Memory optimization packet loss concealment in a voice over packet network
AssigneeTexas Instruments Incorporated
InventorsJohn T. Dowdal, Sachin Adlakha, Dunling Li
Life of this patent
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Abstract
A method to reduce memory requirements for a packet loss concealment algorithm in the event of packet loss in a receiver of pulse code modulated voice signals. A voice playout unit in the receiver shares its nominal delay buffer with a history buffer of a packet loss concealment algorithm up to a maximum limit described in a standard. This reduces or eliminates need to allocate memory for the history buffer. A history buffer can also be extended to retain an original portion of voice signal packets received prior to a packet loss as well as generated voice signals as they are generated. A scratch buffer is used as a working buffer and replaces the function of a pitch buffer.
Claims11
A method for packet loss concealment, comprising:
- receiving voice data signals into a voice playout unit;
- detecting, in the voice playout unit, a lost voice data signal during said receiving;
- buffering, in the voice playout unit, said voice data signals;
- saving, in a history buffer in a packet loss concealment unit, said voice data signals which arrived in the packet loss concealment unit prior to the lost voice data signal but are not yet played out, only when the voice playout unit detects the lost voice signal;
- and
- using, in the packet loss concealment unit, said buffered voice data signals of the voice playout unit instead of at least part of the history buffer of the packet loss concealment unit as a sample history to generate synthesized voice data signals when packet loss concealment unit is ready to replace the lost voice data signal.
A processor that is programmed to:
- receive voice data signals in to a voice playout unit;
- detect, in said voice playout unit, a lost voice data signal during said receive;
- buffer said voice data signals in said voice playout unit;
- save, in a history buffer in a packet loss concealment unit, said voice data signals which arrived in the packet loss concealment unit prior to the lost voice data signal but are not yet played out, only when the voice playout unit detects the lost voice data signal:
- and
- use, in the packet loss concealment unit, said buffered voice data signals instead of at least part of the history buffer of the packet loss concealment unit as a sample history to generate synthesized voice data signals when packet loss concealment unit is ready to replace the lost voice data signal.
Dependencies are inferred from the claim text.