diff --git a/audio/audio_filters/EQ.dsp b/audio/audio_filters/EQ.dsp index 9fb64cdaf9..5a69a68de9 100644 --- a/audio/audio_filters/EQ.dsp +++ b/audio/audio_filters/EQ.dsp @@ -26,9 +26,16 @@ filter0 = eq # Due to frequency domain smearing, you will not get exactly +3 dB at 1 kHz. # By default, this filter has a flat frequency response. -# # Dumps the impulse response generated by the EQ as a plain-text file # with one coefficient per line. # eq_impulse_response_output = "eq_impulse.txt" - +# +# Using GNU Octave or Matlab, you can plot the response with: +# +# f = fopen('/path/to/eq_impulse.txt'); +# l = textscan(f, '%f'); +# res = l{1}; +# freqz(res, 1, 4096, 48000); +# +# It will give the response in Hz; 48000 is the default Output Rate of RetroArch diff --git a/audio/audio_filters/LowPassCPS.dsp b/audio/audio_filters/LowPassCPS.dsp new file mode 100644 index 0000000000..ae42e15cfd --- /dev/null +++ b/audio/audio_filters/LowPassCPS.dsp @@ -0,0 +1,47 @@ +filters = 1 +filter0 = eq + +eq_frequencies = "8000 10000 12500 16000 20000" +eq_gains = "0 -30 -30 -30 -30" + +# Low pass filter for the QSound chip from CPS-1/2. +# Some games have aliasing due low quality samples, so you can hear some annoying noisy near 11 kHz + +# Defaults + +# Beta factor for Kaiser window. +# Lower values will allow better frequency resolution, but more ripple. +# eq_window_beta = 4.0 + +# The block size on which FFT is done. +# Too high value requires more processing as well as longer latency but +# allows finer-grained control over the spectrum. +# eq_block_size_log2 = 8 + +# An array of which frequencies to control. +# You can create an arbitrary amount of these sampling points. +# The EQ will try to create a frequency response which fits well to these points. +# The filter response is linearly interpolated between sampling points here. +# +# It is implied that 0 Hz (DC) and Nyquist have predefined gains of 0 dB which are interpolated against. +# If you want a "peak" in the spectrum or similar, you have to define close points to say, 0 dB. +# +# E.g.: A boost of 3 dB at 1 kHz can be expressed as. +# eq_frequencies = "500 1000 2000" +# eq_gains = "0 3 0" +# Due to frequency domain smearing, you will not get exactly +3 dB at 1 kHz. + +# By default, this filter has a low pass response with cuttof frequency at ~8600 Hz. + +# Dumps the impulse response generated by the EQ as a plain-text file +# with one coefficient per line. +# eq_impulse_response_output = "eq_impulse.txt" +# +# Using GNU Octave or Matlab, you can plot the response with: +# +# f = fopen('/path/to/eq_impulse.txt'); +# l = textscan(f, '%f'); +# res = l{1}; +# freqz(res, 1, 4096, 48000); +# +# It will give the response in Hz; 48000 is the default Output Rate of RetroArch