Spatially formatted enhanced audio data for backward compatible audio bitstreams
In general, techniques are described by which to specify spatially formatted enhanced audio data for backward compatible audio bitstreams. A device comprising a memory and one or more processors may be configured to perform the techniques. The memory may store the backward compatible bitstream that conforms to a legacy transport format. The processor(s) may obtain, from the backward compatible bitstream, legacy audio data that conforms to a legacy audio format and a spatially formatted extended audio stream. The processor(s) may process the spatially formatted extended audio stream to obtain extended audio data that enhances the legacy audio data. The processor(s) may next obtain, based on the legacy audio data and the extended audio data, enhanced audio data that conforms to an enhanced audio format. The processor(s) may output the enhanced audio data to one or more speakers.
1. A device configured to process a backward compatible bitstream, the device comprising:
one or more memories configured to store at least a portion of the backward compatible bitstream, the backward compatible bitstream conforming to a legacy transport format; and
one or more processors configured to:
obtain, from the backward compatible bitstream, legacy audio data that conforms to a legacy audio format;
obtain, from the backward compatible bitstream, one or more parameters that identify how the legacy audio data was obtained from higher order ambisonic audio data;
process, based on the one or more parameters, the legacy audio data to obtain processed legacy audio data;
obtain, from the backward compatible bitstream, a spatially formatted extended audio stream;
process the spatially formatted extended audio stream to obtain extended audio data that enhances the processed legacy audio data;
obtain, based on the processed legacy audio data and the extended audio data, enhanced audio data that conforms to an enhanced audio format; and
output the enhanced audio data to one or more speakers.
2. The device of claim 1 , wherein the spatially formatted extended audio stream conforms to a spatial Advanced Audio Coding (AAC) extended audio stream (spAACe) format.
3. The device of claim 1 , wherein the legacy transport format comprises a psychoacoustic codec transport format.
4. The device of claim 3 , wherein the psychoacoustic coded transport format comprises one of an Advanced Audio Coding (AAC) transport format or an AptX transport format.
5. The device of claim 1 ,
wherein the legacy transport format comprises one of an Advanced Audio Coding transport format or an AptX transport format, and
wherein the one or more processors are configured to obtain the enhanced audio data from one or more fill elements specified in accordance with one of the Advanced Audio Coding transport format or an AptX transport format.
6. The device of claim 1 ,
wherein the one or more processors are further configured to obtain one or more indications indicative of how the extended audio data was specified in the backward compatible bitstream, and
wherein the one or more processors are configured to obtain, from the backward compatible bitstream and based on the indications, the spatially compressed extended audio data.
7. The device of claim 6 , wherein the one or more processors are configured to obtain the one or more indication from a header provided in one or more fill elements.
8. The device of claim 7 , wherein the header directly follows the legacy audio data in the backward compatible bitstream.
9. The device of claim 7 , wherein the one or more indications include an indication identifying that the fill elements include the extended audio data.
10. The device of claim 7 , wherein the one or more indications include an indication identifying a size of the header.
11. The device of claim 6 , wherein the one or more indications include an indication identifying a number of fill elements.
12. The device of claim 1 , wherein legacy audio format comprises one of a monophonic audio format, or a stereo audio format.
13. The device of claim 1 , wherein the enhanced audio format comprises one of a 7.1 surround sound format and a 7.1+4H surround sound format.
14. The device of claim 1 , wherein the extended audio data is representative of higher order ambisonic audio data.
15. The device of claim 1 ,
wherein the one or more processors are configured to de-mix the legacy audio data to obtain first higher order ambisonic audio data,
wherein the spatially compressed extended audio data comprises second higher order ambisonic audio data, and
wherein the one or more processors are configured to render, based on the first higher order ambisonic audio data and the second higher order ambisonic audio data, the enhanced audio data.
16. A method of processing a backward compatible bitstream conforming to a legacy transport format, the method comprising:
obtaining, from the backward compatible bitstream, legacy audio data that conforms to a legacy audio format;
obtaining, from the backward compatible bitstream, one or more parameters that identify how the legacy audio data was obtained from higher order ambisonic audio data;
process, based on the one or more parameters, the legacy audio data to obtain processed legacy audio data;
obtaining, from the backward compatible bitstream, a spatially formatted extended audio stream;
processing the spatially formatted extended audio stream to obtain extended audio data that enhances the legacy audio data;
obtaining, based on the legacy audio data and the extended audio data, enhanced audio data that conforms to an enhanced audio format; and
outputting the enhanced audio data to one or more speakers.
17. The method of claim 16 , wherein the spatially formatted extended audio stream conforms to a spatial Advanced Audio Coding (AAC) extended audio stream (spAACe) format.
18. The method of claim 16 , wherein the legacy transport format comprises a psychoacoustic codec transport format.
19. The method of claim 18 , wherein the psychoacoustic coded transport format comprises one of an Advanced Audio Coding (AAC) transport format or an AptX transport format.
20. The method of claim 16 ,
wherein the legacy transport format comprises one of an Advanced Audio Coding transport format or an AptX transport format, and
wherein obtaining the enhanced audio data comprises obtaining the enhanced audio data from one or more fill elements specified in accordance with the Advanced Audio Coding transport format.
21. A device configured to obtain a backward compatible bitstream, the device comprising:
one or more memories configured to store at least a portion of the backward compatible bitstream, the backward compatible bitstream conforming to a legacy transport format; and
one or more processors configured to:
specify, in the backward compatible bitstream, legacy audio data that conforms to a legacy audio format;
specify, in the backward compatible bitstream, one or more parameters that identify how the legacy audio data was obtained from higher order ambisonic audio data;
process extended audio data that enhances the legacy audio data to obtain a spatially formatted extended audio stream;
specify, in the backward compatible bitstream, the spatially formatted extended audio stream; and
output the backward compatible bitstream.
22. The device of claim 21 , wherein the spatially formatted extended audio stream conforms to a spatial Advanced Audio Coding (AAC) extended audio stream (spAACe) format.
23. The device of claim 21 , wherein the legacy transport format comprises one of an Advanced Audio Coding (AAC) transport format and an AptX transport format.
24. The device of claim 21 ,
wherein the legacy transport format comprises one of an Advanced Audio Coding (AAC) transport format and an AptX transport format, and
wherein the one or more processors are configured to specify the extended audio data in one or more fill elements in accordance with the Advanced Audio Coding transport format.
25. The device of claim 21 , wherein the one or more processors are further configured to specify, in the backward compatible bitstream, one or more indications indicative of how the extended audio data was specified in the backward compatible bitstream.
26. A method of processing a backward compatible bitstream conforming to a legacy transport format, the method comprising:
specifying, in the backward compatible bitstream, legacy audio data that conforms to a legacy audio format;
specifying, in the backward compatible bitstream, one or more parameters that identify how the legacy audio data was obtained from higher order ambisonic audio data;
processing extended audio data that enhances the legacy audio data to obtain a spatially formatted extended audio stream;
specifying, in the backward compatible bitstream, the spatially formatted extended audio stream; and
outputting the backward compatible bitstream.
27. The method of claim 26 , wherein the psychoacoustic codec transport format comprises one of an Advanced Audio Coding (AAC) transport format and an AptX transport format.
28. The method of claim 26 ,
wherein the legacy transport format comprises one of an Advanced Audio Coding (AAC) transport format and an AptX transport format, and
wherein specifying the extended audio data comprises specifying the extended audio data in one or more fill elements in accordance with the Advanced Audio Coding transport format.
29. The method of claim 26 , wherein legacy audio format comprises one of a monophonic audio format, or a stereo audio format.
30. The method of claim 26 , wherein the extended audio data comprises higher order ambisonic audio data.