Analogue, digital or high definition

You have several output options to consider when purchasing a video camera. Analogue is the video camera that would take some sort of tape to record the video. These cameras are quickly being replaced by digital cameras but analogue cameras still can be found and are quite inexpensive. Beware that this technology is obsolete and the materials, like replacement tapes updated software that accompany these cameras are harder to find.

The next two options are tricky in that both styles of cameras can produce a video that can be quickly and easily viewed. The major consideration for you will probably be the ability to manipulate the video in some form, the file sizes and the ease of editing.

The standard definition (SD) video camera has a built in hard drive for saving video files. It also allows you to download your recordings on to your computer and edit them with the software applications which normally come with the camera. Most digital camera software applications have basic options to cut portions of your video and add various video clips together to compile a movie. The ability to shoot long or multiple video files is only limited to the amount of memory in your camera.  Most video cameras also have a memory card slot for additional memory.

The quality of the video output can be adjusted in two ways. The first is to use video settings. All cameras have a setting that affect the output of the video. You will need to become familiar with your video camera settings to learn how to adjust the settings. Normally there are two to three quality settings to consider. It is encouraged that you take into consideration the end video product and the time you have to produce the video before making your selections. Most of the time, you will want the best video quality; and would be using the highest quality setting. You can then reduce the quality of the video through the editing software. However, if you choose a low quality setting and shoot your video, you will be unable to improve the quality through software. SD video is easy to use and edit.  It also has many options for varying the quality of the production. In time, with patience, familiarity with your camera settings and practice with your editing software, you will be able to produce high quality videos.

The high definition (HD) video camera becomes very enticing when you're in the store watching crystal clear images on wide screen HD televisions. Seeing that there is not much difference in price between an SD and an HD camcorder, you might wonder why you would even consider an SD camcorder. So what is the catch? Well, you need to consider a couple of things before throwing down the credit card to buy that HD camcorder. The first consideration is that the output video file can be either burnt straight to a DVD or transferred to a computer only through the video camera's proprietary software application. Because the camera records in HD, this results in large file sizes to account for the clarity of the image. Secondly, there are not many editing software programs that are available for novices. Finally you will not see the added quality of an HD video unless you view it on an HD device.

Flash memory

You may be familiar with many kinds of memory like hard drives, CDs, or RAM. The most basic kind of memory is something like RAM. RAM can be read and written to as long as the power is turned on. When the power is turned off, the RAM loses all of its data. Because data is lost when the memory loses power, this type of memory is called volatile. A hard disk can also be read and written as long as the power is turned on, but it will not lose any data when the power is turned off. Because the hard drive does not lose data when the power is turned off, it can be called non-volatile. A flash memory is also a solid-state memory, meaning it has no moving parts. Flash memory is another type of non-volatile memory, but it has special limitations on when it can be written to.

Flash memory can be read as long as it has power and it is not writing; and it will keep data even when the power is turned off. Writing into a flash memory can be performed when the power is on, but only as long as the section of the flash memory which is being written onto is erased first. In a "normal" memory system, a write operation can change a bit of memory from a 1 to a 0 or vice versa; however, in a write operation to a flash memory a bit can only be changed from a 1 to a 0. In order to change a flash memory bit from 0 to 1, a time-consuming erasure process must occur. The erase command takes much longer than the write process; and, for manufacturing reasons, flash memory chips are not made with the ability to erase individual bits or bytes. Only large sections of memory (usually 512 bytes or more) can be erased at a time.

Figure 3.7 Flash memory

Because of its limitations, flash memories are not useful for access that requires frequent erasure. Flash memory is useful for storing execution code that is not expected to change often because reading a flash memory is much faster than reading a hard drive. For all these reasons flash memory is a good choice for embedded microcontroller code memory, motherboard BIOS, digital camera memory, and memory cards.

To ameliorate the disadvantages of flash memories, flash memory chips have a controller to mediate between other parts and the internal memory array. While all memories have some form of control logic, flash memories have more complicated lists of commands that they can execute. Some flash chips have buffers to improve performance. A buffer is a small, fast memory used to improve the performance of a larger, slower memory.