Lossless audio codec comparison revision 6 - hi-res part

Introduction

This document compares the performance of lossless audio codecs on high resolution material, which are PCM audio files with more than 16 bit per sample or a samplerate higher than 48kHz.

The test corpus consists of four 96kHz, 24 bit per sample sources, three 192kHz, 24 bit per sample sources, one 192kHz, 16 bit per sample source and two 352.8kHz, 24 bit per sample sources. The test corpus has not changed since the previous hi-res comparison, revision 5, part 2.

Method

The method of testing is explained in here.

As not all codecs are able to handle multichannel, two codecs are omitted from the averages: Shorten and LA. Shorten and LA do support high samplerates but not high bit depths, because of that, they are included in the per-source results for the 16-bit sources, which currently is only one. WMA and TAK do support high bit depths and high samplerates, but WMA is limited to 96kHz and TAK is limited to 192kHz. They are included in the per-source results for all sources they support, and a separate average is made with just the sources up to 96kHz.

Results (PDF)

• Average of all hi-res sources
• Average of hi-res sources up to 96kHz
• Results per source, PDF, CSV

The best results will be obtained in the bottom left corner of the graphs: this represents the best compression (smallest file size) and the lowest CPU-usage (fastest compression and/or decompression).

In the graph each codec is represented by a group of markers connected by a line. Each combination of settings as mentioned in the previous table corresponds to one marker, in the order listed in the table. The first combination of settings is (usually) the fastest and the last the slowest. Therefore, the marker closest to the upper left corner of the graph corresponds to the first listed combination of settings, and the marker closest to the lower right corner corresponds to the last listed combination of settings.

Discussion

Compared with the previous hi-res comparison, revision 5, part 2, FLAC got a tremendous improvement in compression, and MonkeysAudio got quite a bit faster.