View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0007127 | ardour | other | public | 2016-11-17 19:47 | 2016-11-20 18:15 |
| Reporter | unfa | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | have not tried |
| Status | new | Resolution | open | ||
| Product Version | 5.4 | ||||
| Summary | 0007127: Ardour resampling is 8 times slower than SoX | ||||
| Description | Accidentally I did a resampling benchmark. The source is a 24-bit stereo WAV at 44.1, I wanted to resample it to 48 kHz. However Ardours seems to do this very slow. I tried using sox for this, and I found out Ardour is actually 8 times slower at this. SoX - 8.5 seconds. Ardour - 65 seconds. This is a dramatic difference. Can something be done to speed things up for Ardour? | ||||
| Steps To Reproduce | 1. Prepare yourself a big WAV file using a differnt sampling rate than your normal Ardour sessions. 2. Use a sox command to convert it to your Ardour session's sampling rate (for example 48 kHz) time sox input.wav -r 48000 output.wav This will also measure the execution time 3. Prepare a stopwatch. 4. Drag the input file into the Ardour session and start the stopwatch. 5. Stop the stopwatch when Ardour finishes the import. 6. Compare the two times. | ||||
| Additional Information | This is the sox command I originally used: sox -V6 input.wav -r 48000 output.wav The -V6 makes SoX very verbose. | ||||
| Tags | No tags attached. | ||||
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Can you also compare against `sndfile-resample` (ardour uses libSRC) on import Ardour also demuxes and reformats the file, but the overhead of that is probably small. |
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Are you comparing SRC methods of similar quality? Last time I tried sox default SRC settings it was quick but the result didn't sound as good to me as the highest quality setting in sndfile-resample. |
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http://src.infinitewave.ca/ FTW |
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After further testing, I suspect that my opinion of sox vs libsamplerate SRC is subjective preference. SoX default src setting appears to use a steeper anti-alias filter than -c 0 setting in libsamplerate*. The libsamplerate SRC still sounds slightly better to my ears, but the SoX SRC is impressively quick. *Tested by recording a 24kHz sine wave to a 96kHz file, downsampling to 48kHz using sox and libsamplerate, and comparing the spectrum plot of the result in jaaa. The libsamplerate version shows a residual 24kHz signal at -116dB, but sox version shows none at all. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2016-11-17 19:47 | unfa | New Issue | |
| 2016-11-17 21:08 | x42 | Note Added: 0018984 | |
| 2016-11-19 13:21 | jrigg | Note Added: 0018989 | |
| 2016-11-19 13:51 | x42 | Note Added: 0018990 | |
| 2016-11-20 17:30 | jrigg | Note Edited: 0018989 | |
| 2016-11-20 18:10 | jrigg | Note Added: 0019012 | |
| 2016-11-20 18:15 | jrigg | Note Edited: 0019012 |
