Stream caching for audio mixers

Patent metadata

Field	Value
Publication number	US-9763002-B1
Application number	US-201514722477-A
Country	US
Kind code	B1
Filing date	May 27, 2015
Priority date	Feb 28, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

Methods and systems are provided for reusing audio streams in an audio mixing environment such that processing resources (e.g., CPU cycles) are not wasted on encoding the same audio streams multiple times (e.g., more than once). Instead, processing resources are conserved without comprising audio quality. The methods described herein are particularly useful when a participant transitions from using a shared encoder to using the participant's own encoder, and when the participant transitions from using the participant's own encoder to using a shared encoder.

First claim

We claim:

1. A method comprising:
performing, by an audio mixing apparatus, a mixing algorithm on audio signals received from a plurality of channels to generate mixed audio signals;
identifying, from the plurality of channels, a unique channel set and one or more non-unique channel sets, wherein the unique channel set includes channels that each receive a unique one of the mixed audio signals, and wherein the one or more non-unique channel sets each includes channels that receive a non-unique one of the mixed audio signals;
determining that in the previous mix cycle a channel in the unique channel set was re-using audio frames encoded by a channel in a non-unique channel set; and
copying a codec state of the channel in the non-unique channel set to the channel in the unique channel set that was re-using the audio frames encoded by the channel in the non-unique channel set.

2. The method of claim 1 , further comprising encoding, for each of the channels in the unique channel set, the unique one of the mixed audio signals corresponding to that channel using an encoder for that channel.

3. The method of claim 1 , further comprising:
identifying, for each of the one or more non-unique channel sets, an encoder used by a channel in the non-unique channel set that was encoding the same non-unique one of the mixed audio signals in the previous mix cycle; and
encoding, for each of the one or more non-unique channel sets, a corresponding one of the non-unique mixed audio signals using the identified encoder.

4. The method of claim 3 , wherein each of the one or more non-unique channel sets receives a different one of the non-unique mixed audio signals.

5. The method of claim 1 , wherein the channel in the non-unique channel set and the channel in the unique channel set are synchronized with respect to buffered audio.

Assignees

• Google Inc

Inventors

• Ellner Lars Henrik
• Shabestary Turaj Zakizadeh
• Enbom Niklas

Classifications

• H04R2499/11

  Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's · CPC title

• H04R3/00 Primary

  Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) · CPC title

• G10L25/78

  Detection of presence or absence of voice signals (switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10) · CPC title

• G10L19/008

  Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing · CPC title

• H04M1/60

  including speech amplifiers · CPC title