PCM audio creates WAV in cache


#1

Hi there.

While doing a bit of housekeeping, I noticed that the audio from the Quicktime videos upload into Ableton, were being decoded into the Cache/Decoding folder, as WAVs.
As far as I can tell, you cannot encode the uncompressed audio, as WAV within a MOV, it will always be PCM.

  • Is there anyway to prevent Ableton from decoding, and therefore doubling up audio data?

  • If not, is there any disadvantage (or advantage) to having audio and video split into 2 separate folders? (besides increasing storage size)

Specs
Quicktime codecs - Hap5 (alpha), Linear PCM, Timecode, 16bit, 44.1Khz, stereo
Ableton 9.7 64-bit
Videosync 7.2 & 7.3

Best regards
Chris.


#2

Hi Chris,

Thanks for the heads up.

As it seems, Live caches everything that is not a wav file. When I load an mp3, it is cached as a wav too. Even when loading a movie without an audio track, Live creates an empty wav file in its cache.

I think we need to conclude that there is no way to prevent Live from doubling up audio data and that splitting the video file in two separate files will actually increase the used disk space.

Best,
Mattijs


#3

Hi Mattijs,

Thank you very much for the response.
Yeah I thought as much, I guess it’s the nature of the beast.
But now you’ve got me interested in folder location.

According to this link:
Main Drive; operating system, applications, and plug ins.
2nd Drive; audio (video) libraries, and factory packs.
3rd Drive; recording (or temporary), and cache (WAVs) files.

  • With a 2 Drive set-up would you recommend putting video files & WAVs in the second drive?
  • And with a 3 Drive set-up, would you recommend splitting it up like the above example?

Please excuse me for nit-picking, but optimization is quite important, as I often use a lot of CPU :electric_plug:

Best regards

Chris


#4

Nit-picking is indeed essential, especially when preparing for a live performance.

When adding Videosync into the equation, I would add that video playback performance, although dependent on the used resolutions and encodings, usually has the storage drive speed as the primary bottleneck. So if possible I would recommend storing video files used for real-time playback on an SSD.

How to split the files into separate drives or folders is then more of an organisational matter, in the end of course the ideal configuration depends on the situation. In my experience, simpler is usually better. I would say this Ableton guide is focused mostly on a non-live setup. For our recent shows though we don’t do audio recording, only audio and video playback, so we don’t need terabytes of hard disk space. We have dedicated Macbook Pros for stage so they can have a single 512 GB SSD that only contains:

  • the OS
  • Live and Videosync in the Applications folder
  • all the files necessary for the show in one folder on the Desktop
  • and nothing else.

A separate practical consideration could be to have your live show files on a separate partition, including a copy of the OS, as described in our performance tips in the manual.

Cheers!


#5

Thanks again for your response, I’m pretty sure that clears things up.
It’s good to know that it’s not always that complicated.

Chris