Do lossy mp3 files see more or less or more of an improvement using upsample filters than lossless CD files? Or, do they the see same relative improvement?
With HQPlayer, there was once I was running Internet radio with HQPlayer and through comparison the upsampling provided by HQPlayer, significantly improves the clarity of the sound. To me, lossless CD is a more original way of getting sound quality and upsampling is still ultimately fabricating data to make up for the loss. While HQPlayer’s upsampling is really good, I avoid them and use HQPlayer as a player, it’s an amazing player when used with Roon and Raspberry Pi NAA. but if I’m listening to MP3 or low quality tracks, I highly think the trade off in using upsampling with HQPlayer is worth it, I was wondering how they were able to recreate the sound so well, it felt like CD quality, though ultimately actual lossless CD is still better to me.
but do not get me wrong, even with lossless CD, HQPlayer upsampling does an amazing job, just I don’t really enjoy the idea of upsampling and leave it to my DAC to do the job. 
I once did a comparison, HQPlayer upsampling does improve clarity, but somehow I prefer it without.
I am looking for a technical and objective reply from the creator of HQPlayer. Not a subjective impression [Moderated].
Nope. Just looking for a technical answer on HQPlayer operation…not subjective impressions.
I have listened to the tracks, compared them, and have my own subjective opinion. What I hear tells me that both are improved about the same amount when upsampling using the same settings. I want to know if there are any objective reasons why mp3 or CD tracks should see more or less of an improvement as I don’t know enough about HQPlayer internals to know the answer.
Similar relative improvement. You cannot undo the damage made by the lossy encoder, but same reconstruction improvements still apply regardless of source.
In some cases for such sources certain apodizing filters can provide extra help, you could try for example poly-sinc-short. And on low bitrate (<= 128 kbps) you could try poly-sinc-mqa. And compare those versus the ones you use for CD rips.
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That’s not how upsampling works. What you are describing is more like CD error correction.
Upsampling is similar to adding whitespace between characters on a page of text to increase the resolution of the page. You can then do things using the higher resolution that were too constrained by the original resolution, such as kerning or justification in the case of text or shifting noise to well outside the audible band in the case of audio (apodising filters do this).
Thank you!
Hi,
Having a special filter for lossy content in the options tab would be really cool, I live ext2 for CD, but it’s too harsh for 192kbps radios 
Bye!
HQPlayer doesn’t support any lossy content, so it is not possible to do…
Ok jussi,
So what is going on when I play a Roon radio? Does roon send pcm to hqplayer?
Yes, Roon always sends just raw decoded PCM or DSD to HQPlayer. HQPlayer has no information where the audio is coming from. So it cannot know if it has been MP3, AAC, FLAC or something else. This is quite different from playing the content directly with HQPlayer where HQPlayer can know where the content originates from and act accordingly.
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