How to improve the Physion latency (2832 samples!)

Home Forums Products Plug-Ins How to improve the Physion latency (2832 samples!)

  • This topic is empty.
Viewing 3 reply threads
  • Author
    Posts
    • #114877
      cauldron
      Participant

      From a series of experimental measurements it appears that Physion’s latency does not change as a number of audio samples compared to the sampling frequency. This means that at 48kHz, 96kHz or 192kHz the latency of 2832 audio samples is 59.0ms, 29.5ms or 14.7ms, respectively. Practically for a live use it is necessary to use a sampling frequency of 96kHz or higher.

      Is it possible to reduce latency to one-tenth or is it a structural fact that can not be improved?

      Thanks

    • #149861
      tlongabaugh
      Moderator
      Eventide Staff

      Hi-

      Where and how are you viewing the latency of the plugin? I can confirm here that the latency in samples changes depending on the sample rate. It should be 2832 samples for 44.1k and 48k, 5392 samples for 88.2k and 96k, and 8672 *10512 samples for 176.4k and 192k.

      This does produce a noticeable delay of roughly 50ms, which of course is fine in a mixing scenario, but isn't acceptable for live use. Unfortunately, this is what is currently required for the structural split to work well. We hope to optimize this in the future.

      -Tom

      *EDIT: revised number of samples to be correct for 176.4k and 192k.

    • #149867
      cauldron
      Participant

      Hi Tom,

      I apologize. I have redoed the measurements and I confirm what you said except for 176.4kHz and 192kHz which are 10512 samples.

      I used a buffer of 8192 samples. The round-trip time is measured (with and without the Physion plugin) using the jack_delay utility ( https://kokkinizita.linuxaudio.org/linuxaudio/downloads/jack_delay-0.4.0.tar.bz2 ). Jack Audio includes the jack_iodelay utility which is equivalent.

      Latency is always constant (just over 50ms).

      192kHz  ***10512***

            26896.000 frames  140.083 ms

            16384.000 frames   85.333 ms

      176.4kHz ***10512***

            26896.000 frames  152.472 ms

            16384.000 frames   92.880 ms

      96kHz ***5392***

            21776.000 frames  226.833 ms

            16384.000 frames  170.667 ms

      88.2kHz ***5392***

      Show More...

            21776.000 frames  246.893 ms

            16384.000 frames  185.760 ms

      48kHz  ***2832***

            19216.000 frames  400.333 ms

            16384.000 frames  341.333 ms

      44.1kHz ***2832***

            19216.000 frames  435.737 ms

            16384.000 frames  371.519 ms

       

      Elia

       

      Show Less...
      • #149875
        tlongabaugh
        Moderator
        Eventide Staff

        Sorry, 10512 samples is correct for 176.4k and 192k. I'll amend my original post to be correct.

        Keep in mind that the buffer size you are running will also factor into the roundtrip delay. 8192 is quite a large buffer size, and will cause a noticeable delay even without any latency-causing plugins, if you are trying to play anything "live".

    • #157554
      cauldron
      Participant
      It would be interesting if three years later it was also possible to add a lower latency version for a live context. Currently the waveform is divided into frames of ~40ms and is analyzed to find stable and/or predictable patterns ( https://www.eventideaudio.com/blog/nsanchez/introduction-structural-effects ). It could be very useful to go from 40 to 30 or 20ms and in many contexts it could be a triumph.

      The current version 2.8.8 always maintains the same latency values that I repeat below (frequency, sample delay, time delay). Currently the least delay is achieved at 192kHz, -10ms compared to 44.1kHz.

      192000f, 10512s, 54.7ms

      176400f, 10512s, 59.6ms

        96000f,   5392s, 56.1ms

      Show More...
        88200f,   5392s, 61.1ms

        48000f,   2832s, 59.0ms

        44100f,   2832s, 64.2ms

      enlightened

       

      Show Less...
Viewing 3 reply threads
  • You must be logged in to reply to this topic.