Questions about audio encoding in Staxrip

[ACKR]

Hello i past i have used Megui for encoding which has encoded the audio files to 136 bitrate using Nero AAC and and FFAudiosource

A couple of questions about Staxrip-

I am trying to shift to qaac as an encoder so when i select true VBR and the bitrate displayed there is of one channel or both channels?

What is difference in using flac as decoder and using the pipeline ?. Seems flac adds another step?

What is the function of Normalize? i didn't see this option in Megui so should i enable it or not

Edit: Maybe i am not being clear in Megui audio workflow used to be Extract lossless tracks>Encode them directly from my understanding. In Staxrip it is Demux tracks>Convert to .wav> Decode using flac > encode using qaac . my system is slow it took me 2 mins to encode audio in Megui and its taking me 30 mins in Stax. any help is appreciated.

[Blue_MiSfit]

This does not belong in the HEVC forum :) Moving to audio encoding forum

[stax76]

It's possible to process audio without demuxing, it can be disabled in the options.

Maybe post the relevant log sections because many people here are familiar with the commands but not with staxrip.

[ACKR]

It's possible to process audio without demuxing, it can be disabled in the options.

Maybe post the relevant log sections because many people here are familiar with the commands but not with staxrip.

How do i make the workflow similar to megui?. i would like to know what decoding does and what does normalize do?

https://i.imgur.com/sD8wDE3.png

here is pic of megui workflow


EDIT:

https://i.imgur.com/HuXakia.png

https://i.imgur.com/pPiSQfO.png

IDK what to select in this second pic here

[stax76]

avisynth audio processing is not really well-supported, it's possible to use avs as audio source since ffmpeg can open it but I don't think there is any feature for stream selection, I don't really remember what this FFAudioSource decoding feature exactly does.

[tebasuna51]

I can't answer about staxrip better than stax76 but some info about MeGUI and general audio concepts:

- Forget the bitrate when recoding audio tracks. Select the desired quality in Qaac or Nero encoder, a silent movie with only dialogs need low bitrate.
Like refrence with a average audio CD track (stereo), than need more bitrate than movie track, we can expect (I don't know the staxrip presets):
Nero Qaac Average over stereo audio CD track
------ ------ ----------------------------------
q 0.35 -V 54 112 Kb/s min for AAC-LC
q 0.4 -V 63 128 Kb/s
q 0.43 -V 73 134 Kb/s
q 0.46 -V 82 150 Kb/s
q 0.5 -V 91 175 Kb/s
q 0.55 -V 100 192 Kb/s
q 0.6 -V 109 224 Kb/s
At high quality (> 128 Kb/s) the test can't difference the quality between encoders, only at low bitrates we know than qaac is better than Nero.

- Flac is not a decoder, the decoder method means use a intermediate file: flac (less size, more time encoding/decoding), WAVE (big size, decompressed PCM samples, less than 4GB) or W64 (like WAV but can be > 4GB for multichannel movie tracks).
The pipe method is send the PCM samples, with RAM without disk read/write, directly to encoder: the fast method

- The Normalize is also present in MeGUI but is different than the Qaac Normalize.

In MeGUI is called Normalize Peaks and AviSynth do a first pass to know the max volume value present in the track and in the second pass amplify the sound to the max percent desired.
This method prevent clip and obtain the max volume without distort.
Recommended for low volume repair or after a downmix 5.1 -> 2.0

The method used by Qaac is only one pass, can be only predictive and can do some distort.

[chros]

At high quality (> 128 Kb/s) the test can't difference the quality between encoders, only at low bitrates we know than qaac is better than Nero.
There was a listening test for music on hydrogenaudio couple of years ago (2-3?, I couldn't find it now quickly), they used the v91 preset and similar switches for other encoders. qaac won, that's why I started to use it back in the day with BatchEncoder (https://github.com/wieslawsoltes/BatchEncoder) by @wieslawsoltes .

[tebasuna51]

Yes, I always use qaac with UsEac3to, MeGUI or BeHappy although it is a bit slower than Nero or other aac encoders.