[FoxForceFive]

Hello Kodi community,

I own a Fire Stick 4k fo a few days days now which is connected to a Samsung Smart TV ue58mu6122 (4k capable etc). 
I am currently using the latest stable version of Kodi 17.6 and the latest Firestick 4k firmware.
 
Having set the kodi to a 4k resolution and 60hz, I tried playing 4K movies around 70GB with auto switching refresh rate.
Movies are shared from a network share with Gigabit ethernet. When I tried to play these movies, the refresh rate changed accordingly but the video
was unwatchable, choppy and a lot of frames were skipped. The same thing happened with 1080p rips around 12GB. Firestick is capable at least to handle easily these rips.

Having set Kodi to use a 1080p resolution, I did the same tests and noticed that, videos were less choppy. It was better but still annoying.

I changed back the resolution to 4k and started to play with the settings of my TV. To my surprise, I found out that if I change HDMI sound input from PCM to Bitstream and then back to PCM again, while a choppy video is playing (frame rate is changed correctly), the movie is then played without errors and no skipped frames at the right frame rate.
I don't know if this is a coincidence.

Has anybody experienced something like that or similar while playing with sound options?

To my understanding, having read a lot in this forum, the best way to watch 24hz movies on Firestick 4k is to disable auto frame switching and configure kodi to sync video to TV's refresh rate?

 Are you using a gigabit ethernet adapter with the firestick?  

 Yes, I mentioned it, in the beginning of this post...
The problem exists even with 1080p movies. 

Was just clarifying as you mentioned gigabit but could have meant using into the official ethernet adapter which is only 100Mbs.

It sounds like you're having a similar issue regards frame rate switching & audio playback not working properly, which I've mentioned in my last couple of posts, only mine is playing fine when I toggle audio passthrough, not toggling PCM.

I suspect it's part of the same bug.

[LukeHansford]

I use just my TV speakers so should I whitelist all resolutions including 1080p ones and it works smoothly even for 23.9 files on RC5?.

I currently am using RC4. Is there much difference in RC5?

I don't have anything whitelisted.

What seems to have helped is setting display settings to RGB and 10 bits in firestick settings.

[FoxForceFive]

Anyone know where/if I should be reporting this audio passthrough issue so it can at least go on a bug fix list to be looked into?

[FoxForceFive]

I use just my TV speakers so should I whitelist all resolutions including 1080p ones and it works smoothly even for 23.9 files on RC5?.

I currently am using RC4. Is there much difference in RC5?

I don't have anything whitelisted.

What seems to have helped is setting display settings to RGB and 10 bits in firestick settings.

 If you're just using your TV speakers then the obvious answer would be to leave the refresh rate alone completely & just have sync playback to display enabled as it will resample the audio, should play all content smoothly that way.

[goldsac]

This confirms that the button names of <rewind> and <fastforward> are indeed correct, so it seems that something else is blocking their re-assignment during fullscreenvideo mode. This also causes my optimism to wain, as I can't really think of anything else to try unless anyone else has further perspective on the matter. It's not the biggest deal, as it's pretty quick to activate the OSD and modify the subtitle and audio settings manually when needed - but I'm a tenacious little monkey, and wouldn't mind knowing the answer to this for its own sake (as well, of course,  as having 100% of the settings I want).

You may already know this, but next audio/subtitle is by default mapped to longpress-up/down.

I don't know why it's not possible to remap fastforward/reverse. I tried it myself (using the keymap editor), and couldn't get it to work.

Edit: there's a bug ticket for this here: https://trac.kodi.tv/ticket/17979

Apparently it's intentional. :-( 

Oh cool - I didn't know about those default longpress assignments. Is there a source for those, or did you just happen to discover them on your own? 

And thanks for the bug ticket, as that's the kind of definitive information I was hoping to get. Looks like it's going to be a difficult one to overcome, so I'll just have to go forward without those customizations.

[Luke M]

Oh cool - I didn't know about those default longpress assignments. Is there a source for those, or did you just happen to discover them on your own? 

I found them while perusing this:
https://raw.githubusercontent.com/xbmc/x...yboard.xml

[LukeHansford]

Won't it speed up the content to 59.9 fps?

I thought it's best to play content at the native refresh rate.

I need to leave switching on because I need 1080p to display at 1080p and switch the TV to 1080p so it upscales to 4K by the TV doing the upscaling I believe then switch the TV to 4K mode when I play a 4k file.

I have the Kodi settings resolution set to 1080p 59.9hz and the firestick settings at auto 4k 10 bits RGB

[FoxForceFive]

Won't it speed up the content to 59.9 fps?

I thought it's best to play content at the native refresh rate.

I need to leave switching on because I need 1080p to display at 1080p and switch the TV to 1080p so it upscales to 4K by the TV doing the upscaling I believe then switch the TV to 4K mode when I play a 4k file.

I have the Kodi settings resolution set to 1080p 59.9hz and the firestick settings at auto 4k 10 bits RGB

It is always best to play content at the native rate, you're correct, the reason I suggested not doing is you'd said that you couldn't play 23.9 without judder, so that would be the easiest solution as you don't need audio passthrough.

Regards your firestick settings, I believe YCbCr formats are the better choice for 4K sets, but I'm not 100% sure on that, some others will know better, it may well depend on your set. Similarly with the 10 bit setting, my tv does 8bit +2 instead of real 10 bit, so I have it set to 8 bit, using the logic that 8 to 8+2 makes more sense as there's less processing involved. Again I may not be correct on that though, someone else more knowledgable may correct me on these matters.

[DaMacFunkin]

Consumer a/v electronics traditionally output ycbcr, the 8 bits +2 question depends on on how your devices handle this, do they throw the extra 2 bits away of do they properly dither them? It may be that 10 bit to the TV is better.

[FoxForceFive]

Latest nightly still has audio pass through issues for me, mostly on 1080p content when frame rate change is enabled & the file has 5.1 surround.

[sgorveatt]

That's disappointing. Do you think the Kodi developers can fix the issues mentioned on here with this stick, or do we have to wait for Amazon to fix their firmware?

[FoxForceFive]

That's disappointing. Do you think the Kodi developers can fix the issues mentioned on here with this stick, or do we have to wait for Amazon to fix their firmware?

 I haven't a clue, I'd guess it's a Kodi issue, but I honestly have no idea.

I really hope it'll be fixed sooner rather than later, cos frame rate changing & audio passthrough are deal breakers for me.

EDIT:

Just realised, this must be a Kodi issue, because if I toggle Audio Passthrough on then off from the video OSD, it plays the file correctly. Hopefully that means it's something they can fix without too much hassle.

I really need to do a debug log & get it added to the bug page, but finding the time is a little tricky currently.

[FoxForceFive]

Ok, tried again, & following a reboot of the firestick (completely removed power) I can't replicate the audio passthrough issue even once.

Great news!

Found one issue, in that one of my files which 4K is playing in 1080p, I've tried 6 files & this the only one that does it, don't have much 4K content to test though, so will get some more & see if I can replicate it & try to narrow down if there's an issue with certain filetypes, etc.

[FoxForceFive]

Ok, it was mentioned earlier in the thread that the firestick was displaying 4k files in 1080p resolution, & TBH, it was driving me mad.

Set out to reproduce it, & I've tracked the culprit down after reading the logs.

In Settings>Display, Set GUI resolution limit is affecting video playback (despite it clearly saying that it doesn't affect video playback).

If you set this to Unlimited, your 4k files will play perfectly at the correct frame rate. The downside is all files will play at 4k resolution, but they'll be in the correct frame rate (basically the firestick will be doing the upscaling for you).

If set to Auto, your 4k files will only play at 1080p at the correct frame rate. The upside is all files will play at their correct native resolution & frame rate.

For me setting it to Unlimited is a decent workaround for the time being, the upscaling isn't far off what my set does itself.

I've created two bug logs, one with unlimited set & one with auto, & will submit it to the bug tracker later this evening or this weekend (when I get the time).

I hope this helps some of you, it's certainly good for those of us who need frame rate switching & want to watch 4k at the correct resolution.

[Hitcher]

Thanks for taking the time to track the problem down. Please file an issue at GitHub.