Re: Opusenc's built-in resampler
Reply #54 – 2024-03-12 18:57:39
Today I was preparing a lossless audiobook for lossy conversion and out of curiosity I tried something I don't usually do: opusenc in.wav out.opus . You can clearly hear that the sound became sharper. But why, is it the internal resampler?$ mediainfo penguin.flac General Complete name : penguin.flac Format : FLAC Format/Info : Free Lossless Audio Codec File size : 55.5 KiB Duration : 2 s 0 ms Overall bit rate mode : Variable Overall bit rate : 227 kb/s Comment : Processed by SoX Audio Format : FLAC Format/Info : Free Lossless Audio Codec Duration : 2 s 0 ms Bit rate mode : Variable Bit rate : 227 kb/s Channel(s) : 1 channel Channel layout : M Sampling rate : 32.0 kHz Bit depth : 16 bits Compression mode : Lossless Stream size : 55.3 KiB (100%) Writing library : libFLAC 1.4.3 (2023-06-23) MD5 of the unencoded content : 8EF803F2F8C39B34A69197E56DA68EC3 $ mediainfo penguin.opus General Complete name : pengiun.opus Format : Ogg File size : 12.4 KiB Duration : 2 s 7 ms Overall bit rate : 50.8 kb/s Writing application : opusenc from opus-tools 0.2-34-g98f3ddc Audio ID : 3623 (0xE27) Format : Opus Duration : 2 s 7 ms Channel(s) : 1 channel Channel layout : M Sampling rate : 32.0 kHz Compression mode : Lossy Writing library : libopus 1.5.1, libopusenc 0.2.1-16-ge4285b5 $ opusenc in.wav out.opus Encoding using libopus 1.5.1 (audio) ----------------------------------------------------- Input: WAV, 32 kHz, 1 channel, mono Output: Opus, 1 channel (1 uncoupled), mono 20ms packets, 49 kbit/s VBR Preskip: 312 Encoding complete ----------------------------------------------------- Encoded: 2.02 seconds Runtime: 0 seconds Wrote: 12734 bytes, 101 packets, 5 pages Bitrate: 46.3802 kbit/s (without overhead) Instant rates: 30 to 59.2 kbit/s (75 to 148 bytes per packet) Overhead: 8.03% (container+metadata)
• Join our efforts to make Helix MP3 encoder great again • Opus complexity & qAAC dependence on Apple is an aberration from Vorbis & Musepack breakthroughs • Let's pray that D. Bryant improve WavPack hybrid, C. Helmrich update FSLAC, M. van Beurden teach FLAC to handle non-audio data