Codec Tables

The goal is to Direct Play all media. This means the container, video, audio and subtitles are all compatible with the client. If the media is incompatible for any reason, Jellyfin will use FFmpeg to convert the media to a format that the client can process. Direct Stream will occur if the audio, container or subtitles happen to not be supported. If the video codec is unsupported, this will result in video transcoding. Subtitles can be tricky because they can cause Direct Stream (subtitles are remuxed) or video transcoding (burning in subtitles) to occur. This is the most intensive CPU component of transcoding. Decoding is less intensive than encoding.

Sorted by efficency (excluding bit depth)	Chrome	Firefox	Safari	Android	AndroidTV	Roku	Kodi	Desktop
MPEG-4 Part 2/SP	❌	❌	❌	❌	❌	✅	✅	✅
MPEG-4 Part 2/ASP	❌	❌	❌	❌	❌		✅	✅
H.264 8Bit	✅	✅	✅	✅	✅	✅	✅	✅
H.264 10Bit	✅	❌	❌	✅	✅	❌	✅	✅
H.265 8Bit	❌	❌	❌¹	🔶²	✅⁵	✅	✅	✅
H.265 10Bit	❌	❌	❌¹	🔶²	🔶⁵	✅	✅	✅
VP9	✅	✅	❌	✅³	🔶³	✅	✅	✅
AV1⁴	🔶	🔶	❌			❌

¹HEVC support is potentially available by offloading to the operating system, but this has not been tested.

²Android playback is currently broken. Client reports that HEVC is supported and attempts to Direct Stream.

³May be (partially) dependent on Hardware support (can be compensated with CPU decoding on Android). Most new Android phones in the higher price range and many "4K" AndroidTV devices have VP9 hardware decoding support. Refer to you manufacturer for supported codecs.

⁴AV1 support is experimental and often too slow for CPU decoding. As of writing this (05.2020) there is no hardware support on most devices yet. Support for AV1 in Jellyfin is tracked in jellyfin#3129.

⁵As of version 0.12, HEVC is enabled on all devices running Android 5.0+, but early generations of the Amazon Fire may not work yet. 10Bit may be supported depending on your device. Before Client 0.12, HEVC support was enabled on specific devices.

Format Cheatsheet:

MPEG-2 Part 2	MPEG-4 Part-2¹	MPEG-4 Part-10	MPEG-4 Part-14	MPEG-H Part 2
H.262	MPEG-4 SP/ASP	H.264	MP4 Container²	H.265
MPEG-2 Video	DivX	MPEG-4 AVC		HEVC
DVD-Video	DX50

¹MPEG-4 Part-2 vs Part-10

²MPEG-4 Part 17: MP4TT Subtitles

Audio Compatibility

If the audio codec is unsupported or incompatible (such as playing a 5.1 channel stream on a stereo device), the audio codec must be transcoded. This is not nearly as intensive as video transcoding.

	Chrome	Firefox	Safari	Android	AndroidTV	Roku	Kodi	Desktop
FLAC	✅	✅	✅	✅		✅	✅	✅
MP3	🔶¹	🔶	✅	✅		✅	✅	✅
AAC	✅	✅	✅	✅		✅	✅	✅
AC3	✅	❌	✅	✅			✅	✅
EAC3²	✅	✅	✅	✅			✅	✅
VORBIS³	✅	✅	✅	✅		✅	✅	✅
DTS⁴	❌	❌	❌	✅		✅⁶	✅	✅
OPUS	✅	✅	✅⁵	✅	✅	✅	✅	✅

Format Cheatsheet:

MPEG-1	MPEG-2
MP2 (layer 2)	AAC (Part 7)
MP3 (layer 3)

¹MP3 Mono is incorrectly reported as unsupported and will transcode to AAC.

²Only EAC3 2.0 has been tested.

³OGG containers are not supported and will cause VORBIS to convert.

⁴Only DTS Mono has been tested.

⁵Safari only supports opus in .caf files

⁶Supported via passthrough on all devices. Native support for AC3 & E-AC3 on Roku TVs & Ultra.

ATSC Standard for AC-3 and EAC-3.

Subtitle Compatibility

Subtiles can be a subtle issue for transcoding. Containers have a limited number of subtitles that are supported. If subtitles need to be transcoded, it will happen one of two ways: they can be converted into another format that is supported, or burned into the video due to the subtitle transcoding not being supported. Burning in subtitles is the most intensive method of transcoding. This is due to two transcodings happening at once; applying the subtitle layer on top of the video layer.

Here is a breakdown of common subtitle formats.

	Format	TS	MP4	MKV	AVI
SubRip Text (SRT)	Text	❌	🔶	✅	🔶
WebVTT (VTT)¹	Text	❌	❌	✅	🔶
ASS/SSA	Formatted Text	❌	❌	✅	🔶
VobSub²	Picture	✅	✅	✅	🔶
MP4TT/TXTT	XML	❌	✅	❌	❌
PGSSUB	Picture	❌	❌	✅	❌
EIA-608/708³	Embedded	✅	✅	✅	❌

¹VTT are supported in an HLS Stream.

²DVB-SUB (SUB + IDX) is another name for VobSub files.

³EIA-608/708 subtitles are embedded in private channels (channel 21) in a MPEG video codec. EIA-608 are standard CC subtitles with the black bar background, while EIA-708 are typically SDH.

Types of Subtitles

There are many variations of subtitles. Closed, open, burned-in, forced, SDH, and CC are among the common types of subtitles. The format (such as SubRIP or VobSUB) does not matter for the type of subtitle.

Closed Subtitles

This is the generic name for subtitles that can be turned on or off. This can be Forced, SDH, CC or normal subtitles.

Burned-in

Open subtitles (also known as burned-in subtitles) are subtitles that have been permanently placed in the video and cannot be turned off. Open subtitles are the most common type of subtitles, where the subtitles are part of the video stream and cannot be toggled on or off.

SDH and Closed Captioning

SDH and CC are subtitles for the Deaf and Hard of Hearing. They include extra content such as background noises. SDH and CC are not defined by a specific type of subtitle, just by their intent. If using an OTA Tuner and DVR, the subtitles will be embedded into the video and transcoding them before extracting the subtitles will destroy the subtitles.

Forced

"Forced subtitles are common on movies and only provide subtitles when the characters speak a foreign or alien language, or a sign, flag, or other text in a scene is not translated in the localization and dubbing process. In some cases, foreign dialogue may be left untranslated if the movie is meant to be seen from the point of view of a particular character who does not speak the language in question." - Wikipedia

Extracting Subtitles

To extract subtitles, the following commands can be used. The section 0:s:0 means the first subtitle, so 0:s:1 would be the second subtitle.

SSA/ASS Subtitles

ffmpeg -dump_attachment:t "" -i file.mkv -map 0:s:1 -c:s ass extracted-subtitle.ass

Recorded OTA Content

Content recorded OTA will typically have subtitles embedded into the video codec itself. These subtitles are typically EIA-608 for analog and EIA-708 for digital.

ffmpeg -f lavfi -i "movie=Ronin (1998).ts[out+subcc]" -map 0:1  "Ronin (1998).srt"

Container Compatibility

If the container is unsupported, this will result in remuxing. The video and audio codec will remain intact, but wrapped in a supported container. This is the least intensive process. Most video containers will be remuxed to use the HLS streaming protocol and TS containers. Remuxing shouldn't be a concern even for an RPi3.

	Chrome	Firefox	Safari	Android	AndroidTV	Kodi	Roku
MP4¹	✅	✅	✅	✅	✅	✅	✅
MKV^{2, 3}	✅	❌		✅	✅	✅	✅
WebM^{3, 5}	✅	✅				✅	✅
TS⁴	✅	✅	✅	✅	✅	✅	✅
OGG⁵	✅	✅	❌	✅	✅	✅	✅

¹MP4 containers are one of the few containers that will not remux.

²MKV containers can hold nearly any codec, but are not compatible with streaming in Firefox and will remux.

³MKV containers are improperly labeled as WebM in Firefox during playback.

⁴TS is one of the primary containers for streaming for Jellyfin.

⁵WebM and OGG have limited codec support (by design), refer to this for WebM and this for OGG.