1 / 23

CSE 380 – Computer Game Programming Audio Engineering

CSE 380 – Computer Game Programming Audio Engineering. Audio Engineering. For games: Sound Effects and Music Sometimes overlooked If not done right, can ruin a game If done right, enhances experience seamless with gameplay not too obvious. What do you need sound effects for?.

rhea-howe
Download Presentation

CSE 380 – Computer Game Programming Audio Engineering

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CSE 380 – Computer Game ProgrammingAudio Engineering

  2. Audio Engineering • For games: • Sound Effects and Music • Sometimes overlooked • If not done right, can ruin a game • If done right, enhances experience • seamless with gameplay • not too obvious

  3. What do you need sound effects for? • Discernable Game Events • Collisions • tied to collision response • Movement • footfalls, rockets, • tied to sprite state • Ambiance • background noise • tied to game state • Gameplay Events • tied to victory, area triggers, power-ups, death, etc • to help give your game meaningful play

  4. Recording & Exporting Sounds • Lots of tools to use • Recommendation: Audacity • free • easy to learn to use • exports to many formats • Ex: mp3 • easy to mix sounds • to make complex sound effects • http://audacity.sourceforge.net/

  5. Sound Properties • Frequency • measures speed of sound vibrations • measured in cycles per second (Hz) • audible range for human ear: 20Hz – 20,000Hz • Intensity • amount of air molecules pushed around by sound • pressure applied by sound wave • measured in decibels (dB), a log scale • sound of whispering 5ft. Away: 20 dB • sound of thunder: 120dB

  6. Sound File Formats • WAV • stores raw sound data, is the largest format • easy on CPU • MP3/M4A, OGG, & WMA • compressed formats ~10:1 compression over WAV • negligible quality difference from WAV • decompression CPU hit • MIDI • programmed sound

  7. Long vs. Short sound files • For short sound effects: • store as MP3/OGG/etc. • decompress data in memory at load time • play as needed in decompressed format • heavy on memory, light on CPU • For long sound effects or music: • store as MP3/OGG/etc. • play in compressed format • again, heavy on CPU usage, light on memory

  8. Music • What role does music play? • emotion • recognition • themes • fill the void • Sound & Music: • should compliment the gameplay, not overwhelm it

  9. For the programmer • Lots of libraries • Keep game code platform independent • Options: • FMod and tools (FMod Designer, etc.) • DirectSound (deprecated) • XAudio/XACT (soon to be deprecated • XAudio2/XACT3 (soon part of Windows) • See DirectX Documentation for C++ • lots of other libraries as well (Miles, WWise, etc.)

  10. Microsoft Audio Technologies

  11. For us? • XACT3 • designer controlled content • easy audio tweaking • XAudio2 • API to build sound engine

  12. What’s so great about that? • The audio designer can focus on audio • Easy to: • test many different sound effects & songs • choose the right sounds & music • alter/improve sounds & music • All without having to bother a programmer

  13. XBox 360 • 3 CPU cores • each with 2 hardware threads • Common approach: • run XAudio2 and XACT on their own threads • Has real-time XMA decoder hardware • XMA is XBox format for WMA • Windows uses ADPCM • Windows is more complicated • How many cores? • GetLogicalProcessorInformation

  14. XAudio Tools/APIs • XACT • XACT Command-Line Tool • AdpcmEncode • Wave Merge Tool • XMA Command-Line Encoder • XMA2 Command-Line Encoder • xWMA Command-Line Encoder • X3DAudio • XAPO • XAPOFX • XMAEncoder

  15. My Recommendation • Each team pick an audio engineer for Benchmark 3 • That person will become the XACT3/XAudio2 expert • start with the DirectX Audio manual • The other team members can continue to concentrate on gameplay • Go to DirectX install directory • Go to Samples/

  16. XACT Terminology • Start by reading about: • wave • wave bank • sound • sound bank • track • events • cues

  17. IXAudio2 • Core of the engine • enumerate available audio devices • configure properties • create & destroy voices • monitor performance • It’s a COM object • create after CoInitializeEx • One can create multiple instances • each operates in own thread

  18. Voices • Used to process, manipulate, and play audio data • Source Voices • used to stream audio data • Submix Voices • manipulate audio data • Mastering Voices • send data to audio hardware

  19. Audio Graph • A collection of voices

  20. To Play a Sound • Initialize XAudio2 • Load Audio Data • init a WAVEFORMATEX & XAUDIO2_BUFFER • Create a Source Voice • Pass data to the voice • Start the voice

  21. For the Designer • Determine all the sound effects for your game • Produce such a list right now • This is a to-do list of recordings to make

  22. A very good reference to start with http://www.ultimategameprogramming.com/BeginningDirectX11%5C58958_App_B_rev01_lores.pdf

  23. References • Programming with DirectX : Sound in DirectX – XAudio 2 • http://programming4.us/multimedia/3830.aspx • Game Coding Complete, 4th Edition • McShaffry/Graham • DirectX Software Development Kit Documentation

More Related