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Topic: Point of transparency of Opus 1.2 (Read 43836 times) previous topic - next topic
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Point of transparency of Opus 1.2

Has anyone done listening tests to find the point where Opus 1.2 becomes transparent to him/her personally? Can this be done using abx?

Re: Point of transparency of Opus 1.2

Reply #1
Yes, I've done some ABX listening tests to find out about my point of transparency.
--bitrate 96 is transparent to me for the vast majority of even critical samples. If you ignore these you can go even lower.
There were samples that weren't totally fine using --bitrate 96. With one exception even they were transparent using --bitrate 128.
The exception was a harpsichord sample, harp40_1. Even this is acceptable using --bitrate 140. harpsichord music can be a special problem to other lossy codecs as well, for instance mp3. As long as you aren't much into this genre I would ignore it when it is about struggling for transparency. As you know what are harpsichord music tracks you can use very high bitrate for these.
lame3995o -Q1.7 --lowpass 17

Re: Point of transparency of Opus 1.2

Reply #2
Yes, I've done some ABX listening tests to find out about my point of transparency.
--bitrate 96 is transparent to me for the vast majority of even critical samples. If you ignore these you can go even lower.
There were samples that weren't totally fine using --bitrate 96. With one exception even they were transparent using --bitrate 128.
The exception was a harpsichord sample, harp40_1. Even this is acceptable using --bitrate 140. harpsichord music can be a special problem to other lossy codecs as well, for instance mp3. As long as you aren't much into this genre I would ignore it when it is about struggling for transparency. As you know what are harpsichord music tracks you can use very high bitrate for these.
Thanks for your reply. I actually have a few CDs of harpsichord music in my collection and I had noticed that the FLAC files are unusually large compared to other genres. If you don't mind me asking, do you listen to opus on a portable device? If so what is the device and what player do you use?

Re: Point of transparency of Opus 1.2

Reply #3
I am waiting for my favorite Poweramp smartphone music player to support Opus and especially Opus replaygain. Until then I stick with mp3 @ higher bitrate..
I also use a Sansa Clip+ with Rockbox, and I think I can use Opus here right now. But I do want my lossy  music collection to be playable on both devices.
lame3995o -Q1.7 --lowpass 17

Re: Point of transparency of Opus 1.2

Reply #4
Here is Spotify mostly but  I have a several albums on my smartphone  in Opus@128kbps. Didn't notice any failures because I listen mostly rock, metal, alternative music etc... No tonality (like classic music) no problem for Opus.  
Player foobar2000 mobile http://mobile.foobar2000.com/. Everything works great.

Re: Point of transparency of Opus 1.2

Reply #5
I am waiting for my favorite Poweramp smartphone music player to support Opus and especially Opus replaygain.
You'll have to wait long for that one. Seems like they have implemented it on dev builds since late 2012 but it is yet to appear on normal builds because devs are sleeping (?). Anyway since Lollipop Android supports natively opus but AFAIK poweramp is not using any of the native decoders and API implementations for sound so you're out of luck.

Re: Point of transparency of Opus 1.2

Reply #6
Okay, thanks, I will try foobar mobile and the dev version of poweramp.
lame3995o -Q1.7 --lowpass 17

Re: Point of transparency of Opus 1.2

Reply #7
The dev builds of poweramp are not available to the public. Your only option is Foobar.

Re: Point of transparency of Opus 1.2

Reply #8
Okay, so just foobar. Thanks.
lame3995o -Q1.7 --lowpass 17

Re: Point of transparency of Opus 1.2

Reply #9
The dev builds of poweramp are not available to the public. Your only option is Foobar.

Opus works on the beta Version 703, you can get it from the Poweramp forum or after signing up for the beta on Google Play here
I haven't tested replay gain though and the Bitrate shown if you enable the option seems wrong

Re: Point of transparency of Opus 1.2

Reply #10
I was also trying to find safe bitrate for mobile use for Opus. http://wiki.hydrogenaud.io/index.php?title=Opus says 96kbps is "Full bandwidth stereo music, good quality approaching transparency", so I just went with 96kbps just to be safe. I never noticed any artifacts at 80kbps though, though I haven't tried to find any either.

For Android, AIMP also seems to support Opus and ReplayGain. So I've been using both AIMP and Foobar2000 Mobile, since both are efficient and have broad compatibility. Curious to know which is better with battery life though.

Re: Point of transparency of Opus 1.2

Reply #11
I tried it and for me it's 80 kbit. I am using opus with my h265 encodes of video material, but not yet for music.
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Re: Point of transparency of Opus 1.2

Reply #12
I'll be honest, I struggled to ABX at 64kbps. 80kbps is enough for me.

God damn Opus is an amazing codec, I hope it continues to improve - although I have no idea how much further it can be pushed. I remember thinking transparency at 128kbps would be an amazing achievement.

 

Re: Point of transparency of Opus 1.2

Reply #13
Opus definitely does a great job at 64kbps, hope future encoders become even better at that bitrate to the point where I can simply reencode to that.
80kbps is pretty much my limit as well, can't be bothered listening to killer samples all the time. 96kbps gives a good buffer for nearly all tracks.

Re: Point of transparency of Opus 1.2

Reply #14
God damn Opus is an amazing codec, I hope it continues to improve - although I have no idea how much further it can be pushed. I remember thinking transparency at 128kbps would be an amazing achievement.
isn't it just :-)

I think the biggest thing right now is getting it supported in software and hardware so it can be used more widely. It seems to be the way forward.

Re: Point of transparency of Opus 1.2

Reply #15
It's interesting to observe that 4 members have mentioned  Opus@80kbps as point where is hard to spot artifacts for them.
Opus ~80 kbps is roughly equivalent to LAME ~130 kbps (V5)  which lands in an "excellent"  area of quality (MOS 4.5+) http://listening-tests.hydrogenaud.io/sebastian/mp3-128-1/results.htm

So one could say that Opus 80 kbps is "excellent" at least for an average listener.  It's clear that an experienced listeners can spot artifacts at much higher rates.

I never noticed any artifacts at 80kbps though, though I haven't tried to find any either.

I tried it and for me it's 80 kbit.

I'll be honest, I struggled to ABX at 64kbps. 80kbps is enough for me.

80kbps is pretty much my limit as well, can't be bothered listening to killer samples all the time.

Re: Point of transparency of Opus 1.2

Reply #16
I've been using Opus 1.2.1 @~64 on iOS foobar2000.

Re: Point of transparency of Opus 1.2

Reply #17
I think the biggest thing right now is getting it supported in software and hardware so it can be used more widely. It seems to be the way forward.
By the time Opus finally gets widely supported by car stereo manufacturers I'm in.

Though I may turn the tables on my own as soon as I finally upgrade my smart phone to one with external storage support, who knows.
Listen to the music, not the media it's on.
União e reconstrução

Re: Point of transparency of Opus 1.2

Reply #18
I think the biggest thing right now is getting it supported in software and hardware so it can be used more widely. It seems to be the way forward.
By the time Opus finally gets widely supported by car stereo manufacturers I'm in.

Though I may turn the tables on my own as soon as I finally upgrade my smart phone to one with external storage support, who knows.
funny you mention cars, as I did also type it in my original post before editing it out. Wouldn't that be great to have that support in cars. But I guess with streaming being "the future", then the digital files most people have is still mp3.

I'd like to see car manufacturers simply make the car stereo easily accessible to a variety of media devices; 3.5mm jack, usb connection, maybe allow CD playback still that supports lossy files such as mp3s and opus... hell, even data-DVD support to playback lossy files. The headphone jack and usb support would be easy and I've seen some cars with that in as standard; but not enough.

Re: Point of transparency of Opus 1.2

Reply #19
Actually, I believe I said that already in an other post but Chinese car stereos, mostly those cheap ones on ebay have a tendency to support open source codecs. Even though mine didn't advertise that it did, it supports APE, FLAC, OGG and OPUS. If you happen to own one of those I would suggest you to do a test. While on the outside some of them may look identical the internals might differ and they may support more or less codecs than the ones that they advertise.

Re: Point of transparency of Opus 1.2

Reply #20
Actually, I believe I said that already in an other post but Chinese car stereos, mostly those cheap ones on ebay have a tendency to support open source codecs. Even though mine didn't advertise that it did, it supports APE, FLAC, OGG and OPUS. If you happen to own one of those I would suggest you to do a test. While on the outside some of them may look identical the internals might differ and they may support more or less codecs than the ones that they advertise.
My case is quite probably hopeless: mine's a Pioneer. ::) 

The only time I saw that sort of behaviour in a branded device, was with a Sony blu-ray player which, though not mentioned on the box, played FLAC files flawlessly - though it required some trickery.
At that time, someone's pointed here on HA that, due to it probably running Android on its firmware, the ffmpeg library was quite probably kicking in when fooled to play the unsupportedlossless format.

Listen to the music, not the media it's on.
União e reconstrução

Re: Point of transparency of Opus 1.2

Reply #21
I'd like to see car manufacturers simply make the car stereo easily accessible to a variety of media devices; 3.5mm jack, usb connection, maybe allow CD playback still that supports lossy files such as mp3s and opus... hell, even data-DVD support to playback lossy files. The headphone jack and usb support would be easy and I've seen some cars with that in as standard; but not enough.
I wouldn't place any bet of most of those media formats you mentioned ever being supported by a single brand new device at this day and age though.
Listen to the music, not the media it's on.
União e reconstrução

Re: Point of transparency of Opus 1.2

Reply #22
I don't use lossy since my DAP has 400GB of space. But from testing opus when i had a phone with 128gb memory, it was 160kbps with one album needing 448kbps.

Re: Point of transparency of Opus 1.2

Reply #23
Did some Foobar2k ABX testing using the "Bachpsichord" and "Applaud" samples:

Bachpsichord sample*
   Opus@64kbps          : Guessing Probability 0.0%
Applaud sample*
   Opus@64kbps, @96kbps : Guessing Probability 0.0%
   Vorbis@112kbps       : Guessing Probability 0.0%
   AAC-LC (fdkaac 0.6.2, libfdk-aac 3.4.12, VBR mode 4) : Guessing Probability 0.0%
  
*Test logs attached.

The artifact heard is noise like "a puff of steam" :
Reducing_noise_due_to_microattacks

Is the issue with Block Switching (see link above and below) adressed in Opus or this artifact due to other issues ?
Block Switching Issue

I thought FDK AAC @145kbps would do better but the artefact is audibly similar but a bit less pronounced...

Re: Point of transparency of Opus 1.2

Reply #24
Actually, I believe I said that already in an other post but Chinese car stereos, mostly those cheap ones on ebay have a tendency to support open source codecs. Even though mine didn't advertise that it did, it supports APE, FLAC, OGG and OPUS. If you happen to own one of those I would suggest you to do a test. While on the outside some of them may look identical the internals might differ and they may support more or less codecs than the ones that they advertise.

I have owned two Chinese headunits (Android 4 + 5), and both were fucking horrendous. Constant issues with both software and hardware. Neither unit was what I would consider cheap, being around the £250 mark. The sounds quality was some of the worst I've eve heard (no, I didn't ABX).

The problem with using a non branded unit as suggested is that you get hardware which (in my opinion) has very little testing, and low test standards. The software is always junk. The reason good manufactures are limited to a small amount of formats is two reasons:

1) They are limited by available chips sets which are automotive grade. The Chinese ones tend just to use phone / tablet innards.
2) They need to limit the amount of support cost for the unit. I'd guess more formats means more customer support calls.

I've now moved to a Sony Apple Car Play unit now, which is of course, super limited in what it supports. But what it does, it does well.

Attached is a picture of the first Chinese unit I had. Looked ok, worked horribly.