“Constant Framerate” is selected. This should ensure your
video stays within Plex’s recommended 30fps and 8-bit video
depth setting. In terms of quality, this has no bearing on Plex’s
ability to direct-play the video, but a rule of thumb is to choose
“Constant Quality” and then experiment around 20–23, with
a larger figure reducing the file size at the expense of quality.
Again, consider experimenting with a 45-second preview clip to
strike the right balance.
>> The “Encoder Options” section is again largely about quality
rather than compatibility, although remember that all-important
“Level” setting (maximum 4.0 for HD; 3.1 for SD) [Image D].
We also recommend checking “Fast Decode” here to improve
playback on lower-powered devices.
>> When it comes to the “Audio” tab, the key option here is
choosing “A AC” as your codec. From here, Plex seems happy to
direct-play multi-channel (up to 7.1 in our tests) audio streams,
although support for multiple audio streams enables you to
provide a fallback basic stereo option—select the audio stream
before playback on your target device by clicking or tapping
“Audio” next to the currently selected stream. Other audiooptions are a matter of personal preference—we stray
toward a bitrate of 160 for simple TV stereo channels,
going up to 448 for surround-sound movie setups.
>> When it comes to adding subtitles, one setting
often applied is the foreign audio scan—this ensures
that subtitles are provided when non-English languages
are spoken. If you have need of this feature, now is the
perfect time to “burn” them into the video feed, so they’re
part of the native video stream (thus reducing the need
to transcode to include them later). Choose “Foreign
Audio Scan” from the drop-down menu, and check both
“Forced Only” and “Burn in.”
>> Review your settings one last time, then save your
preset if necessary, before adding the title to the queue
or starting the conversion process. Once complete, open
the file in your media player to check it plays, looks, and
sounds correct.6
TWEAK PLAYER SETTINGS
You’ve diligently created a media library with the
above universal settings, but some streams still
refuse to direct-play on certain devices. There’s not an
awful lot you can do at the server level to force direct-
play—you need to take the time to go into each player’s
settings and attempt to influence things from there.
>> If you’re accessing Plex on your browser or through
the Windows or Mac app, click the “Settings” button
f o l l o w e d b y “ S h o w A d v a n c e d .” N a v i g a t e t o “ D e b u g” u n d e r
“Plex” in the left-hand pane to ensure both “Direct Play”
and “Direct Stream” are checked. Switch to “Quality” to
verify “Use recommended settings” is checked under
“Home Streaming.” To minimize transcoding over the
Internet, check “Play smaller videos at original quality”
and set “Video quality” to “Maximum.”
>> It’s a similar situation for mobile use: Android, iOS,
and Apple TV users should navigate first to “Settings >
Quality” to set similar streaming settings to above, while
heading on to “Settings > Advanced” to make sure
“Allow Direct Play” has been enabled. Android users
should also tap “Settings > Advanced > Player” to view
the “H264 Maximum Level.” Remember, the app should
direct-play all content encoded with all versions up to
and including the maximum level specified.
>> If you attempt to set the maximum level to a higher
setting on your device, you’ll get a warning that it may
cause issues—but don’t let that stop you. On our Android
phone, the recommended setting was 4.0, but we were
able to bump it up to 4.1, at which point a 1080p movieEWhere transcoding is unavoidable, you’ll need to either
limit the number of transcoded streams to prevent your
CPU being overwhelmed, or find ways of offloading all that
work from sof t ware-based to hardware-based encoding.
Hardware encoding is restric ted to Intel CPUs that suppor t
Intel Quick Sync video, which covers most bases since 2011
(confirm your processor is supported by searching for it at
https://ark.intel.com/#@Processors).
Using hardware to transcode streams means the effect
on your CPU is almost as negligible as direc t streaming
or direct play, but before jumping for joy, be aware it may
not be the magic bullet you hope it is. Hardware encoding
almost always results in lower-quality streams, but how
noticeable this is comes down to several factors. First is the
quality of the source material—ironically, low bitrate, SD
resolutions fare worse than HD and 4K movies, but in most
cases, you shouldn’t need to transcode these streams if you
follow our guide.
Second—and ultimately more importantly—is the age
and type of your processor. Older processors, such as the
Intel Celeron J1900 powering our QNAP TS-251+, produce
lower-quality videos using their hardware transcoding
engine than newer ones—in our case, the degradation is
too noticeable for us to use it.HARDWARE
TRANSCODING
64 MAXIMUMPC DEC 2019 maximumpc.com
R&D