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Topic: exhale - Open Source xHE-AAC encoder (Read 35724 times) previous topic - next topic
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Re: exhale - Open Source xHE-AAC encoder

Reply #400
slower than what?

Re: exhale - Open Source xHE-AAC encoder

Reply #401
Slower than all the other modes.

And I made a mistake. It's mode 5 at 128kbps that's slower.

On the new 1.0.7 RC1, mode 0 is clearly faster than all the modes (x86 binary).
"Something bothering you, Mister Spock?"

Re: exhale - Open Source xHE-AAC encoder

Reply #402
I have come to completely wrong conclusions in the past because I did a lot of testing and have confused the files produced by myself. The forum terms of service in point 8 state that graphs, non-blind listening tests, waveform difference comparisons, and so on, are not acceptable. Or at least that's what I understand.

Wanting to avoid myself further ugly figures, I thought of writing directly to the developer, although I have enormous doubts about the graphics provided. I hope not to irritate the administrators if I use this scam to show a software bug, but I consider your opinions very important and otherwise I would not be a regular reader of this forum.

I ask forgiveness in advance, thank you.

https://gitlab.com/ecodis/exhale/-/issues/14

Re: exhale - Open Source xHE-AAC encoder

Reply #403
Your graphs show that exhale's resampler is different from the other resampler you compared it against, but that's all. They don't show that one is better than the other by any metric.

If you want to compare the technical merits of resamplers, you need graphs like these.

If you want to know which one sounds better, you need blind listening tests.

Re: exhale - Open Source xHE-AAC encoder

Reply #404
Final commit for this release, I was informed of an inaccuracy in exhale's loudness estimation and corrected that, at least for 44.1 and 48 kHz sampling rate it should now be quite accurate. If you manage to compile this release without errors, please call it version 1.0.7. I'll tag this later, after having run it through my own test suite. Btw, the audio quality hasn't changed since the last release candidate, only the loudness value inside the file header might have.

It's mode 5 at 128kbps that's slower.
On the new 1.0.7 RC1, mode 0 is clearly faster than all the modes (x86 binary).
Two reasons for this. First, at the lower CVBR modes where a sampling rate of 32 kHz or less is used, the encoder needs to process fewer samples (i.e., frames) per second. Second, the more frequency coefficients are quantized to zero, which of course happens a lot at mode 0, the faster exhale's entropy coder can run. Regarding mode 5 being the slowest mode: I configured the higher modes such that they are roughly as fast/slow as modes 4 or 5, but that configuration is quite coarse. Do you have a detailed table of speeds per CVBR mode and sampling rate by any chance?

Your graphs show that exhale's resampler is different from the other resampler you compared it against, but that's all.
What I believe I can read from celona's screenshots (the waveform display in the background) is that his resampler has a slightly lower (possibly unnecessarily low) cutoff frequency. But to be sure, Christian, can you share your manually 32-kHz downsampled sweep WAV file, i.e., the one you used to obtain the Sweep20-20_20sec_-6dB_32k.wav.png screenshot in the Git issue?

A note on the loudness metadata: xHE-AAC has built-in loudness and sample peak value metadata according to ISO/IEC 23003-4 (DRC standard) similar to ReplayGain, so it should not be necessary to write ReplayGain tags to xHE-AAC files (with that file format, doing so is considered obsolete). Still, exhale cannot write album loudness information since it doesn't know about albums, only files (where each file is considered an "audio program"). If there is interest in extending the xHE-AAC file headers written by exhale with ISO/IEC 23003-4 album loudness values (and, possibly, album sample peak values), I'm open to disuss this, e.g. with Peter and Christopher in the context of foobar2000.

Chris
If I don't reply to your reply, it means I agree with you.

Re: exhale - Open Source xHE-AAC encoder

Reply #405
Intel compiles of exhale-v.1.0.7-54a7bcd7 now available at Rarewares. :)

Re: exhale - Open Source xHE-AAC encoder

Reply #406
Christian, can you share your manually 32-kHz downsampled sweep WAV file, i.e., the one you used to obtain the Sweep20-20_20sec_-6dB_32k.wav.png screenshot in the Git issue?


Obtained with afconvert --src-complexity norm, I can supply also the best quality version (bats) but my purpose was not to evaluate the quality of the encoder, but only to evaluate whether to use internal SRC or other.


I also add the compressed version obtained, of only 31,688 bytes.

Re: exhale - Open Source xHE-AAC encoder

Reply #407
... my purpose was not to evaluate the quality of the encoder, but only to evaluate whether to use internal SRC or other.
Well, that I can easily answer: if your original source material is in 48 kHz, use exhale's built-in resampler ;) Seriously, don't worry about the resampling if you don't have to. exhale's 48-to-32-kHz resampler was specifically designed to run fast, have a high cutoff frequency (it starts rolling off around 15 kHz IIRC while your afconvert version starts rolling off already at 14 kHz), avoid unnecessary stop-band and near-Nyquist aliasing rejection which will be masked by the low-rate compression errors, and always result in the maximum bit-depth entering the encoding process (around 24 bits per sample). Oh, and you would either have to use some on-the-fly resampling with a stdout-to-stdin cascade or you'd need to create temporary 32-kHz resampled files which you then feed into exhale.

Lots of things I wouldn't want to worry about if I were you :)

Chris
If I don't reply to your reply, it means I agree with you.

Re: exhale - Open Source xHE-AAC encoder

Reply #408
Do you have a detailed table of speeds per CVBR mode and sampling rate by any chance?

I can PM my entire benchmark history going back to 1.0.2.

If my memory serves, my machine encodes most modes with 44 khz material at 10.5x to 11, and even mode 1 is close to the same speed despite its resampled by SoX at 24khz. Mode 5 encodes slower at about 9.5x. Mode 0 (resampled by SoX to 24khz) in 1.0.7 RC1 encodes faster at over 13x. These test were with 86 binaries. (Thanks again, john33 :)
"Something bothering you, Mister Spock?"

Re: exhale - Open Source xHE-AAC encoder

Reply #409
OK, I've encoded some music with exhale 1.07 and tested it on my Samsung A50, with latest updates, It runs Android 10.
PowerAmp won't play these files, which is expected as its decoders are based on ffmpeg. Samsung Music plays these files, but I can't jump inside some position in song, just says it is not playable (and it was playing that exact file!) and skips to next song.
Didn't test any other player, because I don't really know which one should work - does anyone has suggestions?
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Re: exhale - Open Source xHE-AAC encoder

Reply #410
whats about playing this files on PC ?

Re: exhale - Open Source xHE-AAC encoder

Reply #411
Everything as expected. playing in foobar2000, with that extra decoder installed. can play, can jump around the song.
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