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Topic: Smarc audio rate converter (Read 4211 times) previous topic - next topic

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  • forart.eu
  • [*][*]
Smarc audio rate converter
Quote
Smarc is a fast and high quality audio rate converter. It allows conversion between any samplerate. Smarc is a command-line program and a C library to be integrated in other applications.

Features
  • signal rate conversion between any sample rates.
  • optimized for conversion between standard audio sample rates.
  • command-line tool to convert audio files
  • C library to integrate smarc converter into other applications.
  • Initially designed to convert audio, but also any 1-D signals such as EEG, seismic signals, etc.
  • Convert sample rate using polyphase decimation and interpolation filters. This method guarantees high-quality for upsampling and downsampling.
  • Internal filters can be tuned to emphasize speed or quality.


Official website
Official download page

  • Martel
  • [*][*][*][*][*]
Smarc audio rate converter
Reply #1
Well, I've read through the "internals" document (15 pages).

It contains an alarming number of typos. Some parts are still in French.
I did not find anything revolutionary. There seem to be just some speed and memory-related optimizations.

Quote
... For others ratios, the decompostion is automatically computed but the result is often not optimal
and a manual help is recommanded, in this way one can manually defined a better decomposition.


This quote from the conclusion is not too convincing.
  • Last Edit: 25 October, 2011, 02:02:19 PM by Martel
IE4 Rockbox Clip+ AAC@192; HD 668B/HD 518 Xonar DX FB2k FLAC;

  • klonuo
  • [*][*][*][*]
Smarc audio rate converter
Reply #2
Seems good and fast. 2x slower than SoX or zita, but that's still fast IMHO

Swept


1kHz


At 150 dB none artifact

Above images are from default settings. One can use "--rs=180" and get clear picture at almost same speed
  • Last Edit: 25 October, 2011, 04:35:20 PM by klonuo

  • lvqcl
  • [*][*][*][*][*]
  • Developer
Smarc audio rate converter
Reply #3
BTW, frequency response (passband) for 96000 -> 44100 conversion (smarc -r 44100 in.wav out.wav):


  • klonuo
  • [*][*][*][*]
Smarc audio rate converter
Reply #4
Yeah, like default value for stop band is 140, ripple factor is set to 0.1
It seems it can go down to 0.001: