File doesn't play in web app (transcoding)

[Mike_S 0]

Hi, I have a file which plays OK in Emby for Android app on my smartphone (direct play), but not in the web app (Chrome 140.0.7339.80 (Official Build) (64-bit)).

When I click the Play button, the screen goes to the player (OSD or how it's called), it hangs a few seconds without starting the playback, then exits back to the details screen without any message.

The file is MKV container with only 2 tracks - AV1 video and AC3 audio - I know AC3 is not supported by browsers, so a transcoding was expected, but it doesn't happen. First I thought it might be this issue, but, again, the transcoding doesn't happen.

Emby version: emby-server-qnap_4.8.11.0_x86_64.qpkg

Attaching all log files created during the test, and the mediainfo of the test file.

 

ffmpeg-remux-a1ad7f91-7ca0-497e-9340-e3d3c28e1989_1.txt ffmpeg-transcode-7cee23b9-3623-4a91-a7e9-095fdd8fb3e6_1.txt ffmpeg-transcode-20836340-11a3-4cb1-a226-65ab6e60dc37_1.txt embyserver.txt mediainfo.txt

[Luke 42077]

HI, in this example it is happening. It is converting the audio. First it tries by copying the video directly. The player then has trouble with that, so it switches to a full video transcode, and for this, I think your NAS just can't transcode it quickly enough.

Can you provide a sample video for testing? Thanks.

[Mike_S 0]

6 hours ago, Luke said:

Can you provide a sample video for testing? Thanks.

Sure, here I've cut the short sample - https://drive.google.com/file/d/1VkWG_Z6PSjlWu6OQv32KW_DYaHQwq_rJ/view?usp=drive_link

[Luke 42077]

Did you verify that the cut version exhibits the same problem?

[Mike_S 0]

Yes, I verified. The same problem with the cut version.

[Luke 42077]

HI, the good news is I'm able to play, although granted I tested on the 4.9 beta channel. I also tested on windows though, but barring some platform-specific problem, it looks like you'll have a better experience with this with the upcoming 4.9 release. Thanks.

[Mike_S 0]

Hi Luke, thanks for testing it on your side.

I also did some testing - I installed Emby 4.9.1.26 beta (docker image) on the same Qnap NAS, and, unfortunately result seems to be the same, except this time there a "loading" circle is showing between I click "Play" and it exits to the details screen.

I'm attaching logs from this test if you want to check them. I tested with the sample video file that I shared earlier.

I ran a container with the following command:

docker run -d --name embyserver --volume /tmp/emby_test_programdata:/config --volume /share/CACHEDEV1_DATA/Multimedia/test:/mnt/share1 --publish 18096:8096 emby/embyserver:beta

I also tested other files, just to check that I didn't mess with the installation, and they played fine, either directly or with audio transcoding.

So it seems like the video transcoding can't be handled by my Qnap. And I wonder why it was unable to play with just a copy of the video track (without transcoding). Is there any way to find that out?

ffmpeg-remux-fe0ed890-fe1c-4cd9-8ff8-8ede24bdd175_1.txt ffmpeg-transcode-ebc78746-2dd2-4b7a-9b78-0fee244fb8f9_1.txt ffmpeg-transcode-90bd8bf4-60a9-405b-add6-8accef3e0d91_1.txt embyserver.txt

[Mike_S 0]

I've attempted to read and understand the logs. And I saw this:

Quote

[mpegts @ 0x2567d40] Stream 0, codec av1, is muxed as a private data stream and may not be recognized upon reading.

Then I also saw that the ffmpeg version used is 5.1 (in both stable and beta Emby versions).

Is this the reason that av1 track copy can't be directly played?

[pwhodges 2012]

Emby's ffmpeg is a custom build, based on 5.1 but incorporating much from later versions.  They are also flagging a replacement based on the current version to appear soon in the current beta.

Paul

[Luke 42077]

7 hours ago, Mike_S said:

 

Then I also saw that the ffmpeg version used is 5.1 (in both stable and beta Emby versions).

 

Not exactly. That's just the number, but it incorporates a lot of things from newer versions of ffmpeg.

[Luke 42077]

7 hours ago, Mike_S said:

 

Is this the reason that av1 track copy can't be directly played?

It normally can. It looks like in this case it tried, but the browser video player had trouble with it, that's why it switched to transcoding.