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 PlatformT encoders, 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 PlatformA encoders, 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 multiple channel video encoders, this command is read-only command and the CHANNEL 1 module's VIDEO_GOP configuration will be returned. If the CHANNEL 1 module does not connect to the router, the error message will be returned.
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 frame interval in two successive I frames).Note:
In Platform-A1 firmware, it use seconds for GOP settings. Therefore the value n has to be the multiple of frame rate.
The n could be 0~150.
0: The GOP length is 1 second.
The GOP value in the return message will be changed by firmware if the value n is not the multiple of frame rate.
The firmware will use the close but larger GOP value.
For example: The return value is OK: VIDEO_GOP=60 for the URL VIDEO_GOP=38 when frame rate is 30.
VIDEO_GOP='0'
OK: VIDEO_GOP='0'
or
ERROR: VIDEO_GOP='0'
Valid
VIDEO_ENCODER, VIDEO_MPEG4_QUALITY, VIDEO_H264_QUALITY, VIDEO_FPS_NUM, VIDEO_FPS
http://ip:port/cgi-bin/encoder?USER=Admin&PWD=123456&VIDEO_GOP
or
http://ip:port/cgi-bin/cmd/encoder?VIDEO_GOP
http://ip:port/cgi-bin/encoder?USER=Admin&PWD=123456&VIDEO_GOP=0
or
http://ip:port/cgi-bin/cmd/encoder?VIDEO_GOP=0