Digital still cameras (DSCs) have made rapid progress in the last 10 years, almost replacing silver-halide film technology. Even at a very low retail price, with a pocket-sized form factor, the user can expect brilliant pictures at a resolution of 5-million pixels and a 3x to 5x zoom lens. Many of the DSCs currently on the market have a video function, but it is usually limited to 30 fps VGA and mediocre compression. It is fair to say that the video function of a still camera is no match for that of a camcorder.

On the other hand, the digital videotape (DV) camcorder delivers sharp video with standard definition (SD) resolution of 720x480 60i. The camcorder has not really changed much in the last ten years: prices have come down and size has become more user-friendly. Today, camcorders typically include a still image function, but it is equally fair to say that the majority of camcorders are far away from matching the still image capability of a DSC.

Ideally, a consumer product will integrate the best of both worlds and will have the still quality of a DSC and the video quality of a camcorder. It is an unrealistic expectation that the user will continue to carry two devices. In addition, there appears to be a diminished appeal for the camcorder. Is it that the end user is disenchanted with video overall? Perhaps it’s too hard to use; too hard to edit; too hard to share? Or is it just that size, form factor and quality remain such a strong advantage with the DSC that a user chooses this device when traveling on vacation?

Hybrid Digital Cameras
Video will increasingly be a key function of a digital camera and there is strong demand for a device that has the best of both a DSC and a camcorder in terms of quality, convenience and form factor. This new breed of camera, the hybrid, will eliminate the need for tape and will integrate both video and still using a single flash storage device. This camera will also be capable of recording in high definition--the next generation in video recording and playback.

In order for the new hybrid digital camera to achieve widespread consumer adoption, several technology conditions must be met:

Innovation in sensor technology for still image and video
While still-image resolution must be at least five megapixels, video resolution should be sufficient to support the high definition standards: 720p60 or 1080i60. As an alternative, a compromise of 720p30 might result is a lower-cost version of a hybrid camera. (See: Image Processing)

Improved compression and storage
In a hybrid camera, the primary storage technology will be flash memory or hard disk drive (HDD). Optical storage can be used as alternative for mass storage or for sharing content (i.e., CD or DVD storage).

The compression technology must be sufficiently advanced to be able to compress one hour of video onto flash. This can only be achieved with an advanced compression algorithm such as H.264/AVC (See: Video Compression)

State-of-the-art optics
The optics of a hybrid camera must be a reasonable compromise between size and functionality. While 5x to 6x zoom is a minimum, a 10x zoom will fit most of the requirements for both still and video. The lens must be able to zoom, focus and set the iris while shooting video. And, these operations must be done at a sufficiently low noise level so as not to preclude sound recording.

The SoC for Hybrid Digital Cameras
During the development of the A1 platform, Ambarella considered all of these important technology tradeoffs to create an SoC that targets hybrid digital cameras, and delivers both high definition video and 5 to 8 megapixel still images. The Ambarella processor integrates all the image processing, video and audio compression, storage I/O and graphics functions in order to implement a high-quality hybrid digital camera.

Conclusion
While many industry watchers have been anticipating a leveling-off or even a decline in the mature digital camera market, it is clear that new technology innovations will jump-start the adoption of new and improved devices. With advances in storage, video compression and sensor technology, it is now possible to develop a hybrid digital camera that allows the user to record in high definition and take high resolution still photos—all at the highest quality. The Ambarella A1 SoC is a market first that delivers the quality, functionality, power and cost requirements to drive rapid market adoption of the next generation in digital cameras.