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The Eighteenth Annual Interactive Audio Conference
PROJECT BAR-B-Q 2013
BBQ Group Report: When is Hardware Offloading Preferable, Now and in the Future?
   
Participants: A.K.A. "Outsourced! (The musical)"
David Berol, Audience, Inc. Kate Werner, Microsoft
Andy Rumelt, Cirrus Logic, Inc. Adam Fluckey, Dolby Laboratories
David Roach, Optimal Sound Konstantin Merkher, CEVA DSP, Ltd
Howard Brown, IDT Mike Spence, Texas Instruments
Miguel Chavez, Analog Devices Facilitator: Linda Law, Project Bar-B-Q
 
  PDF download the PDF

Problem Statement

Audio is a basic feature of the most popular computing platforms today. When building a device based on these platforms the location of audio processing is always considered. To put it simply, architects have two options where the audio processing is executed: the host or the offload processor. This report explores the use cases that justify the need for the additional engineering effort, expense, and implementation of audio hardware offloading.

Summary of Findings

During the initial discussions the team quickly found that this topic can get use case and device specific very quickly. In order to up-level, the team created the following boundaries:

  • Use cases were segregated into two groups: now and future (1-5 years out).
  • Use cases were based on latency (performance), power, and cost.
  • Scope was limited to general architectures, relevant operating systems, and mainstream products.
  • Edge cases and outliers were ignored.

Generally the team found that individual feature sets make audio hardware offload less attractive. However as more and more feature sets are grouped together the benefits start to add up thus making audio hardware offload appealing. In addition, the team found some specific use cases that should always be offloaded (e.g. ANC and speaker protection) due to the latency requirements.

As day turned to night, the team discussed the impact of “walled gardens” in the industry and concluded that “walled gardens” are driven by individual business strategies. A deep dive explaining the keys to the walled gardens was mutually destructive.

Driving Forces
The hardware offloading has to solve an end user or a system or implementation problem.

  • Power
    • Impact of devices battery life
    • Standby time
      • Voice triggers
      • Low Power Audio
    • Energy Star Specs / European Power Standard
  • OEM Time to Market
  • Innovation
  • Improve system responsiveness (freeing up CPU / AP)
  • Lower latency
    • Process
    • System
  • Ease of System Integration for OEM
    • Architecture Portability
      • OS Agnostic 
      • AP Agnostic
      • SKU Agnostic
    • Off the shelf / Buy over build
  • Accountability (Counting ability) for royalties

Expanded solution description

We analyzed each use case to determine whether hardware acceleration provides an advantage in latency (performance), power usage, and/or cost, for both the present and a 3-to-5 year future. Here are the results:

hardware acceleration advantages chart

Wake on Voice/Word Capture
Speaker Authentication
Speaker ID
Long Music Playback Times w/o Video
Long Video Playback Times
Speaker Protection
Smart EQ Reverse Masking
Automatic Noise Cancellation
Ultrasonic Gesture Detection
Noise Suppression and Beamforming
VoIP

Here are some categories of future products (edge cases for the “then” use cases) which we did not analyze.

  • Watch
  • Google Glass
    • Bone conduction
  • TV w/ Microphones
  • Set top w/ Microphones
  • Speakers w/ Microphones
    • On device decode for Wireless Speakers
  • Sound bars (w/ microphones)
  • ANC Chip in Smartphone with Digital connection to headset for ANC
  • Cars in future
  • Ubiquitous Audio Network Group Impact
    • Smart mics + smart speakers (Echo cancellation)

Future Technology Breakthroughs that affect offloading

  • Wireless Power
  • Power Harvesting

Other reference material

Cite Matrix from Doppler Chickens 2012 Project Bar-B-Q Workgroup:
http://www.projectbarbq.com/reports/bbq12/Project_Bar-B-Q_2012_report_section_3.pdf

section 7


next section

select a section:
1. Introduction
2. Workgroup Reports Overview
3. Ubiquitous Networked Audio
4. HD Audio Capture in Consumer Devices
5. Enabling More Profound Human Expression with Modern Musical Instruments
6. Using Sensor Data to Improve the User Experience of Audio Applications
7. When is Hardware Offloading Preferable, Now and in the Future?
8. Schedule & Sponsors