I’ve been using Audacity to record streaming audio for years and now all of a sudden, with no changes to the settings, the audio is at a lower pitch and playback sounds slower than normal. Imagine recording something with a cassette recorder and then playing it back with the motor going slightly slower. That’s the sound. Very annoying.
Specs: Kubuntu 13.10 with Audacity 2.0.3, downloaded from the Ubuntu repo. I removed and re-installed it the other day and that seemed to have “fixed” the problem, until today. Today’s recording session sounds exactly like it did the other day.
Linux 3.5.0-17-generic i386
distro: Linux Mint 14, fully updated
Audacity 2.0.6-alpha-Feb 24 2014 installed through Software Manager
Pulse Audio volume control installed.
I was able last night to record from a streaming video after uninstalling Audacity, shutting down, restarting and reinstalling Audacity. However, I had tried this before without success, and indeed, the slow playback resumed on my next attempt to record audio from another video stream. I tried uninstalling, shutting down and reinstalling again, but the slowness continued. I had already experimented extensively with changing sample rates, quality, dither, etc., in Audacity’s Preferences. Just for the hell of it, I tried changing Default View Mode from “Waveform” to “Spectrogram”. Lo and behold, recording was now normal! I switched back to “Waveform” and the fix persisted. Today I started the computer from Sleep, and went back to try to record from the same stream I’d finally had success with yesterday. Again, the slow playback. So I tried setting Default View Mode to “Spectrogram” and again Audacity started recorded normally. Set it back to “Waveform” and tried recording again, and everything still seemed normal. Closed Audacity and restarted it. Again the slow behavior. Switched to Spectrogram, still slow. Switched back to Waveform, and everything normal again. I have tried this a number of times, and usually, switching the Default View Mode will fix the problem for the current session with the slowness returning again when I restart Audacity.
I still don’t know what is causing the slow-sounding recording. There is a noticable pitch decrease of maybe 10% or so. This seems to correspond to the ratio between 48000 and 44100, but that could just be a coincidence.
In the past, I seemed to be able to prevent the slowness by starting the video stream before starting Audacity. This no longer works.
This will probably not solve the problem, but the first thing that I would do would be to set “Real Time Conversion > Sample Rate Converter: Medium Quality”.
Since Audacity’s resampling library was updated, even “Medium Quality” is very good, and going down from “High Quality” to “Medium” is a lot less demanding on your computer. This will not adversely effect the quality of the recording, it just slightly reduces the resampling quality if Audacity needs to convert sample rates on the fly. Exporting and mixing down use the High Quality Conversion settings.
Regarding the problem, this does not sound like an Audacity problem. I think it is almost certainly somewhere between Firefox, whatever plug-in is playing the media, and PulseAudio.
A common issue when playing media in a web browser (though not generally a “problem”) is that the ports into PulseAudio are not closed properly when the video stops. I suspect that this is related to the problem that you are experiencing. The change in speed and pitch (with no mention of stuttering or rapid clicking) does sound like a sample rate mismatch.
If, as I suspect, the problem is in this area, then we are probably not going to be able to “fix” this problem but hopefully find a practical “solution” (aka “workaround”).
That’s probably because the copyright holder does not want you to copy it.
Nevertheless, assuming that you have obtained the legal rights to copy this content, I find that “FlashGot” (not to be confused with “FlashGet”) Firefox plug-in works with most on-line video content.
I’d Like to thank gbell12 for the workaround, it’s certainly cured my frustrations, this happened every time I recorded anything be it a radio stream, voice recording, or a file on my hdd. Everything was recording at around 10% quicker resulting in around a 10% slower playback, I even resorted to running Audacity in wine (which actually recorded fine) but the trade off was I had to save as .wav then open the file in my native Audacity version to convert into my preferred file format. so thanks yet again to gbell12 for the workaround
However do note that the solution of changing project rate is not foolproof and has just as often been reported not to work (or only to work sometimes) which is probably why none of us mentioned it.
Assuming you are choosing the pulse device to record from in Audacity, pulse should be able to handle the conversions without speed changes. But if that handling does not work and for example you have a 44100 Hz only device and the stream is 48000 Hz, you may see the problem you describe.