Gxv3501/Gxv3504 Video & Audio - Grandstream Networks GXV3501 User Manual

GXV3501/GXV3504 Digital Video Server
GXV3501/GXV3504 Video & Audio Page
Video Settings
Preferred Video Codec – The
GXV3501/GXV3504 supports the H.264 video
codec.
Resolution – The higher the resolution is, the
better the video quality is, and higher
bandwidth is required.
Low ----------------------- High
Resolution QCIF CIF 2CIF D1
Bit Rate – The number of bits that are
conveyed or processed per unit of time.
Maximum Frame Rate – The video frame rate is adjustable based on network conditions.
Increasing the frame rate will increase the amount of data significantly therefore consuming
more bandwidth. Video will be impaired due to packet loss when there is insufficient
bandwidth.
Bit Rate Control – Variable Bit rate (VBR) and Constant Bit Rate (CBR).
Variable Bit Rate - If VBR is selected, the codec varies the amount of output data per time
segment. VBR produces a better quality-to-space ratio. The bits available are used to enable
more flexibly and encode sound or video data more accurately, with fewer bits used in less
demanding passages and more bits used in difficult-to-encode passages.
Constant Bit Rate - If CBR is selected, the codec‟s output data is constant regardless of the
input data. The output bit rate is defined in "Bit rate". CBR is useful for streaming multimedia
content on limited capacity channels. It is easier to calculate required bandwidth as well as
the required storage space using CBR.
Image Quality – If „Bit Rate Control‟ is set to "VBR", "Image quality" needs to be configured.
The better the video quality is, the higher the bit rate will be.
I-frame Interval – While streaming video over a network, compression technologies are used
to show the incremental difference between each frame. I-frames are used to help keep the
video looking normal. When intervals are shorter, the video quality is higher but uses more
bandwidth.
NOTE: The users might need to configure the Primary Stream and Secondary Stream
properly. Sometimes, the user might like to watch the live video stream from the web GUI in
low resolution mode while recording a copy in high resolution mode due to the limitation of
internet bandwidth. In this case, for example, primary stream can be configured to have better
resolution, and then the users can use primary stream to record while watching secondary
video streams.
Audio Settings
Audio Compression – Audio compression is a form of data compression designed to reduce
Firmware 1.0.2.3 Page 17 of 34
Grandstream Networks, Inc. 11/2009