FFmpeg: libavdevice/v4l.c Source File

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libavdevice

v4l.c

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1 /*

2 * Linux video grab interface

4 *

5 * This file is part of FFmpeg.

6 *

7 * FFmpeg is free software; you can redistribute it and/or

8 * modify it under the terms of the GNU Lesser General Public

9 * License as published by the Free Software Foundation; either

10 * version 2.1 of the License, or (at your option) any later version.

11 *

12 * FFmpeg is distributed in the hope that it will be useful,

13 * but WITHOUT ANY WARRANTY; without even the implied warranty of

14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

15 * Lesser General Public License for more details.

16 *

17 * You should have received a copy of the GNU Lesser General Public

18 * License along with FFmpeg; if not, write to the Free Software

19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

20 */

22 #include "avdevice.h"

24 #undef __STRICT_ANSI__ //workaround due to broken kernel headers

25 #include "config.h"

26 #include "libavutil/rational.h"

27 #include "libavutil/imgutils.h"

28 #include "libavutil/internal.h"

29 #include "libavutil/log.h"

30 #include "libavutil/opt.h"

31 #include "libavformat/internal.h"

32 #include "libavcodec/dsputil.h"

33 #include <unistd.h>

34 #include <fcntl.h>

35 #include <sys/ioctl.h>

36 #include <sys/mman.h>

37 #include <sys/time.h>

38 #define _LINUX_TIME_H 1

39 #include <linux/videodev.h>

40 #include <time.h>

42 typedef struct {

43 AVClass *class;

44 int fd;

45 int frame_format; /* see VIDEO_PALETTE_xxx */

46 int use_mmap;

47 AVRational time_base;

48 int64_t time_frame;

49 int frame_size;

50 struct video_capability video_cap;

51 struct video_audio audio_saved;

52 struct video_window video_win;

53 uint8_t *video_buf;

54 struct video_mbuf gb_buffers;

55 struct video_mmap gb_buf;

56 int gb_frame;

57 int standard;

58 } VideoData;

60 static const struct {

61 int palette;

62 int depth;

63 enum AVPixelFormat pix_fmt;

64 } video_formats [] = {

65 {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = AV_PIX_FMT_YUV420P },

66 {.palette = VIDEO_PALETTE_YUV422, .depth = 16, .pix_fmt = AV_PIX_FMT_YUYV422 },

67 {.palette = VIDEO_PALETTE_UYVY, .depth = 16, .pix_fmt = AV_PIX_FMT_UYVY422 },

68 {.palette = VIDEO_PALETTE_YUYV, .depth = 16, .pix_fmt = AV_PIX_FMT_YUYV422 },

69 /* NOTE: v4l uses BGR24, not RGB24 */

70 {.palette = VIDEO_PALETTE_RGB24, .depth = 24, .pix_fmt = AV_PIX_FMT_BGR24 },

71 {.palette = VIDEO_PALETTE_RGB565, .depth = 16, .pix_fmt = AV_PIX_FMT_BGR565 },

72 {.palette = VIDEO_PALETTE_GREY, .depth = 8, .pix_fmt = AV_PIX_FMT_GRAY8 },

73 };

76 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)

77 {

78 VideoData *s = s1->priv_data;

79 AVStream *st;

80 int video_fd;

81 int desired_palette, desired_depth;

82 struct video_tuner tuner;

83 struct video_audio audio;

84 struct video_picture pict;

85 int j;

86 int vformat_num = FF_ARRAY_ELEMS(video_formats);

88 av_log(s1, AV_LOG_WARNING, "V4L input device is deprecated and will be removed in the next release.");

90 if (ap->time_base.den <= 0) {

91 av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);

92 return -1;

93 }

94 s->time_base = ap->time_base;

96 s->video_win.width = ap->width;

97 s->video_win.height = ap->height;

99 st = avformat_new_stream(s1, NULL);

100 if (!st)

101 return AVERROR(ENOMEM);

102 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */

103

104 video_fd = open(s1->filename, O_RDWR);

105 if (video_fd < 0) {

106 av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));

107 goto fail;

108 }

109

110 if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {

111 av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));

112 goto fail;

113 }

114

115 if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {

116 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");

117 goto fail;

118 }

119

120 /* no values set, autodetect them */

121 if (s->video_win.width <= 0 || s->video_win.height <= 0) {

122 if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {

123 av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));

124 goto fail;

125 }

126 }

127

128 if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)

129 return -1;

130

131 desired_palette = -1;

132 desired_depth = -1;

133 for (j = 0; j < vformat_num; j++) {

134 if (ap->pix_fmt == video_formats[j].pix_fmt) {

135 desired_palette = video_formats[j].palette;

136 desired_depth = video_formats[j].depth;

137 break;

138 }

139 }

140

141 /* set tv standard */

142 if (!ioctl(video_fd, VIDIOCGTUNER, &tuner)) {

143 tuner.mode = s->standard;

144 ioctl(video_fd, VIDIOCSTUNER, &tuner);

145 }

146

147 /* unmute audio */

148 audio.audio = 0;

149 ioctl(video_fd, VIDIOCGAUDIO, &audio);

150 memcpy(&s->audio_saved, &audio, sizeof(audio));

151 audio.flags &= ~VIDEO_AUDIO_MUTE;

152 ioctl(video_fd, VIDIOCSAUDIO, &audio);

153

154 ioctl(video_fd, VIDIOCGPICT, &pict);

155 ff_dlog(s1, "v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",

156 pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness);

157 /* try to choose a suitable video format */

158 pict.palette = desired_palette;

159 pict.depth= desired_depth;

160 if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {

161 for (j = 0; j < vformat_num; j++) {

162 pict.palette = video_formats[j].palette;

163 pict.depth = video_formats[j].depth;

164 if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))

165 break;

166 }

167 if (j >= vformat_num)

168 goto fail1;

169 }

170

171 if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {

172 /* try to use read based access */

173 int val;

174

175 s->video_win.x = 0;

176 s->video_win.y = 0;

177 s->video_win.chromakey = -1;

178 s->video_win.flags = 0;

179

180 if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {

181 av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));

182 goto fail;

183 }

184

185 s->frame_format = pict.palette;

186

187 val = 1;

188 if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {

189 av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));

190 goto fail;

191 }

192

193 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;

194 s->use_mmap = 0;

195 } else {

196 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);

197 if ((unsigned char*)-1 == s->video_buf) {

198 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);

199 if ((unsigned char*)-1 == s->video_buf) {

200 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));

201 goto fail;

202 }

203 }

204 s->gb_frame = 0;

205 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;

206

207 /* start to grab the first frame */

208 s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;

209 s->gb_buf.height = s->video_win.height;

210 s->gb_buf.width = s->video_win.width;

211 s->gb_buf.format = pict.palette;

212

213 if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {

214 if (errno != EAGAIN) {

215 fail1:

216 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));

217 } else {

218 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");

219 }

220 goto fail;

221 }

222 for (j = 1; j < s->gb_buffers.frames; j++) {

223 s->gb_buf.frame = j;

224 ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);

225 }

226 s->frame_format = s->gb_buf.format;

227 s->use_mmap = 1;

228 }

229

230 for (j = 0; j < vformat_num; j++) {

231 if (s->frame_format == video_formats[j].palette) {

232 s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;

233 st->codec->pix_fmt = video_formats[j].pix_fmt;

234 break;

235 }

236 }

237

238 if (j >= vformat_num)

239 goto fail;

240

241 s->fd = video_fd;

242

243 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

244 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;

245 st->codec->width = s->video_win.width;

246 st->codec->height = s->video_win.height;

247 st->codec->time_base = s->time_base;

248 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;

249

250 return 0;

251 fail:

252 if (video_fd >= 0)

253 close(video_fd);

254 return AVERROR(EIO);

255 }

256

257 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)

258 {

259 uint8_t *ptr;

260

261 while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&

262 (errno == EAGAIN || errno == EINTR));

263

264 ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];

265 memcpy(buf, ptr, s->frame_size);

266

267 /* Setup to capture the next frame */

268 s->gb_buf.frame = s->gb_frame;

269 if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {

270 if (errno == EAGAIN)

271 av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");

272 else

273 av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));

274 return AVERROR(EIO);

275 }

276

277 /* This is now the grabbing frame */

278 s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;

279

280 return s->frame_size;

281 }

282

283 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)

284 {

285 VideoData *s = s1->priv_data;

286 int64_t curtime, delay;

287 struct timespec ts;

288

289 /* Calculate the time of the next frame */

290 s->time_frame += INT64_C(1000000);

291

292 /* wait based on the frame rate */

293 for(;;) {

294 curtime = av_gettime();

295 delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;

296 if (delay <= 0) {

297 if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {

298 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */

299 s->time_frame += INT64_C(1000000);

300 }

301 break;

302 }

303 ts.tv_sec = delay / 1000000;

304 ts.tv_nsec = (delay % 1000000) * 1000;

305 nanosleep(&ts, NULL);

306 }

307

308 if (av_new_packet(pkt, s->frame_size) < 0)

309 return AVERROR(EIO);

310

311 pkt->pts = curtime;

312

313 /* read one frame */

314 if (s->use_mmap) {

315 return v4l_mm_read_picture(s, pkt->data);

316 } else {

317 if (read(s->fd, pkt->data, pkt->size) != pkt->size)

318 return AVERROR(EIO);

319 return s->frame_size;

320 }

321 }

322

323 static int grab_read_close(AVFormatContext *s1)

324 {

325 VideoData *s = s1->priv_data;

326

327 if (s->use_mmap)

328 munmap(s->video_buf, s->gb_buffers.size);

329

330 /* mute audio. we must force it because the BTTV driver does not

331 return its state correctly */

332 s->audio_saved.flags |= VIDEO_AUDIO_MUTE;

333 ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);

334

335 close(s->fd);

336 return 0;

337 }

338

339 static const AVOption options[] = {

340 { "standard", "", offsetof(VideoData, standard), AV_OPT_TYPE_INT, {.i64 = VIDEO_MODE_NTSC}, VIDEO_MODE_PAL, VIDEO_MODE_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },

341 { "PAL", "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_PAL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },

342 { "SECAM", "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_SECAM}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },

343 { "NTSC", "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_NTSC}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },

344 { NULL },

345 };

346

347 static const AVClass v4l_class = {

348 .class_name = "V4L indev",

349 .item_name = av_default_item_name,

350 .option = options,

351 .version = LIBAVUTIL_VERSION_INT,

352 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,

353 };

354

355 AVInputFormat ff_v4l_demuxer = {

356 .name = "video4linux,v4l",

357 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux device grab"),

358 .priv_data_size = sizeof(VideoData),

359 .read_header = grab_read_header,

360 .read_packet = grab_read_packet,

361 .read_close = grab_read_close,

362 .flags = AVFMT_NOFILE,

363 .priv_class = &v4l_class,

364 };

AV_PIX_FMT_UYVY422

packed YUV 4:2:2, 16bpp, Cb Y0 Cr Y1

Definition: pixfmt.h:83

NULL

#define NULL

Definition: coverity.c:32

val

const char const char void * val

Definition: avisynth_c.h:634

const char * s

Definition: avisynth_c.h:631

AVOption

AVOption.

Definition: opt.h:245

imgutils.h

misc image utilities

AV_LOG_WARNING

#define AV_LOG_WARNING

Something somehow does not look correct.

Definition: log.h:182

AVCodecContext::bit_rate

int64_t bit_rate

the average bitrate

Definition: avcodec.h:1597

LIBAVUTIL_VERSION_INT

#define LIBAVUTIL_VERSION_INT

Definition: version.h:70

avpriv_set_pts_info

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:4149

AV_OPT_TYPE_INT

Definition: opt.h:223

VideoData::video_cap

struct video_capability video_cap

Definition: v4l.c:50

AVRational::num

int num

numerator

Definition: rational.h:44

AVPacket::size

int size

Definition: avcodec.h:1468

AVCodecContext::pix_fmt

enum AVPixelFormat pix_fmt

Pixel format, see AV_PIX_FMT_xxx.

Definition: avcodec.h:1752

time.h

VideoData::use_mmap

int use_mmap

Definition: v4l.c:46

AVInputFormat

Definition: avformat.h:656

pkt

static AVPacket pkt

Definition: demuxing_decoding.c:54

AVCodecContext::time_base

AVRational time_base

This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...

Definition: avcodec.h:1661

AVFormatContext

Format I/O context.

Definition: avformat.h:1314

AVClass::class_name

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:72

AV_OPT_TYPE_CONST

Definition: opt.h:231

VideoData::video_win

struct video_window video_win

Definition: v4l.c:52

config.h

uint8_t

Definition: audio_convert.c:194

opt.h

AVOptions.

avformat_new_stream

AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)

Add a new stream to a media file.

Definition: utils.c:3805

AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT

Definition: log.h:42

av_q2d

static double av_q2d(AVRational a)

Convert rational to double.

Definition: rational.h:80

AVPacket::data

uint8_t * data

Definition: avcodec.h:1467

ff_dlog

#define ff_dlog(a,...)

Definition: tableprint_vlc.h:29

read_close

static av_cold int read_close(AVFormatContext *ctx)

Definition: libcdio.c:145

pix_fmt

enum AVPixelFormat pix_fmt

Definition: v4l.c:63

video_formats

static const struct @128 video_formats[]

av_log

#define av_log(a,...)

Definition: tableprint_vlc.h:28

VideoData::time_base

AVRational time_base

Definition: v4l.c:47

avdevice.h

Main libavdevice API header.

av_new_packet

int av_new_packet(AVPacket *pkt, int size)

Allocate the payload of a packet and initialize its fields with default values.

Definition: avpacket.c:86

grab_read_packet

static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)

Definition: v4l.c:283

AV_LOG_ERROR

#define AV_LOG_ERROR

Something went wrong and cannot losslessly be recovered.

Definition: log.h:176

av_default_item_name

Definition: libopenh264enc.c:68

AVERROR

#define AVERROR(e)

Definition: error.h:43

NULL_IF_CONFIG_SMALL

#define NULL_IF_CONFIG_SMALL(x)

Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...

Definition: internal.h:176

VideoData

Definition: bktr.c:54

internal.h

VideoData::fd

int fd

Definition: v4l.c:44

fail

#define fail()

Definition: checkasm.h:80

depth

int depth

Definition: v4l.c:62

AVStream::codec

AVCodecContext * codec

Codec context associated with this stream.

Definition: avformat.h:896

internal.h

common internal API header

av_image_check_size

int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)

Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...

Definition: imgutils.c:251

v4l_class

static const AVClass v4l_class

Definition: v4l.c:347

AVFormatContext::filename

char filename[1024]

input or output filename

Definition: avformat.h:1390

AVCodecContext::width

int width

picture width / height.

Definition: avcodec.h:1711

v4l_mm_read_picture

static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)

Definition: v4l.c:257

AV_PIX_FMT_BGR24

packed RGB 8:8:8, 24bpp, BGRBGR...

Definition: pixfmt.h:66

AVCodecContext::height

int height

Definition: avcodec.h:1711

FF_ARRAY_ELEMS

#define FF_ARRAY_ELEMS(a)

Definition: sinewin_tablegen_template.c:36

read_header

static int read_header(FFV1Context *f)

Definition: ffv1dec.c:638

VideoData::gb_buf

struct video_mmap gb_buf

Definition: v4l.c:55

av_gettime

int64_t av_gettime(void)

Get the current time in microseconds.

Definition: time.c:39

AVStream

Stream structure.

Definition: avformat.h:877

read_packet

static int read_packet(void *opaque, uint8_t *buf, int buf_size)

Definition: avio_reading.c:42

AVCodecContext::codec_type

enum AVMediaType codec_type

Definition: avcodec.h:1540

AVCodecContext::codec_id

enum AVCodecID codec_id

Definition: avcodec.h:1549

AV_PIX_FMT_YUYV422

packed YUV 4:2:2, 16bpp, Y0 Cb Y1 Cr

Definition: pixfmt.h:64

buf

void * buf

Definition: avisynth_c.h:553

VideoData::standard

int standard

Definition: bktr.c:60

AVClass

Describe the class of an AVClass context structure.

Definition: log.h:67

AVRational

rational number numerator/denominator

Definition: rational.h:43

AV_OPT_FLAG_DECODING_PARAM

#define AV_OPT_FLAG_DECODING_PARAM

a generic parameter which can be set by the user for demuxing or decoding

Definition: opt.h:276

VideoData::video_buf

uint8_t * video_buf

Definition: v4l.c:53

#define s1

Definition: regdef.h:38

options

static const AVOption options[]

Definition: v4l.c:339

AV_PIX_FMT_BGR565

#define AV_PIX_FMT_BGR565

Definition: pixfmt.h:322

flags

static int flags

Definition: cpu.c:47

VideoData::frame_format

int frame_format

Definition: v4l.c:45

palette

int palette

Definition: v4l.c:61

VideoData::frame_size

int frame_size

Definition: v4l.c:49

AV_PIX_FMT_YUV420P

planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)

Definition: pixfmt.h:63

AV_PIX_FMT_GRAY8

Y , 8bpp.

Definition: pixfmt.h:71

AVFMT_NOFILE

#define AVFMT_NOFILE

Demuxer will use avio_open, no opened file should be provided by the caller.

Definition: avformat.h:477

rational.h

rational numbers

grab_read_close

static int grab_read_close(AVFormatContext *s1)

Definition: v4l.c:323

VideoData::gb_frame

int gb_frame

Definition: v4l.c:56

AVRational::den

int den

denominator

Definition: rational.h:45

VideoData::gb_buffers

struct video_mbuf gb_buffers

Definition: v4l.c:54

grab_read_header

static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)

Definition: v4l.c:76

ff_v4l_demuxer

AVInputFormat ff_v4l_demuxer

Definition: v4l.c:355

AVFormatContext::priv_data

void * priv_data

Format private data.

Definition: avformat.h:1342

log.h

VideoData::time_frame

int64_t time_frame

Definition: v4l.c:48

AVInputFormat::name

const char * name

A comma separated list of short names for the format.

Definition: avformat.h:661

AVMEDIA_TYPE_VIDEO

Definition: avutil.h:193

AV_CODEC_ID_RAWVIDEO

Definition: avcodec.h:120

VideoData::audio_saved

struct video_audio audio_saved

Definition: v4l.c:51

AVPixelFormat

Pixel format.

Definition: pixfmt.h:61

AVPacket

This structure stores compressed data.

Definition: avcodec.h:1444

AVPacket::pts

int64_t pts

Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...

Definition: avcodec.h:1460

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