vMix 29: replay, high-frame-rate cameras, SRT and files for editing

Define replays and deliverables before assigning cameras

List the cameras needed for replay and those whose complete recordings must be retained. Include program, presentation feeds and audio when they are part of the delivery. A marked replay of a play or demonstration covers a segment; it does not determine everything the editor will receive.

The vMix 29 Replay manual describes continuous camera recording and event export. Treat these as separate deliverables. Ask the editor for a sample of the expected format and record which test file opened successfully on their workstation.

Assign responsibility for marking and playing events, monitoring capture and checking files at wrap. If one person covers several tasks, rehearse those operational changes and allow time to verify the delivery.

SRT is visible live, but Replay fails to record

Check the documented configuration for SRT inputs in Replay, then test recording and playback under the expected load.

The official note, updated April 26, 2024, states that vMix 26 and later can use SRT inputs directly in Replay when Use Hardware Decoder is cleared as the input is added. It warns of higher CPU usage. The vMix 29 SRT Input manual and Replay requirements retain this condition.

Make the change off air in a test preset. Smooth GPU-decoded playback does not prove the computer can handle CPU decoding, recording and replay playback together. The manual specifies how to configure this path; it does not diagnose every error or guarantee performance.

If recording fails, keep the full error message and note whether it happened during setup, recording or playback. Use the worksheet and compare the SRT reception checks (Spanish) before changing several settings.

1. Save a test configuration

   Use Save As to create another file; Save overwrites the open preset. Identify the sources and destinations that will remain active.

2. Add an SRT input for Replay

   In Add Input > Stream / SRT, choose the intended connection and clear Use Hardware Decoder when adding it. Check picture and voice before configuring Replay.

3. Assign the source and test an event

   Add Instant Replay and select the source under Cameras. Record movement and an identifiable voice, mark an event and play it through the intended output. Compare your setup with Getting Started.

4. Repeat under event load

   Add the sources, streaming and recording tasks the production will use. In Statistics, save input and SRT data alongside the visible and audible result. Record CPU and GPU usage with the tool used to measure them; those readings alone do not prove file quality.

Replay and MultiCorder cannot run together in vMix 29

The MultiCorder manual and Replay System Requirements explicitly state this restriction. A faster processor does not remove it. If the plan calls for replay and ISO recording with MultiCorder on the same system, revise how those files will be captured.

Assess whether continuous Replay recordings cover the delivery or whether another capture computer is needed. Size storage and network capacity using the actual source formats and bitrates.

First check whether the cameras assigned to Replay and their files cover the delivery. If sources are missing or another recording is needed, design and test a separate path. A second computer adds another operating task: check signal routing, networking or capture, storage, audio and software versions on both systems.

If you send NDI to another computer, identify the source being sent and what the receiver records. The source versus Output guide (Spanish) explains why they are not interchangeable. Sharing a camera, encoder or network can leave a common failure point; a second computer alone does not establish an independent backup.

Record the chosen path in the worksheet and check the session deliverables with our cameras and recording service.

Keep session recordings and exported clips separately

In vMix 29, Instant Replay documents vMix AVI 4:2:2 recordings. The workflow changes since version 23 explain the move to that format in version 24 and MP4 export through Export Clips.

Getting Started calls for dedicated SSD storage for Session Folder. Replay splits each camera recording every 20 minutes. If Automatically delete prior video when disk space is low is enabled, it can delete the oldest segment to keep recording, along with events in that segment. With that option disabled, recording stops and a low-space warning appears.

Before the event, review the configured behavior and allow capacity for rehearsal, the session and an extended program. If everything must be retained, plan sufficient space and monitor usage; do not use automatic deletion as an archive policy. Copy previous material before reusing a folder.

Configure Storage lets you assign additional drives to cameras; it does not move earlier recordings. Record every location. At wrap, check the file list for each camera and identify the periods covered. Copying only the main folder can omit footage if the session uses other drives.

For a delivery test, open a copy of the continuous recordings and an exported event in the intended editing application. Check picture, voice, duration and joins between segments you need to assemble. IN/OUT points describe an event; retaining those clips does not prove the whole session was saved. Document the check with the worksheet and delivery guide.

Test format, audio and the return to live with every source

The Replay 29 requirements call for the same resolution across cameras. They allow different frame rates for progressive or PsF sources and explain that frames are duplicated or dropped to match the session rate. For SRT, check its own input limits too; general support for interlaced video in Replay does not define what SRT accepts.

Rehearse with fast movement, a visible and audible reference, and the program transitions. Play each angle, switch between them and return to live. Note any discontinuity or change in lip sync. A frame-rate conversion supported by the software still needs testing with the event content.

Under Getting Started, Playback Audio Source, Master plays the mix that existed when the event occurred; Follow switches to the embedded audio of the active angle. Master Audio Channels selects the mix channels to record. Choose the behavior required by the program and listen through every switch: a camera with different audio can change the replay sound when you switch angles.

Check what reaches program and the streaming platform as well as local monitoring. For editing, open the test file and verify the agreed channels. Record the replay audio source and each delivery’s audio source as separate checks.

Keep samples, settings and outstanding checks in the worksheet. Include the rehearsal in the production continuity plan and the cameras and streaming brief.

The camera records at 120 fps, but the replay input arrives at 60

Distinguish playing a high-frame-rate recording from receiving a live output at that rate. These are different paths and need different checks.

The Replay 29 High Frame Rate Requirements require a camera that outputs the high frame rate and a compatible capture device. Recording 120 fps to a card is not enough to qualify it as a live replay source. Playing a slow-motion file later is another workflow: plan its transfer, availability and playback.

To find the limit, record every stage in the high-frame-rate worksheet. Start with the camera connected directly to the capture device. If the input works at the intended format, add intermediate devices one at a time and note where the format changes. Keep the test preset and a sample before changing configuration.

Compare fast movement live and in replay. Open a copy in the editing application, step through it frame by frame and look for repeated images: a file labeled 120 fps can contain duplicate frames. Record the section examined and the tool used; the format label alone does not establish how many distinct images the chain captured.

GH7 and DeckLink 8K Pro G2: check HDMI format before replay

Before choosing this combination, identify the camera, firmware, exact capture card model and driver. Individual equipment specifications do not replace checking the received format and captured movement with that configuration.

For an FHD test with the Panasonic DC-GH7, the DVQP3109 manual, HDMI Output Image Quality, lists 1080/119.88p with System Frequency at 59.94Hz (NTSC), Rec Quality at 1080/119.88p and Down Convert OFF. Record the full 119.88p value. The table distinguishes this from recording 4K/119.88p and converting the output to 1080/59.94p. With Down Convert set to 1080p, an incompatible receiver can reduce 119.88p to 59.94p or 29.97p.

The specification for the exact DeckLink 8K Pro G2 model, under HDMI 2.1 Video Standards, includes 1080p120; the fractional-rate entry is written as 1080p119. Do not assume this wording confirms 119.88p reception: confirm the format with the manufacturer and in a capture test. UHD/4K at 100/119/120p is marked Uncompressed only. Check the actual port, format and driver in capture; other DeckLink models are not interchangeable.

For high-frame-rate 4K/C4K, the GH7 HDMI Output Settings section requires 4K/120p Output—or 4K/100p Output—to be ON. With an incompatible receiver, output falls to FHD/60p or below. Card recording is unavailable during that output, and HDMI RAW Data Output excludes the setting. If an internal copy is required, revise the recording path for this mode.

In the same section, 4K/120p Power Save Live View ON limits the sensor to 60p in standby even when the receiver identifies 120p; OFF maintains the high rate in standby too. Test movement before and after starting from the camera, and check focus magnification, which can reduce refresh rate. For GH6, use the model-specific section.

Choose the format required by replay first, then check what vMix receives. If capture reports a different rate, review the menu combination and receiver compatibility before continuing with the session. If it reports the intended rate but movement contains repeated frames, keep a sample and check camera state and the complete signal chain.

Expecting 120 fps from Larix, but receiving SRT at 60: compare the path

Identify the phone, Larix edition and available formats before planning a 120 fps output. Check the effective rate at the source and receiver; a 60 fps input alone does not locate the limit.

The Larix Broadcaster for iOS documentation allows frame-rate selection from supported values and separate parameters for local recording. Available values depend on the device and configuration; a local recording option does not guarantee the same transmission rate. Record the phone, iOS, Larix version, capture mode, resolution, codec and transmission setting; compare the local recording and received stream as separate files.

In vMix 29 Display, Master Frame Rate converts inputs for program. For Replay, also record Recording Format and the assigned source: selecting Output uses the processed program rather than establishing direct camera capture. Compare the path with Getting Started and the session requirements.

Start with one input and a separate preset. Save transmission and received-format details; check movement and an identifiable voice, then record and play an event. Add the other sources and outputs only after this path is established. If it returns to 60, document where and when the change happens; increasing bitrate or changing several settings together will not isolate it.

In Statistics 29, Video reports frame-arrival timing; SRT adds loss, bandwidth and RTT. Use them alongside the sample, without confusing regular arrivals with distinct images. SRT directly into Replay still requires Use Hardware Decoder to be cleared. Clearing it does not establish 120 fps reception.

The manufacturer’s general CPU guideline treats one 120 fps Replay source as equivalent to two 60 fps sources. This is a load estimate to test with the event’s sources and outputs. Record results and files in the worksheet; connect the test to source versus Output recording (Spanish) and our cameras and streaming service.

GH6: select the FHD output format before assigning it to Replay

For live replay, HDMI output must provide a format the capture device accepts. Select the FHD combination for the chosen System Frequency and check the received signal before configuring the session.

The GH6 DVQP2441 manual, HDMI Output Image Quality, shows high-frame-rate FHD with Down Convert OFF. In NTSC, Rec Quality 1080/119.88p outputs 1080/119.88p; in PAL, 1080/100.00p outputs 1080/100.00p; in CINEMA, 1080/120.00p outputs 1080/120.00p. System frequency also changes which formats are available.

The Rec Quality names use 120p for both NTSC and CINEMA. High Frame Rate Video identifies the actual values: 119.88p and 120.00p. Choose a format that matches the camera, capture device and session, and record the full value; changing the system just to find a menu option can create mismatches with other sources.

The HDMI table distinguishes FHD from recording 4K/119.88p and converting to 1080p: that combination is listed as 1080/59.94p. With Down Convert at 1080p, an incompatible receiver can lower a 119.88p FHD signal to 59.94p or 29.97p. For high-frame-rate 4K output, also consult the firmware supplement; the base table alone does not cover that addition.

Connect GH6 directly to the capture device first, without converters, save a sample and check the received format and movement. Then add the installation’s intermediate devices one at a time. Only assign the input to Replay after the live feed is correct, then verify recording. Keep settings and results in the GH6 worksheet; the chain must still meet the vMix 29 requirements.

GH6: high-frame-rate 4K output has its own settings and limits

The official DC-GH6 firmware history identifies version 2.3, released July 11, 2023, as adding HDMI 4K120p/100p output. It also added a RAW path to Blackmagic recorders. These are different functions: RAW recorder compatibility does not establish a camera input for replay. Record the installed firmware before comparing a tutorial or an older table.

The DVQP2441 supplement, Support for 4K/120p HDMI Output, requires a high-frame-rate 4K/C4K Rec Quality, Down Convert OFF and 4K/120p Output—4K/100p Output in PAL—ON. With an incompatible receiver, output can fall to FHD/60p or below.

This mode excludes card recording and HDMI RAW Data Output. If the brief requires an internal recording and replay, resolve how the additional copy will be captured before the event and check both paths.

In standby, 4K/120p Power Save Live View ON limits the sensor to 60p even when the receiver identifies 120p; OFF maintains the high rate. In PAL, the limit is 50p. Focus magnification can also lower the refresh rate. Check movement as well as the reported format.

Prepare an off-air test using the worksheet. The capture device must accept the selected signal; converting to HD before capture can change the frame rate. Compare the replay requirements with the material retained for editing in the delivery guide.

1. Identify the camera and configuration

   Record DC-GH6, firmware, System Frequency, Rec Quality, output, capture device and driver. Preserve the previous configuration.

2. Check standby and start behavior

   Record a moving reference before and after starting from the camera. Record Power Save Live View and magnification settings; look for repeated frames in a copy.

3. Test the planned delivery

   Verify the input, a Replay event and the editing file. Then add the event’s sources and outputs; save the observed result rather than inferring it from specifications.

GH6: VFR changes file playback speed and excludes audio and AF during recording

On GH6, Variable Frame Rate uses an acquisition rate different from Rec Quality to create slow or fast motion. The manual states that it does not record audio, switches to MF and allows AF ON only before recording starts. This mode requires MOV and a quality marked VFR available. That label does not mean VFR is enabled: check its state.

High Frame Rate Video describes a different MOV workflow: it retains the file’s high frame rate and supports audio recording and AF. Slow motion is prepared later in compatible software. In PAL it offers 100p; in NTSC the 120p quality corresponds to 119.88p. AF availability does not guarantee useful tracking for the shot: test the lens, settings and movement.

If ambient sound is needed for a play, demonstration or show, decide which recordings must retain it first. Record the same voice and movement in each planned mode, open the samples and check playback speed, audio and focus. Note VFR state, recording quality and the reviewed file before attributing silence to a faulty microphone.

For the live path, separately check Sound Output (HDMI) under HDMI Rec Output and the audio received by the capture device. The VFR file’s audio limitation does not describe the whole HDMI chain. In Replay Playback Audio Source, Master uses the event mix and Follow uses the angle’s audio: listen to the file and the replay as separate checks.

Record samples in the GH6 worksheet and agree on the camera, capture and file workflow with our cameras and streaming service. If a high-frame-rate recording quality is unavailable, check Dynamic Range Boost: the HFR manual excludes qualities above 60p when it is ON. This does not diagnose every other recording failure.