System and method for processing audio data into a plurality of frequency components
An encoder operable to filter audio signals into a plurality of frequency band components, generate quantized digital components for each band, identify a potential for pre-echo events within the generated quantized digital components, generate an approximate signal by decoding the quantized digital components using inverse pulse code modulation, generate an error signal by comparing the approximate signal with the sampled audio signal, and process the error signal and quantized digital components. The encoder operable to process the error signal by processing delayed audio signals and Q band values, determining the potential for pre-echo events from the Q band values, and determining scale factors and MDCT block sizes for the potential for pre-echo events. The encoder operable to transform the error signal into high resolution frequency components using the MDCT block sizes, quantize the scale factors and frequency components, and encode the quantized lines, block sizes, and quantized scale factors for inclusion in the bitstream.
1. A system comprising:
a computer-usable non-transitory storage resource; and
one or more processors communicatively coupled to the storage resource, wherein the processors are configured to execute application code instructions that are stored in the storage resource to cause the system to:
process an audio signal into a plurality of frequency components;
generate quantized digital components for each of the processed frequency components by adaptive pulse code modulating the processed frequency components;
detect an event within the generated quantized digital components;
determine block sizes in response to the detected event; and
determine if a Q band value within the quantized digital components exceeds a predetermined value.
2. The system of claim 1 wherein the application code instructions further comprise application code instructions that cause the system to determine Modified Discrete Cosine Transform (MDCT) block sizes based on a magnitude of the Q band value and characteristics of a band that contains the Q band value.
3. The system of claim 2 wherein the application code instructions further comprise application code instructions that cause the system to determine scale factors based on the MDCT block sizes for the audio signal.
4. The system of claim 3 wherein the application code instructions further comprise application code instructions that cause the system to transform the audio signal into higher resolution frequency components using the MDCT block sizes.
5. The system of claim 4 wherein the application code instructions further comprise application code instructions that cause the system to quantize the scale factors and the higher resolution frequency components.
6. The system of claim 5 wherein the application code instructions further comprise application code instructions that cause the system to encode the quantized frequency components, block sizes, and quantized scale factors for inclusion in a bitstream.
7. The system of claim 1 wherein the application code instructions further comprise application code instructions that cause the system to process the audio signal into a plurality of second frequency components using at least one Pseudo-Quadrature Mirror Filter (PQMF).
8. The system of claim 7 wherein the application code instructions further comprise application code instructions that cause the system to modulate the plurality of second frequency components into a plurality of quantized values using an adaptive pulse code modulation technique.
9. The system of claim 8 wherein the application code instructions further comprise application code instructions that cause the system to detect a pre-echo event from the quantized values.
10. A method comprising:
processing audio samples into a plurality of frequency components;
generating quantized digital components for each of the processed frequency components by modulating the frequency components;
detecting an event within the generated quantized digital components;
determining block sizes in response to the detected event; and
determine if a Q band value within the quantized digital components exceeds a predetermined value.
11. The method of claim 10 further comprising:
determining Modified Discrete Cosine Transform (MDCT) block sizes based on a magnitude of a Q band value and characteristics of a band that contains the Q band value; and
determining scale factors based on the MDCT block sizes for the audio samples.
12. The method of claim 11 further comprising:
transforming the audio samples into higher resolution frequency components using the MDCT block sizes;
quantizing the scale factors and the higher resolution frequency components; and
encoding the quantized frequency components, block sizes, and quantized scale factors for inclusion in a bitstream.
13. The method of claim 10 further comprising:
processing the audio samples into a plurality of second frequency components using at least one Pseudo-Quadrature Mirror Filter (PQMF); and
detecting the event using the plurality of second frequency components.
14. A system comprising:
a computer-usable non-transitory storage resource; and
one or more processors communicatively coupled to the storage resource, wherein the processors are configured to execute application code instructions that are stored in the storage resource to cause the system to:
process a sampled audio signal into a plurality of frequency components;
generate quantized digital components for each of the processed frequency components by modulating the frequency band components;
detect an event within the generated quantized digital components;
determine block sizes in response to the detected event; and
determine if a Q band value within the quantized digital components exceeds a predetermined value.
15. The system of claim 14 wherein the block size is a scaled Modified Discrete Cosine Transform (MDCT) block size.
16. The system of claim 15 further comprising application code instructions that cause the system to determine the MDCT block sizes based on a magnitude of the Q band value.
17. The system of claim 16 further comprising application code instructions that cause the system to determine the MDCT block sizes based on characteristics of a band that contains the Q band value.
18. The system of claim 14 wherein the block size is a Modified Discrete Cosine Transform (MDCT) block size, and the application code instructions further comprise application code instructions that cause the system to determine scale factors based on the MDCT block size.
19. The system of claim 14 wherein the block size is a Modified Discrete Cosine Transform (MDCT) block size.