits_per_pixel
Definition: fbdev.c:48