Monkey's Audio / .APE decoder available for VS1005

[Henrik]

Hello!

I present with the greatest pleasure the newest decoder coming from VLSI's vaults for VS1005 / VSOS: Monkey's Audio. VS1005 is now capable of playing .APE files in real time.

Of the five different .APE profiles, VS1005 supports Fast, Normal, and High compression levels up to 48 kHz stereo. Files with higher sample rates are decoded, but not in real time. Extra High and Insane compression levels are not supported.

A stereo 16-bit 48 kHz file using the Normal profile requires about 54-57 MHz to decode. When system overheads are added, and if no S/PDIF output or input drivers are loaded and ective, a CPU clock of 86 MHz or more should be enough for uninterrupted audio playback, even for files that are 24-bit 48 kHz stereo encoded with High profile. Thus, it is a good idea to run e.g. the following command in config.txt:

Code: Select all

RUN SetClock -l87 86

or on the command line:

Code: Select all

S:>setclock -l87 86

Before trying this package, update VSOS to the current release, which is 3.57. Future releases will contain Monkey's Audio as a default.

Attached to this message is a .zip file, containing:

• Updated versions of audiodec, AuInfo, and Dir as VSIDE Solutions. You can edit these if you like, but most user's don't need to edit these.
• All updated .dl3 files collected in folder SYS/ . Copy the new versions to your VS1005 / VSOS 3.57 system disk's SYS/ folder.
• 1khz.ape is a one second long example file

Things you can try on the command line if you have copied the whole ape folder to your SD Card:

Code: Select all

S:>setclock -l87 86
S:>cd d:ape
D: SD/SD Card
D:APE/>auinfo 1khz.ape
1khz.ape:
     size: 26.4 KiB
   format: Ape
     conf: 1 channels at 44100 Hz
     time: 0:01.0 seconds
  bitrate: 215.9 kbit/s
  analyze: 0.00 seconds
D:APE/>dir -a
-    4. 1KHZ.APE        0:01.0  44100 1 2019-05-22 10:38:24 1khz.ape
D:APE2/>playdir
~0205'1
~0308=1
~0205=1
~050b'1khz.ape
~030a=0
~030b=15
>
~0308'0
D:APE/>

We would be very happy to hear of your experiences with the .APE decoder. Did you get it working? Were there issues? Do you have problematic files?

Kind regards,
- Henrik

[Henrik]

Hello!

The APE decoder has been updated to v1.01. The new version contains a bug fix that fixes occasional noise bursts and lock-ups, as well as speed optimization, which makes the worst case .APE files decode with approximately 3 MIPS less clock cycles than before. Instructions for use are the same as before, so check the previous message for them.

Kind regards,
- Henrik

PS. This is my 1138th message. Feeling very THX today.