Presentation on theme: "Preparing Audio for the Internet - Nick Kereakos - MPR Topics Covered: Topics Covered: Static Audio Files Audio Streams Automation."— Presentation transcript:
Preparing Audio for the Internet - Nick Kereakos - MPR Topics Covered: Topics Covered: Static Audio Files Audio Streams Automation
Static Audio Files What is it? What is it? Standard computer data file Data reduced for internet broadcast Audio encoded using a bit reduced perceptual audio coder.
What do I need? Digital Audio Workstation (DAW) Digital Audio Workstation (DAW) Personal Computer with an audio card. Digital Audio Workstation software. Ex.) Protools, Cubase, Sonic Solutions, Peak Audio, Sonic Foundry, Cool Edit, etc…
Preparing Audio for the Web Step 1 - Convert Analog source to Digital
Method’s Use DAW: Use DAW: Prepare & Edit Digital Audio File Process the file Encode file with Encoder of choice Use Only Encoder: Use Only Encoder: Record audio source with Encoder Create an encoded audio file.
MPR’s Method Use a DAW: Use a DAW: Increased flexibility Original Source file Can be use for multiple Encoders Ability to edit content Better sound quality Integration with Broadcasting & Automation systems.
Audio Processing & Dynamics Compression - Reduces dynamic range the Encoder needs to calculate. For lower bit rates, this is especially important and effective. Limiting - This avoids distortion for the end user listening via the Web. EQ - Softens inherent harshness of low bit rate encoded audio.
Coding Effects Comparison Original Source File Wave Convert Processed file Real Audio Encoded
Web Audio Stream Uses same exact principles Uses same exact principles Audio is sent as a continuous data stream rather than existing as a static file. Data is reduced for internet broadcast Audio encoded using a bit reduced perceptual audio coder.
Audio Processing & Dynamics Process the source: Process the source: Compression - reduces dynamic range Limiting - to set brick wall upper audio limit EQ, to soften upper frequencies Use outboard audio equipment: Use outboard audio equipment: Compressor/Limiter EQ, to manipulate frequencies
What if there are problems? Monitor your stream: Monitor your stream: Install a PC to playback the stream. Wire the output of the PC’s audio card to a silence sensor. When the alarm goes off, you know there is a problem with the stream.
Monitoring the Stream will alert you when: The Encoder fails The source is interrupted or fails Your Network fails
Automated Static Web Encoding Process: Process: Source Audio file is compiled/recorded Dynamics are applied to the audio file File is processed in Real Producer Web Encoded file is delivered to destination
MPR’s Design ENCO - Dad Pro 32: ENCO - Dad Pro 32: Controls SAS Router Records appropriate source to a PCM Linear.WAV file.
MPR’s Design Static Encode Box: Static Encode Box: Running Windows NT 4.0 NT script moves file from ENCO drive WaveConvert Pro applies dynamics to.WAV file and creates new file Real Producer encodes new.WAV file Newly encoded file waits for delivery
MPR’s Design Caravan: Caravan: Developed by MPR Online personnel Script runs 24 days monitoring directory contents When a new Real Audio file is delivered, Caravan moves it to its proper location
Overall Goals Reduce Bit Rate: Reduce Bit Rate: Keeps data costs down. Reaches more people simultaneously. Allows access to people on a dial up modem.
Online Resources Real Networks: Real Networks: http://www.real.com Real Producer is free Real Player is free User forums and FAQS are helpful http://service.real.com/help/library/guides/production/ht mfiles/whatsnew.htm