Recording
Recording writes media to files on disk. With the default Original source, it records source media, not the composed viewer image, so overlays, opacity changes, viewport layout, object-detection graphics, and other on-screen UI are not burned into the recording.
Recording can also use Flywheel as its source. In that mode, STView records the Flywheel program output instead of the original source media.
Configure recording from the Recorder tab in File > Open File or File > Open Stream. The dialog stores the selected recorder settings for the current source. After the source is open and playback is running, use the round Record button in the transport controls to start or stop recording.
Before recording, verify that the output directory exists, is writable, and has enough free space. Use a unique base name for important captures. If STView detects an existing output with the same name, it asks before overwriting.
Basic workflow
- Open File > Open File or File > Open Stream.
- Select the source on the Source tab.
- Open the Recorder tab and enable Enable Recording.
- Choose the recording Source: Original or Flywheel.
- Choose the required output Format.
- Choose an Output directory.
- Enter a Base name. This is the filename stem used for the generated files. Do not include folder separators in the base name.
- Optionally enable Add date to append a local timestamp to the base name.
- Choose whether to record one continuous file or split the output into segments.
- Open the source, start playback, then press Record.
The record button is disabled until playback is active and Enable Recording
is on.
Press the button to start recording.
When recording is active, the record button turns red and the status bar
shows a Recording section with REC and the current output size.
Original-source recording is not available while looping file playback. If Loop is enabled for a file source, turn it off, disable recording, or choose Flywheel as the recording source before opening the file.
Recording formats
STView supports three recording modes:
| Mode | Output | Use when |
|---|---|---|
| MPEG-TS | .ts file, or numbered .ts segments | You need transport-stream output or want to preserve KLV metadata when the source exposes it. |
| MP4 | .mp4 file, or numbered .mp4 segments | You need broad media-player and editor compatibility. MP4 output does not preserve KLV metadata. |
| HLS | .m3u8 playlist plus numbered segments | You need a segmented HTTP Live Streaming style output. |
For MPEG-TS and MP4, leaving Split into segments off writes one continuous output file:
- MPEG-TS:
base-name.ts - MP4:
base-name.mp4
When Split into segments is enabled, STView writes numbered segment files
such as base-name_000000.ts or base-name_000000.mp4. The segment duration
must be greater than 2 seconds.
HLS always writes segments. STView creates a playlist named
base-name.m3u8 and segment files named from the same base name. The HLS
segment format option controls whether those segments are MPEG-TS (.ts) or
MP4/fMP4-style (.mp4). Use HLS MPEG-TS segments when KLV preservation matters;
use HLS MP4 segments when player compatibility with fragmented MP4 is more
important.
Segment duration is a target duration. Actual segment cuts depend on the source's keyframes/GOP cadence, so segments may not be exactly the requested length.
Naming and overwriting
The Base name is combined with the selected format to produce the output
paths. If Add date is enabled, STView appends a timestamp in the form
YYYYMMDD-HHMMSS before recording starts, for example
mission-20260624-153012.ts.
Before starting, STView checks the expected continuous file, HLS playlist, or first segment path. If one already exists, the Recording Exists dialog shows the conflicting path and lets you cancel or overwrite.
Be careful when overwriting segmented outputs. For segmented recordings, STView removes matching segment files that start with the selected base name and use the selected segment extension. For HLS, it also removes the matching playlist. Use separate folders or distinct base names when you need to keep older segments.
Video pass-through
Video passthrough is enabled by default. In this mode, STView muxes the incoming encoded video into the selected output without re-encoding it when the source codec and target format are compatible. This preserves video quality and uses less CPU/GPU work.
Passthrough is usually the best choice for MPEG-TS sources, especially when KLV metadata must remain with the recording. MP4 passthrough is useful when the incoming video can be placed into MP4 cleanly, but MP4 output intentionally drops KLV metadata.
If passthrough cannot be linked for the selected source and target, recording can fail. Check the Session Info > Recording tab for the recording state, current output path, segment count, total size, and any reported error.
Video params
Turn Video passthrough off when you want STView to decode and re-encode the video before writing it. The Video params button opens the transcode settings:
- Codec selects H.264, H.265, or AV1.
- Video bitrate sets the target bitrate in kbps. Higher values usually preserve more detail and produce larger files.
- Keyframe interval controls how often the encoder should request keyframes. Shorter intervals can make seeking and segmenting easier, at the cost of larger files.
AV1 recording is only available for MP4 targets or HLS with MP4 segments. STView does not allow AV1 for MPEG-TS files or HLS MPEG-TS segments.
Transcoding is more expensive than passthrough. If the computer cannot encode fast enough for the source frame rate and resolution, lower the bitrate, choose a lighter codec, reduce source load, or use passthrough.
Using Recording With Flywheel
Choose Flywheel in the Recorder Source field when the recording should capture STView's Flywheel program output instead of the original media source. Enable and configure Flywheel on the Flywheel tab before selecting it as the recording source. For more information about the Flywheel output path, see Flywheel.
Flywheel affects recording in these ways:
- Recording uses the Flywheel codec, CBR/VBR mode, target and maximum bitrate, keyframe interval, frame rate, width, and height settings. CBR is the default; maximum bitrate is configurable for VBR.
- The recording is a newly encoded output. Video passthrough is not available for Flywheel recording.
- Flywheel recording supports MPEG-TS and HLS with MPEG-TS segments. MP4 output and HLS MP4 segments are disabled.
- Flywheel-generated MPEG-TS files and HLS MPEG-TS segments are not suitable for reopening in STView as normal MPEG-TS input.
- Flywheel recording can be used while looping file playback.
- Because Flywheel records the program output, it can include the composed presentation content instead of only the source media stream.
Use Original-source recording when preserving the input bitstream, KLV behavior, or lowest CPU/GPU load is more important. Use Flywheel recording when a controlled output size, frame rate, or composed program feed is more important.
Monitoring recordings
Use the Recorder status-bar indicator for a quick check. Hover or keyboard-focus it to see measured bitrate and recorded size.
For detailed diagnostics, open View > Session Info and select the Recording tab. It lists recordings started in the current session, including recording ID, running state, format, elapsed time, accumulated size, segment count, current output path, and any error text. This is the first place to look if recording stops unexpectedly or if segments are not appearing.
Stop recording with the Record button before closing STView, stopping the source, or changing to another source. Continuous MP4 files are finalized when recording stops, so wait for recording to stop cleanly before moving or opening the file in another application.
Recorder status
The Recorder status-bar indicator follows Recast. While recording, it shows the recorded size in MB (1 MB = 1,000,000 bytes) in the same text color as Framerate and KLV Rate. Its green dot means recording bytes are growing; orange means starting or waiting for data; red means an error. Hover or keyboard-focus it for measured bitrate, recorded size, output path, source, and current/previous errors. Multiple recordings have separate tooltip entries. Successful stop hides the indicator. See Output status indicators for sampling and recovery behavior.
Original recording from a running UDP or SRT MPEG-TS stream shares the existing reception path, including after stop/start and when using MP4 or HLS. Starting another recording does not open a competing receiver on the source port.