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JamesDSP (Audio Effect Digital Signal Processing library for Android)

GUI is based on Omnirom DSP Manager and able to run on most Android devices from 5 to 10 include Samsung, AOSP, Cyanogenmod, recent HTC and Huawei(arm64). This app include many cool features.

Features:
  1. Auto dynamic range compression --> A highly automated multiband dynamic range adjusting effect

  2. Auto Bass Boost --> Frequency detecting bass boost. Effect detect interesting frequency, and adjust gain, bandwidth and cut-off frequency arcordingly

  3. Reverb --> Progenitor 2 (Complicated IIR network)

  4. Interpolating FIR Equalizer

  5. Partitioned Convolver (Auto segmenting convolution) --> Support mono, stereo, full/true stereo(LL, LR, RL, RR) IR

  6. Live programmable DSP --> A effect that can compile EEL code into opcode, and do processing base on the compiled code. The EEL virtual machine had pre-built tons of advanced math routines and DSP function. Including: Basic C String manipulation functions, Linear algebra solver(Least square, inv(), pinv()), Mathematical optimization(linprog(), quadprog(), lsqlin()), polynomial roots solver(roots()), spectral processing(Short-time Fourier Transform), Constant Q Transform, multi-purpose FIR filter designer(firls()), IIR Subbands transform, Direct form FIR filter, Fractional delay line.

Although STFT, DF-FIR and Fractional delay line are the only components that have been opened.

More details:EEL2 open source variant

  1. Stereo Widen --> Algorithm detect stereo phase relation in a few spectral region, and enhance the stereo soundstage without affect vocal integrity

  2. Crossfeed --> Include traditional BS2B mode and convolution-based HRTF

  3. Vacuum tube modelling

  4. Viper DDC (IIR Cascaded Second-Order Sections Form II)

Supported bit depth:
# bits Status
8 Unsupported
16 Supported
24(Int) Unsupported
32(Int) Supported
32(Float) Supported

Important

FAQ

1. Computation datatype?

A: Float32(Close source due to proprietary spatialization algorithm).

2. What is convolver?

A: Convolver is a effect apply convolution(a mathematical operation) on input signal, that perfectly apply user desired response on music, it could simulate physical space.

Effect itself require audio file(.wav/.irs/.flac) to become impulse response source.

For more info: Convolution and Convolution reverb

3. What is Analog Modelling?

A: Analog Modelling internal work as a vacuum tube amplifier, was designed by ZamAudio. The tube they used to model is 12AX7 double triode. They also provide a final stage of tonestack control, it make sound more rich. However, the major parameters is amplifier preamp, this is how even ordered harmonic come from, but this parameter have been limited at maximum 12.0. Input audio amplitude is decided by user, thus louder volume will generate more harmonics and internal amplifier will tend to clip the audio. Analog amplifier was built from real mathematical model, most notably is nonlinearity of vacuum tube.

Example circuit for triode amplifier and tonestack:

Diagram1

4. Installation method

A: Advanced method(Manual installation)

Effect may get unloaded by Android system if no audio stream for while.

audio_effects.conf is a file specified for system to load effect using known UUID.

  1. you need to add
jdsp {
 path /system/lib/soundfx/libjamesdsp.so
}

under

bundle {
 path /system/lib/soundfx/libbundlewrapper.so
}

AND

jamesdsp {
 library jdsp
 uuid f27317f4-c984-4de6-9a90-545759495bf2
}

under

effects {
  1. copy libjamesdsp.so to /system/lib/soundfx
  2. Reboot
  3. Install APK

B: Automatic installation(Supported up to Android Pie)

Join Telegram group JDSP and V4A group to receive latest update. Methods:

  1. Copy zip package to your phone, reboot to custom recovery, install package, reboot, done.
  2. Get Magisk manager to install JDSP. Now work on most Android device from Lollipop to Pie
Coming up:
  1. Auto-detected bit rates MP3 high frequency harmonic excitor

Download Link

  1. See my project release page

Screenshot

  1. Equalizer screenshot(Dark theme)
  2. Convolver screenshot(Idea theme)

Important

Modify SELinux is not required(in most case), let your device become safer. Also, it's good to customizing your own ROM or even port ROM with JamesDSP. Some device does require SELinux workaround to work correctly

Contact

Better contact me by email. Send to james34602@gmail.com

Terms and Conditions / License

The engine frame is based on Antti S. Lankila's DSPManager.

Credit

  1. Joseph Young (Impulse response provider)
  2. Christopher Blomeyer (Very patient app tester and inspiring me bit depth issue)
  3. ahrion (Making installation tools)
  4. Zackptg5 (Making installation tools)

More Credit

  1. Matlab, a great tool that do all sort of modelling