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v4l2.c File Reference

Video4Linux2 grab interface. More...

#include "v4l2-common.h"

Go to the source code of this file.

Data Structures

struct  video_data
 
struct  buff_data
 

Macros

#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 SET_WRAPPERS(prefix)
 
#define v4l2_open   s->open_f
 
#define v4l2_close   s->close_f
 
#define v4l2_dup   s->dup_f
 
#define v4l2_ioctl   s->ioctl_f
 
#define v4l2_read   s->read_f
 
#define v4l2_mmap   s->mmap_f
 
#define v4l2_munmap   s->munmap_f
 
#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 (const struct video_data *s, int fd)
 
static void list_formats (AVFormatContext *ctx, int fd, int type)
 
static void list_standards (AVFormatContext *ctx)
 
static int mmap_init (AVFormatContext *ctx)
 
static void mmap_release_buffer (void *opaque, uint8_t *data)
 
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 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 V4L_ALLFORMATS   3

Definition at line 41 of file v4l2.c.

#define V4L_RAWFORMATS   1

Definition at line 42 of file v4l2.c.

Referenced by list_formats().

#define V4L_COMPFORMATS   2

Definition at line 43 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 48 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 53 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 58 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 65 of file v4l2.c.

Referenced by init_convert_timestamp().

#define SET_WRAPPERS (   prefix)
Value:
do { \
s->open_f = prefix ## open; \
s->close_f = prefix ## close; \
s->dup_f = prefix ## dup; \
s->ioctl_f = prefix ## ioctl; \
s->read_f = prefix ## read; \
s->mmap_f = prefix ## mmap; \
s->munmap_f = prefix ## munmap; \
} while (0)

Referenced by device_open().

#define v4l2_open   s->open_f

Referenced by device_open().

#define v4l2_close   s->close_f
#define v4l2_dup   s->dup_f
#define v4l2_ioctl   s->ioctl_f
#define v4l2_read   s->read_f
#define v4l2_mmap   s->mmap_f

Referenced by mmap_init().

#define v4l2_munmap   s->munmap_f

Referenced by mmap_close().

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

Definition at line 993 of file v4l2.c.

#define DEC   AV_OPT_FLAG_DECODING_PARAM

Definition at line 994 of file v4l2.c.

Function Documentation

static int device_open ( AVFormatContext ctx)
static

Definition at line 106 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 185 of file v4l2.c.

Referenced by device_try_init().

static int first_field ( const struct video_data s,
int  fd 
)
static

Definition at line 228 of file v4l2.c.

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

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

Definition at line 271 of file v4l2.c.

Referenced by v4l2_read_header().

static void list_standards ( AVFormatContext ctx)
static

Definition at line 309 of file v4l2.c.

Referenced by v4l2_read_header().

static int mmap_init ( AVFormatContext ctx)
static

Definition at line 333 of file v4l2.c.

Referenced by v4l2_read_header().

static void mmap_release_buffer ( void opaque,
uint8_t data 
)
static

Definition at line 406 of file v4l2.c.

Referenced by mmap_read_frame().

static int init_convert_timestamp ( AVFormatContext ctx,
int64_t  ts 
)
static

Definition at line 437 of file v4l2.c.

Referenced by convert_timestamp().

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

Definition at line 470 of file v4l2.c.

Referenced by mmap_read_frame().

static int mmap_read_frame ( AVFormatContext ctx,
AVPacket pkt 
)
static

Definition at line 491 of file v4l2.c.

Referenced by v4l2_read_packet().

static int mmap_start ( AVFormatContext ctx)
static

Definition at line 593 of file v4l2.c.

Referenced by v4l2_read_header().

static void mmap_close ( struct video_data s)
static

Definition at line 624 of file v4l2.c.

Referenced by v4l2_read_close().

static int v4l2_set_parameters ( AVFormatContext s1)
static

Definition at line 641 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 757 of file v4l2.c.

Referenced by v4l2_read_header().

static int v4l2_read_header ( AVFormatContext s1)
static

Definition at line 809 of file v4l2.c.

static int v4l2_read_packet ( AVFormatContext s1,
AVPacket pkt 
)
static

Definition at line 960 of file v4l2.c.

static int v4l2_read_close ( AVFormatContext s1)
static

Definition at line 979 of file v4l2.c.

Variable Documentation

const int desired_video_buffers = 256
static

Definition at line 39 of file v4l2.c.

Referenced by mmap_init().

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 = -1 }, -1, 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" },
{ "use_libv4l2", "use libv4l2 (v4l-utils) convertion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
{ NULL },
}

Definition at line 996 of file v4l2.c.

const AVClass v4l2_class
static
Initial value:
= {
.class_name = "V4L2 indev",
.item_name = av_default_item_name,
.option = options,
}

Definition at line 1021 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_packet = v4l2_read_packet,
.read_close = v4l2_read_close,
.flags = AVFMT_NOFILE,
.priv_class = &v4l2_class,
}

Definition at line 1029 of file v4l2.c.