Hi Peder, thank you for your reply. On Sun, May 22, 2011 at 02:26:19PM +0200, Peder Hedlund wrote: Right, I have shifted through the decimator source, and other excellent plugins by Steve, however, I had not seen any way to reduce the emitted signal size. I had a second look now and it still doesn't seem to be possible, please correct me if I am wrong. The following are the steps I took. I only list the decimator_1202 tests, the smooth_decimate_1414 tests gave the same results. Create a one second 100Hz file ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ $ sox -r 44100 -n -b 16 out.wav synth 1 sine 100 trim 0 1 $ soxi out.wav Input File : 'out.wav' Channels : 1 Sample Rate : 44100 Precision : 16-bit Duration : 00:00:01.00 = 44100 samples = 75 CDDA sectors File Size : 88.2k Bit Rate : 706k Sample Encoding: 16-bit Signed Integer PCM Plugin takes two parameters ~~~~~~~~~~~~~~~~~~~~~~~~~~~ $ analyseplugin decimator_1202 Plugin Name: "Decimator" Plugin Label: "decimator" Plugin Unique ID: 1202 Maker: "Steve Harris <steve(a)plugin.org.uk>" Copyright: "GPL" Must Run Real-Time: No Has activate() Function: No Has deactivate() Function: No Has run_adding() Function: Yes Environment: Normal Ports: "Bit depth" input, control, 1 to 24, default 24 "Sample rate (Hz)" input, control, 0.001*srate to 1*srate, default 1*srate "Input" input, audio, -1 to 1 "Output" output, audio, -1 to 1 Apply decimator plugin with sox as host ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ $ sox -V out.wav out2.wav ladspa decimator_1202 16 1000 sox: SoX v14.3.2 sox INFO formats: detected file format type `wav' Input File : 'out.wav' Channels : 1 Sample Rate : 44100 Precision : 16-bit Duration : 00:00:01.00 = 44100 samples = 75 CDDA sectors File Size : 88.2k Bit Rate : 706k Sample Encoding: 16-bit Signed Integer PCM Endian Type : little Reverse Nibbles: no Reverse Bits : no Output File : 'out2.wav' Channels : 1 Sample Rate : 44100 Precision : 16-bit Duration : 00:00:01.00 = 44100 samples = 75 CDDA sectors Sample Encoding: 16-bit Signed Integer PCM Endian Type : little Reverse Nibbles: no Reverse Bits : no Comment : 'Processed by SoX' sox INFO sox: effects chain: input 44100Hz 1 channels sox INFO sox: effects chain: ladspa 44100Hz 1 channels sox INFO sox: effects chain: dither 44100Hz 1 channels sox INFO sox: effects chain: output 44100Hz 1 channels Using appplyplugin(1) gives the same results. AFAICT the decimator plugin sets stretches of samples to the same, so a later resampling would have the desired effect. On Sun, May 22, 2011 at 02:26:19PM +0200, Peder Hedlund wrote: Sorry, I should have been more verbose in my request. It is not resampling per se that I am after, I want to be able to write a plugin that can emit a reduced signal after analysis. One application I'm aiming for is to create compressed views of long signals. The reason for using LADSPA is the ease of implementation. If it is not possible with LADSPA plugins, I plan on writing a sox effect instead, unless someone has other good ideas for accomplishing this, of course in a CLI friendly way? [...] -- best regards Thor Andreassen

On Sun, May 22, 2011 at 06:15:03PM +0200, Thorsten Wilms wrote: Yes. So I'll look at a different solution. This would work, but for the applications I intend to use it [*], the reduction of data travelling down the pipeline is important. Thank you for your suggestion. [*] There are several, and probably more to come. The ones I'm looking into now are realtime plotting of multichannel ultrasonic signals, with reduction of datasize, but without losing activity. And creating compressed views of many hours of recordings, again without activity getting lost. -- best regards Thor Andreassen