Audio coding method and related apparatus
First Claim
1. A method for encoding an audio signal, performed by an audio signal encoder which comprises a processor and a memory storing program instructions for execution by the processor, the method comprising:
- performing, by the encoder, a time-frequency transformation on a current frame of a time-domain audio signal, to obtain spectral coefficients of the current frame;
obtaining, by the encoder, one or more reference coding parameters of the current frame;
determining, by the encoder, whether the reference coding parameters satisfy any one of a set of parameter conditions;
(1) when any one of the parameter conditions is satisfied, encoding the audio signal comprising;
quantizing, by the encoder, the spectral coefficients of the current frame using a transform coded excitation (TCX) algorithm; and
writing the quantized spectral coefficients into a bitstream for storing or transmitting;
or(2) when none of the parameter conditions is satisfied, encoding the audio signal comprising;
quantizing, by the encoder, the spectral coefficients of the current frame using a high quality transform coding (HQ) algorithm; and
writing the quantized spectral coefficients into a bitstream for storing or transmitting;
wherein the current frame comprises a subband z, and two subbands i and j;
wherein the subband z and the subbands i and j are such that;
a highest frequency bin of the subband z is higher than a critical frequency bin F1, and F1 is in a range of 6.4 kHz to 12 kHz; and
a highest frequency bin of the subband i is lower than a highest frequency bin of the subband j, the highest frequency bin of the subband j is higher than a critical frequency bin F2, and F2 is in a range of 4.8 kHz to 8 kHz;
wherein the obtained reference coding parameters comprise;
a peak value of spectral coefficients that are located within the subband z, and an average value of spectral coefficients that are located within the subband z; and
an average energy of spectral coefficients that are located within the subband and an average energy of spectral coefficients that are located within the subband j;
and wherein the parameter conditions comprise a parameter condition as following;
the peak value of the spectral coefficients that are located within the subband z is greater than the average value of the spectral coefficients that are located within the subband z multiplied by a threshold T2; and
the average energy of the spectral coefficients that are located within the subband j is greater than a product of the average energy of the spectral coefficients that are located within the subband i multiplied by a threshold T4.
1 Assignment
0 Petitions
Accused Products
Abstract
An audio encoding method and a related apparatus are disclosed. The audio coding method includes: performing a time-frequency transformation on a current frame of a time-domain audio signal, to obtain spectral coefficients of the current audio frame; obtaining one or more reference coding parameters of the current frame; and determining whether the reference coding parameters satisfy a set of parameter conditions. If any one of the parameter conditions is satisfied, the spectral coefficients of the current frame are encoded by using a transform coded excitation (TCX) algorithm. If none of the parameter conditions is satisfied, the spectral coefficients of the current audio frame are encoded using a high quality transform coding (HQ) algorithm. The audio encoding method and the related apparatus help improve encoding quality or encoding efficiency in audio signal encoding.
-
Citations
22 Claims
-
1. A method for encoding an audio signal, performed by an audio signal encoder which comprises a processor and a memory storing program instructions for execution by the processor, the method comprising:
-
performing, by the encoder, a time-frequency transformation on a current frame of a time-domain audio signal, to obtain spectral coefficients of the current frame; obtaining, by the encoder, one or more reference coding parameters of the current frame; determining, by the encoder, whether the reference coding parameters satisfy any one of a set of parameter conditions; (1) when any one of the parameter conditions is satisfied, encoding the audio signal comprising; quantizing, by the encoder, the spectral coefficients of the current frame using a transform coded excitation (TCX) algorithm; and writing the quantized spectral coefficients into a bitstream for storing or transmitting; or (2) when none of the parameter conditions is satisfied, encoding the audio signal comprising; quantizing, by the encoder, the spectral coefficients of the current frame using a high quality transform coding (HQ) algorithm; and writing the quantized spectral coefficients into a bitstream for storing or transmitting; wherein the current frame comprises a subband z, and two subbands i and j;
wherein the subband z and the subbands i and j are such that;a highest frequency bin of the subband z is higher than a critical frequency bin F1, and F1 is in a range of 6.4 kHz to 12 kHz; and a highest frequency bin of the subband i is lower than a highest frequency bin of the subband j, the highest frequency bin of the subband j is higher than a critical frequency bin F2, and F2 is in a range of 4.8 kHz to 8 kHz; wherein the obtained reference coding parameters comprise; a peak value of spectral coefficients that are located within the subband z, and an average value of spectral coefficients that are located within the subband z; and an average energy of spectral coefficients that are located within the subband and an average energy of spectral coefficients that are located within the subband j; and wherein the parameter conditions comprise a parameter condition as following; the peak value of the spectral coefficients that are located within the subband z is greater than the average value of the spectral coefficients that are located within the subband z multiplied by a threshold T2; and the average energy of the spectral coefficients that are located within the subband j is greater than a product of the average energy of the spectral coefficients that are located within the subband i multiplied by a threshold T4. - View Dependent Claims (2, 3, 4)
-
-
5. A method for encoding an audio signal, performed by an audio signal encoder which comprises a processor and a memory storing program instructions for execution by the processor, the method comprising:
-
performing, by the encoder, a time-frequency transformation on a current frame of a time-domain audio signal, to obtain spectral coefficients of the current frame; obtaining, by the encoder, one or more reference coding parameters of the current frame; determining, by the encoder, whether the reference coding parameters satisfy any one of a set of parameter conditions; (1) when any one of the parameter conditions is satisfied, encoding the audio signal comprising; quantizing, by the encoder, the spectral coefficients of the current frame using a transform coded excitation (TCX) algorithm; and writing the quantized spectral coefficients into a bitstream for storing or transmitting; or (2) when none of the parameter conditions is satisfied, encoding the audio signal comprising; quantizing, by the encoder, the spectral coefficients of the current frame using a high quality transform coding (HQ) algorithm; and writing the quantized spectral coefficients into a bitstream for storing or transmitting; wherein the current frame comprises subband i and subband j; wherein a highest frequency bin of the subband i is lower than a highest frequency bin of the subband j, the highest frequency bin of the subband j is higher than a critical frequency bin F2, and F2 is in a range of 4.8 kHz to 8 kHz; wherein the obtained reference coding parameters comprise; an average energy of spectral coefficients that are located within the subband and an average energy of spectral coefficients that are located within the subband j; and wherein the parameter conditions comprise a parameter condition as following; the average energy of the spectral coefficients that are located within the subband j is greater than a product of the average energy of the spectral coefficients that are located within the subband i multiplied by a threshold T4. - View Dependent Claims (6, 7, 8)
-
-
9. A method for encoding an audio signal, performed by an audio signal encoder which comprises a processor and a memory storing program instructions for execution by the processor, the method comprising:
-
performing, by the encoder, a time-frequency transformation on a current frame of a time-domain audio signal, to obtain spectral coefficients of the current frame; obtaining, by the encoder, one or more reference coding parameters of the current frame; determining, by the encoder, whether the reference coding parameters satisfy any one of a set of parameter conditions; (1) when any one of the parameter conditions is satisfied, encoding the audio signal comprising; quantizing, by the encoder, the spectral coefficients of the current frame using a transform coded excitation (TCX) algorithm; and writing the quantized spectral coefficients into a bitstream for storing or transmitting; or (2) when none of the parameter conditions is satisfied, encoding the audio signal comprising; quantizing, by the encoder, the spectral coefficients of the current frame using a high quality transform coding (HQ) algorithm; and writing the quantized spectral coefficients into a bitstream for storing or transmitting; wherein the current frame comprise subband x and subband y; wherein a highest frequency bin of the subband x is lower than or equal to a lowest frequency bin of the subband y; wherein the obtained reference coding parameters comprise; a peak value of spectral coefficients that are located within the subband x, an average value of spectral coefficients that are located within the subband x, a peak value of spectral coefficients that are located within the subband y, and an average value of spectral coefficients that are located within the subband y; and wherein the parameter conditions comprise a parameter condition as following; a product of the peak value of spectral coefficients that are located within the subband x multiplied by the average value of coefficients that are located within the subband y is less than a product of the peak value of spectral coefficients that are located within the subband y multiplied by the average value of coefficients that are located within the subband x and multiplied by a lowest value of an interval R1;
ora product of the peak value of spectral coefficients that are located within the subband x multiplied by the average value of coefficients that are located within the subband y is greater than a product of the peak value of spectral coefficients that are located within the subband y multiplied by the average value of coefficients that are located within the subband x and multiplied by a highest value of the interval R1. - View Dependent Claims (10, 11)
-
-
12. An audio signal encoder, comprising a processor and a memory storing program instructions for execution by the processor;
- wherein the processor is configured to execute the program instructions to;
perform a time-frequency transformation on a current frame of a time-domain audio signal, to obtain spectral coefficients of the current frame; obtain one or more reference coding parameters of the current frame; determine whether the reference coding parameters satisfy any one of a set of parameter conditions; (1) when any one of the parameter conditions is satisfied, encode the audio signal comprising; quantize the spectral coefficients of the current frame using a transform coded excitation (TCX) algorithm; and write the quantized spectral coefficients into a bitstream for storing or transmitting; or (2) when none of the parameter conditions is satisfied, encode the audio signal comprising; quantize the spectral coefficients of the current frame using a high quality transform coding (HQ) algorithm; and write the quantized spectral coefficients into a bitstream for storing or transmitting; wherein the current frame comprises a subband z, and two subbands i and j;
wherein the subband z and the subbands i and j are such thata highest frequency bin of the subband z is higher than a critical frequency bin F1, and F1 is in a range of 6.4 kHz to 12 kHz; and a highest frequency bin of the subband i is lower than a highest frequency bin of the subband j, the highest frequency bin of the subband j is higher than a critical frequency bin F2, and F2 is in a range of 4.8 kHz to 8 kHz; wherein the obtained reference coding parameters comprise; a peak value of spectral coefficients that are located within the subband z, and an average value of spectral coefficients that are located within the subband z; and an average energy of spectral coefficients that are located within the subband i, and an average energy of spectral coefficients that are located within the subband j; and wherein the parameter conditions comprise a parameter condition as following; the peak value of the spectral coefficients that are located within the subband z is greater than the average value of the spectral coefficients that are located within the subband z multiplied by a threshold T2; and the average energy of the spectral coefficients that are located within the subband j is greater than a product of the average energy of the spectral coefficients that are located within the subband i multiplied by a threshold T4. - View Dependent Claims (13, 14, 15)
- wherein the processor is configured to execute the program instructions to;
-
16. An audio signal encoder, comprising a processor and a memory storing program instructions for execution by the processor;
- wherein the processor is configured to execute the program instructions to;
perform a time-frequency transformation on a current frame of a time-domain audio signal, to obtain spectral coefficients of the current frame; obtain one or more reference coding parameters of the current frame; determine whether the reference coding parameters satisfy any one of a set of parameter conditions; (1) when any one of the parameter conditions is satisfied, encode the audio signal comprising; quantize the spectral coefficients of the current frame using a transform coded excitation (TCX) algorithm; and write the quantized spectral coefficients into a bitstream for storing or transmitting; or (2) when none of the parameter conditions is satisfied, encode the audio signal comprising; quantize the spectral coefficients of the current frame using a high quality transform coding (HQ) algorithm; and write the quantized spectral coefficients into a bitstream for storing or transmitting; wherein the current frame comprises subband i and subband j; wherein a highest frequency bin of the subband i is lower than a highest frequency bin of the subband j, the highest frequency bin of the subband j is higher than a critical frequency bin F2, and F2 is in a range of 4.8 kHz to 8 kHz; wherein the obtained reference coding parameters comprise; an average energy of spectral coefficients that are located within the subband and an average energy of spectral coefficients that are located within the subband j; and wherein the parameter conditions comprise a parameter condition as following; the average energy of the spectral coefficients that are located within the subband j is greater than a product of the average energy of the spectral coefficients that are located within the subband i multiplied by a threshold T4. - View Dependent Claims (17, 18, 19)
- wherein the processor is configured to execute the program instructions to;
-
20. An audio signal encoder, comprising a processor and a memory storing program instructions for execution by the processor;
- wherein the processor is configured to execute the program instructions to;
perform a time-frequency transformation on a current frame of a time-domain audio signal, to obtain spectral coefficients of the current frame; obtain one or more reference coding parameters of the current frame; determine whether the reference coding parameters satisfy any one of a set of parameter conditions; (1) when any one of the parameter conditions is satisfied, encode the audio signal comprising; quantize the spectral coefficients of the current frame using a transform coded excitation (TCX) algorithm; and write the quantized spectral coefficients into a bitstream for storing or transmitting; or (2) when none of the parameter conditions is satisfied, encode the audio signal comprising; quantize the spectral coefficients of the current frame using a high quality transform coding (HQ) algorithm; and write the quantized spectral coefficients into a bitstream for storing or transmitting; wherein a highest frequency bin of the subband x is lower than or equal to a lowest frequency bin of the subband y; wherein the obtained reference coding parameters comprise; a peak value of spectral coefficients that are located within the subband x, an average value of spectral coefficients that are located within the subband x, a peak value of spectral coefficients that are located within the subband y, and an average value of spectral coefficients that are located within the subband y; and wherein the parameter conditions comprise a parameter condition as following; a product of the peak value of spectral coefficients that are located within the subband x multiplied by the average value of coefficients that are located within the subband y is less than a product of the peak value of spectral coefficients that are located within the subband y multiplied by the average value of coefficients that are located within the subband x and multiplied by a lowest value of an interval R1;
ora product of the peak value of spectral coefficients that are located within the subband x multiplied by the average value of coefficients that are located within the subband y is greater than a product of the peak value of spectral coefficients that are located within the subband y multiplied by the average value of coefficients that are located within the subband x and multiplied by a highest value of the interval R1. - View Dependent Claims (21, 22)
- wherein the processor is configured to execute the program instructions to;
Specification