The TW5864 is a H. 264 encoder solution with integrated 4-channel analog A/V decoders. The TW5864 can be used as a low cost single chip solution for 4-channel H. 264 hardware compression PC cards, or 16-channel cards by using additional external TW2866 chips. There are 3 versions of TW5864 that can support no external video decoder (TW5864A), 4 channel external video decoders (TW5864B), and 12 channel external video decoders (TW5864C). The TW5864 can also be used in embedded DVR applications as an AV front-end chip with H264 encoding capability. It can work with existing H. 264 hardcore or DSP based CODECs. In existing H264 CODECs, performance may be limited due to limitation in both memory bandwidth and hardware resources. With the H. 264 encoder built in at the front-end, the number of encoding channel supported scales with number of TW5864 chips used. The front-end H264 encoder offloads the processing from the backend CODECs to allow higher port count support and allows DSP resources saved and reserved for product differentiation features such as video analytic intelligence. The TW5864 features H. 264 baseline level 3 compliant encoder capable of performing up to 5 D1 equivalent video encoding (125 fps for PAL and 150 fps for NTSC), 17 channel G. 726 ADPCM hardware audio encoder with one channel for two way audio communication. The H. 264 video encoder supports dual-bitstream compression for both local storage and network port outputs. It also features a motion JPEG encoder for up to 25 frames per second shared among all video channels. The TW5864 integrates 4 A/V decoders. It has 4 CVBS analog inputs fed into four internal high quality NTSC/PAL video decoders. In addition, it has 3 digital BT. 656 input, running up to 108 MHz, capable of receiving up to 12 D1 video channels from external multi-channel video decoders such as TW2866/TW2867. This allows the TW5864 to support a total of 16 video input channels. The video streams from both on-chip/off-chip video decoders are fed into H. 264 encoder as well as to external interfaces for preview purposes. The preview stream can go through either four BT. 656 video output interfaces or PCI interfaces. The four BT 656 ports support both multi-channel byte or line interleaved output to interface with various external display solutions. The TW5864 has built-in de-interlacers and OSDs before encoding is performed. There are also 16 sets of motion detection/night detection/blind detection engine for channel alarm notification. In addition, the hardware encoder generated motion information of each channel is accessible to the external CPU for analytic purposes. The TW5864 also integrates many sets of scalers for each of the H264 encoder, MJPEG, and preview paths. Each of these scalers is independently configured. The TW5864 provides both asynchronous host interface and PCI interface for external CPU control and bitstream upload. The PCI interface can run at 33 or 66 MHz.