What happens when you press play
With the default settings, Spectati requests the file exactly as it sits on the server. Its player reads the container on the device, decodes H.264 and HEVC in hardware, and decodes what the hardware cannot, such as VC-1 or MPEG-2, in software. The server’s CPU does nothing but serve the file.
The settings that allow a transcode
In Settings, Playback, under Server Transcoding:
Transcoding
Automatic (the default), Direct Play or Allow Transcoding. Automatic plays the original file until a bitrate cap is set. Direct Play never asks the server to transcode. Allow Transcoding lets the server convert files it cannot send as they are.Maximum bitrate
From 0 to 200 Mb/s in steps of 5, where 0 means no limit. With a cap set, a file above it is sent at a lower bitrate by the server. Direct Play ignores the cap.
Each server can override both. Open Settings, Sources, Providers, choose the server and then Edit: the Playback section takes Inherit or any of the three modes, and a cap of 4, 8, 20 or 40 Mb/s. A server reached over a slow link can transcode while the one at home never does.
Plex and Jellyfin differ slightly
Plex. With Automatic and a cap, Plex decides, and Spectati honours a Plex verdict to direct play. Transcoding needs the server to be signed in with a Plex account.
Jellyfin. Spectati always asks with transcoding off first. When transcoding is allowed, it switches to Jellyfin’s transcoded stream only when the file is over the cap, when the server cannot direct play it (some MPEG-2, VC-1 and WMV video, and image subtitles such as PGS), or when its audio is TrueHD.
When a file buffers
If a direct-played file stalls, the player shows Playback is buffering with a choice: Keep Direct, or a lower bitrate marked Recommended. Picking a bitrate switches that session to a server transcode and leaves your settings alone.
The player’s Quality control does the same by hand: Direct for the original stream, or a bitrate, on titles whose server can send a smaller one.
What plays directly
Containers: MKV, MP4, WebM, MPEG-TS, AVI, WMV, OGG, FLV and MPEG program streams (.mpg and .vob).
Video: H.264 and HEVC, including 10-bit, in hardware; AV1 in hardware where the device has an AV1 decoder and in software elsewhere; VP9, VP8, MPEG-2, MPEG-4 Part 2 and VC-1 in software.
Subtitles: SRT, ASS and SSA with their styling, WebVTT, PGS, DVB and DVD image subtitles, and external subtitle files next to the video.
Audio: Dolby Atmos in Dolby Digital Plus reaches the receiver untouched, TrueHD and DTS play as 5.1 Dolby Digital Plus, and TrueHD Atmos and DTS:X keep their height channels on AirPods, HomePods and Atmos receivers.
On the free tier
The free tier direct-plays your 4K remuxes with no transcoding, in SDR. HDR and surround sound are what a subscription adds. HDR is tone-mapped to SDR on the device, and when a file has a stereo track in the same language, that is the one that plays.
