Inhaltsverzeichnis
Werbung
AXIS Q1615-E Mk II Network Camera
Video and Audio
•
Resolution. Select the default resolution.
•
Compression. The compression level affects the image quality, bandwidth and file size of saved images; the lower the
compression, the higher the image quality with higher bandwidth requirements and larger file sizes.
•
Mirror image. If required, the image can be mirrored.
•
Rotate image. If required, the image can be rotated.
•
Maximum frame rate. To avoid bandwidth problems, the frame rate allowed to each viewer can be Limited to a fixed
amount. Alternatively, the frame rate can be set as Unlimited, which means the Axis product always delivers the highest
frame rate possible under the current conditions.
•
Overlay settings. See About overlay text on page 29.
Click Save to apply the new settings.
About H.264
H.264, also known as MPEG-4 Part 10/AVC, is a video compression standard that provides high quality video streams at low bitrates.
An H.264 video stream consists of different types of frames such as I-frames and P-frames. An I-frame is a complete image, whereas
P-frames only contain the differences from previous frames.
About Zipstream
Axis' Zipstream Technology is a bitrate reduction technology optimized for video surveillance. Zipstream reduces the average bitrate
in the H.264 stream by removing unnecessary data and makes it possible to allow higher resolutions, reduce storage cost or
to keep recordings for a longer time.
To reduce the bitrate, Zipstream reduces the number of bits in the areas of the image that are less interesting from a video
surveillance perspective, for example the background. Image details that are important for forensic video analysis, for example faces
and license plates, are preserved with enough number of bits.
Axis' Zipstream Technology for H.264 conforms to the H.264 standard and is compatible with third-party clients and VMS solutions
that decode H.264 video.
Recommended use of bitrate reduction
Zipstream offers a number of bitrate reduction presets, from Low to Extreme. Low bitrate reduction is enabled by default and is
safe to use in all applications while still reducing the bitrate.
For cloud-connected cameras or cameras using edge storage that need to limit the bitrate for increased storage time it is
recommended to select the Extreme bitrate reduction. This setting is suitable to combine with motion detection triggering and
variable bitrate (VBR) where the bitrate is allowed to adapt to changes in complexity in the scene.
How to save bandwidth and storage using Zipstream
The bitrate controller built into the product can be combined with Zipstream to ensure a maximum bitrate (MBR) limit. We
recommend using VBR or MBR with a high bitrate limit to enable the full potential of Zipstream. For instance in railway surveillance
where at times there is a lot of movement in the scene and where it is important to capture details, such as facial features, the MBR
should be set to 10Mbit/s (for 1080p resolution at 30 fps).
To further save bandwidth go to Setup > Video & Audio > Video Stream and do one or more of the following:
•
Go to the Image tab and set a low Maximum frame rate value.
•
Go to the H.264 tab and set a high GOP length value.
•
Go to the Zipstream tab and select Extreme H.264 bitrate reduction.
•
Go to the Zipstream tab. Enable Dynamic GOP and set a high Max dynamic GOP length value.
24
Werbung
Inhaltsverzeichnis
