Binaural virtual surround sound reproduction and surround sound stereo downmix.
Now able to take 7.1.4 Audio files as input for virtual surround.
- 7.1.4 layout: L, R, C, LFE, LS, RS, RLS, RRS, FLU, FRU, RLU, RRU
- HRIRs from database:
- L: Elevation 0 degree, Azimuth -65 degree
- R: Elevation 0 degree, Azimuth 65 degree
- C: Elevation 0 degree, Azimuth 0 degree
- LFE: N/A
- LS: Elevation 180 degree, Azimuth -20 degree
- RS: Elevation 180 degree, Azimuth 20 degree
- RLS: Elevation 180 degree, Azimuth -55 degree
- RRS: Elevation 180 degree, Azimuth 55 degree
- FLU: Elevation 45 degree, Azimuth -30 degree
- FRU: Elevation 45 degree, Azimuth 30 degree
- RLU: Elevation 135 degree, Azimuth -30 degree
- RRU: Elevation 135 degree, Azimuth 30 degree
From Soundly 5.0 Surround Sound library: https://getsoundly.com/
Content: Garage ambience with water dripping.
Processing:
- Get HRIR from database for L, C, R, Ls, Rs.
- L: Elevation 0 degree, Azimuth -30 degree
- C: Elevation 0 degree, Azimuth 0 degree
- R: Elevation 0 degree, Azimuth 30 degree
- Ls: Elevation 180 degree, Azimuth -60 degree
- Rs: Elevation 180 degree, Azimuth 60 degree
- Convolve Each channel with respective HRIR.
- Left ear signal = Original file * Left Ear HRIR
- Right ear signal = Original file * Right Ear HRIR
- Sum 5 left ear channel to one left channel, and 5 right ear channel to one right channel.
- Combine left and right channel to stereo file.
- Normalize: Normalize according to change in volume (ratio)
- ratio: Original signal / Processed signal
Processing:
- Left All: L + (–3 dB × C) + (–3 dB × Ls)
- Right All: R + (–3 dB × C) + (–3 dB × Rs)
- Normalize: Normalize according to change in volume (ratio)
- ratio: Original signal / Processed signal
- HRTF data from CIPIC database by UC Davis: https://www.ece.ucdavis.edu/cipic/spatial-sound/hrtf-data/
- Stereo downmix method reference Dolby website (Lo/Ro - default): https://professionalsupport.dolby.com/s/article/How-do-the-5-1-and-Stereo-downmix-settings-work?language=en_US