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Gracus · (This post was last modified: 2016-12-21, 21:58 by Gracus.)

I made some quick samples

-original wav file grab from kodi wiki
-aac file encoded from wav
-ac3 file encoded from aac
-dts file encoded from aac

I use an online converter so not sure the quality will be the best possible

Could be helpful until madmax2 provide better samples

Here

wesk05 · 2016-12-21, 22:04

Not sure whether things have changed since Jan 2016. There was this discussion on doom9 forum about FFmpeg DTS encoder.

There were two issues: 1) bitrate of the DTS stream was slightly off spec. 2) distortions in decoded audio

**da-anda** · (This post was last modified: 2016-12-21, 22:43 by da-anda.)

I converted a 5.1 FLAC song to AC3 448kbit, AC3 640kbit and DTS using ffmpeg (hope I used the correct params). Will give it a test run on my SPDIF AVR. Can share the song for testing with team members on request

madmax2 · (This post was last modified: 2016-12-21, 23:21 by madmax2.)

(2016-12-21, 19:36)da-anda Wrote: @madmax2 - could you do us a favor and convert a 5.1 AAC (or FLAC) sample to AC3 and DTS and compare those? Maybe also share the samples for our devs to test. If devs can't be convinced it's adding value, they are not interested to add another feature that only needs maintenance.

Sorry, I don't have a sample..
Most of my samples are very large movies - 1080p with AAC 5.1 audio

Audio quality perception is just an opinion..
All I know is it sounds better to me when I choose DTS over AC3 when I test on potplayer..

I also said there is another advantage of DTS is not needing to turn up the volume

Because when I watch an AC3 transcoded movie I need to turn up the volume due to the lower volume sound
then need to turn down the volume again, when I change to a standard 2 / 2.1 audio video / movie / music

Also why should a third party software (potplayer) have this DTS transcoding feature but it is missing in Kodi?
Why does potplayer have this feature and Kodi is missing this feature?

Kodi is suppose to take over my Living room as my primary media center..
yet if I want to transcode to DTS audio I need to resort to a third party software (potplayer).

madmax2 · (This post was last modified: 2016-12-21, 23:19 by madmax2.)

(2016-12-21, 22:42)da-anda Wrote: I converted a 5.1 FLAC song to AC3 448kbit, AC3 640kbit and DTS using ffmpeg (hope I used the correct params). Will give it a test run on my SPDIF AVR. Can share the song for testing with team members on request

If you are going to do the test, please test on a movie (preferably an action type of movie)

You should use a movie with AAC 5.1 audio
and you can test it on potplayer with the output mode as AC3 or DTS after transcoding as shown in my previous screenshot..

madmax2 · 2016-12-21, 23:25

(2016-12-21, 21:56)Gracus Wrote: I made some quick samples

-original wav file grab from kodi wiki
-aac file encoded from wav
-ac3 file encoded from aac
-dts file encoded from aac

I use an online converter so not sure the quality will be the best possible

Could be helpful until madmax2 provide better samples

Here

Sorry but my "samples" are very large size 1080p AAC 5.1 movies..

If you want to test yourself, just get a 1080p AAC 5.1 movie (preferably an action type of movie)
and you test it on potplayer using the settings output mode I posted in the screenshot

**da-anda** · 2016-12-22, 00:25

the volume is really louder when you use DTS transcoding over AC3? This is somewhat odd, but will test.

madmax2 · 2016-12-22, 01:52

(2016-12-22, 00:25)da-anda Wrote: the volume is really louder when you use DTS transcoding over AC3? This is somewhat odd, but will test.

Yes,

Please use Potplayer software and the screenshot setting I posted to get DTS or AC3 Output..

And try to get an action movie with AAC 5.1 (e.g of some actions movies that I tested are Xmen movies, The Wolverine etc)

As I said another advantage is I don't need to turn up the volume and turn it back down when using DTS transcoding..

With AC3, I will need to keep doing this volume adjustment, when I switch to AC3 (volume UP) then back to 2 / 2.1 Audio (Volume Down) and so on etc...

madmax2 · (This post was last modified: 2016-12-22, 05:31 by madmax2.)

(2016-12-21, 11:23)FernetMenta Wrote:
(2016-12-21, 08:50)Memphiz Wrote: There is no dts encoder available in ffmpeg i guess. Might be because of licensing issues.

ffmpeg has a DTS encoder

I just contacted the developer of potplayer to ask what DTS encoder was used to transcode to DTS audio
and the developer confirm that potplayer is using FFmpeg

DJ_Izumi · 2016-12-24, 07:04

In most cases your AAC 5.1 source has already been transcoded from AC3 or DTS, both of which are already lossy formats. Then Kodi is transcoding from AAC to AC3. So this has been through THREE lossy compression passes and you're saying that sounds less compressed (I want to say 'artifacts' but does that apply to audio) in comparison to the DTS audio tracks you have that were surely directly copied from the original media, and only went through one lossy conversion from the original uncompressed master format to the DTS format for the media's retail release. ...Yeah, that's going to sound like garbage in comparison to an original DTS track. But even if Kodi could trans-code to DTS, you still have audio that's been through THREE lossy compression conversions. It's basically been through the wringer three times an you want it to sound pristine, it won't no matter how you do it.

nickr · 2016-12-24, 09:41

@DJ_Izumi - precisely. @madmax2 should probably stop ripping his DVDs to aac, and grab the DTS stream directly.

ozorfis · 2022-12-03, 09:48

Yes DTS transcoding would be awesome! For people with older AV receivers [email protected] sounds much better than AC-3 transcoding @640kbit. You can do it Nod

**ashlar**

(2022-12-03, 09:48)ozorfis Wrote: Yes DTS transcoding would be awesome! For people with older AV receivers [email protected] sounds much better than AC-3 transcoding @640kbit. You can do it

Problem is... this is all in your mind, as multiple tests have proven. Do not get offended, as placebo effect is a real thing.

Not only DTS is not superior to DD, it requires a higher bitrate to get equal quality. The myth about DTS being better stems from it having only two main bitrates available in its encoder: full bitrate (1,5360kbps) and half bitrate (768kbps).

Back in DVD times, DD tracks were typically encoded at 384kbps and DTS tracks at 768kbps. There you had probably an advantage for DTS, due to 384kbps not being enough for DD to do a great job.

Problem is, Kodi transcodes at 640kbps (as you correctly pointed out), which is pretty much as perceptually transparent as you're gonna get with a lossy codec. Better codecs simply reach that level at lower bitrates (HE-AAC for instance), DTS reaches it at an even higher bitrate (which for all intents and purposes speaks of a *less* advanced compression codec).

Sources, if you have the time and will to learn:

https://tech.ebu.ch/docs/tech/tech3324.pdf
https://tech.ebu.ch/docs/tech/tech3339.pdf

**jjd-uk** · 2022-12-14, 19:08

I'm also sure I've read somewhere that DTS tracks tend to be mastered at a higher volume level, so when people switch audio tracks for a movies with both DD5.1 & DTS 5.1 then the DTS track can seem more dynamic simply from the volumn being higher.

**ashlar** · 2022-12-15, 16:29

(2022-12-14, 19:08)jjd-uk Wrote: I'm also sure I've read somewhere that DTS tracks tend to be mastered at a higher volume level, so when people switch audio tracks for a movies with both DD5.1 & DTS 5.1 then the DTS track can seem more dynamic simply from the volumn being higher.

It would make sense, similar to the "loudness war" that plagued (and keeps plaguing) pop music from the end of the Eighties.