1. AUDIO VIDEO FLASH DIGITAL MEDIA: COMMUNICATION AND DESIGN 24.04.2007

2. Digital Media: Communication and DesignF2007 Comments Web 2.0 guest lecture Evaluation Intro to scripting (PHP) Intro to Flash Mandatory assignment due to 01.05 at 9.59

3. Digital Media: Communication and DesignF2007

4. Index Audio Video Flash

5. Digital Media: Communication and DesignF2007 Audio What can audio do for us?

6. Digital Media: Communication and DesignF2007 Audio Audio is analogue Encoding: we sample the wave and round the value to an allowed value

7. Digital Media: Communication and DesignF2007 Sampling rate (Hz) How many times per second we have a sample Max frequency and recommended sampling rate  Voice: ~ 4000 Hz -> 8000 Hz  Music: ~20000 Hz -> 44100 Hz

8. Digital Media: Communication and DesignF2007 Bit rate (bits) How many bits we use to describe the values 8 bits: 256 values 16 bits: 65536 values (CD quality)

9. Digital Media: Communication and DesignF2007 Ripping a CD to MP3 Bitrate: how many bits per second  Radio: 64 kbps  CD: 128 kbps (192) Sampling rate:  CD: 44.1 KHz  Radio: 8 KHz Channels:  Mono / stereo / joint stereo

10. Digital Media: Communication and DesignF2007 File formats WAV: Wave file  Not compressed  NOT for the web MP3: MPEG 1 Layer 3  Lossy compression (1/10 of WAV) OGG (Vorbis):  Lossy compression  Free format MIDI:  Contains information about notes and instruments to play

11. Digital Media: Communication and DesignF2007 File formats II QuickTime:  Container for audio, video, images... RealAudio  Pioneer on streaming audio  PC World: #2 worst tech products of all time#2 worst tech products of all time Windows Media Audio  Popular for streaming (.asf files) AAC (Advanced Audio Coding)  Substitute of MP3 (?) Flash

12. Digital Media: Communication and DesignF2007 This is Sparta 44 KHz, 228 KB 22 KHz, 114 KB 11 KHz, 57 KB 8 KHz, 42 KB

13. Digital Media: Communication and DesignF2007 Audio 2 methods:  Link to file  Streaming

14. Digital Media: Communication and DesignF2007 Link to a file Download song (1.5 Mb)

15. Digital Media: Communication and DesignF2007 Streaming The file starts playing right away The file is not downloaded: protect copyright The server must have a special configuration Good for broadband connections

16. Digital Media: Communication and DesignF2007 Streaming Typical formats:  RealAudio  QuickTime  Windows Media  Flash

17. Digital Media: Communication and DesignF2007 Audio editing Audacity (open source, free) Audacity Sound Forge Audition (old Cool Edit) Garage Band (Mac)

18. Digital Media: Communication and DesignF2007 Index Audio Video Flash

19. Digital Media: Communication and DesignF2007 Video What can video do for us?

20. Digital Media: Communication and DesignF2007 Properties of video Movie length Frame size  Streaming: 320x240  Download: 640x480 (HD: up to 1920x1080) Frame rate (fps)  TV: 25 fps (interlaced, 50Hz)  Streaming: 10 fps

21. Digital Media: Communication and DesignF2007 Properties of video II Quality:  Degree of compression Bit depth:  Number of colours (usually 24 bits) Bit rate:  Number of bits per second (kbps)  Audio + video

22. Digital Media: Communication and DesignF2007 Compression Lossless: no information is lost Lossy: throw away information we cannot see Spatial:  Every frame, similar to JPEG Temporal:  Areas that don’t change over time

23. Digital Media: Communication and DesignF2007 Popular codecs MPEG-1: VHS, VCD MPEG-2: DVD, Digital TV MPEG-4 Part 10: HD-DVD, Blu-ray, iPod, PSP MPEG-4 Part 2: DivX, Xvid Sorenson 3: QuickTime Theora: OGG video WMV: Similar to MPEG-4

24. Digital Media: Communication and DesignF2007 Popular formats QuickTime (.mov)  Can contain audio, video, images...  Good for streaming AVI (Audio Video Interleave) MP4 (.mp4,.m4a,.m4p) ASF (Advanced Systems Format)  Windows Media Real Media (.rm)  Broadcasting Flash

25. Digital Media: Communication and DesignF2007 Video

26. Digital Media: Communication and DesignF2007 Streaming

27. Digital Media: Communication and DesignF2007 Video in an HTML document See the video of my holidays (90 Mb) <object classid=“clsid:02BF25D5-8C17-4B23-BC80-D3488ABDDC6B” codebase=“http://www.apple.com/qtactivex/qtplugin.cab” width=“480” height=“276”> <object type=“video/quicktime” data=“poster.png” width=“480” height=“276” class=“hide”> QuickTime: http://www.ceprix.net/examples/qt/example4-1.htmlhttp://www.ceprix.net/examples/qt/example4-1.html Flash: http://www.ceprix.net/examples/qt/example4-2.htmlhttp://www.ceprix.net/examples/qt/example4-2.html

28. Digital Media: Communication and DesignF2007 Index Audio Video Flash

29. Digital Media: Communication and DesignF2007 Flash What can Flash do for us?

30. Digital Media: Communication and DesignF2007 Questions?