1. Int 2 Multimedia Revision

2. Digitised Sound Analogue sound recorded from person, or real instruments

3. Digitised Sound Data Sound card –Circuit board managing recording and playback of sound –Own processor and memory to help CPU. Microphone (input) –Captures sound Speakers (output) –Playback sound

4. Storage of Sound Data RAW –Uncompressed file format WAV –Lossless compression file format MP3 –Lossy compression file format

5. Terms Lossy Compression –Reduces file size, but also reduces quality Sampling depth / resolution –No of bits to store sample of sound –More bits = better quality = larger file size Sampling frequency (Hz) –No of samples of sound per second Sound time –Duration in seconds

6. Features of Sound Editing Crop –Shortens track length Decrease Sampling depth –less bits = poorer quality = smaller file size Decrease Sampling frequency –poorer quality & smaller file size Volume –Adjust loudness Reverse –Playing track backwards Special effects –Echoes, reverberation

7. Synthesised Sound Artificially produced by computer

8. MIDI (Musical Instrument Digital Interface) Record synthesised music on computer system. Midi keyboard used to play music Each note described by attributes (bit like vector graphics)

9. MIDI Attributes Instrument –Produces different sounds to represents various instruments – violin, flute… Pitch –Frequency of note Volume –How loudly or softly music note is played Duration –Length of note Tempo –Speed of music

10. Macros Recording series of actions and then assigning this to a set of keystrokes Used to customise a package. Advantages Saves time Always playback accurately Customises a package Examples Changing page layout Automating mail merge

11. Standard Algorithms Input validation –To ensure that data entered falls within a valid range Example 1.Loop 2.Get value from user 3.If value not in range then 4.Display error message 5.End if 6.Until value in range

12. Standard Algorithms Counting Occurrences –Counts no of times a value appears in a list Linear Search –Finds a value within a list Finding Maximum –Finds the highest number within a set Finding Minimum –Finds the smallest number within a set