Lame 3.97 Alpha 8 Testing Thread
Reply #10 – 2005-03-12 06:35:09
[span style='font-size:14pt;line-height:100%']LAME 3.97 alpha 8 TEST #1: -V 3 [/span] For the following tests, I tried to obtain the most accurate results. That’s why I didn’t include extra elements (like comparison with --vbr-new, or with an ancient lame version): my full attention was focused on difference between alpha8 and the previous one. For that reason, I put all efforts on ABX direct comparison between both encodings. 12 trials for each sample, no more, no less (except on training). No ABX tests between reference and encodings: unnecessary waste of time. I’ve used previously 54 samples to test V4 preset. It was a luxury I can’t afford anymore, because my time is limited and my motivation quite over. Therefore, I returned to the general samples’ set used for alpha 5 and alpha 6 (20 samples, melting ‘general’ music, ‘classical’ and two critical samples). I’ve just replaced the cello’s sample (BachS1007.wav , too transparent at high bitrate) by another cello sample (Kodály.wav ), more detailed and consequently harder to encode. Other change: I’m now using the new java version of abc/hr, which is remarkable. It has a precious feature: it automatically saves the playback range. Now, developers could easily link all written comments to the corresponding part of the sample. I’ll precise all tested range in my synoptic table of results. Other good point for schnofler’s software: it systematically cleans all comments wrote by the tester after each fresh test. ff123’s abchr beta 2 is buggy here, and often keeps previous comments. It’s sometimes funny (e.g. “distorted trumpet” on a solo piano sample…), but it’s often confusing. Comments are now fully reliable. I’ll recap the audible problems in my tables. RESULTS [/u] ABX log files are here .COMMENTS Gabriel’s tuning have the same impact on -V3 than on -V4: it lowers the bitrate, and increase the quality. It’s important to note that the progress are also very similar to the progress noticed by testing -V4: there are less distortions (noticeable on cymbals mostly), no more issues with low volume parts, and less pre-echo (at least on non critical samples: castanets2.wav is still heavily smeared). It’s probably not a coincidence… I suppose that -V3 alpha 8 benefits from similar tunings than -V4 alpha7. I’ve only noticed two serious regressions (ATrain and MidnightVoyage.wav ). But on average, the new alpha 8 appeared to me clearly better than the old one.