If audio and video are out of sync on a Castr playlist stream to YouTube, first find the earliest point where the mismatch appears: the uploaded file, Castr preview, or YouTube playback. Compare the same visible and audible event at the start and later in the programme before changing settings.
A cloud playlist and an OBS-fed stream are different workflows. OBS offset advice only applies when OBS is actually in the source path; Castr’s public documentation does not provide a guaranteed repair procedure for sync drift in its cloud playlist feature.
Start by identifying the workflow
Castr’s pre-recorded feature takes uploaded video files and can play them as a scheduled broadcast or a continuous loop to destinations including YouTube. In that workflow, Castr plays the playlist from the cloud, so OBS is not required and OBS audio controls do not directly adjust Castr’s playout. Castr describes those playlist modes on its pre-recorded video page.
Before troubleshooting, write down which route you use. It may be a Castr playlist made from uploaded files, or a live source such as OBS sent through Castr to YouTube. Do not assume that because the symptom is on YouTube, YouTube is where it began. A timing error already present in an uploaded file will travel with that content; a mismatch that first appears later needs a different investigation.
Also note whether the mismatch is roughly constant or grows. If a speaker’s mouth and words are apart by the same amount near the beginning and much later, that looks different from a stream that starts aligned and gradually separates. This is a useful distinction, not a diagnosis by itself.
Check the uploaded file before changing anything
Play the exact file that you uploaded, rather than a different export or a preview assembled from another copy. Use a clear cue where both picture and sound make the timing visible: a clap, a hand striking a drum, a door closing, or the start of a spoken word. Compare the instant the event appears with the instant you hear it.
Check at least one cue near the beginning and another well into the file. If both show about the same separation, the mismatch may be a fixed offset already baked into the source. If the later cue is further out than the first, the file may have progressive drift. Keep the observations descriptive: “the clap appears before the sound at the opening and near the end” is more useful than “the export is broken”.
Use a local player you trust and make sure it is not adding unusual playback processing. If possible, inspect the file on a second device or player before concluding that the file itself is at fault. A preview can be affected by the device, browser, or player as well as by the actual stream path.
If local playback is already out of sync, repair or re-export the media before uploading again. Keep the original safe, make one corrected copy, and repeat the same cue comparison. Castr’s troubleshooting page recommends file compatibility checks, including AAC audio averaging 128 kbps; that is a delivery recommendation, not evidence that changing audio encoding will correct timing. Castr also mentions HandBrake for reducing bitrate when a file fails to reach destinations, not as a demonstrated sync repair. See Castr’s pre-recorded troubleshooting guidance for its file-specific advice.
Avoid changing several export settings at once. If you alter the audio encoding, frame rate, and video compression together, a better or worse result will not tell you which change mattered. First establish that the source file itself is aligned, then use a controlled test to see whether the problem appears downstream.
Run a private or unlisted YouTube test
Do not use a public broadcast as your first diagnostic. Set up a private or unlisted test destination, using the visibility choice appropriate for your channel and test. Castr’s test guide explicitly describes testing a destination separately, including an unlisted or private YouTube stream. Follow the current Castr stream-testing instructions and YouTube’s current live stream privacy guidance.
Keep the test simple. If your workflow allows it, first confirm the source reaches Castr preview with other platforms disabled, then add the YouTube destination as a separate step. This helps distinguish “the source does not reach preview as expected” from “preview looks right but the destination does not”. Record the time the test started and the point in the programme you watched, especially if the mismatch only appears after a while.
A short glance at the opening seconds cannot rule out a problem that builds over time. Let the test run long enough to compare a later cue from the same file. For a loop, note whether the timing changes within a single pass or only after a loop boundary. Do not infer a cause from the point where you happened to notice the problem; compare matched events.
Check the result on YouTube playback, rather than assuming that the Castr preview represents the final destination. If the file and Castr preview appear aligned but the YouTube test does not, preserve the details before changing the playlist. The public materials cited here do not document a universal YouTube-side sync control for a Castr cloud playlist.
Compare playback at each point in the path
Treat the test as a sequence of checkpoints. For the same event, compare local file playback, Castr preview, and YouTube playback. Write down whether audio leads the picture or trails it, and whether that relationship is stable or changes later. You are looking for the first checkpoint where the result differs, not trying to prove a cause from one observation.
| What you observe | What it suggests to check next | What it does not prove |
|---|---|---|
| Local file is out of sync | Correct or re-export the source, then upload and test again | That Castr or YouTube introduced the mismatch |
| Local file and Castr preview look aligned; YouTube differs | Repeat a private or unlisted destination test and retain its time and details | That YouTube is necessarily responsible |
| Local file looks aligned; Castr preview differs | Confirm the exact uploaded file and test again, then ask Castr support with evidence | That a particular playlist setting is the cause |
| Timing is aligned early, then separates later | Compare the same later cue locally, in preview, and on YouTube | That one fixed offset will solve progressive drift |
| Sync issue appears with buffering, dropped frames, or interruptions | Investigate broader stream health as a separate issue | That those symptoms caused a stable offset |
These are decision points, not a fault-finding guarantee. A second test can help distinguish an inconsistent result from a repeatable one, but keep the source and settings unchanged while you repeat it. If you change visibility, source file, and stream settings at the same time, comparisons become harder to interpret.
For a channel that plays a sequence of devotional tracks or study videos, choose cues from more than one point in the programme. A spoken introduction may be easy to judge, while a sustained music passage can conceal a small mismatch. If audio levels also vary between files, that is a separate issue from sync; see how to normalise audio levels across videos in a playlist.
Check stream quality without assuming it caused sync
Once the source and checkpoints are clear, inspect broader stream health only where the symptoms call for it. If playback also buffers, drops frames, becomes choppy, or disconnects, note those symptoms and the times they occur. Castr’s article on buffering, lag, and playback issues recommends looking at source settings, connection stability, stream health charts and ingest location as broader quality checks.
Those checks can help investigate an unstable stream, but they are not proof that a steady audio lead or lag comes from the network. Likewise, codec or bitrate changes may affect compatibility and delivery without correcting a timing error. Castr’s file guidance mentions AAC audio averaging 128 kbps, while general stream-quality advice discusses H.264 video and other encoder settings. Treat those as context for compatibility, not as a recipe for sync repair.
If the test shows dropped frames alongside an increasing mismatch, retain both observations. If the stream remains smooth and the same offset is present throughout, do not make network changes simply because the issue involves timing. You are more likely to learn from one evidence-led change than from a sequence of unrelated adjustments.
For a home setup in India, it can be tempting to treat a particular broadband connection as the explanation for every stream symptom. A connection issue may matter where there are interruptions or unstable delivery, but a clean, repeatable offset in an otherwise smooth private test needs evidence before you attribute it to the connection. The practical advice in a JioFiber setup guide is relevant to connection planning, not a substitute for this sync comparison.
When an OBS offset may be relevant
Only consider OBS audio offset advice when OBS is actually generating the source sent into the stream path. That might be an OBS live scene or an OBS playlist workflow. It does not apply directly to files uploaded into Castr’s cloud playlist feature, because OBS is not controlling that playout.
Castr’s wedding-streaming guidance describes opening OBS Advanced Audio Properties and measuring an offset during rehearsal. It gives 50–100 ms as an example to try, not as a standard value for every source. The guidance is specifically about an OBS-based workflow; it is not a prescribed Castr playlist repair. See Castr’s OBS sync example in its original context.
If your OBS source is the path, first determine whether sound leads or trails the visual event. Make a measured, small adjustment in the direction indicated by your observation, then test again with the same source and cue. Avoid copying a number from another setup without measuring yours. Audio devices, capture paths and scene sources can differ, and an offset that improves one source may make another worse.
A fixed OBS offset is intended to shift timing by a set amount. If the mismatch grows over time, a single static adjustment may not address the underlying behaviour. Do not keep increasing the offset to chase a drift that changes as the stream runs; gather a longer comparison and investigate the source and stream path instead. You can also consult the blog’s guide to OBS YouTube stream key settings for an always-on loop, while keeping stream-key setup distinct from sync diagnosis.
Retest after one controlled change
Once you have evidence about where the mismatch first appears, choose a change that matches that checkpoint. A source file that is misaligned calls for correcting the file; an OBS-fed source may call for a measured OBS test; a clean file and preview but repeatably different destination result calls for better documentation and support investigation. Do not apply all three branches at once.
For each test, keep a short record: the exact source file or version, the workflow (Castr playlist or OBS-fed), the cue and its approximate position, which checkpoint was aligned, and whether the mismatch was constant or grew. Add the date and time of the test, plus any symptoms such as buffering or dropped frames. A simple note is enough; the point is to make the next comparison repeatable.
After one change, rerun the private or unlisted YouTube test and compare the same cue near the start and later in the programme. If the result has not changed, revert a change that is unrelated to the observed checkpoint rather than stacking further adjustments. If it improved, make a fresh repeat before treating the result as dependable. A successful test does not guarantee that every future file or broadcast will behave identically.
For a continuous playlist, include a cue near a transition if that is where the audience reports the mismatch. A problem around a transition may differ from one that is present within every file, so compare the outgoing and incoming audio against their own picture. Keep a separate note if the issue occurs only after a loop repeats.
When the issue needs further diagnosis
Escalate when the source appears aligned but the mismatch is repeatable in Castr preview or YouTube, or when a cloud playlist continues to drift despite clean source checks. Contact Castr support for a playlist-path issue, providing the test time, destination, workflow, source-file details, and matched observations from local playback, preview, and YouTube. Do not send a stream key publicly; use the support channel’s secure process for any account-specific information.
If only the YouTube destination differs, include whether the test was private or unlisted, what device and player you used to review it, and whether the timing was fixed or progressive. If playback was also unstable, report those symptoms separately. This gives the team useful evidence without presuming Castr, YouTube, the network, or a codec caused the mismatch.
Castr’s public material covers pre-recorded troubleshooting, destination tests and general stream quality, but it does not specify a guaranteed automatic correction for sync drift in cloud playlists. A support conversation may identify what to investigate next, but avoid treating any one test or setting as a promise of a fix. For readers choosing how to operate an always-on channel, the distinction between a cloud playlist and a computer-driven workflow also matters; ways to keep a YouTube channel live without a computer describes that broader operating question.
If you are considering a different playback workflow because repeated diagnosis is taking time, compare it on the practical terms that matter to your channel: who prepares the source, how you can run a private test, what you need to monitor, and how you will investigate if playback changes overnight. A change of workflow is not itself evidence that it will solve a timing issue; test the actual file and destination before relying on it.
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
Does an OBS audio offset fix a Castr cloud playlist?
No. OBS offset controls are relevant only when OBS is in the source path, and Castr’s published example is for an OBS workflow. The public documentation does not give a guaranteed OBS-based repair for a playlist uploaded to Castr’s cloud feature.
Should I change the audio bitrate to fix sync?
Not on the evidence of a timing mismatch alone. Castr’s pre-recorded guidance recommends AAC audio averaging 128 kbps as a file-delivery setting, but does not identify it as a sync correction. First compare the local file, preview and private or unlisted destination test.
What if the stream is aligned at first and drifts later?
Compare a later cue in the local file, Castr preview and YouTube test, and record whether the separation increases at each checkpoint. A fixed offset may not address progressive drift, and the available public guidance does not provide a playlist-specific drift diagnosis.
Is YouTube responsible if Castr preview looks right?
That observation narrows where the difference appears, but does not by itself prove the cause. Repeat a private or unlisted test, record the playback device and time, and share the evidence with Castr support if the result persists.