search for: 440hz

...ives ~100kbps (this is understandable because in this sample practically there are no sounds above 5kHz) but the artifacts can be easily heard. Mode -b350 gives ~310kbps but still there is a difference (subtle though). I also noticed that you get similar artifacts when you encode simple tones (like 440Hz or 1kHz), no matter what bitrate is used. - The most occurring artifact in -b128,160,192 modes is pre-echo (-b256+ seems to be free from this curse). The leader in eliminating pre-echo is AAC (Liquid Audio, Low Profile AAC), because even at ~128kbps stereo there is very little or no pre-echo (Temp...

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 We just released Opus 1.1-rc, which should be the last step before the final 1.1 release. Compared to 1.1-beta, this new release further improves surround encoding quality. It also includes better tuning of surround and stereo for lower bitrates. The complexity has been reduced on all CPUs, but especially ARM, which now has Neon assembly for the

...able model are determined from the spectral content of the source. For each peak (formant) frequency in the spectrum 1 pole is required. Two coefficients are required for each pole in the model. With human speech it is typical to see one peak resonance for the fundamental frequency (typically 50-440Hz) and one additional peak per 1000Hz. From this we can see that the best order for an LPC speech model is based upon the bandwidth of the sampled audio. In speex linear prediction is used to model the vocal tract of the speaker. For narrow-band mode we low-pass filter the speech to 4000Hz. Using...

Hi list I'm writing some unit tests for a piece of software using the opus library for audio encoding before transfering though RTP. In order to test my RTP implementation I thought I would transfer an encoded 440Hz sinus, and then do a diff of the received/decoded signal. However, my strategy seems to fail completely since the recreated sinus looks nothing like the one in the decoded signal. So my question is; is the phase not likely to be preserved during opus encoding/decoding or did I simply make an err...

Hi FLAC team. I feel I have found a super high compression way of FLAC. I have tested a 1 hour WAV file of 440HTZ with a 5,25,50,75,100 normalize volume preset. This dramatically changes the compression size of the end FLAC file even though the WAV file size is identical for all 5 WAV files. Only the volume is different. When you renormalize the WAV to its original volume the file is still 100%