Clock speed is too low - Githubissues

Chordian / sidfactory2

SID Factory II is a cross-platform editor for composing music that will work on a Commodore 64. It uses the reSID emulator and is currently in open BETA.

http://blog.chordian.net/sf2/

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Clock speed is too low #114

Closed micheldebree closed 2 years ago

micheldebree commented 3 years ago

The clock speed seems to be slightly lower than a real c64, and other emulators. This results in the tune being slightly slower ~~and lower in pitch~~.

micheldebree commented 3 years ago

repro:

composed a track in SF2 (WIN10)
captured the playback with OBS
recorded the audio from a real C64
on a multitrack DAW (i use Reaper), there's clear difference of SF2 vs C64 audio tracks

my system runs on 48khz all the time since this one, i made 2-3 new tracks with SF2 and captured playback with OBS. had the same experience, SF2 vs C64 audio was different

sf2_vs_c64_audio_output

i don't really hear pitch difference between c64 and sf2 audio to be honest it's the speed that's different 0.6sec in 2 minutes there are no dropouts, the audio signal is fluent so it's not a slow cpu/sampledrop issue even

micheldebree commented 3 years ago

From the log:

INFO: Sound.Output.Gain = 1.000000 INFO: Audio device 0: Speakers (RME Fireface UCX) INFO: Audio device 1: Realtek Digital Output (Realtek High Definition Audio) INFO: Audio device 2: Analog (5+6) (RME Fireface UCX) INFO: Audio device 3: ADAT (5+6) (RME Fireface UCX) INFO: Audio device 4: SPDIF/ADAT (1+2) (RME Fireface UCX) INFO: Audio device 5: Analog (7+8) (RME Fireface UCX) INFO: Audio device 6: ADAT (3+4) (RME Fireface UCX) INFO: Audio device 7: ADAT (7+8) (RME Fireface UCX) INFO: Audio device 8: SPDIF coax. (RME Fireface UCX) INFO: Audio device 9: Analog (3+4) (RME Fireface UCX) INFO: Audio device 10: Speakers (Realtek High Definition Audio) INFO: Succesfully opened audio device @ 44100 Hz

micheldebree commented 3 years ago

I did a little test myself:

Above:

SIDFactoryII output to Blackhole virtual audio device
Record the output with Audacity from Blackhole

Below:

WAV output of jsidplay2

At the beginning of the file, I lined the two up almost perfectly: Screenshot 2021-05-05 at 07 44 59

After two minutes, the SF2 output (top) is lagging behind by around 300ms Screenshot 2021-05-05 at 07 45 41

I can not hear a difference in pitch

micheldebree commented 3 years ago

References: