Example for ffmpeg_grabber (ffmpeg_grabber_video4linux)

Instantiates ffmpeg_grabber device implemented by FfmpegGrabber. More...

Collaboration diagram for Example for ffmpeg_grabber (ffmpeg_grabber_video4linux):

Instantiates ffmpeg_grabber device implemented by FfmpegGrabber.

# read from a video4linux source
device ffmpeg_grabber
v4l2
v4ldevice /dev/video0
width 640
height 480

If this text is saved in a file called ffmpeg_grabber_video4linux.ini then the device can be created by doing:

yarpdev --file ffmpeg_grabber_video4linux.ini

Of course, the configuration could be passed just as command line options, or as a yarp::os::Property object in a program:

Property p;
p.fromConfigFile("ffmpeg_grabber_video4linux.ini");
// of course you could construct the Property object on-the-fly
PolyDriver dev;
dev.open(p);
if (dev.isValid()) { /* use the device via view method */ }

Here is a list of properties checked when starting up a device based on this configuration file. Note that which properties are checked can depend on whether other properties are present. In some cases properties can also vary between operating systems. So this is just an example

PROPERTY	DESCRIPTION	DEFAULT
device
source	media file to read from	default.avi
loop	media should loop (default)
noloop	media should not loop
sync	sync on image or audio (if have to choose)?	image
nodelay	media will play in simulated realtime unless this is present
pace	simulated realtime multiplier factor (must be <1 right now)	1.0
v4l	if present, read from video4linux
v4l1	if present, read from video4linux
v4l2	if present, read from video4linux2
v4ldevice	device name	/dev/video0
time_base_num
channel
standard
width	width of image	640
height	height of image	480
audio	optional audio device

See also

FfmpegGrabber