AVC+FLAC codec got ignored during metadata scan

[DPaO Chow]

recently i download a season of anime with MKV container, mediainfo are as follow:

Code:

Overview
UniqueID/String                  : 215693623813995480229869315981286706493 (0xA24514B5512319489CA47696E99E0D3D)
CompleteName                    : \\....\xxx.mkv
Format/String                    : Matroska
Format_Version                  : Version 4
FileSize/String                  : 1.14 GiB
Duration/String                  : 23 m 43 s
OverallBitRate_Mode/String      : VBR
OverallBitRate/String            : 6 910 kb/s
FrameRate/String                : 23.976 FPS
Encoded_Date                    : 2016-03-14 13:30:31 UTC
Encoded_Application/String      : mkvmerge v8.3.0 ('Over the Horizon') 64bit
Encoded_Library/String          : libebml v1.3.1 + libmatroska v1.4.2

Video
ID/String                        : 1
Format/String                    : AVC
Format/Info                      : Advanced Video Codec
Format_Profile                  : High 10@L5.1
Format_Settings                  : CABAC / 10 Ref Frames
Format_Settings_CABAC/String    : Yes
Format_Settings_RefFrames/String : 10 frames
CodecID                          : V_MPEG4/ISO/AVC
Duration/String                  : 23 m 42 s
BitRate/String                  : 6 174 kb/s
Width/String                    : 1 920 
Height/String                    : 1 080 
DisplayAspectRatio/String        : 16:9
FrameRate_Mode/String            : CFR
FrameRate/String                : 23.976 (24000/1001) FPS
ColorSpace                      : YUV
ChromaSubsampling/String        : 4:2:0
BitDepth/String                  : 10 位
ScanType/String                  : Progressive
Bits-(Pixel*Frame)              : 0.124
StreamSize/String                : 1.02 GiB (89%)
Encoded_Library/String          : x264 core 148 r2665kMod a01e339
Encoded_Library_Settings        : cabac=1 / ref=10 / deblock=1:-1:-1 / analyse=0x3:0x133 / me=umh / subme=10 / psy=1 / fade_compensate=0.00 / psy_rd=0.60:0.15 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-3 / threads=16 / lookahead_threads=4 / sliced_threads=0 / nr=0 / decimate=0 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / fgo=0 / bframes=10 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=720 / keyint_min=1 / scenecut=40 / intra_refresh=0 / rc_lookahead=72 / rc=crf / mbtree=1 / crf=16.5000 / qcomp=0.80 / qpmin=0 / qpmax=81 / qpstep=4 / vbv_maxrate=28000 / vbv_bufsize=30000 / crf_max=0.0 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=3:0.80
Language/String                  : English
Default/String                  : Yes
Forced/String                    : No
colour_range                    : Limited
matrix_coefficients              : BT.709

Audio
ID/String                        : 2
Format/String                    : FLAC
Format/Info                      : Free Lossless Audio Codec
CodecID                          : A_FLAC
Duration/String                  : 23 m 43 s
BitRate_Mode/String              : VBR
BitRate/String                  : 735 kb/s
Channel(s)/String                : 2 ch
ChannelLayout                    : L R
SamplingRate/String              : 48.0 kHz
FrameRate/String                : 11.719 FPS (4096 SPF)
BitDepth/String                  : 16 b
Compression_Mode/String          : Lossless
StreamSize/String                : 125 MiB (11%)
Encoded_Library/String          : libFLAC 1.3.1 (2014-11-25)
Language/String                  : Japanese
Default/String                  : Yes
Forced/String                    : No
MD5 of the unencoded content    : AE59E15C214B3FBB527484F0AC2E89F5

Menu
00:00:00.000                    : en:Avant
00:02:57.177                    : en:Opening
00:04:27.267                    : en:A Part
00:13:43.823                    : en:B Part
00:21:56.315                    : en:Ending
00:23:26.405                    : en:Yokoku

But all of this got ignored while library scanning, with the log output:

Code:

Unsupported codec with id 98310 for input stream 30
Unsupported codec with id 98310 for input stream 31
Unsupported codec with id 98310 for input stream 32
Unsupported codec with id 98310 for input stream 33
Unsupported codec with id 98304 for input stream 34
[02:10:33] [ERR] [66] MediaBrowser.MediaEncoding.Encoder.MediaEncoder: Codec Type attachment unknown. The stream (index: 6) will be ignored. Warning: Subsequential streams will have a wrong stream specifier!
[02:10:33] [ERR] [66] MediaBrowser.MediaEncoding.Encoder.MediaEncoder: Codec Type attachment unknown. The stream (index: 7) will be ignored. Warning: Subsequential streams will have a wrong stream specifier!
[02:10:33] [ERR] [66] MediaBrowser.MediaEncoding.Encoder.MediaEncoder: Codec Type attachment unknown. The stream (index: 8)will be ignored. Warning: Subsequential streams will have a wrong stream specifier!
[02:10:33] [ERR] [66] MediaBrowser.MediaEncoding.Encoder.MediaEncoder: Codec Type attachment unknown. The stream (index: 9) will be ignored. Warning: Subsequential streams will have a wrong stream specifier!
[02:10:33] [ERR] [66] MediaBrowser.MediaEncoding.Encoder.MediaEncoder: Codec Type attachment unknown. The stream (index: 10) will be ignored. Warning: Subsequential streams will have a wrong stream specifier!
[02:10:33] [ERR] [66] MediaBrowser.MediaEncoding.Encoder.MediaEncoder: Codec Type attachment unknown. The stream (index: 11) will be ignored. Warning: Subsequential streams will have a wrong stream specifier!

Usually only Track like subtitles got ignored. The MKV i downloaded only contains 1 video and 1 audio stream, they are common AVC and FLAC, any reason why Jellyfin cannot recognize?

What should i do next? use some tool (e.g. mp4box) to repack them as mp4?

[TheDreadPirate]

It depends on what track number they are? The default ffprobe size is pretty limited so if they are not tracks 0 and 1 they may not get probed? I've never seen a file where the video track is not track 0.