Multimedia Applications and Digital Video Production
Interactive Multimedia Applications
Interactive multimedia applications, such as web pages, can use all available resources and means (pictures, music, etc.). The main drawback is the difficulty of transmitting video over the Internet, as video files are often too large, resulting in slow data transmission. Web pages are often programmed using languages such as XML or Flash.
Digital Videos
Digital videos are created through image capture, video, and sound editing. Digital video production aims to preserve sound and video images for retouching, resulting in a multimedia product that can be presented on a TV screen or other displays.
Presentations
Multimedia presentations are made through a slideshow of elements. These presentations are designed to be projected using a projector during an exposition. They can also be played on a computer.
Sound Recording: Digitizing Sound
Sound waves are transmitted in analog form. However, computers are unable to work directly with analog signals. Therefore, the computer must convert the analog signal to a digital one. This process is called digitizing sound. The reverse process occurs when the computer generates sounds to be heard through speakers, earphones, etc. Digitizing involves taking samples of the sound signal (sampling) from time to time (sampling frequency) and measuring the intensity of the analog signal. The more times the sound is measured per second (higher sampling frequency) and the greater the range to measure the intensity (a greater number of bits to represent values), the better the quality and the more the digitized sound will resemble the actual sound.
Audio Formats
- WAV: These store actual sounds in digital form.
- MIDI: These do not save real sounds, but rather orders for a musical synthesizer to generate music. They take up less space, but have lower quality.
- MP3: These are similar to WAV, storing real audio in a compressed format, occupying less space with minimal quality loss.
- OGG: A compressed audio format offering high quality, but with distribution limitations.
- WMA: These are compressed files with good sound quality.
- Real Audio: This format plays audio in real-time as it is being read.
Video Sources
- Analog Cameras: These are older cameras that require a capture card to be installed in the computer.
- Webcam: These capture live video and still images and connect to a USB port.
- Other: TV capture cards, mobile phones, etc.
Video Formats
- MPEG: Used to store high-quality video with a reduced file size.
- AVI: One of the most widespread video formats.
- DivX: A compressed video format that provides very good quality videos in a small space.
- DV: Usually the standard in digital camcorders.
- Codec: Software that allows you to compress video and audio files to reduce disk space usage.
What is a Montage?
A montage involves inserting different clips to be used in the chronological order in which they will be visualized.
What is a Clip?
A clip is a video segment or a still image. A finished film usually has several clips arranged in the chronological order in which they will later appear in the film.
Video Clip Editing
- Divide Clip: A clip can be divided into two or more pieces if it is too large.
- Combine Clips: Two or more clips can be combined.
- Trim a Clip: Parts of a clip that are not desired in the final movie can be cut.