Video preview: see the result before starting
A preview is one copy made with the current project settings. It lets you see the result before starting the whole batch. The preview does not affect bulk video creation. It is shown in the right column of the project window. Below is what works in the preview and what you cannot check in it.
Where is the preview?
There is no separate window. The preview panel is the permanent right column of the project tab. You do not open or close it. The smallest column width is 480 px. The "Preview" button starts creating a preview, it does not open a window.
How do I put a video into the panel?
There are three ways:
- Double-click a row in the "Imported videos" list.
- Right-click a row and choose "Open in the preview".
- Import videos into the project. The panel opens the video you chose last on its own.
The first way does not ask for confirmation. If a preview has already been created, it is deleted without a question. The second way asks: the title is "Replace the video in the preview?", the text is "The preview already holds a result. A new video will replace it.", the buttons are "Open" and "Cancel". "Cancel" is selected by default.
How do I create a preview?
Please do this:
- Put a video into the panel in one of the three ways.
- Click the "Preview" button in the bottom right corner of the panel.
- Wait for the green dot and the line "Preview is ready - compare it with the original".
- Switch between "Original" and "Result".
The button tooltip: "Generate a preview: apply the current settings to the video in the preview. This does not affect bulk video creation." It has no keyboard shortcut.
The button is inactive in three cases: no video is loaded into the panel, a preview is already being created, bulk video creation is running.
What is visible in the panel?
- Header. The file name as a scrolling line. The tooltip has the full path and a line like "1080x1920 · 0:42 · h264". Next to it are two toggles: "Original" and "Result". "Result" is not hidden but dimmed until the preview is created.
- Frame. There is no "full screen" button. Double-clicking the frame does nothing.
- Transport over the frame. Three buttons: "Back 10 seconds (Shift+←)", "Play (Space)", "Forward 10 seconds (Shift+→)".
- Track and bottom line. The seek slider, the timecode "00:00:00 / 00:00:00", the indicator dot, the status line, the volume button, the "Express" switch, the "Preview" button.
The panel has no "save preview" button. The interface offers no way to put a finished preview into a permanent folder.
What keyboard shortcuts are there?
They work only when the focus is inside the panel.
| Key | Action |
|---|---|
| Space | play and pause |
| ← and → | back and forward 5 seconds |
| Shift+← and Shift+→ | back and forward 10 seconds |
| M | mute |
How long do I wait?
There is no fixed time. A preview is the full creation of one video in one thread on your device. The time depends on the video length and the set of project settings.
The "Express" switch cuts the work down to the first second. Its tooltip: "Express preview: when it is on, the preview is built from the first second of the video only". This is a project setting, it is saved with the project.
"Express" has a peculiarity. It also trims the original in the panel. For a long video the track shows 00:00:01. This is done so that there is something to compare.
The upper time limit is set by the video creation watchdog. It stops the work after 300 seconds without progress.
What will the preview not show?
This is the main difference between a preview and bulk video creation. Some project settings are not applied in the preview at all.
| Setting | In the preview |
|---|---|
| Similarity check | does not run at all |
| Recreating a copy that is too similar | never happens |
| Codec and container | not applied: the result is always mp4, H.264 codec, AAC audio |
| Audio frequency, keyframe interval | cannot be checked, this follows from the row above |
| ProRes, VP9, WebM, MOV, hardware codecs | cannot be checked, for the same reason |
| Save folder | not used, the file is written to a temporary folder |
| File name rules | not applied, the name is random |
| Number of threads | always one thread |
| Video creation in the cloud | never used, even when the project is set up for the cloud |
| Credits | not spent |
| Row in the results table | not created |
| Speed counters | do not change |
| Checksums | not computed |
The conclusion in one line: a preview is fine for checking the picture and the sound, but not for checking the file format, the name and the similarity.
What is applied in full?
The preview computes everything else the same way as bulk video creation:
- watermark;
- text over the frame;
- template;
- color correction and frame geometry;
- metadata;
- additional audio.
The settings are taken from the saved ones. Before starting, the project saves itself. If writing to the database failed, the preview does not start.
Does a preview spend the daily video limit?
Yes, one video. This is true for "Express" mode too. No credits are spent: a preview is always computed on your device.
"Express" saves time, not the limit: one video is deducted in both modes. Only clicking "Preview" fewer times saves the limit.
What does the panel say?
An empty panel shows one of three sets of texts.
| When | Title | Hint | Button |
|---|---|---|---|
| there are no source groups | "No video selected" | "Pick a video in the "Imported videos" section by double-clicking the row." | "Import video" |
| there are groups, the export type is "Periodic" | "No videos yet" | "The app will download videos itself from the "Sources" pages - after you start it." | "Download one video now" |
| there are groups, the export type is different | "No videos yet" | "Pages from "Sources" are checked only when the export type is "Periodic"." | "Open the "Export" section" |
Then the status line changes as the work goes on.
| State | What is shown |
|---|---|
| a video is loaded | "Ready to watch", the dot is neutral |
| downloading from a source | "Downloading a video from the source" and a progress bar |
| the preview is being created | a ring with percentages, a "Stop" button, the statuses "Authorizing", "Creating video", Transcoding video to <codec> |
| the preview is created | "Preview is ready - compare it with the original", the dot is green |
| failure | the dot is red, next to it is the "Copy the error text" button |
There is no "seconds left" indicator under the ring. The app gives no estimate of the remaining time.
How do I stop preview creation?
Click the "Stop" button on the frame. Its tooltip is "Stop preview generation". Stopping takes two steps. First the status line shows "Stopping preview creation...", the ring is still visible. Then the line changes to "Preview creation stopped".
A second click does nothing. The panel stays busy while the previous worker thread finishes writing its file. After a stop the result is not shown, even if the file managed to appear.
Closing the tab while a preview is being created does not ask for confirmation. The tab closes even if the preview is not created yet.
Where does the preview file go?
It is written to the app folder, into the nested folder temp_videos_<project number>. The file name is random, 16 characters, with the mp4 extension.
Files pile up there: one for each click of the "Preview" button. The app deletes them all at once, as a whole folder, when the tab or the app closes. Deleting them one file at a time is not provided.
Clicking "Preview" again resets the previous result. The "Result" toggle goes dim, and a new file is created.
What do I do if the preview is not created?
| Text in the panel | What to do |
|---|---|
| "This video does not open - the file seems to be damaged. Please download it again." | download the source video again and import it into the project |
| "The finished video does not open - the file seems to be damaged. Please create the preview again." | click "Preview" again |
| "Please wait until the other videos are created." | wait for the batch to end or click "Stop" on the start bar |
| "No sources are enabled. Add a source in the "Sources" section." | add a source or import videos into the project by hand |
| "Could not download a video from the source." and the reason from the platform | check the link and the cookies file of the source group |
| "The downloaded video did not open. Please try again." | click "Download one video now" again |
Error: <failure name> | click the copy button next to the line and pass the text to support |
| "Error: could not create the preview" | the same: copy the text and pass it to support |
There is also a separate window titled "Preview creation". Its text: "Could not create a temporary file. Please check the permissions on the folder where the program is installed." Check the permissions on the app folder or reinstall the app.
The copy button belongs to a failure, not to every refusal. Clear refusals do not have it: there is nothing to copy there.
Frequently asked questions
Why did the preview come out as mp4 although I chose a different container?
This is how the preview works. The codec and container choice is not applied in it. The result is always mp4 with the H.264 codec and AAC audio. A different container shows only in bulk video creation. More on the Export settings page.
Why does the preview not show the similarity to the original?
The similarity check runs only in bulk video creation. It does not run through the preview at all. About this check: the Similarity check page.
Are credits deducted for a preview?
No. A preview is always computed on your device, even in "Cloud" mode. Only one video from the daily limit is spent.
Why did the original become one second long?
The "Express" switch is on. It trims both the result and the original. Turn it off and create the preview again.
Can I save a preview to my own folder?
No. The panel has no save button, and the temporary folder is cleared when the tab closes. Please start video creation the usual way.
Why is the "Preview" button gray?
There are three reasons: no video is selected, a preview is already being created, bulk video creation is running. In the last case the button tooltip says that you need to wait for the work to end or stop it.