MKV unexpectedly transcoded

[jervine 3]

HI,

I have an NVIDIA ShieldTV (running the latest ShieldTV software: 6.2) and using version 1.5.26g of the Emby app on AndroidTV. The Emby server side is running on 3.2.60.0 (running on CentOS 7) on the same LAN all connected via ethernet cable. I have some MKV movie files that are being transcoded, such the one form the mediainfo output below:

 

Complete name : /plex-library/movies/Die Hard (1988)/Die Hard-1080p.mkv

Format : Matroska
Format version : Version 1
File size : 13.1 GiB
Duration : 2 h 12 min
Overall bit rate : 14.2 Mb/s
Encoded date : UTC 2008-05-05 11:17:30
Writing application : mkvmerge v2.2.0 ('Turn It On Again') built on Mar 4 2008 12:58:26
Writing library : libebml v0.7.7 + libmatroska v0.8.1

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, RefFrames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 2 h 12 min
Bit rate : 12.7 Mb/s
Width : 1 920 pixels
Height : 812 pixels
Display aspect ratio : 2.35:1
Frame rate mode : Constant
Frame rate : 23.976 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.339
Stream size : 11.4 GiB (87%)
Title : X264 - 2 passes
Writing library : x264 core 59 r819M 0414d78
Encoding settings : cabac=1 / ref=4 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=umh / subme=7 / me-prepass=0 / brdo=1 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=10,6 / chroma_qp_offset=0 / threads=3 / nr=0 / decimate=0 / mbaff=0 / bframes=8 / b_pyramid=1 / b_adapt=1 / b_bias=0 / direct=1 / wpredb=1 / bime=1 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=2pass / bitrate=12657 / ratetol=2.0 / rceq='blurCplx^(1-qComp)' / qcomp=1.00 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=38000 / vbv_bufsize=30000 / ip_ratio=1.40 / pb_ratio=1.30 / aq=2:1.00
Language : English
Default : Yes
Forced : No

Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Mode : 16
Format settings, Endianness : Big
Codec ID : A_DTS
Duration : 2 h 12 min
Bit rate mode : Constant
Bit rate : 1 509 kb/s
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 93.750 FPS (512 SPF)
Bit depth : 24 bits
Compression mode : Lossy
Stream size : 1.39 GiB (11%)
Title : DTS - 1536 kbit/s
Language : English
Default : Yes
Forced : No

Text #1
ID : 3
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Language : Dutch
Default : Yes
Forced : No

Text #2
ID : 4
Format : ASS
Codec ID : S_TEXT/ASS
Codec ID/Info : Advanced Sub Station Alpha
Compression mode : Lossless
Language : English
Default : No
Forced : No

 

 

whereas another MKV is reported as direct playing:

 

Unique ID : 221118760082741272196070582310006011083 (0xA659EC93D7EFE3D2923A1C34B2E5B4CB)
Complete name : /plex-library/movies/Stronger (2017)/Stronger-1080p.mkv
Format : Matroska
Format version : Version 4 / Version 2
File size : 14.2 GiB
Duration : 1 h 58 min
Overall bit rate : 17.1 Mb/s
Encoded date : UTC 2017-12-14 20:09:18
Writing application : mkvmerge v18.0.0 ('Apricity') 64-bit
Writing library : libebml v1.3.5 + libmatroska v1.4.8

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings : CABAC / 5 Ref Frames
Format settings, CABAC : Yes
Format settings, RefFrames : 5 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1 h 58 min
Bit rate : 15.6 Mb/s
Width : 1 920 pixels
Height : 804 pixels
Display aspect ratio : 2.40:1
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.421
Stream size : 12.9 GiB (91%)
Title : x264 2 passes
Writing library : x264 core 152 r2851 ba24899
Encoding settings : cabac=1 / ref=5 / deblock=1:-3:-3 / analyse=0x3:0x133 / me=umh / subme=10 / psy=1 / psy_rd=1.05:0.00 / mixed_ref=1 / me_range=64 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=0 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=9 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=0 / crf=19.5 / qcomp=0.65 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=62500 / vbv_bufsize=78125 / crf_max=0.0 / nal_hrd=none / filler=0 / ip_ratio=1.25 / pb_ratio=1.15 / aq=3:0.80 / zones=0,279,crf=18/463,1265,crf=18/4362,4402,crf=18.1/52014,52068,crf=18.4/52328,52655,crf=18.4/72609,73412,crf=18/75613,75757,crf=18/78906,82515,crf=18/104429,105003,crf=18.4/158651,158684,crf=18.4/162273,171046,crf=22
Language : English
Default : Yes
Forced : No

Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Mode : 16
Format settings, Endianness : Big
Codec ID : A_DTS
Duration : 1 h 58 min
Bit rate mode : Constant
Bit rate : 1 509 kb/s
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 93.750 FPS (512 SPF)
Bit depth : 24 bits
Compression mode : Lossy
Stream size : 1.25 GiB (9%)
Title : DTS@1510
Language : English
Default : Yes
Forced : No

Text #1
ID : 3
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Duration : 1 h 51 min
Bit rate : 70 b/s
Count of elements : 2011
Stream size : 57.9 KiB (0%)
Language : English
Default : No
Forced : No

Text #2
ID : 4
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Duration : 1 h 52 min
Bit rate : 69 b/s
Count of elements : 1879
Stream size : 56.8 KiB (0%)
Language : Spanish
Default : No
Forced : No
 

 

I understand that the MKV file is simply a container for the audio and video, however, as far as I can tell (limited knowledge on this) the audio and video in these two files should be capable of direct play (or at worst direct stream?). When playing the Die Hard MKV file, the transcode information says:

 

Reason for transcoding:

Container not supported

Video codec not supported

Audio codec not supported

 

Any pointers greatly appreciated.

[mastrmind11 722]

attach the transcode log for this instance.

[Luke 42078]

Hi @@jervine, yes please attach the ffmpeg log from this example. Thanks.

[jervine 3]

Attaching the ffmpeg trancode log file.

ffmpeg-transcode-ae379ea1-b20d-4ed3-bb77-151a64bdcb04.txt

[ebr 16178]

Based on that log I'm guessing that was due to a failure trying to direct play the item. Can you follow the instructions for sending a log from the app when you play this?

[jervine 3]

OK, will try and capture those logs from the app later today.

 

I agree that it's probably a direct play failure, as the emby dashboard does initially show 'direct play', however the display output is not showing anything at that point (the buffering circle is shown). Once video is displayed, the dashboard shows that the content is being transcoded.

[jervine 3]

@@ebr - ok I have just sent a log file from Emby on my Shield to the developer, so hopefully that should have arrived.

[Luke 42078]

Thanks, we'll see what @@ebr thinks.

[ebr 16178]

Okay, the issue is the specific type of encoding for this file which is very rare and not supported by the player.  So the app is reacting to that and transcoding it for proper playback.

[jervine 3]

@@ebr - thanks ... so I need to re-encode the file in that case (or use a player that does support the encoding).

 

Cheers.

[ebr 16178]

If you are going to re-encode the specific issue is that you will need to either eliminate lacing or use simpleBlocks.

 

It is possible that future player updates will solve this as well.