r8brain PRO is a professional sample rate converter designed to deliver an unprecedented sample rate conversion (SRC) quality. Unlike many existing SRC algorithms available on the market, r8brain PRO implements sample rate conversion processing in its full: interpolation and decimation steps without exploiting any kind of simplifications; the signal is first resampled to a least common multiple sample rate which makes conversion perfect. In the core of the SRC algorithm, we use the convolution methods of our Pristine Space convolution processor which is known for its highly precise convolution processing. This gives us high sample rate conversion quality in combination with comparably small processing times: sample rate conversion without compromises!

Like many existing SRC programs, r8brain PRO offers you a linear-phase conversion mode. But more importantly, you also have an option of using the minimum-phase conversion mode, which finally brings SRC with true analog qualities to affordable digital audio workstations: in this mode, r8brain PRO works like an ideal digital-to-analog converter followed by an analog-to-digital converter to resample the audio. This eliminates pre-ringing associated with linear-phase designs, while introducing only a minimal amount of phase coloration.

r8brain PRO can read mono, stereo and multi-channel files in both WAV and AIFF file formats, creating 16-, 24- and 32-bit mono, stereo and multi-channel WAV files in fixed and floating point formats. EBU BWF (broadcasting) extensions, extensible wave format, sample loops and textual data residing inside the file are also supported. For the sake of convenience, r8brain PRO allows you to perform batch conversions in a convenient manner.

r8brain PRO's bit-depth conversion is limited to flat dithering. We have decided not to implement noise-shaping dithering because pro audio production software available on the market usually offers the user noise-shaping dithering of some kind already. We also based our decision on the fact that the sample rate conversion process often adjusts peak structure of the original program material, thus, in many cases, making a subsequent peak-limiting a necessity. To prevent output audio from clipping we have implemented a level normalization feature.

The demo version of r8brain PRO allows you to evaluate all features of the software, but its conversion is limited to the first minute of an audio file. The demo version does not support batch conversions. You may register to obtain either a Full or Light license of r8brain PRO. The Light version offers you a linear-phase conversion mode and up to 48 kHz output sample rates only while supporting all input sample rates. The Full version offers you all features of the software.

r8brain PRO features:

File folder. This is the name of the folder containing the original WAV or AIFF files. To select a folder, just select any file in it. In parallel, the program will put the selected file into the file list which you can immediately process without first pressing the "Scan folders" button. However, if you have selected file folder with the "Browse folders" function you should use the "Scan folders" option as well.

Files to process list box lists all the files which shall be processed when you press the "Process" button. You can use the Del key to remove list entries. Several files can be selected for deletion. The Enter key (or mouse double click) can be used to open the currently selected file.

Scan folders button scans the specified folder for WAV and AIFF files and adds them into the file list. Before scanning starts, the file list is cleared. You can also use the "Clear list" button to clear the file list manually.

Output folder specifies the folder where output files should be created. This field is filled automatically after each new input file folder is selected. Please note that if you have enabled the "Include subfolders" option files in these subfolders will all be exported to the Output folder preserving the folder structure.

Add suffix to the converted file switch allows you to append any specified suffix to the output filename. This allows you to easily identify resampled copies of your files. Please note that disabling this option may overwrite the original file. Disable this option with care!

Out sample rate selects which samplerate resulting files should have.

Out bitdepth selects which bit-depth resulting files should have.

Filter specifies filter type to use during sample rate conversion.

Ignore already processed files switch enables skipping of already processed files. Such files are identified by r8brain PRO via special marker which is created for each output file which passes processing stage.

Prevent clipping switch enables automatic normalization for files with detected clipping. Normalizing is engaged only if the clipping occurs in the resulting file. It is a counter-measure against clipping.

Normalize peak dBFS option can be used to normalize the resulting file to the specified dB (full scale) peak value. Peak value should be specified in decibells, with decimal part separated with the point (e.g. -0.3).

Ultra-steep mode option enables mode which offers an increased output bandwidth. In this "ultra-steep" mode only the most high frequencies get filtered out (about 1.4% of the total linear bandwidth, in non-ultra mode it nears 6.25%, which is still acceptable). This means that during conversion there will be almost no loss of high-frequency information. However, in this mode conversion takes roughly 3 times more time.

About button brings program's version and registration information.

Process button starts processing of the files listed in the file list. Any file that could not be processed will be listed again after the batch finishes. This allows you to check/edit any such file in the default audio file editor and continue the batch processing later.