HydrogenAudio

Lossy Audio Compression => Ogg Vorbis => Ogg Vorbis - General => Topic started by: Faelix on 2016-06-04 18:41:40

Title: Does "resample 44100" on Oggenc leave 44,1Khz files untouched?
Post by: Faelix on 2016-06-04 18:41:40
I want to set up a conversion routine to Ogg Vorbis on Foobar2000. If I add "--resample 44100" to my command line, will the oggenc encoder leave the files already at 44.1Khz untouched?

My problem is that Cowon players are consistently compatible with Ogg Vorbis only at 44.1Khz. If I need to convert some hi-res FLAC, it may end up as a 48Khz or higher Ogg Vorbis.

For me, it would be more comfortable to set up some command line option, and leave the decision to the encoder. But I'd not like it to resample unnecessarily.
Title: Re: Does "resample 44100" on Oggenc leave 44,1Khz files untouched?
Post by: greynol on 2016-06-04 18:52:01
Short of being told the answer (which I don't know), this is easy enough to test.  Feed the same 44.1k file to the encoder, with and without the switch. and compare the output.
Title: Re: Does "resample 44100" on Oggenc leave 44,1Khz files untouched?
Post by: visaton on 2016-06-04 19:02:43
As far as i know, the sample rates higher than 44.1 don't bring any advantages. Besides Vorbis is lossy codec, and I guess it is best tuned to work with standart sample rate, rather than higher ones. I don't know if Vorbis has a built-in resampler, but Foobar has a great ones, called SSRC. You can activate/deactivate it in DSP chain, with one click of the mouse.
Title: Re: Does "resample 44100" on Oggenc leave 44,1Khz files untouched?
Post by: Faelix on 2016-06-04 19:13:21
Short of being told the answer (which I don't know), this is easy enough to test.  Feed the same 44.1k file to the encoder, with and without the switch. and compare the output.

Fair enough, I did this with two music tracks. The Ogg files were identical regardless of the resample option. Also, there was no difference in encoding time, so it seems that oggenc leaves files already at the intended sampling rate untouched. So I can add the option to my command line.
Title: Re: Does "resample 44100" on Oggenc leave 44,1Khz files untouched?
Post by: Faelix on 2016-06-04 19:15:57
As far as i know, the sample rates higher than 44.1 don't bring any advantages. Besides Vorbis is lossy codec, and I guess it is best tuned to work with standart sample rate, rather than higher ones. I don't know if Vorbis has a built-in resampler, but Foobar has a great ones, called SSRC. You can activate/deactivate it in DSP chain, with one click of the mouse.

When I converted hi-res FLAC, I ended up with Ogg files at higher sampling rates. But Cowon players have specification stating specifically 44.1Khz Ogg Vorbis.

The Oggenc executables from Rarewares employ the SoXR resampling library, so I think I'm well covered here.