White Paper: WiseStream II Technology. hanwhasecurity.com

Transcription

1 White Paper: WiseStream II Technology hanwhasecurity.com

2 Contents 1. Introduction & Background p WiseStream II Technology p WiseStream II Setup p Conclusion p.7

3 1. Introduction & Background Introduction The expansion of high quality content in broadcast and digital cameras raised expectations on video quality, fueling the demand for high resolution cameras in the video surveillance market. And as the adoption of high quality cameras increases, so does the data size from these video surveillance systems. Expanded system scale affects the system infrastructure. For example, a broadband network environment is required for large video data transmission. Storage capacity also increases with resolution and bitrate increases and is proportional to system development and maintenance costs. The system can accommodate more cameras and record more footage without system expansion while reducing data size and maintaining video quality. This advancement will be more valuable for large scale surveillance systems. The trend for security cameras is to provide high quality video while reducing overall data transmission size. Hanwha Techwin developed the WiseStream technology to address this trend. WiseStream allows users to reduce overall data size while maintaining high quality video. Hanwha Techwin introduces WiseStream II technology that provides higher video quality at even lower data size. The WiseStream II can reduce data size by up to 99% in very low-motion environments. WiseStream II builds upon WiseStream I by adding two additional components: High Frequency Engine and Dynamic Frame Rate control. Background Data compression is required for efficient network streaming due to the large data size of the original video. Video codecs are used for compression and restoration. H.264, H.265 and MPEG are the most common compression formats in the video surveillance industry and are the most widely adopted codecs in video security, providing good video quality at substantially lower bit rates than other formats. Frame composition of H.264/H.265 Unlike compression methods such as MJPEG, H.264 and H.265 codecs reduce data size by not transmitting duplicate data. H.264/H.265 codecs consist of an l-frame, which has complete data, and multiple P-frames, which only have data updated from the previous frame. This combination of l-frame and P-frames is called GOV (Group of Video) l-frame P-frame GOV length Figure 1. Composition of GOV 2

4 2. WiseStream II Technology WiseStream II Technology Hanwha Techwin WiseStream II is an advanced video compression technology based on motion analytics to maintain video quality while lowering data demands. While WiseStream II works with both H.264 and H.265, it is more effective with H.265. Dynamic GOV The data size of the l-frame from H.264/H.265 video is significantly larger than the P-frame. If the length of the GOV is made longer (meaning, more P-frames and fewer l-frames), then the size of the video data will decrease. Therefore, in situations where there is minimal movement, the optimal setting for GOV is long. For situation where there is a lot of movement, a short GOV is more appropriate. Hanwha Techwin's Dynamic GOV techwin's Dynamic GOV technology analyzes both motion and complexity in video, controlling the intervals between l-frames to maintain excellent video quality while lowering bandwidth consumption. l-frame transmission P-frame transmission Low scene complexity High scene complexity --> l-frame insertion Figure 2. Normal GOV bitrate Dynamic enabled Dynamic FPS In addition to adjusting the length of the GOV, WiseStream II also features Dynamic FPS technology to adjust the number of frames transmitted from the camera depending on the degree of motion in the video. The Dynamic FPS function detects the motion level within the specified motion detection zones, reducing the frame rate to 1 fps if there is no motion, and restoring the frame rate when motion is detected. This reduces unnecessary frame encoding when the captured frame is similar to the previous one, providing a savings in accumulated data over a period of time. No motion detected Motion detected No motion detected Figure 3. Dynamic Frame Rate adjustment based on motion detection Smart ROI In video, there are both dynamic and static areas of the scene. Users are normally more interested in viewing dynamic areas, where there is a lot of movement and activity, rather than the static areas which contain little motion. Hanwha Techwin's Smart ROI (Region of Interest) technology analyzes static and dynamic areas in video based on Hanwha Techwin's advanced intelligent video analytics. It then applies a different compression rate to each area affecting both video quality and bandwidth reduction. Motion areas will retain high quality, while static or background areas employ higher compression and lower quality. This allows critical movements to be captured in full definition. Traditionally, a user can 3

5 2. WiseStream II Technology specify a fixed Region of Interest for high quality video. The WiseStream II algorithm allows the camera to automatically and dynamically adapt to changing elements in the scene, not requiring a static ROI area. ROI Low Quality High Quality Figure 4. Compression rate adjustment by dynamic ROI areas 6.4 mbps 5.8 mbps 5.4 mbps 4.9 mbps Figure 5. Bandwidth 4.3 mbps 3.9 mbps Comparison of WiseStream Smart ROI Off and On 3.3 mbps 2.2 mbps No movement 3.0 mbps 2.0 mbps No movement 1.2 mbps 1.1 mbps WiseStream Off WiseStream high Dynamic GOV enable Predictive Control (PBC) H.264/H.265 codecs predict and calculate the complexity of a scene for compression. However, higher bitrates often occur because of the challenges associated with real-time calculations. Hanwha Techwin's PBC technology has an improved logic for real-time complexity calculations. It predicts changes in the scene by examining the motion vectors and controls compression rate (quantization parameters) in advance to stabilize a bitrate overshoot. This prevents unnecessary increases in bitrate and optimizes the streaming data Legacy QP Control 10 QP Pre-Reduce Engine More bitrate overshoot in case of high complexity - Overshoot Increase - Overall Increase QP adjustment by complexity prediction - Overshoot Decrease - Overall Decrease Figure 6. QP control comparison Other Technologies Wisestream II reduces noise and minimizes image quality degradation caused by traditional image compression artifacts and image noise due to low light scenes. It applies a low pass filter and 3D-noise reduction techniques with different intensity depending on the level of sensitivity selected (low, medium, or high). 4

6 3. WiseStream II Setup WiseStream II Setup When using WiseStream II, it is necessary to consider how to compress data, adjust the GOV length, and select the approriate settings for the required video quality and network environment. Dynamic GOV setup If a video contains high motion levels, the GOV length will be kept as per user configuration. If the camera is placed in a situation where little motion occurs, the camera extends the GOV up to the dynamic GOV setting, allowing for bandwidth reductions. The dynamic l-frame setting options are based on frame rate and GOV length setting. When there is movement, l-frames will be inserted immediately. The camera's GOV length setup ranges from 1 to 240 frames (maximum 8 x frame rate) while the Dynamic GOV ranges from the GOV length to 480 frames (maximum 16 x frame rate). Settings are configured per video profile. 30fps / GOV length 30 30fps / GOV length fps / GOV length l-frame per 1 second 1 l-frame per 8 seconds 1 l-frame per 16 seconds Profile properties Resolution 2560 X 1920 (4:3) Frame rate 30 fps Maximum bitrate 4096 kbps (1536 ~ 30720) Advanced control VBR Encoding priority Frame rate GOV length 60 (1 ~ 240) Profile High Entropy coding CABAC Smart codec Disable Dynamic GOV Enable 240 (60 ~ 480) Dynamic FPS Enable Figure 7. Frame Rate, GOV, & Dynamic GOV Settings, per profile Dynamic FPS setup To save on bandwidth and storage, the video stream can be reduced to 1 frame per second. To configure this, simply enable the Dynamic FPS setting in the desired video profile in the camera setup. The camera will stream at 1 FPS when there is no motion detected in the motion detection areas. Ensure that Motion Detection is enabled and at least one detection area is defined. When motion is detected, the camera will return to the frame rate specified in the profile configuration. Dynamic FPS Enable Figure 8. Dynamic FPS Setting, per profile WiseStream II Smart ROI mode setup One can set the WiseStream compression rate for static areas by selecting the level of compression: low, middle and high. This setup is configured globally for all H.264/H.265 profiles. The dynamic areas will retain their compression level. Below is the average reduction rate for each level. 5

7 3. WiseStream II Setup Low: Average 15% data reduction versus WiseStream: Off Middle: Average 30% data size reduction versus WiseStream: Off High: Average 50% data reduction versus WiseStream: Off WiseStream Mode Off Low Medium High Figure 9. WiseStream Smart ROI global setting Change of data size Hanwha Techwin has tested WiseStream II in various real-life situations. Below are the results for a daytime, normal motion scene as well as a nighttime low motion scene, demonstrating significant data reductions. < Table 1 - Day, normal motion> Camera Setting Resolution Codec Figure 10. Day & high motion (left), Night & low motion (right) Average Saving Codec Average Saving WiseStream II Off 4.5Mbps - 3 Mbps 33% + Dynamic GOV (480) 2560 x 1920 H Mbps 42% H Mbps 57% + Dynamic FPS 2.0Mbps 55% 1.6 Mbps 64% < Table 2 - Night, very low motion> Camera Setting Resolution Codec Average Saving Codec Average Saving WiseStream II Off 6.9Mbps Mbps 36% + Dynamic GOV (480) 2560 x 1920 H Mbps 86% H Mbps 97% + Dynamic FPS 0.8Mbps 88% 0.06 Mbps 99% 6

8 4. Conclusion Conclusion As the video data size handled by video surveillance increases, the importance and necessity of data reduction techniques increases. WiseStream II is a technology that effectively reduces the data size while maintaining image quality. It can reduce data size by more than 50% when used with the H.264 codec, and has an additional data savings of 25% or more when used with H.265. It can further provide up to 99% data reduction in low-motion scenes. We hope that you will be able to add more/higher resolution cameras without needing more network resources and record for longer periods of time using less storage when you take advantage of the reduced data size achieved by using Hanwha Techwin's WiseStream II. 7

9 Hanwha Techwin America 500 Frank W. Burr Blvd. Suite 43 Teaneck, NJ Toll Free: Hanwha Techwin Co., Ltd. All rights reserved. Under no circumstances, this document shall be reproduced, distributed or changed, partially or wholly, without formal authorization of Hanwha Techwin Co.,Ltd. 8