FH8735 is in multiple ways H. 264 HD video coding system application

1 Introduction

After the development of the analog era, the digital age, and the network era, video surveillance products have gradually entered the high-definition era. HD video has a qualitative leap in video quality compared to traditional SD video. In the past, HD video has not been widely used due to many factors such as chip encoding capability, network bandwidth and storage technology. However, with the rapid development of video encoding, IC design, broadband network and mass storage technology, HD video applications The main obstacles have been cleared. Due to its excellent coding efficiency, the H.264/AVC video coding standard can greatly reduce the network bandwidth and storage capacity requirements of high-definition video transmission, and has been widely used, becoming an inevitable choice for high-definition video coding.

At present, high-definition video surveillance has been paid attention to and applied by more and more industries. A common feature of users in these industries is the need for higher definition video images. Shanghai Fuyi Microelectronics Co., Ltd. launched the FH8735 H.264 encoding ASIC and its corresponding solutions in September 2008. It has a single-chip 1-channel 1080p@30fps or two-way 720p@30fps HD video real-time encoding capability. It is the most competitive high-performance video encoding chip on the market, which can greatly meet the development needs of high-definition video.

Based on the FH8735 chip, FX Microelectronics has launched a series of high-definition video product solutions, such as HD network camera solutions, HD network video server solutions and PCI HD video compression cards.

After more than a year of market testing, the FH8735 has been widely used in video security surveillance, video conferencing, distance education, telemedicine, high-definition screen recording and personal consumer electronics.

2 FH8735 HD encoding chip introduction

The FH8735 is a high-performance audio and video encoding chip that supports H.264 Main profile and Baseline profile video coding standards. It can encode and control one 1080i and two 720p HD signals in real time. At the same time of encoding the video data, the related multi-channel audio data is also encoded, and the audio and video synchronization is completed, and the compressed code stream in the format of ES/PES/PS/TS is output. The internal functional modules of the FH8735 are shown in Figure 1.

The main technical features of FH8735 are as follows:

1) Super coding performance

The H.264 encoding of the FH8735 is implemented in pure hardware with high coding capability, high coding quality and low power consumption. The FH8735 supports video input with a maximum resolution of 2048x1024 and supports 1 channel 1920x1080@30fps or 2 channel 1280x720 (1280x720@60fps) real-time encoding. The comparison of typical video coding shows that the FH8735 is close to the video coding quality of JM12.0 at the same code rate.

2) Rich peripheral interface

The FH8735 supports a variety of high-definition video input modes. The HD video data format and synchronization mode can be configured to receive digital video from CMOS/CCD modules, video decoders, etc.:

Support ITU-R BT.709/SMPTE 274M (24Bit 4:4:4 YCbCr, 16Bit 4:2:2 YCbCr, RGB 24 (8:8:8));

Support SMPTE296M-2001 (24Bit 4:4:4 YCbCr, 16Bit 4:2:2 YCbCr, RGB 24 (8:8:8))

Support 8bit 4:2:2 YCbCr;

Support internal synchronization and external synchronization mode;

In addition, the FH8735 also has a variety of peripheral interfaces such as SPI/PCI/SD/UART/I2S/GPIO/I2C/MAC.

3) Patent code rate control technology

FH8735 provides four rate control strategies: QP: quantization parameter, constant bit rate (CBR), variable bit rate (VBR: Variable Bit Rate) and average bit rate (ABR: Average Bit) Rate). Each algorithm has been carefully optimized to adaptively detect and judge the video scene in advance, so as to ensure the subjective quality of the video while making the output rate of the encoder smooth and stable, ensuring the efficiency and stability of network transmission.

4) Flexible function settings

In addition to high-performance video encoding capabilities, the FH8735 offers a rich set of video pre-processing features and flexible video encoding options. The search range of the encoder, the Intra prediction type, the GOP length, the number of reference frames, the coding rate and the code rate control mode, the coding profile and the Level are all flexibly set as needed, so that decoding with different decoding capabilities can be guaranteed. Seamlessly dock. In addition, FH8735 supports de-interlacing, de-noising, multiple text and graphics OSD overlay, image reduction, motion detection and other image processing functions. It also supports capturing the lossless original video signal for the host. Some intelligent analysis and processing such as license plate recognition, face recognition and so on.

The FH8735 has two independent DDR controllers that can be connected to two external DDR SDRAMs. One or two sets of external DDR SDRAMs are configured according to the actual system requirements for encoder performance. For example, when encoding a 720p video, you only need to configure a set of DDRs to reduce the system BOM cost.

5) Optimized design of ultra-low latency real-time coding technology

In high-definition video systems, system latency is also an important consideration. The FH8735 reduces the internal delay of the entire video encoding by supporting flexible image segmentation encoding. For example, when encoding high-definition video in 720P format, the data buffering time per frame is about 16.7 ms. The time from the start of the input system buffer to the encoder output of the entire frame of the compressed code stream from the first valid line data of the image can be controlled within 20 ms. This ultra-low latency real-time encoding technology can greatly reduce the end-to-end latency of the entire system, thereby improving and improving the user's subjective experience.

2 Multi-channel HD video coding board based on FH8735

In order to meet the needs of the FH8735 in the early evaluation and development of high-definition encoding applications, Fuyi provides a multi-channel HD video encoding card reference design based on FH8735. The HD encoding card supports HD video input and PCI host interface of DVI/HDMI and YPbPr interfaces, and can complete HD video capture, encoding, and send to the host through the PCI interface. The reference design supports Windows XP and Linux, and the corresponding driver and evaluation software is provided, and the firmware can be modified to meet the customization function according to the user's specific application.

The system diagram of the multi-channel high-definition video encoding card is as follows:

3 Conclusion

The FH8735 has a single-chip 1-channel 1920x1080@30fps HD video real-time encoding capability, and is the most competitive new generation high-performance video encoding chip on the market.

The high performance and ease of use of the FH8735 provide a new choice and space for HD or multi-channel video compression applications, significantly improving customer product performance and reducing development time.