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An unexpected perf feature
LWN.net Weekly Edition for May 16, 2013
A look at the PyPy 2.0 release
PostgreSQL 9.3 beta: Federated databases and more
LWN.net Weekly Edition for May 9, 2013
Improving ext4: bigalloc, inline data, and metadata checksums
Posted Nov 30, 2011 15:35 UTC (Wed) by pr1268 (subscriber, #24648)
From that article: Mp3 to Ogg Ogg -q6 was required to achieve transparency against the (high-quality) mp3 with difficult samples.
I used -q8 (or higher) when transcoding with oggenc(1); I've done extensive testing by transcoding back-and-forth to different formats (including RIFF WAV) and have never noticed any decrease in audio quality or frequency response, even when measured with a spectrum analyzer. I do value your point, though.
Posted Dec 1, 2011 22:54 UTC (Thu) by job (guest, #670)
Posted Dec 10, 2011 1:04 UTC (Sat) by ibukanov (subscriber, #3942)
Lossy format conversion
Posted Dec 10, 2011 15:20 UTC (Sat) by corbet (editor, #1)
Posted Dec 12, 2011 2:54 UTC (Mon) by jimparis (subscriber, #38647)
You can't replace missing information, but you could still make something that sounds better -- in a subjective sense. For example, maybe the mp3 has harsh artifacts at higher frequencies that the ogg encoder would remove.
It could apply to lossy image transformations too. Consider this sample set of images.
An initial image is pixelated (lossy), and that result is then blurred (also lossy). Some might argue that the final result looks better than the intermediate one, even though all it did was throw away more information.
But I do agree that this is off-topic, and that such improvement is probably rare in practice.
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