A Remark: I saw that I did encode that stereo Waveform using 448kbits in each encoder! Which is not real condition like!
Now the test shows how those encoders do behave if we do use on that stereo Waveform a 192kbit encode and a 128kbit encode.
192kbit CBR is fully sufficient for a stereo signal at 48000Hz, 16bit seen on a technical point of view.
192kbit - Softencode:
A clean full up to 20.3KHz freq Range.
192kbit - FFmpeg:
Also here up to 20.8Hz freq Range but a phase error which rises from 13Hz. BUT this is minimal -- check if you can recognise it!
128kbit - Softencode:
As shown in the SFSE encoder config settings at 128kbit the encoder forces the Freq being cut at 13.55Khz!
128kbit - FFmpeg:
Full Hz range but a phase error starting at an even earlier Hz point compared to 192!
What do these diagrams say? Very easy:
If you want "no" compromise in stereo AC3 audioencoding then you should go for Softencode at 192kbit as a full very phase-error-free freq range will be provided after decoding the AC3.
If you go for 128kbit AC3 then you have to choose between freq fullrange but minimal phase-errors (ffmpeg) or a limited freq range incl. no errors (SFSE).
Now you should make tests using your ears especiall on the phase errors ....
And then you decide what will be your choice.
A point to freq range: dont be affected by reading specs/values! "Normal" human ears wont recognise in a "normal attention" freqs above 16Khz, if so then congrats to excellent ears and for shure mega congrats to an EXCELLENT playback/speaker combination! Audiophile systems which do provide signals in "an accurate db state" so that you can recognise these high freq are very expensive. Shure technical specs of some speakers/Receivers do often mention high freq outputs about 18-22Khz but thats theory and beside this it depends WHAT these high freqs are made of and for shure if they can be provided at a needed db ratio.
BTW: A regular very good TV broadcast in PAL wont exceed 16Khz!
Quote:
Inc,
have you had the chance to try any more recent commercial AC3 encoder? My friend has the Sony Vegas 6 suite which contains an AC3 encoder - if you cannot do the test encode, I'll ask if he would do so.
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No sorry, I dont have any other choice. When doing tests be shure NO DRC is set as this will provide an almost untouched range.
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