Universal container for audio data

• US 8,117,038 B2
• Filed: 04/25/2008
• Issued: 02/14/2012
• Est. Priority Date: 07/02/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Stewart, William G., McCartney, James E., Wyatt, Douglas S.
• Primary Examiner(s): Saint Cyr, Leonard
• Application Number:
  US12/109,690
• Publication Number:
  US 20090019087A1
• Time in Patent Office: 1,390 Days
• Field of Search: None
• US Class Current: 704/500
• CPC Class Codes: G10L 19/167 Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

Storing audio data encoded in any of a plurality of different audio encoding formats is enabled by parametrically defining the underlying format in which the audio data is encoded, in audio format and packet table chunks. A flag can be used to manage storage of the size of the audio data portion of the file, such that premature termination of an audio recording session does not result in an unreadable corrupted file. This capability can be enabled by initially setting the flag to a value that does not correspond to a valid audio data size and that indicates that the last chunk in the file contains the audio data. State information for the audio data, to effectively denote a version of the file, and a dependency indicator for dependent metadata, may be maintained, where the dependency indicator indicates the state of the audio data on which the metadata is dependent.

Claims

1. A method for storing audio information comprising:

storing, as part of a single audio file conforming to a particular file format, audio data for a plurality of channels, wherein the plurality of channels are stored within the single audio file in a particular sequence, wherein each channel of the plurality of channels has a position within the particular sequence of channels;

storing, as part of the single audio file, a plurality of channel descriptors, one channel descriptor for each channel of the plurality of channels, wherein the plurality of channel descriptors are stored within the single audio file in a particular sequence, wherein each descriptor of the plurality of descriptors has a position within the particular sequence of descriptors;

wherein the particular file format requires that the plurality of channel descriptors precede the audio data within the single audio file in order for the single audio file to conform to the particular file format;

wherein storing the plurality of channel descriptors and the audio data as part of the single audio file comprises storing the plurality of channel descriptors and the audio data within the single audio file so that the plurality of channel descriptors precedes the audio data within the single audio file in conformance with the particular file format;

wherein the particular file format dictates that, for each descriptor of the plurality of channel descriptors, the position of the descriptor within the particular sequence of descriptors indicates the channel of the plurality of channels to which the descriptor applies;

wherein the method is performed by a computing device.

2. The method of claim 1, wherein storing at least one channel descriptor of the plurality of channel descriptors includes storing metadata indicating a speaker position for the channel of the plurality of channels to which the at least one descriptor applies.

3. The method of claim 2, wherein the speaker position is indicated in the metadata with rectangular coordinates.

4. The method of claim 2, wherein the speaker position is indicated in the metadata with spherical coordinates.

5. The method of claim 1, wherein storing at least one channel descriptor of the plurality of channel descriptors includes storing a channel label for the channel of the plurality of channels to which the at least one descriptor applies.

6. A method for handling audio information comprising:

reading, from a single audio file conforming to a particular file format, audio data comprising a plurality of channels;

wherein prior to reading the audio data, the plurality of channels are stored within the single audio file in a particular sequence, wherein each channel of the plurality of channels has a position within the particular sequence of channels;

reading, from the single audio file, a plurality of channel descriptors;

wherein prior to reading the plurality of channel descriptors, the plurality of channel descriptors are stored within the single audio file in a particular sequence, wherein each descriptor of the plurality of descriptors has a position within the particular sequence of descriptors;

wherein the number of channels in the plurality of channels and the number of channel descriptors in the plurality of channel descriptors are equal;

wherein the particular file format dictates that, for each descriptor of the plurality of channel descriptors, the position of the descriptor within the particular sequence of descriptors indicates the channel of the plurality of channels to which the descriptor applies; and

determining which descriptor of the plurality of descriptors applies to which channel of the plurality of channels by determining, for each descriptor of the plurality of descriptors, the channel of the plurality of channels having a position in the particular sequence of channels corresponding to the position of the descriptor in the particular sequence of descriptors;

wherein the method is performed by a computing device.

7. The method of claim 6, wherein reading at least one channel descriptor of the plurality of channel descriptors includes reading metadata indicating a speaker position for the channel of the plurality of channels to which the at least one descriptor applies.

8. The method of claim 7, wherein the speaker position is indicated in the metadata with rectangular coordinates.

9. The method of claim 7, wherein the speaker position is indicated in the metadata with spherical coordinates.

10. The method of claim 6, wherein reading the plurality of channel descriptors includes reading a channel label for each channel of the plurality of channels, the method further comprising:

determining a channel layout presented by the plurality of channels from the plurality of channel labels.

11. A non-transitory computer-readable medium storing instructions which, when executed by a computing device, cause the computing device to perform:

storing, as part of a single audio file conforming to a particular file format, audio data for a plurality of channels, wherein the plurality of channels are stored within the single audio file in a particular sequence, wherein each channel of the plurality of channels has a position within the particular sequence of channels;

storing, as part of the single audio file, a plurality of channel descriptors, one channel descriptor for each channel of the plurality of channels, wherein the plurality of channel descriptors are stored within the single audio file in a particular sequence, wherein each descriptor of the plurality of descriptors has a position within the particular sequence of descriptors;

wherein the particular file format requires that the plurality of channel descriptors precede the audio data within the single audio file in order for the single audio file to conform to the particular file format;

wherein storing the plurality of channel descriptors and the audio data as part of the single audio file comprises storing the plurality of channel descriptors and the audio data within the single audio file so that the plurality of channel descriptors precedes the audio data within the single audio file in conformance with the particular file format;

wherein the particular file format dictates that, for each descriptor of the plurality of channel descriptors, the position of the descriptor within the particular sequence of descriptors indicates the channel of the plurality of channels to which the descriptor applies.

12. The medium of claim 11, wherein storing at least one channel descriptor of the plurality of channel descriptors includes storing metadata indicating a speaker position for the channel of the plurality of channels to which the at least one descriptor applies.

13. The medium of claim 12, wherein the speaker position is indicated in the metadata with rectangular coordinates.

14. The medium of claim 12, wherein the speaker position is indicated in the metadata with spherical coordinates.

15. The medium of claim 11, wherein storing at least one channel descriptor of the plurality of channel descriptors includes storing a channel label for the channel of the plurality of channels to which the at least one descriptor applies.

16. A non-transitory computer-readable medium storing instructions which, when executed by a computing device, cause the computing device to perform:

reading, from a single audio file conforming to a particular file format, audio data for a plurality of channels;

wherein prior to reading the audio data, the plurality of channels are stored within the single audio file in a particular sequence, wherein each channel of the plurality of channels has a position within the particular sequence of channels;

reading, from the single audio file, a plurality of channel descriptors, wherein the plurality of channel descriptors are stored within the single audio file in a particular sequence, wherein each descriptor of the plurality of descriptors has a position within the particular sequence of descriptors;

wherein the number of channels in the plurality of channels is equal to the number of descriptors in the plurality of descriptors;

wherein the particular file format dictates that, for each descriptor of the plurality of channel descriptors, the position of the descriptor within the particular sequence of descriptors indicates the channel of the plurality of channels to which the descriptor applies; and

determining which descriptor of the plurality of descriptors applies to which channel of the plurality of channels by determining, for each descriptor of the plurality of descriptors, the channel of the plurality having a position in the particular sequence of channels corresponding to the position of the descriptor in the sequence of descriptors.

17. The medium of claim 16, wherein reading at least one channel descriptor of the plurality of channel descriptors includes reading metadata indicating a speaker position for the channel of the plurality of channels to which the at least one descriptor applies.

18. The medium of claim 17, wherein the speaker position is indicated in the metadata with rectangular coordinates.

19. The medium of claim 17, wherein the speaker position is indicated in the metadata with spherical coordinates.

20. The medium of claim 16, wherein reading the plurality of channel descriptors includes reading a channel label for each channel of the plurality of channels, the medium further storing instructions which, when executed by the computing device, cause the computing device to perform:

determining a channel layout presented by the plurality of channels from the plurality of channel labels.