Graphic Equalizer, Blackfin
The Multiband Graphic Equalizer library for the Blackfin processor allows audio signals to be filtered with a bank of band filters.
- Number of bands is user-configurable within the range 3 to 9 inclusive
- Number of channels per instance is user-configurable within the range 1 to 8 inclusive
- Maximum boost/cut per band is +12 dB / -12 dB gain, adjusted in 0.01dB steps
- Each band uses a 4th order IIR filter
- THD+N ratio is less than 0.004% (-20 dB FS, <10-20k Hz BW CCIR-468) alternating 12 dB cut/boost gain configuration)
- THD+N ratio is less than 0.00005% (-20 dB FS, <10-20k Hz BW CCIR-468, alternating 0 dB / -12 dB gain configuration)
- SNR (in presence of signal) is > 140 dB FS ( <10-20k Hz BW CCIR-468 )
- Constant Q Filter (3-band Q=10; 5-band Q=3.98; 7-band Q=2.68)
- 3 band ISO center frequencies: 63Hz, 630Hz, 6300Hz
- 5-band ISO center frequencies: 40Hz, 160Hz, 630Hz, 2500Hz, 10000Hz
- 7-band ISO center frequencies: 32Hz, 90Hz, 236Hz, 630Hz, 1700Hz, 4480Hz, 12000Hz
- Target Processor: Code compatible across the Blackfin processor Family ADSP-BF5xx
- Release format: Object code module with C source wrapper
- Input format: interleaved multichannel 32-bit signed PCM little-endian audio samples
- Input buffer samples per block: User-configurable
- Framework dependencies: None
- Output format: interleaved multichannel 32-bit signed PCM little-endian audio samples
- Sample Rate: 44kHZ to 48kHz
- Multi-threading: Fully re-entrant and multi-instancing capable
The Multiband Graphic Equalizer allows audio signals to be filtered with a bank of band filters. The number of bands and the number of channels is configurable, and audio signals can be processed between 44kHz and 48kHz. Up to 12dB of gain or cut can be applied to each band independently. The same equalizer configuration is applied to each input channel. Internal filter saturation is avoided and the output is clipped to full scale.
|Code memory (KiB)||Data RAM (KiB)
||Constant Data Tables (KiB)
- For the optimal memory layout, all code and data used by the module was located in on-chip L1 memory.
- MIPS measured for a 2-channel 7 band equalizer configuration, Fs=48kHz, 220 samples per block, optimal memory layout, Stereo channel test vector, ADSP-BF527, ADSP BF533, ADSP-BF548.
- "Data RAM" for one instance, includes Stack, Scratch, Instance/Stage, Minimum Input and Output Single Buffers.
- 1 KiB = 1024 Bytes.
- Windows XP Professional SP3 (32-bit only).
- Windows Vista Business/Enterprise/Ultimate SP2 (32-bit only). It is recommended to install the software in a non-UAC-protected location.
- Windows 7 Professional/Enterprise/Ultimate (32 and 64-bit). It is recommended to install the software in a non-UAC-protected location.
- Minimum of 2 GHz single core processor, 3.3 GHz dual core is recommended.
- Minimum of 1 GB memory (RAM), 4 GB is recommended.
- Minimum of 2 GB hard disk (HDD) space is required.