Video4Linux2 grab interface. More...

#include "config.h"
#include "libavformat/internal.h"
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <linux/videodev2.h>
#include "libavutil/avassert.h"
#include "libavutil/imgutils.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "avdevice.h"
#include "timefilter.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/avstring.h"

Data Structures
struct	video_data

struct	buff_data

struct	fmt_map

Macros
#define	v4l2_open open

#define	v4l2_close close

#define	v4l2_dup dup

#define	v4l2_ioctl ioctl

#define	v4l2_read read

#define	v4l2_mmap mmap

#define	v4l2_munmap munmap

#define	V4L_ALLFORMATS 3

#define	V4L_RAWFORMATS 1

#define	V4L_COMPFORMATS 2

#define	V4L_TS_DEFAULT 0
	Return timestamps to the user exactly as returned by the kernel.

#define	V4L_TS_ABS 1
	Autodetect the kind of timestamps returned by the kernel and convert to absolute (wall clock) timestamps.

#define	V4L_TS_MONO2ABS 2
	Assume kernel timestamps are from the monotonic clock and convert to absolute timestamps.

#define	V4L_TS_CONVERT_READY V4L_TS_DEFAULT
	Once the kind of timestamps returned by the kernel have been detected, the value of the timefilter (NULL or not) determines whether a conversion takes place.

#define	OFFSET(x) offsetof(struct video_data, x)

#define	DEC AV_OPT_FLAG_DECODING_PARAM

Functions
static int	device_open (AVFormatContext *ctx)

static int	device_init (AVFormatContext ctx, int width, int *height, uint32_t pix_fmt)

static int	first_field (int fd)

static uint32_t	fmt_ff2v4l (enum AVPixelFormat pix_fmt, enum AVCodecID codec_id)

static enum AVPixelFormat	fmt_v4l2ff (uint32_t v4l2_fmt, enum AVCodecID codec_id)

static enum AVCodecID	fmt_v4l2codec (uint32_t v4l2_fmt)

static void	list_formats (AVFormatContext *ctx, int fd, int type)

static int	mmap_init (AVFormatContext *ctx)

static void	mmap_release_buffer (AVPacket *pkt)

static int	init_convert_timestamp (AVFormatContext *ctx, int64_t ts)

static int	convert_timestamp (AVFormatContext ctx, int64_t ts)

static int	mmap_read_frame (AVFormatContext ctx, AVPacket pkt)

static int	mmap_start (AVFormatContext *ctx)

static void	mmap_close (struct video_data *s)

static int	v4l2_set_parameters (AVFormatContext *s1)

static uint32_t	device_try_init (AVFormatContext s1, enum AVPixelFormat pix_fmt, int width, int height, enum AVCodecID codec_id)

static int	v4l2_read_header (AVFormatContext *s1)

static int	v4l2_read_packet (AVFormatContext s1, AVPacket pkt)

static int	v4l2_read_close (AVFormatContext *s1)

Variables
static const int	desired_video_buffers = 256

static struct fmt_map	fmt_conversion_table []

static const AVOption	options []

static const AVClass	v4l2_class

AVInputFormat	ff_v4l2_demuxer

Detailed Description

Video4Linux2 grab interface.

Part of this file is based on the V4L2 video capture example (http://v4l2spec.bytesex.org/v4l2spec/capture.c)

Thanks to Michael Niedermayer for providing the mapping between V4L2_PIX_FMT_* and AV_PIX_FMT_*

Definition in file v4l2.c.

Macro Definition Documentation

#define v4l2_open open

Definition at line 62 of file v4l2.c.

Referenced by device_open().

#define v4l2_close close

Definition at line 63 of file v4l2.c.

Referenced by device_open(), v4l2_read_close(), and v4l2_read_header().

#define v4l2_dup dup

Definition at line 64 of file v4l2.c.

#define v4l2_ioctl ioctl

Definition at line 65 of file v4l2.c.

Referenced by device_init(), device_open(), first_field(), mmap_close(), mmap_init(), mmap_read_frame(), mmap_release_buffer(), mmap_start(), v4l2_read_header(), and v4l2_set_parameters().

#define v4l2_read read

Definition at line 66 of file v4l2.c.

#define v4l2_mmap mmap

Definition at line 67 of file v4l2.c.

Referenced by mmap_init().

#define v4l2_munmap munmap

Definition at line 68 of file v4l2.c.

Referenced by mmap_close().

#define V4L_ALLFORMATS 3

Definition at line 73 of file v4l2.c.

#define V4L_RAWFORMATS 1

Definition at line 74 of file v4l2.c.

Referenced by list_formats().

#define V4L_COMPFORMATS 2

Definition at line 75 of file v4l2.c.

Referenced by list_formats().

#define V4L_TS_DEFAULT 0

Return timestamps to the user exactly as returned by the kernel.

Definition at line 80 of file v4l2.c.

#define V4L_TS_ABS 1

Autodetect the kind of timestamps returned by the kernel and convert to absolute (wall clock) timestamps.

Definition at line 85 of file v4l2.c.

Referenced by init_convert_timestamp().

#define V4L_TS_MONO2ABS 2

Assume kernel timestamps are from the monotonic clock and convert to absolute timestamps.

Definition at line 90 of file v4l2.c.

Referenced by init_convert_timestamp().

#define V4L_TS_CONVERT_READY V4L_TS_DEFAULT

Once the kind of timestamps returned by the kernel have been detected, the value of the timefilter (NULL or not) determines whether a conversion takes place.

Definition at line 97 of file v4l2.c.

Referenced by init_convert_timestamp().

#define OFFSET ( x ) offsetof(struct video_data, x)

Definition at line 924 of file v4l2.c.

#define DEC AV_OPT_FLAG_DECODING_PARAM

Definition at line 925 of file v4l2.c.

Function Documentation

static int device_open ( AVFormatContext * ctx )

static

Definition at line 161 of file v4l2.c.

Referenced by v4l2_read_header().

static int device_init	(	AVFormatContext *	ctx,
		int *	width,
		int *	height,
		uint32_t	pix_fmt
	)

static

Definition at line 216 of file v4l2.c.

Referenced by device_try_init().

static int first_field ( int fd )

static

Definition at line 257 of file v4l2.c.

Referenced by dnxhd_decode_frame(), dnxhd_encode_picture(), and v4l2_read_header().

static uint32_t fmt_ff2v4l	(	enum AVPixelFormat	pix_fmt,
		enum AVCodecID	codec_id
	)

static

Definition at line 273 of file v4l2.c.

Referenced by device_try_init().

static enum AVPixelFormat fmt_v4l2ff	(	uint32_t	v4l2_fmt,
		enum AVCodecID	codec_id
	)

static

Definition at line 289 of file v4l2.c.

Referenced by list_formats(), and v4l2_read_header().

static enum AVCodecID fmt_v4l2codec ( uint32_t v4l2_fmt )

static

Definition at line 303 of file v4l2.c.

Referenced by device_try_init(), and list_formats().

static void list_formats	(	AVFormatContext *	ctx,
		int	fd,
		int	type
	)

static

Definition at line 342 of file v4l2.c.

Referenced by v4l2_read_header().

static int mmap_init ( AVFormatContext * ctx )

static

Definition at line 381 of file v4l2.c.

Referenced by v4l2_read_header().

static void mmap_release_buffer ( AVPacket * pkt )

static

Definition at line 451 of file v4l2.c.

Referenced by mmap_read_frame().

static int init_convert_timestamp	(	AVFormatContext *	ctx,
		int64_t	ts
	)

static

Definition at line 485 of file v4l2.c.

Referenced by convert_timestamp().

static int convert_timestamp	(	AVFormatContext *	ctx,
		int64_t *	ts
	)

static

Definition at line 514 of file v4l2.c.

Referenced by mmap_read_frame().

static int mmap_read_frame	(	AVFormatContext *	ctx,
		AVPacket *	pkt
	)

static

Definition at line 535 of file v4l2.c.

Referenced by v4l2_read_packet().

static int mmap_start ( AVFormatContext * ctx )

static

Definition at line 598 of file v4l2.c.

Referenced by v4l2_read_header().

static void mmap_close ( struct video_data * s )

static

Definition at line 632 of file v4l2.c.

Referenced by v4l2_read_close().

static int v4l2_set_parameters ( AVFormatContext * s1 )

static

Definition at line 649 of file v4l2.c.

Referenced by v4l2_read_header().

static uint32_t device_try_init	(	AVFormatContext *	s1,
		enum AVPixelFormat	pix_fmt,
		int *	width,
		int *	height,
		enum AVCodecID *	codec_id
	)

static

Definition at line 744 of file v4l2.c.

Referenced by v4l2_read_header().

static int v4l2_read_header ( AVFormatContext * s1 )

static

Definition at line 777 of file v4l2.c.

static int v4l2_read_packet	(	AVFormatContext *	s1,
		AVPacket *	pkt
	)

static

Definition at line 895 of file v4l2.c.

static int v4l2_read_close ( AVFormatContext * s1 )

static

Definition at line 914 of file v4l2.c.

Variable Documentation

const int desired_video_buffers = 256

static

Definition at line 71 of file v4l2.c.

Referenced by mmap_init().

struct fmt_map fmt_conversion_table[]

static

Initial value:

= {
    
    { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420  },
    { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YVU420  },
    { AV_PIX_FMT_YUV422P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
    { AV_PIX_FMT_YUYV422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV    },
    { AV_PIX_FMT_UYVY422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY    },
    { AV_PIX_FMT_YUV411P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
    { AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410  },
    { AV_PIX_FMT_RGB555LE,AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555  },
    { AV_PIX_FMT_RGB555BE,AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555X },
    { AV_PIX_FMT_RGB565LE,AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565  },
    { AV_PIX_FMT_RGB565BE,AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565X },
    { AV_PIX_FMT_BGR24,   AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24   },
    { AV_PIX_FMT_RGB24,   AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24   },
    { AV_PIX_FMT_BGR0,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32   },
    { AV_PIX_FMT_0RGB,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB32   },
    { AV_PIX_FMT_GRAY8,   AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY    },
    { AV_PIX_FMT_NV12,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12    },
    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MJPEG,    V4L2_PIX_FMT_MJPEG   },
    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MJPEG,    V4L2_PIX_FMT_JPEG    },
}

Definition at line 132 of file v4l2.c.

const AVOption options[]

static

Initial value:

= {
    { "standard",     "TV standard, used only by analog frame grabber",            OFFSET(standard),     AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0,       DEC },
    { "channel",      "TV channel, used only by frame grabber",                    OFFSET(channel),      AV_OPT_TYPE_INT,    {.i64 = 0 },    0, INT_MAX, DEC },
    { "video_size",   "A string describing frame size, such as 640x480 or hd720.", OFFSET(width),        AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL},  0, 0,       DEC },
    { "pixel_format", "Preferred pixel format",                                    OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
    { "input_format", "Preferred pixel format (for raw video) or codec name",      OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
    { "framerate",    "",                                                          OFFSET(framerate),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
    { "list_formats", "List available formats and exit",                           OFFSET(list_format),  AV_OPT_TYPE_INT,    {.i64 = 0 },  0, INT_MAX, DEC, "list_formats" },
    { "all",          "Show all available formats",                                OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_ALLFORMATS  },    0, INT_MAX, DEC, "list_formats" },
    { "raw",          "Show only non-compressed formats",                          OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_RAWFORMATS  },    0, INT_MAX, DEC, "list_formats" },
    { "compressed",   "Show only compressed formats",                              OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_COMPFORMATS },    0, INT_MAX, DEC, "list_formats" },
    { "timestamps",   "Kind of timestamps for grabbed frames",                     OFFSET(ts_mode),      AV_OPT_TYPE_INT,    {.i64 = 0 }, 0, 2, DEC, "timestamps" },
    { "default",      "Use timestamps from the kernel",                            OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_DEFAULT  }, 0, 2, DEC, "timestamps" },
    { "abs",          "Use absolute timestamps (wall clock)",                      OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_ABS      }, 0, 2, DEC, "timestamps" },
    { "mono2abs",     "Force conversion from monotonic to absolute timestamps",    OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
    { "ts",           "Kind of timestamps for grabbed frames",                     OFFSET(ts_mode),      AV_OPT_TYPE_INT,    {.i64 = 0 }, 0, 2, DEC, "timestamps" },
    { NULL },
}

Definition at line 927 of file v4l2.c.

const AVClass v4l2_class

static

Initial value:

= {
    .class_name = "V4L2 indev",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
}

Definition at line 946 of file v4l2.c.

AVInputFormat ff_v4l2_demuxer

Initial value:

= {
    .name           = "video4linux2,v4l2",
    .long_name      = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
    .priv_data_size = sizeof(struct video_data),
    .read_header    = v4l2_read_header,
    .read_packet    = v4l2_read_packet,
    .read_close     = v4l2_read_close,
    .flags          = AVFMT_NOFILE,
    .priv_class     = &v4l2_class,
}

Definition at line 953 of file v4l2.c.

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation