Can't fast forward or rewind MKV files on Fire TV Stick

[Gigabit]

When trying to fast forward or rewind certain MKV files, the playback always restarts.

This only happens on Jellyfin on my Fire TV Stick, when the files direct play. I have no issue direct playing them on any other device.

What is going on here?

Code:

General
Complete name                            : Snackmasters.S02E02.Dominos.1080p.HDTV.H264-DARKFLiX.mkv
Format                                  : Matroska
Format version                          : Version 4
File size                                : 1.56 GiB
Duration                                : 47 min 0 s
Overall bit rate                        : 4 758 kb/s
Frame rate                              : 25.000 FPS
Writing application                      : no_variable_data
Writing library                          : no_variable_data

Video
ID                                      : 1
Format                                  : AVC
Format/Info                              : Advanced Video Codec
Format profile                          : High@L4
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                  : Yes
Format settings, Reference frames        : 4 frames
Codec ID                                : V_MPEG4/ISO/AVC
Duration                                : 47 min 0 s
Width                                    : 1 920 pixels
Height                                  : 1 080 pixels
Display aspect ratio                    : 16:9
Active Format Description                : Letterbox 16:9 image, with alternative 14:9 center
Frame rate mode                          : Constant
Frame rate                              : 25.000 FPS
Standard                                : Component
Color space                              : YUV
Chroma subsampling                      : 4:2:0 (Type 0)
Bit depth                                : 8 bits
Scan type                                : Progressive
Language                                : English
Default                                  : Yes
Forced                                  : No
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                : BT.709
Matrix coefficients                      : BT.709

Audio
ID                                      : 2
Format                                  : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                : 2 / A_AAC-2
Duration                                : 47 min 0 s
Channel(s)                              : 2 channels
Channel layout                          : L R
Sampling rate                            : 48.0 kHz
Frame rate                              : 46.875 FPS (1024 SPF)
Compression mode                        : Lossy
Language                                : English
Default                                  : Yes
Forced                                  : No

Text
ID                                      : 3
Format                                  : UTF-8
Codec ID                                : S_TEXT/UTF8
Codec ID/Info                            : UTF-8 Plain Text
Language                                : English
Default                                  : No
Forced                                  : No

Menu
00:00:00.000                            : en:PART_01
00:09:20.000                            : en:PART_02
00:22:29.000                            : en:PART_03
00:34:31.000                            : en:PART_04

It feels like a bug with the Fire TV Stick app.

[TheDreadPirate]

Are you certain the problem files are also direct playing on other devices? What you are describing usually indicates that there is something wrong with the MKV container. Though the video and audio are usually fine.

What you can try is remuxing the file to repair any issues with the MKV container.

Code:

/usr/lib/jellyfin-ffmpeg/ffmpeg -fflags +genpts+igndts -i "/path/to/problem/video.mkv" -map 0 -codec copy -max_muxing_queue_size 2048 -max_interleave_delta 0 -avoid_negative_ts disabled newFile.mkv

If you are running Windows I can provide a Windows version. If you are using docker, you can open a bash shell into the container to run that command.

[Gigabit]

Are you certain the problem files are also direct playing on other devices?  What you are describing usually indicates that there is something wrong with the MKV container.  Though the video and audio are usually fine.

What you can try is remuxing the file to repair any issues with the MKV container.

Code:

/usr/lib/jellyfin-ffmpeg/ffmpeg -fflags +genpts+igndts -i "/path/to/problem/video.mkv" -map 0 -codec copy -max_muxing_queue_size 2048 -max_interleave_delta 0 -avoid_negative_ts disabled newFile.mkv

If you are running Windows I can provide a Windows version.  If you are using docker, you can open a bash shell into the container to run that command.

This is what it says when playing the same file on Edge.



I get that you think the container is broken but that doesn't explain why every media player, device etc has worked except for the Fire TV Stick? It even plays fine on Just Player, VLC, Kodi on the same device.

I do think this is a Jellyfin bug, what information can I provide so you can fix it?

[TheDreadPirate]

"The video plays in <insert robust player>" is not a good measure for whether a file is broken or not. VLC and MPV in particular will move heaven and earth to try to play corrupt files. Exoplayer, the playback engine built into Android/Fire OS, expects compliant and properly formatted video files.

Give my remux command a try. It does not involve re-encoding and should process as quickly as your hard drive can read and write.

[Gigabit]

"The video plays in <insert robust player>" is not a good measure for whether a file is broken or not.  VLC and MPV in particular will move heaven and earth to try to play corrupt files.  Exoplayer, the playback engine built into Android/Fire OS, expects compliant and properly formatted video files.

Give my remux command a try.  It does not involve re-encoding and should process as quickly as your hard drive can read and write.

But why does it work in the Jellyfin web client?

[TheDreadPirate]

Different player, different behaviors, different tolerance for corrupt files.