VIDEO_GOP

Description

Get or set the GOP configuration (the frame interval in two successive I frames).

The URL is valid if only if the encoder is MPEG4 or H264.in EPL and PlatformT encoding devices.

In PlatformT encoder, it supports the H.246, MPEG4 and MJPEG. In MPEG4 and H264, they share the same variable of GOP. In dual streaming mode, the CHANNEL=n indicates the video stream for setting the video encoder GOP. For example, the CHANNEL=1&VIDEO_GOP=5 sets the video stream 1 GOP to 5.

The benefit of larger GOP is lower average bit rate in video streaming if there is less big moving objects. But, it might still get high bit rate or poor image quality if there are many moving objects.

In constant video bit rate mode, the device adapts bit rate by 1 second basis. The bit rate will not be affected when we enlarge the GOP. Therefore, the GOP setting is only valid in the variable bit rate mode.

In EPL, there is a video variable FPS mode, in this mode, the GOP is fixed to 2. This URL will not take effective even the device is in variable bit rate mode and encoder is MPEG4.

The device will accept the GOP change and will be applied to the device when the FPS mode, encoder type and video bit rate mode are changed to the constant FPS mode, MPEG4/H.264 encoder and variable bit rate mode,

If the CHANNEL=n was not set with this URL to the Multi-Channel device, this command is read-only command and the CHANNEL 1 video server's VIDEO_GOP configuration will be returned. If the CHANNEL 1 video server does not connect to the router, the error message will be returned.

Input argument

n
where n could be 0~60.
0: means the GOP sync with the frame rate. One I frame in 1 second. This is the default setting. People do not need to change the GOP as they changed the frame rate in MPEG4 or H.264.
1~60: set the GOP value. The number of I frames in a second depends on GOV and frame rate then.

Attribute

Return Message

VIDEO_GOP='0'

OK: VIDEO_GOP='0'
or
ERROR: VIDEO_GOP='0'

Applicability

Status

Valid

See Also

VIDEO_ENCODER, VIDEO_MPEG4_QUALITY, VIDEO_H264_QUALITY, VIDEO_FPS_NUM, VIDEO_FPS_RATIO, VIDEO_FPS

Example

Back To

HOME, ENCODER CGI