ELE 791 Real World Signal Processing

1. ELE 791Real World Signal Processing Spring 2005 Syracuse University 22 Feb 2005

2. ELE 791 :: Outline [22 Feb 2005] • Assignments • Simple System Design Tasks • Digital Mixing Console Design

3. ELE 791 :: Assignments • Expectations: 3xx, 5xx, 7xx • Assignment # 1 • Assignment # 2

4. ELE 791 :: Simple System Design Tasks • Determine: Block diagram, Flowchart, Components, Interface signals, Clocking, Memory, Processor speed, Host communications requirements. Justify choices! • TASK 1 :: Peak Predictor vs Reality ::Analog stereo line level audio in and out; low frequency amplitude prediction on both channels; host adjusts digital gain; host displays predicted + real peaks of input • TASK 2 :: Dancing Lights ::Analog stereo mic level in, line level out; music application; 1024 FFT on each channel ; host adjusts digital gain; host displays input spectrum • TASK 3 :: Fading to Black ::Analog camera video signal in and out; host adjusts fade to black with variable time; host displays average luminance and average chrominance of input and output • TASK 4 :: How much Color? ::Analog camera video signal in and out; host adjusts amount of color; host displays average luminance and average chrominance of input and output

5. ELE 791 :: Digital Mixing Console Design • Have you ever seen a mixing console? • In some ways it could be considered the ultimate audio signal processing device • Have you attended a concert? • Have you listened to a CD? • Have you listened to the radio? • 3 broad CATEGORIES of mixing consoles: • Live Sound • Recording • Broadcast

6. ELE 791 :: Digital Mixing Console Design • FUNCTIONS of an audio mixing console: • nerve center of a control room • mixes various signals from different sources • allows control over signal level and spectral balance • allows signals to be routed to different destinations • allows of copies of signals to be sent to different devices and then recombined • allows signal paths to be monitored and allows corrective action to be taken • http://www.audioed.com.au/LearnOL_synopses/MIXER1Free_synop.html

7. ELE 791 :: Digital Mixing Console Design • Wheatstone Corporation • 20 years old analog company specialized in making high-end audio mixing consoles for broadcast applications • Had a desire to migrate to digital technology • Product Line • Radio Console [least complicated, 24/7 operation] • Current Example :: Analog :: A-5000, Brochure • Current Example :: Digital :: D-4000, Brochure, D-8000 Flow • Production Console [more complicated] • Current Example: SP-8, Brochure • Television Console [even more complicated, 24/7 operation] • Current Example: D-5.1, Brochure

8. ELE 791 :: Digital Mixing Console Design • GOALS: • Shall be a drop-in replacement for existing analog consoles • Shall present the same familiar work surface to the user • Shall be upgradeable -- from completely analog to completely digital or somewhere in between • Shall have the bells and whistles normally associated with digital products – reconfigurable, external control, etc. • Shall serve as a platform for future products

9. ELE 791 :: Digital Mixing Console Design • TASK: • Good news: start from scratch • Bad news: start from scratch • MARKETPLACE: • Digital Recording consoles were starting to appear • All broadcast consoles were analog • Wheatstone was considered a leader in this field: CNN, ABC, The White House, … • QUESTIONS: • What kind of console should be built? • How would we architect the system?