Difference between revisions of "Apple AAC"
From Hydrogenaudio Knowledgebase
(This is not a codec but an encoder. Taking this out of the category:codec) |
(→afconvert) |
||
| (26 intermediate revisions by 15 users not shown) | |||
| Line 1: | Line 1: | ||
| − | ''' | + | {{aac-encoders}} |
| − | [[ | + | '''Apple AAC''' is an [[AAC]] codec developed by Apple Inc. and included in Apple's audio framework, ''Core Audio''. ''Core Audio'' is used in [[iTunes]], Safari web browser, and other Apple products. Apple's AAC encoder is known to be one of the highest quality medium-bitrate [[CBR]] and [[VBR]] LC [[AAC]] encoders. The encoder started as part of the ''QuickTime'' media framework, but Apple has transitioned away from ''QuickTime'', to ''AV Foundation''. |
| − | + | ||
| − | + | The encoder does consistently well in [[Hydrogenaudio Listening Tests|Hydrogenaudio listening tests]]. | |
| − | + | ||
| − | + | <br clear="right" /> | |
| + | == afconvert == | ||
| + | Apple's macOS includes a command-line utility for transcoding audio files that employs this encoder when encoding to AAC. | ||
| − | + | Usage: | |
| + | afconvert [options] <infile> <outfile> | ||
| − | {{ | + | Options: |
| + | ;-f --file <string>:File format. Several; use 'm4af' for '.m4a' file or 'adts' for raw '.aac' file. | ||
| + | ;-d --data <string>:Data format. Several; use 'aac'. | ||
| + | ;-s --strategy <0,1,2,3>:Bitrate allocation strategy. 0 for CBR, 1 for ABR, 2 for VBR_constrained, 3 for VBR | ||
| + | ;-b --bitrate <n>:Bitrate in bits per second. Does nothing when used with strategy 3. | ||
| + | ;-ue vbrq <0-127>:Output quality for VBR mode. Only applicable when using strategy 3. | ||
| + | ;-q --quality <0-127>:Speed/quality trade-off. Internally rounded to a value of either 32, 64, or 96. | ||
| + | |||
| + | == QAAC == | ||
| + | {{Software Infobox | ||
| + | | name = qaac | ||
| + | | logo = | ||
| + | | screenshot = | ||
| + | | caption = | ||
| + | | maintainer = nu774 | ||
| + | | stable_release = 2.72 | ||
| + | | preview_release = | ||
| + | | operating_system = Windows | ||
| + | | use = Encoder | ||
| + | | license = Various | ||
| + | | website = [https://github.com/nu774/qaac github/qaac] | ||
| + | }} | ||
| + | |||
| + | QAAC is an open-source wrapper for ''Core Audio's'' AAC and [[ALAC]] encoders that allow them to be used directly in applications that don't otherwise use ''Core Audio''. It exists only for Windows. | ||
| + | |||
| + | * [https://github.com/nu774/qaac/wiki QAAC documentation] | ||
| + | |||
| + | <br clear="right" /> | ||
| + | |||
| + | ==External links== | ||
| + | *[http://www.apple.com/quicktime Apple's Quicktime Website] | ||
Revision as of 17:52, 15 August 2021
| Current AAC encoders (most to least recommended) | |
|---|---|
| 1 | Apple AAC M/W |
| 2 | FhG AAC (Winamp) W |
| 3 | Fraunhofer FDK AAC S/L/M/W |
| 4 | Nero AAC L/W |
| 5 | FFmpeg 3.0+ AAC encoder S/L/M/W |
| 6 | FAAC S/L/M/W |
| 7 | Libav (pre-3.0 FFmpeg) AAC encoder S/L/M/W |
| S Source code available; L Linux; M macOS; W Windows | |
| List of AAC encoders | |
Apple AAC is an AAC codec developed by Apple Inc. and included in Apple's audio framework, Core Audio. Core Audio is used in iTunes, Safari web browser, and other Apple products. Apple's AAC encoder is known to be one of the highest quality medium-bitrate CBR and VBR LC AAC encoders. The encoder started as part of the QuickTime media framework, but Apple has transitioned away from QuickTime, to AV Foundation.
The encoder does consistently well in Hydrogenaudio listening tests.
afconvert
Apple's macOS includes a command-line utility for transcoding audio files that employs this encoder when encoding to AAC.
Usage:
afconvert [options] <infile> <outfile>
Options:
- -f --file <string>
- File format. Several; use 'm4af' for '.m4a' file or 'adts' for raw '.aac' file.
- -d --data <string>
- Data format. Several; use 'aac'.
- -s --strategy <0,1,2,3>
- Bitrate allocation strategy. 0 for CBR, 1 for ABR, 2 for VBR_constrained, 3 for VBR
- -b --bitrate <n>
- Bitrate in bits per second. Does nothing when used with strategy 3.
- -ue vbrq <0-127>
- Output quality for VBR mode. Only applicable when using strategy 3.
- -q --quality <0-127>
- Speed/quality trade-off. Internally rounded to a value of either 32, 64, or 96.
QAAC
| Developer(s) | nu774 |
| Release information | |
|---|---|
| Stable release | 2.72 |
| Compatibility | |
| Operating system | Windows |
| Additional information | |
| Use | Encoder |
| License | Various |
| Website | github/qaac |
QAAC is an open-source wrapper for Core Audio's AAC and ALAC encoders that allow them to be used directly in applications that don't otherwise use Core Audio. It exists only for Windows.
