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 void	list_standards (AVFormatContext *ctx)

static int	mmap_init (AVFormatContext *ctx)

static int	enqueue_buffer (int fd, int index)

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 int	device_try_init (AVFormatContext s1, enum AVPixelFormat pix_fmt, int width, int height, uint32_t desired_format, 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://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html)

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(), enqueue_buffer(), first_field(), list_standards(), mmap_close(), mmap_init(), mmap_read_frame(), 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 1030 of file v4l2.c.

#define DEC AV_OPT_FLAG_DECODING_PARAM

Definition at line 1031 of file v4l2.c.

Function Documentation

static int device_open ( AVFormatContext * ctx )

static

Definition at line 169 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 218 of file v4l2.c.

Referenced by device_try_init().

static int first_field ( int fd )

static

Definition at line 261 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 277 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 293 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 307 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 346 of file v4l2.c.

Referenced by v4l2_read_header().

static void list_standards ( AVFormatContext * ctx )

static

Definition at line 385 of file v4l2.c.

Referenced by v4l2_read_header().

static int mmap_init ( AVFormatContext * ctx )

static

Definition at line 409 of file v4l2.c.

Referenced by v4l2_read_header().

static int enqueue_buffer	(	int	fd,
		int	index
	)

static

Definition at line 480 of file v4l2.c.

Referenced by mmap_read_frame(), and mmap_release_buffer().

static void mmap_release_buffer ( AVPacket * pkt )

static

Definition at line 497 of file v4l2.c.

Referenced by mmap_read_frame().

static int init_convert_timestamp	(	AVFormatContext *	ctx,
		int64_t	ts
	)

static

Definition at line 526 of file v4l2.c.

Referenced by convert_timestamp().

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

static

Definition at line 555 of file v4l2.c.

Referenced by mmap_read_frame().

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

static

Definition at line 576 of file v4l2.c.

Referenced by v4l2_read_packet().

static int mmap_start ( AVFormatContext * ctx )

static

Definition at line 659 of file v4l2.c.

Referenced by v4l2_read_header().

static void mmap_close ( struct video_data * s )

static

Definition at line 689 of file v4l2.c.

Referenced by v4l2_read_close().

static int v4l2_set_parameters ( AVFormatContext * s1 )

static

Definition at line 707 of file v4l2.c.

Referenced by v4l2_read_header().

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

static

Definition at line 816 of file v4l2.c.

Referenced by v4l2_read_header().

static int v4l2_read_header ( AVFormatContext * s1 )

static

Definition at line 868 of file v4l2.c.

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

static

Definition at line 999 of file v4l2.c.

static int v4l2_read_close ( AVFormatContext * s1 )

static

Definition at line 1020 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

Definition at line 136 of file v4l2.c.

const AVOption options[]

static

Initial value:

= {
    { "standard",     "set TV standard, used only by analog frame grabber",       OFFSET(standard),     AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0,       DEC },
    { "channel",      "set TV channel, used only by frame grabber",               OFFSET(channel),      AV_OPT_TYPE_INT,    {.i64 = 0 },    0, INT_MAX, DEC },
    { "video_size",   "set frame size",                                           OFFSET(width),        AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL},  0, 0,   DEC },
    { "pixel_format", "set preferred pixel format",                               OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
    { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
    { "framerate",    "set frame rate",                                           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" },
    { "list_standards", "list supported standards and exit",                      OFFSET(list_standard), AV_OPT_TYPE_INT,   {.i64 = 0 },  0, 1, DEC, "list_standards" },
    { "all",            "show all supported standards",                           OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 },  0, 0, DEC, "list_standards" },
    { "timestamps",   "set type of timestamps for grabbed frames",                OFFSET(ts_mode),      AV_OPT_TYPE_INT,    {.i64 = 0 }, 0, 2, DEC, "timestamps" },
    { "ts",           "set type 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" },
    { NULL },
}

Definition at line 1033 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 1058 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 1065 of file v4l2.c.

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation