When a VLC playlist in OBS contains clips with different aspect ratios, set the source inside a fixed bounding box and centre it. That gives each item the same placement reference; then choose whether to show the whole frame, crop its edges to fill the canvas, or accept distortion by stretching.
A landscape clip followed by a portrait one will not naturally occupy the same shape. The workflow below makes the trade-off explicit and gives you a repeatable way to check transitions in the preview before you rely on the scene for a long broadcast.
Why mixed aspect ratios shift in a playlist
Aspect ratio is the relationship between a video's width and height. A wide 16:9 clip, a 4:3 recording and a portrait phone video have different shapes, even if OBS displays them in the same scene. When a VLC Video source advances to an item with different dimensions, the visible image can appear smaller, larger or differently placed in the scene.
The source itself is the playlist container, but its current item supplies the video dimensions. A transform that looks right for one clip may therefore leave another with bars, cropped edges or a different apparent size. If you are preparing a channel around a repeating sequence, this is worth settling before you tune the rest of the scene. The guide to scheduling a YouTube playlist with OBS and VLC covers the broader playlist setup; this article focuses on keeping its changing items framed consistently.
The key is to distinguish a stable box from a stable image shape. A fixed bounding box gives the source a consistent area and anchor point in the scene. It does not make differently shaped clips identical, nor does it guarantee that every subject stays in frame. Your fit choice determines what viewers see within that box.
Add a VLC Video source and playlist
In OBS, add a VLC Video source to the scene that will carry the loop, then add your video files to that source's playlist. OBS describes VLC Video as a source for playing a list of media items, rather than only a single item. If you do not see VLC Video in the source menu, check the VLC installation requirement below before troubleshooting scene transforms.
The OBS sources guide explains the available source types. Keep the playlist in the scene you intend to use on air, and give the source a recognisable name if the scene contains several media elements. That makes it easier to select the correct item before editing its transform.
Before adjusting dimensions, confirm that the playlist itself moves from one clip to the next as expected. Use representative items with noticeably different shapes: for example, a wide video, a portrait clip and a square or older-format recording if those are in your actual list. The aim is not to test every possible file; it is to find out whether your chosen framing behaves acceptably at the transitions you expect to broadcast.
Avoid using a different source for each clip merely to get a desired position unless you specifically need separate scene control. A single VLC Video source keeps playlist handling simple, while a fixed transform supplies the common framing reference. If one item needs special treatment, note that exception rather than silently changing the transform for the whole playlist.
Set a fixed bounding box in Edit Transform
Select the VLC Video source in the scene, open its context menu and choose Transform → Edit Transform. OBS provides controls for position, size, alignment, cropping and bounding-box behaviour in this dialog. The OBS Media Sources guide describes the media-source controls; OBS's aspect-ratio guide also documents common transform actions such as Fit to Screen, Center to Screen and Stretch to Screen.
Set the box to the dimensions of the area you want the playlist to occupy. For a full-canvas background, use the canvas as the reference. For a smaller panel beside a presenter or schedule, use that panel's intended width and height instead. The important part is consistency: do not resize the source by eye each time a new playlist item appears.
Choose a bounding-box mode that preserves proportions if you do not want the image warped. The precise outcome depends on whether the selected behaviour fits the image inside the box or fills it, so make the choice deliberately in the transform controls and confirm it in the preview. In practice, the box describes the target area, while the proportional behaviour describes how a clip of a different shape occupies that area.
Do not assume a numeric size copied from another tutorial will match your canvas or intended panel. Your OBS canvas may have a different resolution, and a box meant for a full-screen background is not suitable for a small overlay region. Set the target area for your own scene, then use the actual playlist clips to judge the result.
Choose a proportional fit behaviour
For a mixed playlist, decide first whether keeping every edge visible matters more than filling the box. A proportional fit preserves the clip's original shape. Depending on the selected fit behaviour, it either leaves empty space when the shapes differ or enlarges the clip until the box is covered and trims the excess edges. These outcomes are not interchangeable: the first can show the entire frame, while the second sacrifices some of it.
A practical rule is to use the full-frame fit when captions, lyrics, signs or faces near the edges must remain visible. Choose crop-to-fill when empty bands would be more distracting than losing some peripheral image. If different clips have important content in different areas, a single crop cannot guarantee that all of it stays visible; inspect those clips and decide whether they need separate preparation or a different presentation.
In a scene where you want a poster, album art or branded card to occupy an exact rectangle, stretching may seem convenient. It changes the proportions of the source to match the destination, which can make circles look oval and faces look wider or narrower. OBS warns that stretching warps and distorts the image and is generally not recommended. Use it only when that distortion is acceptable for the material, rather than treating it as a neutral way to fit mixed clips.
Do not confuse a fixed bounding box with a promise that every frame will be completely shown or cropped in the same meaningful way. The box stabilises placement. The proportional fit choice governs geometry, but each clip's composition still determines whether a particular crop cuts into something important.
Centre the source in the box
Once the target box and fit behaviour are set, centre the VLC Video source in that box. A centred alignment makes the remaining space or cropped excess fall evenly around the source, rather than making each new aspect ratio appear anchored to one side. That is the part that helps prevent the visible image from jumping towards an edge when the playlist changes items.
Use the alignment controls in Edit Transform where available, or apply OBS's centre-to-screen transform when the box is the full canvas. If you are fitting to a smaller region, check that the selected alignment is relative to the intended box and not an unrelated part of the scene. A centred full-screen source and a centred small panel are different placements.
Community discussion on the OBS forum thread about centring a playlist with differing dimensions recommends setting a transform and centred alignment for this problem. Treat forum suggestions as useful practical guidance, not a guarantee for every OBS version or playlist. Verify the result with your own files, as the preview is the evidence that matters for your scene.
If an item still seems off-centre, distinguish a transform problem from the composition inside the video. A person positioned at the left edge of the original clip will remain there after a correctly centred source transform; OBS centres the frame, not the subject. You may need to edit that source video, give it a separate treatment, or accept that the subject is not centred in the common layout.
Compare fit, crop and stretch outcomes
These three outcomes answer different questions: should the whole source be visible, should the box be filled, or may the image shape change? Compare them using a clip whose edges contain something you care about, not only a plain background. The table describes the general result; it does not imply that a mode preserves all content in every frame.
| Choice | What happens in a box with a different shape | Main trade-off |
|---|---|---|
| Fit the complete frame | The source stays proportional and the whole frame can remain visible; unused space may appear as bars or empty bands. | You retain the edges, but the image may not fill the box. |
| Crop to fill | The source stays proportional and is enlarged until the box is covered; excess edges are cut off. | The box is filled, but some image content is lost. |
| Stretch to box | Width and height are forced to the box dimensions. | The box is filled, but the image is distorted. |
To crop manually in OBS, hold Alt while dragging a source edge on Windows or Linux, or Option on macOS. Cropped edges appear green in the preview. For exact crop values, use Edit Transform rather than relying on a drag that may be difficult to repeat precisely. Manual cropping is useful when the same unwanted border appears on every item, but a fixed manual crop can cut into a different clip if its content is arranged differently.
For crop-to-fill behaviour, keep an eye on the most vulnerable edge: subtitles, lyrics or a station logo can sit close to the boundary. For full-frame fit, look at the empty bands and decide whether they belong in the design, perhaps as a plain background or a second visual layer. The right choice can vary by channel: a devotional lyric video may need its text intact, while an ambience loop may tolerate trimming a quiet edge.
A low-quality stream checklist for VLC over a 4G hotspot is relevant if the image looks soft or unstable after the framing is settled. Framing and transmission quality are separate issues: a crop setting does not fix a weak connection, and changing bitrate does not correct a source that is stretched.
Check the playlist transitions before going live
Test the scene in the OBS preview with the actual playlist sequence, or with a temporary list of representative files if the full sequence is not ready. Observe the first frame after each change, since that is where a change of dimensions is easiest to notice. Check that the source remains in the intended box, that the fit choice gives the expected bars or crop, and that no essential text or subject disappears at the edges.
Include at least one clip that is narrow or tall if your playlist contains one. A portrait item fitted into a wide box will look different from a landscape clip, and a fill-and-crop choice may remove substantial portions of its top and bottom. Conversely, a wide item in a tall panel may lose its sides. The transform is doing geometry, not understanding what the clip depicts.
If only one item causes trouble, do not immediately alter the common transform. First check the original file dimensions and how its important content is composed. You can re-export or reframe that file if the source needs to match the channel's presentation, or keep it separate with its own scene treatment. Then retest the sequence after any playlist or transform change.
This preview check is a practical verification step, not a promise that every codec, file or current OBS/VLC build behaves identically. If you operate a long-running channel, plan a way to notice when the broadcast source or scene needs attention. The article on monitoring an unattended OBS nature stream discusses the broader monitoring problem; it does not remove the need to check a changed playlist after editing it.
Check VLC and source setup requirements
VLC must be installed for the VLC Video source to be available in OBS. On a 64-bit OBS installation, install the 64-bit VLC edition. If the source is missing from the add-source list, confirm that VLC is installed and that the architecture matches before rebuilding the scene or changing transforms. OBS's source documentation is the primary reference for the source requirement and available media options.
After installation, reopen OBS if the source list has not updated, then add VLC Video and load the playlist. If a file does not play, check the file itself and the playlist entry before assuming the fit settings are at fault. A transform only changes how a source is placed and displayed; it does not make an unreadable or unsupported media item play.
For a channel where the difficult part is keeping a computer and local playlist available overnight, StreamNeo removes that specific burden by taking an uploaded video and running it as a YouTube live stream without keeping your computer switched on. That is a different workflow from managing a live OBS scene with a VLC playlist, so decide based on whether you need OBS's scene controls and local playlist or want a file-based channel broadcast.
Before committing, compare the operating options on the pricing page. When the file and channel are ready, start free — 24-hour trial, no card.
FAQ
Why does my VLC playlist source change size when the next clip starts?
Playlist items can have different dimensions and aspect ratios, so the visible image does not naturally occupy the same shape in the scene. A fixed bounding box and centred alignment provide a common reference, while the fit behaviour determines whether you see empty space, cropped edges or distortion.
How do I keep the whole video visible in OBS?
Choose a proportional fit that keeps the full frame inside the target area. When the video's shape differs from the box, expect unused space or bars rather than forcing the image to fill the box. Check that this remains legible for the clips you intend to play.
Can I crop a VLC Video source in OBS?
Yes. Hold Alt while dragging an edge on Windows or Linux, or Option on macOS; OBS shows cropped edges in green. For exact values, use Edit Transform, then test other playlist items because a crop that suits one composition may remove content from another.
Why is VLC Video missing from the OBS source menu?
VLC needs to be installed for that source to be available. If OBS is 64-bit, install 64-bit VLC, then check the source list again; consult OBS's current documentation if the source still does not appear.