yavta(1)

Yet Another V4L2 Test Application

Section 1 yavta bookworm source

Description

YAVTA

NAME

yavta - Yet Another V4L2 Test Application

SYNOPSIS

yavta [options] device

DESCRIPTION

Supported options: -B, --buffer-type Buffer type ("capture", "output",

"capture-mplane" or "output-mplane")

-c, --capture[=nframes] Capture frames -C, --check-overrun Verify dequeued frames for buffer overrun -d, --delay Delay (in ms) before requeuing buffers -f, --format format Set the video format

use -f help to list the supported formats

-F, --file[=name] Read/write frames from/to disk

For video capture devices, the first ’#’ character in the file name is expanded to the frame sequence number. The default file name is ’frame-#.bin’.

-h, --help Show this help screen -i, --input input Select the video input -I, --fill-frames Fill frames with check pattern before queuing them -l, --list-controls List available controls -n, --nbufs n Set the number of video buffers -p, --pause[=n] Pause after n frames (0 if n isn’t specified) -q, --quality n MJPEG quality (0-100) -r, --get-control ctrl Get control ’ctrl’ -R, --realtime=[priority] Enable realtime RR scheduling -s, --size WxH Set the frame size -t, --time-per-frame num/denom Set the time per frame (eg. 1/25 = 25 fps) -u, --userptr Use the user pointers streaming method -w, --set-control ’ctrl value’ Set control ’ctrl’ to ’value’
--buffer-prefix

Write portions of buffer before data_offset

--buffer-size

Buffer size in bytes

--enum-formats

Enumerate formats

--enum-inputs

Enumerate inputs

--fd

Use a numeric file descriptor insted of a device

--field field

Set the format field order

Valid values for field are none, top, bottom, interlaced, seq-tb, seq-bt, alternate, interlaced-tb and interlaced-bt.

--log-status

Log device status

--no-query

Don’t query capabilities on open

--offset

User pointer buffer offset from page start

--premultiplied

Color components are premultiplied by alpha value

--queue-late

Queue buffers after streamon, not before

--requeue-last

Requeue the last buffers before streamoff

--reset-controls

Reset all available controls to their default value

--timestamp-source

Set timestamp source on output buffers [eof, soe]

--skip n

Skip the first n frames

--sleep-forever

Sleep forever after configuring the device

--stride value

Line stride in bytes