Some MKV files stuck on orange buffering circle

Greetings,
Both Synology and Plex noob here.
I am slowly moving my collection to Plex, and there are some MKVs that get stuck as soon as they start on the orange spinning circle. Doing some research I realized the MKV is a container and it seems some media may not be transcoded… But, this is a kinda outside my tech knowledge. Would anyone care to point me to the right direction on how I can fix them?

I am attaching the logs from the media XML…

Mitsaoua

Server Version#: 1.20.3.3437
Player Version#: 4.34.4
Greetings,
Both Synology and Plex noob here.
I am slowly moving my collection to Plex, and there are some MKVs that get stuck as soon as they start on the orange spinning circle. Doing some research I realized the MKV is a container and it seems some media may not be transcoded… But, this is a kinda outside my tech knowledge. Would anyone care to point me to the right direction on how I can fix them?

I am attaching the logs from the media XML…

Mitsaoua

Server Version#: 1.20.3.3437
Player Version#: 4.34.4

<MediaContainer size="1" allowSync="1" identifier="com.plexapp.plugins.library" librarySectionID="19" librarySectionTitle="Brakhage" librarySectionUUID="58b90f3b-cda9-4b91-a3e7-035b3553fe5e" mediaTagPrefix="/system/bundle/media/flags/" mediaTagVersion="1602676305">
<Video ratingKey="4509" key="/library/metadata/4509" guid="plex://movie/5e16337afef2d4003e896224" type="movie" title="Brakhage Splices Boultenhouse" librarySectionTitle="Brakhage" librarySectionID="19" librarySectionKey="/library/sections/19" summary="Casual, intimate look at Brakhage exploring footage left behind by his friend, the filmmaker Charles Boultenhouse, who had previously passed away" year="1997" thumb="/library/metadata/4509/thumb/1602813375" art="/library/metadata/4509/art/1602813375" duration="6847166" originallyAvailableAt="1997-06-01" addedAt="1601521835" updatedAt="1602813375" chapterSource="media">
<Media id="9227" duration="6847166" bitrate="4573" width="720" height="480" aspectRatio="1.33" audioChannels="2" audioCodec="pcm" videoCodec="mpeg2video" videoResolution="480" container="mkv" videoFrameRate="NTSC" audioProfile="pcm_s16le" videoProfile="main">
<Part accessible="1" exists="1" id="9504" key="/library/parts/9504/1601521835/file.mkv" duration="6847166" file="/volume1/Film/Brakhage/Brakhage Splices Boultenhouse/brakhage-splices-boultenhouse.mkv" size="3919787135" audioProfile="pcm_s16le" container="mkv" deepAnalysisVersion="4" requiredBandwidths="5698,5102,4703,4703,4703,4703,4703,4703" videoProfile="main">
<Stream id="20927" streamType="1" codec="mpeg2video" index="0" bitrate="3037" language="English" languageCode="eng" anamorphic="1" bitDepth="8" chromaLocation="left" chromaSubsampling="4:2:0" codedHeight="480" codedWidth="720" colorPrimaries="smpte170m" colorRange="tv" colorSpace="smpte170m" colorTrc="smpte170m" frameRate="29.970" height="480" level="8" pixelAspectRatio="8:9" profile="main" refFrames="1" requiredBandwidths="4162,3566,3312,3312,3312,3312,3312,3312" scanType="interlaced" width="720" displayTitle="480i (MPEG2VIDEO)" extendedDisplayTitle="480i (MPEG2VIDEO)"/>
<Stream id="20928" streamType="2" selected="1" default="1" codec="pcm" index="1" channels="2" bitrate="1536" language="English" languageCode="eng" profile="pcm_s16le" requiredBandwidths="1536,1536,1536,1536,1536,1536,1536,1536" samplingRate="48000" title="Stereo" displayTitle="English (PCM Stereo)" extendedDisplayTitle="Stereo (English PCM)"/>
</Part>
</Media>
<Guid id="tmdb://637749"/>
<Chapter id="23028" filter="thumb=23028" index="1" startTimeOffset="0" endTimeOffset="592491" thumb="/library/media/9227/chapterImages/1"/>
<Chapter id="23028" filter="thumb=23028" index="2" startTimeOffset="592491" endTimeOffset="3321618" thumb="/library/media/9227/chapterImages/2"/>
<Chapter id="23028" filter="thumb=23028" index="3" startTimeOffset="3321618" endTimeOffset="6847140" thumb="/library/media/9227/chapterImages/3"/>
<Preferences>
<Setting id="languageOverride" label="Metadata language" summary="Language to use for item metadata such as synopsis and title." type="text" default="" value="" hidden="0" advanced="0" group="" enumValues=":Library default|ar-SA:العربية|ca-ES:Català|cs-CZ:Česky|da-DK:Dansk|de-DE:Deutsch|el-GR:Ελληνικά|en-AU:English (Australia)|en-CA:English (Canada)|en-GB:English (United Kingdom)|en-US:English (United States)|es-ES:Español|es-MX:Español Mexicano|et-EE:Eesti Keele|fa-IR:فارسی|fi-FI:Suomi|fr-CA:Français Canadien|fr-FR:Français|he-IL:עברית|hi-IN:हिन्दी, हिंदी|hu-HU:Magyar|id-ID:Bahasa Indonesia|it-IT:Italiano|ja-JP:日本語|ko-KR:한국어|lt-LT:Lietuvių kalba|lv-LV:Latviešu valoda|nb-NO:Norsk bokmål|nl-NL:Nederlands|pl-PL:Polski|pt-BR:Português Brasileiro|pt-PT:Português|ro-RO:Română|ru-RU:русский язык|sk-SK:Slovenčina|sv-SE:Svenska|th-TH:ไทย|tr-TR:Türkçe|uk-UA:українська|vi-VN:Tiếng Việt|zh-CN:中文|zh-HK:香港|zh-TW:正體中文"/>
<Setting id="useOriginalTitle" label="Use original title" summary="Use the original title for this item regardless of the library language." type="int" default="-1" value="-1" hidden="0" advanced="0" group="" enumValues="-1:Library default|0:No|1:Yes"/>
</Preferences>
<Extras size="0"> </Extras>
<Related> </Related>
</Video>
</MediaContainer>

Mod-Edit: added some code tags to show the xml info

When you try playing this video… what information is showing in the “now playing” tile for that playback on the Plex server dashboard?
Exemplary screenshot from the "now playing" section

Hi Tom - thanks for the reply.
This is what it looks like:
image

Please click the icon highlighted below to expand the information showing on your dashboard tile
example screenshot on how to expand the now-playing tile on a dashboard

Aha! Thank you for that hint…

image

Thanks – with which Synology model are you experiencing this?

DS420+

image

I understood from another post that there’s an issue with the hardware accelerated transcoding on the Celeron J4025 which is used with the 2020 models of Synology. The thread linked below contains a link on how to work around this until Intel will fix this driver issue). Maybe it’s worth a shot.

Alternatively you could disable the hw transcoding to see if the CPU alone can deal with those videos.

Thank you so much!!!
The Tip at Synology FAQ - Questions, Answers, and a few How-To's did it!