Subject: Re: [AUDITORY] Online rhythm production experiments : follow-up From: Bob Masta <audio@xxxxxxxx> Date: Sat, 24 Oct 2020 20:24:50 -0400Are you asking about an *online* system, or is this something else? If the latter, my Daqarta for Windows package includes a macro app called Auto_Recorder that may be of interest, even if only as a starting point. The Help topic is at <https://www.daqarta.com/dw_0o0a.htm>. It includes the full source code, in Daqarta's macro language. Auto_Recorder uses a standard Windows sound card to record 1 or 2 channels of 16-bit sound. It is essentially a "sound-activated recorder", with fully-adjustable thresholds to determine event detection and release, and includes the ability to record up to 1 second before the trigger event. It can log event times to a separate text file, but as it stands it doesn't send out any trigger pulses to external devices. It writes DQA files, which are standard WAV files with additional info. They can be read by anything that follows the rules for RIFF files (which WAV is a type of), though you might have to rename the extension to get some software to consider it. RIFF files like WAV and DQA are limited to 4 GB due to 32-bit address limits, which for a single 16-bit channel is about 12 hours continuous recording. If your events are infrequent, the total time can of course be much longer without exceeding 4 GB. If you really need to record all the background sound between events, you can't do it with a single conventional WAV file. There are a couple of RIFF replacements that use 64-bit addresses, but you'd be on your own with those. The other approach would be to break the recording into multiple smaller files. Can you give details of what the trigger is supposed to be or do? Does this need to be an external pulse, or some signal to another piece of software? For the former, I'd recommend something like Arduino (which Daqarta supports) that can create 5V on/off states. <https://www.daqarta.com/dw_rraa.htm> For pure software, Daqarta can send signals via standard Windows methods. <https://www.daqarta.com/dw_ooxx.htm> The worst-case lag is going to be around 21 msec as it stands, since the event detector looks at the RMS level (or instantaneous peak) in 1024-sample chunks. That could be improved if needed by using an untriggered display, which defaults to about 10 ms for waveform or spectrum, or a spectrogram, which can be set much faster since it only needs to show one column per update. Feel free to contact me with any questions. Of course you are welcome to try Daqarta; the free trial is 30 sessions or 30 days, after which you can't record from the sound card. But you get to use almost everything else forever, including file analysis, 8-channel signal generation, psychoacoustics demonstrations, MIDI music generation, and more. Tip: Right-click any control to open the extensive Help system to that topic. Best regards, Bob Masta =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D On 24 Oct 2020 at 10:46, Timoth=E9e Proix wrote: > > Dear all, > > we are looking for some advice to do long audio recordings (potentially = a few days). We are > looking for a system which is able to record voices autonomously and sen= d triggers related to the > audio (for instance marking the start of the recording), with minimal de= lays between the input > signal and the output trigger. The system should also be able to retain = large amounts of data, > because of the length of the recordings. An alternative way would be to = implement something to > do that ourselves. > > If you have knowledge of a vendor/technology that could do that, or tips= about how to set up such > a system, we would really appreciate it. We will share on this list the = responses we get. > > All the best, > > Timoth=E9e Proix >