Details
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Sub-task
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Status: Resolved
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Minor
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Resolution: Fixed
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None
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None
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Description
Currently tika-mimetypes only recognizes audio/aac files by the file extension. PRONOM recently added support for identifying aac files, but the signature is tricky. There are two signatures, below in PRONOM format curly braces mean to look ahead between the two values for the subsequent patterns.
The first pattern is pretty basic, the second pattern is the first pattern after a 2048 ID3 header.
| Name | Audio Data Transport Stream sig.1 |
|---|---|
| Description | An FF pattern from BOF with variation of byte stream |
| Byte sequences | |
| Position type | Absolute from BOF |
| Offset | 0 |
| Maximum Offset | 0 |
| Byte order | |
| Value | FF(F0|F1|F8|F9)(40|41|44|45|48|49|4C|4D|50|51|54|55|58|59|5C|5D|60|61|64|65|68|69|6C|6D|70|71|80|81|84|85|88|89|8C|8D|90|91|94|95|98|99|9C|9D|A0|A1|A4|A5|A8|A9|AC|AD|B0|B1)(00|01|20|40|41|60|80|81|60|A0|C0|C1|E0) |
| Name | Audio Data Transport Stream sig.2 |
| Description | ID3 tag variation with variable byte stream |
| Byte sequences | |
| Position type | Absolute from BOF |
| Offset | 0 |
| Maximum Offset | 0 |
| Byte order | |
| Value | 494433{0-2045}FF(F0|F1|F8|F9)(40|41|44|45|48|49|4C|4D|50|51|54|55|58|59|5C|5D|60|61|64|65|68|69|6C|6D|70|71|80|81|84|85|88|89|8C|8D|90|91|94|95|98|99|9C|9D|A0|A1|A4|A5|A8|A9|AC|AD|B0|B1)(00|01|20|40|41|60|80|81|60|A0|C0|C1|E0) |