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Topic: Smarc audio rate converter (Read 4246 times) previous topic - next topic

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Smarc audio rate converter
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.

  • 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
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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.

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



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

  • klonuo
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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: