1. 4/7 Multimedia Roll call Video Lecture: –multimedia sound –multimedia video Image courtesy of http://www.wheeloftime.com

2. Multimedia: What is it? Refers to audio and video capabilities of a computer. Animation, movies stereo sound voice recognition Image courtesy of http://www.GTgames.com

3. The sound card Converts analog to digital and vice versa. A coprocessor for the CPU, specialized for dealing with sound processing and compression.

4. The sound card: recording Analog signals from the microphone (or other source) are sent to the ADC (Analog-to-Digital Converter). They are converted to digital data.

5. The sound card: recording The digital data is sent to the DSP (Digital Signal Processor), where a ROM chip has the instructions for what to do with the data. ADC

6. The sound card: recording The DSP sends the processed data off to the CPU. Typically, the DSP has compressed the data. ADC

7. The sound card: playing The DSP receives the compressed data from the CPU. Default file type: –WAV ADC

8. The sound card: playing The DSP decompresses the.WAV file and sends it to the DAC, which converts it and sends it out to the speakers. ADC

9. .WAV versus.MIDI files WAV files are simply recordings of sounds. MIDI files have instructions on how an instrument sounds, and the notes that it will play. ADC

10. .WAV versus.MIDI files: analogy WAV files are like a disk jockey playing albums. MIDI files are like a live band playing requests. ADC

11. Multimedia Video Multimedia video works similarly to multimedia sound, but stores images and sound..AVI is the default video format. (Audio/Video Interleave)

12. Multimedia Video Compression is more important in video, because there’s more data to store. Other file types: –MPEG, MOV, GIF89a...

13. .AVI Compression Compression is more important in video, because there’s more data to store. Other file types: –MPEG, MOV, GIF89a...

14. .AVI Compression The first frame is recorded. Blocks of color are recorded not as individual pixels, but a map with information on what color to put there.

15. .AVI Compression To record the next frame, it is compared with the 1st frame. Any differences are recorded. The sections that did not change are ignored. My hair! Aughh!