Multimedia

1. Multimedia Chapter 20

2. Overview In this chapter, you will learn how to Describe how to implement sound in a PC Install and configure video capture hardware and software Set up a PC to view television signals

3. Sound-Capture Basics Four components for capturing and outputting sound Sound card Speakers Microphone Recording/Playback software

4. Sound-Capture Basics (continued) Sampling = capturing sound Sampling rate is measured in cycles per second (KHz) Low quality (11 KHz) to high quality (192 KHz) Doesn’t capture every nanosecond of sound Takes samples and extrapolates, or predicts, what the data is between samples Dotted line—can you connect the dots?

5. Sampling = capturing sound Bit depth—number of characteristics of a particular sound (for each sample) Amplitude (loudness) Frequency (tone) Timbre (qualities from different instruments) Sound-Capture Basics (continued)

6. Sound-Capture Basics (continued) Sound waves are commonly sampled with either 8 or 16 bits per sample 8-bit stores 28 or 256 different characteristics 16-bit stores 216 or 65,536 different characteristics Tracks Monaural—one track Stereo—two tracks CD quality 44.1 KHz 16-bit depth

7. Recorded Sound Formats Pulse code modulation (PCM) Developed for telephone calls Better known as the WAV format (waveform) Large files Four-minute song at 44.1 KHz and 16-bit stereo is greater than 40 MB Compressor/decompressor (CODEC) programs Algorithms developed to compress sound files MPEG-1 Layer 3 codec or MP3 is one example of a codec

8. Playing Sounds Every sound card can play WAV files using sound player software Windows Media Player comes with Windows iTunes is Apple’s media program Many other good sound players are available

9. MIDI Musical Instrument Digital Interface MIDI file is a text file Contains a series of commands that describe What note to play How long to play it Which instruments to use Tiny in size compared to WAV files First movement of Beethoven’s Fifth Symphony is 78 MB as a WAV file and 60 KB as a MIDI file

10. MIDI (continued) Sound cards play MIDI files using one of two technologies FM synthesis Strictly electronic—software says what to play Wave table synthesis Uses recorded sounds (WAV files) to start Modifies characteristics of sounds to create amplitude, frequency, and timbre desired Polyphony of card—how many instruments it can play at once (64 instruments is common)

11. Other File Formats Over 100 sound formats AAC –Advanced Audio Coding –the native format for Apple’s iTunes AIFF –Audio Interchange File Format – popular format for Macintosh computers ASM - Assembly Language Source – compressed files often seen on the Internet and used in streaming sound ASX – Microsoft Advanced Streaming Redirector AU –Often seen in Windows, Sun, Next, UNIX, and Mac OGG – Vorbis format – open source codex RM – RealMedia – audio or audio and video WMA – Windows Media Audio - proprietary

12. Playing Sounds Streaming quality improving, with many stations outputting 128-Kbps signals Media Player iTunes RealPlayer WinAmp

13. Getting the Right Sound Card Getting the Right Sound Card

14. Sound Cards A sound card typically has many built-in features Two separate processors (one for MIDI and one for the rest) Support chips for joysticks Recording capabilities MIDI instrument support Surround sound Can be a separate sound card Often just a chip on the motherboard or part of the Southbridge

15. Sound Card Differences Sound cards differ in six basic areas Processor capabilities Audio standards Speaker support Recording quality Jacks Extra features Processor handles communication among the application, OS, and CPU Low-end sound cards let your CPU do most of the work Better sound cards do most of the processing, which accelerates the sound process and provides better sound quality

16. Audio Standards AC’97 Up to 6 channels 48 KHz/20-bit Obviously an old standard, but implemented on many motherboards still High Definition Audio (HDA) Intel standard Up to 8 channels 192 KHz/32-bit Code name: Azalia Often see implementations using “Azalia”

17. Sound Card Differences (continued) Speaker support Basic support—two speakers or headphones Better sound cards support five or more speakers Often have a subwoofer 5.1 means 5 speakers with 1 subwoofer Recording quality Signal-to-noise (S/N) ratio expressed in decibels Low-end cards have S/N ratio of 30 to 50 decibels Records artifacts (noise) when there is no actual noise High-end cards offer a 96 to 100+ S/N ratio

18. Sound Card Differences (continued) Jacks Line In and Line Out converters enable the sound card to send and receive input and output from other devices The Line In connector runs to a Line Out or Aux connector on the back of a stereo receiving system Rear Out connects to the rear speakers for surround sound Analog/Digital Out for external digital connections Microphone and Joystick

19. Sound Card Connections Mini-audio connections Main stereo speaker is green Line In connector is blue Microphone connector is pink

20. Sound Card Differences (continued) Extra Features Almost all motherboards have built-in sound Extra goodies needed to entice buyers for standalone sound cards Digital output to integrate PC with home entertainment system or DVD receiver Surround-sound speaker connections Breakout box adding ports to front of PC More

21. Lab – Sound Hardware Most current motherboards have built-in sound, does yours? How can you determine if the motherboard has built-in sound hardware? What audio standard does the sound hardware support? How many speakers does it support?

22. Audio Cables Playing audio CDs through your sound card used to require a cable from your optical drive to the sound card Most optical drives come with an MPC2 audio cable for this purpose Modern systems don'tuse this cable

23. Speaker Standards Stereo Left and right 2.1 systems Pair of speakers calledsatellites and a subwoofer

24. Surround-Sound Standards Dolby Digital Supports five channels plus subwoofer (5.1) Front right, front left, front center, rear left, rear right Digital Theatre System (DTS) Competing standard that also supports 5.1 Sony/Philips Digital Interface (S/PDIF) Uses single connector for entire 5.1 (or greater) system

25. Surround-Sound Standards (continued) DirectX provides applications, primarily games, with direct access to hardware Offers developers easy-to-use commands Easy to program sounds in the desired channel DirectSound3D (DS3D) Can place a sound anywhere in 3-D space Known as positional audio R.I.P. in Vista (Try OpenAL now) Environmental audio extensions (EAX) Creative Labs’ response to DS3D Audio presets for realism in sound

26. Speaker Features Controls Volume controllers On/off switch Can be on speakersor on special box Headphone jack Some systemscan automaticallysense when plugged in

27. Installing a Sound Card in a Windows System

28. Physical Installation Installs like any other PCI card Plug in the card Load the drivers Test Hardest part may be identifying where to plug in speakers Refer to documentation Typical stereo or 2.1 speaker system plugs into Speaker or Speaker 1 port Surround-sound speakers may use single S/PDIF

29. Physical Installation (continued) Basic steps Shut down your computer, unplug it, and open the case Find an open PCI or PCIe slot and install the card Connect the CD audio cable to the drive and the card

30. Installing Drivers Let Windows install drivers If necessary/desired, use CD that came with sound card If installing a USB sound card Follow the cardinal rule for USB drivers: Install the USB driver before the USB device Verify driver is installed by checking Device Manager Test

31. Windows Configuration Applications Most sound card configuration can be done with the operating system utilities Control Panel applet: Sound in Vista, Sounds and Audio Devices applet in Windows XP, Sounds and Multimedia in Windows 2000 Five tabs in 2000/XP Volume Sounds Audio Voice Hardware

32. Windows Configuration Applications (continued) Vista has better support for multiple speakers and HDMI

33. Proprietary Configuration Apps Adds access to other features that aren’t otherwise available Autosensing—allows hardware to be plugged in using different ports and the ports adjust Plug microphone into speaker port and speaker port becomes a microphone port

34. Some sound cards install extra software Goal is to provide user with extra free software These programs aren’t needed to use any of the features Intended to provide extra value for the purchase Installing Applications

35. Hardware Problems Volume Check physical controls Check software controls Windows Volume controls Speakers Ensure they are turned on and getting good power Make sure they are plugged in Check for visual indicators that a sound is playing Replace speakers if blown speakers suspected

36. Configuration Problems First place to check: Device Manager Consider reinstalling driver Ensure the latest device drivers are installed Check the manufacturer’s Web site for updates Review the Sounds and Audio Devices applet settings

37. Application Problems First, look for an error message Check the application’s support site Second, check the sound file Sound files might be corrupted Last, reinstall the application

38. Hardware Designed to accept incoming video Video Capture

39. Software Controls the hardware Usually also edits Video Capture (continued)

40. Consists of two parts, video and audio Each part may have its own compression Compressed audio and video combined into a container file (wrapper) The file name does not always tell you the compression Multimedia File Formats

41. Videos typically have sound built in Some common video codecs: Video Codecs Acronym Description MPEG-2 Used for DVDs MPEG-4 Used in Internet broadcasts H.264 Used in high-def movies for Blu-ray discs & others WMV Windows Media Video Theora Open source codec for Ogg project TrueMotion Used in Adobe Flash (VP6) and Skype (VP7) VC-1 Microsoft hi-def codec usually wrapped in WMV file

42. Video Wrappers Somecommon multimedia wrappers Acronym Description ASF Mainly for WMA/WMV streams AVI Standard file for Windows FLV Flash Video can use H.263, VP6 or H.264 MOV Apple QuickTime container for Mac and Windows MPEG-TS MPEG-2 Transport Stream for many streams Ogg Open source container for Vorbis & Theora codecs

43. Troubleshooting Video Try these if you experience dropped frames Turn off unnecessary programs Turn off background processes Turn off playback/preview Try these for sync problems Change or update software Try capturing analog to digital video cam and then go from video cam to PC Check out www.digitalfaq.com

44. Troubleshooting Video (continued) For poor capture quality, try these See “dropped frames” Upgrade hardware Should have a top-notch CPU Need gobs of RAM Check video source Not much can be done if source is degraded

45. Troubleshooting Video (continued) Missing Codecs Sound, but no video Player will warn you Check your codecs

46. Tuner Hardware Acts as the interface between cable/satellite or over-the-air TV signals and your computer

47. Tuner Software Controls the tuner hardware to let you watch TV programs

48. Beyond A+ Sound card benchmarking PC performance issues may be related to your sound card Analyze your sound card with RightMark 3DSound from iXBT.Com/Digit-Life http://audio.rightmark.org