Ambarella, Inc., the leader in low-power, high- definition video compression and image processing semiconductors, announced its third-generation low-power A3 System-on-a-Chip (SoC). The A3 is targeted at high-definition (HD) camcorders using H.264/AVC compression technology. The SoC comes in two versions: the A350 supporting the 1080i 60 interlaced HD standard; and the A380 supporting the emerging 1080p60 progressive video format.
HD Camcorder SoC and Progressive Format
The A3 HD system-on-chip (SoC) enables the development of full high-resolution camcorders at the highest image quality with smooth 60 frames/second video. Ambarella’s A3 is the first single-chip H.264 codec capable of encoding full 1080p60 at 1920 pixels per line resolution. In addition, A3 integrates a high-performance image processing pipeline with high speed signal acquisition, still image compression, audio compression and all key system functions. The Ambarella A3 platform has low operating power and increased system integration that makes the high-definition experience a reality for mainstream consumers.
The A3 platform is based on the H.264/AVC video compression standard, which is the next generation of video compression technology. Ambarella’s patent-pending platform delivers a 2.5x compression gain over current MPEG-2/4 solutions, providing the efficiency required to store HD video content in convenient flash-based memory, hard disk drive or recordable DVD. The Ambarella platform programmability enables implementation of multiple formats for HD Video such as the AVCHD specification for 1080i HD camcorders as well as many formats commonly used on PC platforms.
1080i and 1080p60
In a recent survey more than 90 percent of the TV’s sold in Japan, 88 percent of the TVs sold in the EU, and 76 percent of the TV’s sold in North America were flat progressive TV’s. All of these displays are progressive in nature with a refresh rate at 50 Hz (EU) or 60Hz (North America and Japan). Among these TV ‘s, the large majority of the devices with screens larger than 36 inches have a “full HD” configuration and can display a raster of 1920×1080. The 1080p60 standard has become the de facto HD display format. Because the CMOS sensors used in HD camcorder are also progressive devices it is only natural that camcorders adopt the same format as sensors and TV’s.
The advantage of progressive formats are evident in three different aspects: 1) twice the resolution i.e. more details; 2) lack of motion induced interlaced artifacts, particular noticeable on a large TV; and, 3) ease of editing since video editors would rather avoid the field/frame distinction where two half of a full frame are acquired at different instants in time.
While a progressive 60p format has twice the data rate (about 3Gbps) of the equivalent interlaced video, the signal exhibit much stronger vertical correlation and as such compresses more easily to about 1.2 time more bits that the progressive one. This means that twice the vertical resolution can be obtained for only a small 20% additional bandwidth or storage capacity. The A380 SoC allows consumers to record as much as one hour of 1080p60 video on a 4GB flash card.
Because of the dominance of television sets capable of 1920×1980 60p, the industry has adopted an interface (and a connector) HDMI which supports 1080p 60. This allows DVD players, Cable/Satellite set-top boxes and now camcorders to deliver data at the full resolution of the TV. Ambarella’s A3 platform has a built-in HDMI interface, including support for1080p60 signals.
Motion Compensated 3D Noise Reduction: a Novel Approach
Depending on the amount of light available, imaging sensors have a substantial amount of noise, so filtering this noise is a very important task. The challenge of a full resolution HD camcorder is to reduce the noise without causing a loss of resolution or a loss of detail and spatiotemporal (3D) filters must be used. Most of the solutions available are motion adaptive and switch from a predominantly temporal to a predominantly spatial filter based on detecting the presence of motion. Ambarella’s A3 solution is motion compensated instead of just motion adaptive and truly tracks the motion and uses motion compensation in the filter.
“The combination of a high performance image pipeline, motion compensated 3D noise reduction and a 1080p60 H.264 AVC codec allows us to redefine the HD camcorder,” said Dr. Fermi Wang, Ambarella CEO, “the A3 platform is a key component in our product strategy.”
Pricing and Availability
The Ambarella A3 platform is a solution supporting both the 1080i format (A350) and 1080p (A380) as well as hybrid cameras. The A3 platform is available in multiple configurations for differing requirements. Evaluation kits are available and pricing information can be obtained from Ambarella.
Ambarella is the technology leader in low-power, high-definition video compression and image processing semiconductors. Ambarella products are helping to define a new class of hybrid digital cameras that bring consumers unmatched high definition video and digital still images together in one device. Many cameras and camcorders have been shipping using Ambarella A2 SOC.