From: Martin G. <mar...@gm...> - 2016-05-29 18:35:56
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Hi and thanks for timidity, a truly wonderful program. I'm writing because the Timidity bug tracker, like all the release notes, seem to be down. Here's the bug I am seeing: Whenever I synthesize a MIDI piece using the default instrument, Grand Piano, I get a series of random spikes in the first half second of the right channel of the output - between 6 and 9 random samples at seeming random moments, which sound like a harsh crackle. After these, for the rest of the piece, everything plays perfectly. This is on Ubuntu 16.04 (the current stable release, with Timidity 2.13.2) but has been happening since 2012 for sure. Here is a minimal example of a single MIDI note, synthesized to a WAV martin@score:~/audio/D-D/scores$ timidity -Ow -o note.wav note.mid Playing note.mid MIDI file: note.mid Format: 1 Tracks: 2 Divisions: 480 Copyright: Copyright (c) xxxx Copyright Holder Cue point: Created by Rosegarden Cue point: http://www.rosegardenmusic.com/ Track name: Playing time: ~4 seconds Notes cut: 0 Notes lost totally: 0 The sound is the same when playing directly to the audio output. I attach midi input and pictures of output, as well as a waveform view of the whole noise phenomenon and a zoom of one-pixel-per-sample of the first one. The wav file (400k) is at http://martinwguy.co.uk/test/note.wav Am I the only one seeing/hearing this effect? M |
From: Martin G. <mar...@gm...> - 2016-05-30 20:09:35
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On 30/05/2016, Matthew wrote: >On 29/05/2016, Martin Guy <mar...@gm...> wrote: >> Whenever I synthesize a MIDI piece using the default instrument, Grand >> Piano, I get a series of random spikes in the first half second of the >> right channel of the output - between 6 and 9 random samples at >> seeming random moments, which sound like a harsh crackle. After these, >> for the rest of the piece, everything plays perfectly. >> >> This is on Ubuntu 16.04 (the current stable release, with Timidity >> 2.13.2) but has been happening since 2012 for sure. > > Yes, unfortunately it's been like that for ages. The workaround is to > specify --output-24bit. It seems to be fixed in 2.14.0 Thanks! M |
From: Martin G. <mar...@gm...> - 2016-05-31 03:57:43
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> On 30/05/2016, Matthew wrote: >>. The workaround is to >> specify --output-24bit. The bug report is https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=693011 and it was introduced with the new noise-shaping code. It suggests a less invasive workaround to make it use the old noise shaper: --noise-shaping=1 On 30/05/2016, Matthew wrote: > That's great - still on Ubuntu 14.04 and it's still 2.13.2. I've applied the bug fix to the Ubuntu source code; you'll find the fixed package(s) under http://martinwguy.co.uk/test It is probably enough to fetch and install timidity_2.13.2-40.3+nocrackle_amd64.deb (64-bit) or timidity_2.13.2-40.3+nocrackle_i386.deb (32-bit) I've also submitted a bug report to Ubuntu https://bugs.launchpad.net/ubuntu/+source/timidity/+bug/1587215 so let's hope they apply the fix retroactively as part of the maintenance; If they do, their 2.13.2-40.4 will replace the above packages. Thanks for your help in resolving this issue M |