[iOS] Slow playback start - "Recovering from playback error" error

[Gecko 61]

Hello guys,

 

I discovered a strange behavior using Emby iOS app recently after changing my nginx setup and doing some tests. It seems that for some times now, playback from iOS app is always triggering a "recovering from playback error" whenever I start a stream (either locally directly from Emby server's IP, locally through proxy or remotely through proxy).

Every playback started from the iOS app takes a while to start and creates 4 transcode sessions in the logs but I cannot find why. If, going through web app, no playback error is triggered and the streaming starts immediately (with only one transcode session created in the logs).

Attached are the logs for a single playback session started from iOS. I rotated the logs just before. Can someone look for some clues as fro why this behavior occurs? I'm directly connected to Emby server for this test, so my proxy is not involved at all.

 

EDIT: Here are the differences I found in all 3 failed transcode sessions vs the successful one :

Tentative #1 :

• No DirectPlayError&allowVideoStreamCopy=false in url
• 0.ts instead of 638.ts
• ffmpeg not using -ss 00:31:54.000 (I was resuming a movie)

Tentative #2 : 

• No DirectPlayError&allowVideoStreamCopy=false in url
• Everything seems to be the same

Tentative #3 :

• 0.ts instead of 638.ts
• ffmpeg not using -ss 00:31:54.000 (I was resuming a movie)

 

It seems that the app is trying something with various parameters before falling back to the correct transcode session where DirectPlay and StreamCopy are not usable and started at the correct movie position.

I assume this is normal behaviour for a mpv app that is trying to avoid transcoding at all costs. As the quality has been manually set to a specific value, can't those checks be skipped, remembered or hasten ? I think Emby does know the movie's bitrate before starting any Session so it should know that DirectPlay and StreamCopy isn't possible in this scenario right ?

 

Many thanks for your help solving this !

Gecko

ffmpeg-transcode-51f02f5f-663a-4400-bdc2-6b297cbf05ba_1.txt ffmpeg-transcode-a1c7b4d6-3ae2-49ab-a67c-9797a23a5f67_1.txt ffmpeg-transcode-c5e88388-3dc2-4eb2-8d10-66394d8d9972_1.txt ffmpeg-transcode-c634fe9b-a555-4e06-8f70-cec086972c0b_1.txt embyserver-12.txt

Edited September 23, 2022 by nSGecko
Comparing all transcoding files

[Luke 37022]

Hi, have you compared your nginx setup to this:

 

[Gecko 61]

Hi @Luke,

Like i said, i’m directly connected to emby server, but i noticed the issue because i change my proxy.

 

and yes i followed the recommended nginx config topic

[Luke 37022]

How does your setup compare to that one?

[Gecko 61]

I copied the nginx config from the forum but activated buffering because i had subtitles out of sync.

web app through proxy is working like a charm but iOS app is triggering 4 transcode sessions instead of one as explained above

 

[Gecko 61]

Ok so after some more trials, the issue is not linked to the iOS app because I get the same error on the web app when I playback a mkv file from various browser and when the quality setting is set to a bitrate higher than the mkv's bitrate :

Stream
MKV (1 mbps)
 -> HLS (3 mbps 365 fps)
Converting to compatible container
Recovering from playback error
Video
1080p HEVC
Main 120 1 mbps 23.976 fps
 -> Transcode (H264 3 mbps)
Dropped Frames 0
Corrupted Frames 0
Audio
English AC3 stereo
192 kbps 48000 Hz

 

When asking for a bitrate lower than the file's bitrate, the transcode kicks in and no error to report :

Stream
MKV (1 mbps)
  -> HLS (1,000 kbps 1029 fps)
Reducing bitrate due to quality setting
Video
1080p HEVC
Main 120 1 mbps 23.976 fps
  -> Transcode (H264 808 kbps)
Dropped Frames 0
Corrupted Frames 0
Audio
English AC3 stereo
192 kbps 48000 Hz
 

 

@softworkz maybe you have an idea what's happening here ?

EDIT: ok, i figure it out : When the source media is HEVC and no subtitles needs to be burned in and no quality reduction is needed, then the "Recovering from playback error" occurs. Files encoded in h264 or even and old MPEG2 is playing fine. Question is: why is there an error with HEVC?

Edited September 28, 2022 by nSGecko

[Bagul 146]

Hey! I also have the error since version 2.2.5 on iOS. I have the error on the beta version and on the stable version of the server whether locally or through my reverse proxy.

On the other hand, I also have the error on a media in h264 and HEVC but I have the impression I don't have the error when the audio is in stereo.

[Gecko 61]

16 hours ago, Bagul said:

Hey! I also have the error since version 2.2.5 on iOS. I have the error on the beta version and on the stable version of the server whether locally or through my reverse proxy.

On the other hand, I also have the error on a media in h264 and HEVC but I have the impression I don't have the error when the audio is in stereo.

Hi @Bagul,

When the error occurs, did the auto-start works or do you see the play/pause button in the middle of the screen switch back and forth and just wait that you click on it to start playback ?
I was wondering for months why some videos auto started and some others not, but now I wonder if this is not because of this error. I disabled the option "Allow changing of container formats, if necessary, during media playback" and noticed improvements for that issue. I still get the error but the video autostart every time now.

Edited September 30, 2022 by nSGecko
tagging bagul

[Bagul 146]

8 hours ago, nSGecko said:

Hi @Bagul,

When the error occurs, did the auto-start works or do you see the play/pause button in the middle of the screen switch back and forth and just wait that you click on it to start playback ?
I was wondering for months why some videos auto started and some others not, but now I wonder if this is not because of this error. I disabled the option "Allow changing of container formats, if necessary, during media playback" and noticed improvements for that issue. I still get the error but the video autostart every time now.

I can't tell you. I have noticed this with my users. I don't watch video with my iPhone.

[Luke 37022]

Are you able to test it on your phone to try and reproduce?

[Gecko 61]

10 hours ago, Luke said:

Are you able to test it on your phone to try and reproduce?

Yes, but like I said, the issue is not tied to iOS. I also have it under web app on multiple browser.

Logs and dashboard info attached. "Recovering from playback error" does not appears immediately if that helps.

ffmpeg-transcode-4fa05bd3-a2ae-4416-a10a-031776178e71_1.txt ffmpeg-transcode-e58d4b7a-ca28-4394-9622-801a38110d4d_1.txt embyserver-14.txt

Edited October 12, 2022 by nSGecko

[Chiefmas 26]

On 9/28/2022 at 5:38 AM, nSGecko said:

Question is: why is there an error with HEVC?

I just searched to see what the deal was with this error. I don't think it's HEVC related, I have a user playing back right this moment on an iPhone, H.264, with AC3 audio, and it says it's direct playing both streams. The only conversion happening is to HLS, so maybe something in that? HLS remuxing seems to be the commonality between all of us.

 

[Luke 37022]

Are you still having an issue with this?

[hnorgaar 1]

I am with the latest 3 betas on Nvidia Shield

Edited November 4, 2022 by hnorgaar

[Gecko 61]

On 10/27/2022 at 9:25 PM, Luke said:

Are you still having an issue with this?

@Luke Yes, just tell me when you have time to look at it and I can provide you anything you need.

[Luke 37022]

Hi.  Can you try sideloading our standard android app on the same device and see how that compares?

https://emby.media/emby-for-android.html

Thanks.

 

[hnorgaar 1]

Tried but it is 32 bit and wont work on Nvidia Shield @FrostByte

[FrostByte 5044]

28 minutes ago, hnorgaar said:

Tried but it is 32 bit and wont work on Nvidia Shield @FrostByte

Use the 64bit file if you have anything other than the tube.  You will have to go directly to GitHub to get it.  I've been using it for months on mine.

Emby.Releases/android at master · MediaBrowser/Emby.Releases (github.com)

the file you're look for is 

emby-android-google-arm64-v8a-release.apk

Edited November 6, 2022 by FrostByte

[Bagul 146]

The initial thread is for iOS devices not android. 

[Gecko 61]

+web app as i said earlier  i can reproduce directly connected to emby on safari depending on the source format.

[Luke 37022]

This sounds to me like reverse proxy configuration. Have you taken a look at this?

 

[Bagul 146]

21 minutes ago, Luke said:

This sounds to me like reverse proxy configuration. Have you taken a look at this?

 

I have the problem locally and @nSGecko mentioned it in his first post "either locally directly from the Emby server IP, locally via a proxy or remotely via a proxy"

[Chiefmas 26]

On 10/27/2022 at 3:25 PM, Luke said:

Are you still having an issue with this?

My people on iPhones(where I was seeing the issue) haven't been on recently, so I can't report on if I'm still seeing the issue or not myself. I'm still watching for it though.

Thanks!

 

[Gecko 61]

Tested right now on my iphone directly connected to emby. Latest version of everything. The error message is still there as reported here:

 

How can I sideload an android app on an iPhone ? I never had this error on my shield for example (at least, never saw it)

[pir8radio 1292]

On 11/7/2022 at 12:34 AM, nSGecko said:

Tested right now on my iphone directly connected to emby. Latest version of everything. The error message is still there as reported here:

 

How can I sideload an android app on an iPhone ? I never had this error on my shield for example (at least, never saw it)

you can't ios and android totally different.