1. Compression System Optimization

2. Introduction Compression The reasons behind video compression. Common types of video compressions. The detail of I,P-frame. How does H.264 compress video to smaller data? The common scenario of different compression type to use.

3. Agenda Compressions I-frame, P-frame MJPEG (Motion JPEG) MPEG-4 / H.264 Scenario Compression Comparison

4. Reasoning behind Video Compression Reduce the amount of storage needed Increases the amount of recorded time Reduces the network bandwidth 3 most common types of Video Compressions: MJPEG MPEG-4 H.264 Compressions

5. Mainly 2 types of Frames, I & P I-frame is a self-containing frame that does not need references to other frames. P-frame uses reference to previous I- or P-frame, and will contain only information about the content that is different compared to previous frame. I I PP I I PPPPPP I I

6. Procedure of I-frame, P-frame Step1: Capture the I-frame as a reference frame. Step2: Capture the P-frame. Compare with I-frame and only store the difference in image. Step3: Capture the next P-frame. Compare with previous P-frame and only store the difference in image. The number of P-frame is defined by GOP (Group of Pictures) I I P P I I PPP PP P PP

7. Each image frame as an individual picture and compresses them one by one into a JPEG image Consists of I-frames only JPEG format can compress 4MB image data (BMP format) to 180KB MJPEG (Motion JPEG)

8. Capture one full image as a reference first. Take next images compare with the reference one and only compress and transmit the difference parts for data size saving. MPEG-4 / H.264 Original: Compression: I-frame P-frame

9. H.264 -H.264 uses multi-types of block (macroblock) to be a unit for doing the comparison accurately with object and reducing data size. -H.264 supports 4x4, 8x4, 4x8 and 8x8 blocks - MPEG-4 only supports 16x16 blocks. 4x4 8x8 4x4 8x4 4x8 8x4 Analysis image by H.264

10. Example 1 16 MPEG-4 H.264 : Saving space 16

11. Scenario 1 Transmit Data Storage Capturing Video Data Size Live View/Playback Compression Type Raw DataCompressed Data Stored Data (Compressed) Decompressed Data (Raw) MJPEG1077 MPEG41055 H.2641033

12. Scenario 1 MJPEG Commonly Used In Judicial Systems Access Control Mobile Applications MPEG-4 Commonly Used In Gas stations Retail Stores Corporate Offices H.264 Plays in what Market Large system installations Schools and Colleges Cloud Monitoring

13. Compression Comparison H.264MPEG-4MJPEG Image quality (Same bit rate) HighMediumLow Data Size (Same image quality) Small (50% of MPEG-4 20% of MJPEG) MediumBig Network bandwidth requirement LowMediumHigh Calculating power requirement to decompress for live view and playback HighMediumLow