| Patent application number | Description | Published |
|---|
| 20090099851 | ADAPTIVE BIT POOL ALLOCATION IN SUB-BAND CODING - In a Bluetooth™ Sub-band Codec (SBC), the size of a bit pool allocated for encoding is adapted in a manner that is dependent upon the audio content that is being encoded. In one implementation, the size of the bit pool is increased during periods when the audio input signal represents an active audio signal, such as speech or music, and decreased when the audio input signal represents background noise or silence. This has the effect of increasing the bit rate (and thus the audio quality) in the presence of speech or music but decreasing the bit rate (and thus the audio quality) in the presence of background noise or silence. By adapting the size of the bit pool in this manner, the quality of the encoded bit-stream transmitted from the SBC encoder may be improved or power may be conserved depending upon the implementation. | 04-16-2009 |
| 20090190614 | JITTER BUFFER ADAPTATION BASED ON AUDIO CONTENT - A system and method for discarding or inserting audio frames in a jitter buffer is described. The system and method provides improved audio quality as compared to conventional jitter buffer management systems. In one embodiment, buffer control logic determines whether to discard audio frames to be stored in a jitter buffer or to insert audio frames among audio frames to be output from a jitter buffer based not only on the number of audio frames currently stored in the jitter buffer but also based on the power of the current audio frame to be stored in or output from the jitter buffer. The system and method is generally applicable to any wireless or wired communication system in which audio signals are transmitted between entities operating in different clock domains. | 07-30-2009 |
| 20090222264 | SUB-BAND CODEC WITH NATIVE VOICE ACTIVITY DETECTION - An augmented version of a Low-Complexity Sub-band Coder (LC-SBC) is described herein that is better suited than conventional LC-SBC for wideband voice communication in the Bluetooth™ framework, where minimizing the power consumption is of paramount importance. The augmented version of LC-SBC utilizes certain techniques associated with speech coding, such as Voice Activity Detection (VAD), to reduce bandwidth usage and power consumption while maintaining voice quality. The augmented version of LC-SBC reduces the average bit rate used for transmitting wideband speech in a manner that does not add significant computational complexity. Furthermore, the augmented version of LC-SBC may advantageously be implemented in a manner that does not require any modification of the underlying logic/structure of LC-SBC. | 09-03-2009 |
| 20090238375 | DUAL STREAMING WITH EXCHANGE OF FEC STREAMS BY AUDIO SINKS - A system and method is described herein in which an audio source wirelessly transmits audio content to a first audio sink over one wireless link and to a second audio sink over another wireless link. The two audio sinks also exchange forward error correction (FEC) streams over a wireless link between the two audio sinks, wherein the FEC streams are generated by FEC encoding the audio content received from the audio source. The audio sinks advantageously use the exchanged FEC information to synchronize the playback of the audio content as well as to improve the robustness of the wireless links with the audio source in a manner that does not consume additional bandwidth on those links. | 09-24-2009 |
| 20100125454 | PACKET LOSS CONCEALMENT FOR SUB-BAND CODECS - Packet loss concealment systems and methods are described that may be used in conjunction with a Bluetooth® Low-Complexity Sub-band Coding (LC-SBC) codec or other sub-band codecs, including but not limited to an MPEG-1 Audio Layer 3 (MP3) codec, an Advanced Audio Coding (AAC) codec, and a Dolby AC-3 codec. | 05-20-2010 |
| 20100324911 | CVSD DECODER STATE UPDATE AFTER PACKET LOSS - A system and method is described for updating the state of an audio decoder, such as a CVSD decoder, after a packet loss has occurred. In response to the loss of a packet, the system and method encodes audio samples produced by a packet loss concealment (PLC) algorithm and effectively passes the encoded audio samples through the audio decoder in lieu of the contents of the lost packet. This operation brings the state of the audio decoder into better synchronization with the state of a remote audio encoder, thereby reducing or minimizing the degrading effect of the packet loss on the perceived quality of an output audio signal produced by a voice processing system that includes the audio decoder. | 12-23-2010 |
| 20110051957 | JITTER BUFFER ADAPTATION BASED ON AUDIO CONTENT - A system and method for discarding or inserting audio frames in a jitter buffer is described. The system and method provides improved audio quality as compared to conventional jitter buffer management systems. In one embodiment, buffer control logic determines whether to discard audio frames to be stored in a jitter buffer or to insert audio frames among audio frames to be output from a jitter buffer based not only on the number of audio frames currently stored in the jitter buffer but also based on the power of the current audio frame to be stored in or output from the jitter buffer. The system and method is generally applicable to any wireless or wired communication system in which audio signals are transmitted between entities operating in different clock domains. | 03-03-2011 |
