First identify what is drifting: audio relative to video, the entire stream relative to real time, or playback on one device. Those symptoms can sound alike but need different fixes. For a slowly growing audio/video offset, inspect the input timestamps and clocks before trying FFmpeg’s aresample=async=1; it can adjust audio to follow timestamps, but cannot repair every faulty or independent clock.
Identify the kind of drift before changing the command
Listen and observe at the beginning of a stream and again after the problem appears. Record whether the audio leads or trails the video, and whether the offset is fixed, grows steadily, or changes abruptly. Also check whether the whole stream is increasingly behind wall-clock time. That is growing delivery latency, not necessarily audio/video desynchronization.
As an Amazon Associate I earn from qualifying purchases.
- Fixed offset from the start: the inputs may begin at different times.
- Offset that grows steadily: investigate timestamps and clock-rate mismatch.
- Sudden jump: inspect the log and inputs around the time it occurs.
- Only one player or device sounds wrong: compare another playback path before changing the stream.
These are diagnostic clues, not definitive causes. A meditation stream’s still or slow-moving picture can make sync problems harder to notice, so use a representative test with both audio and movement.
Recommended Free Tools
Collect the command, logs and input details
Save the complete FFmpeg command and note the FFmpeg version and build, operating system, input types, whether audio and video come from the same source, audio sample rates and channel layout, and output codec and sample rate. Keep a log from startup and another from when the offset is apparent. The exact correction depends on these details; without them, no single filter or option can be guaranteed to fix the cause.
#1 Best Overall
- Pro performance with great pre-amps - Achieve a brighter recording thanks to the high performing mic pre-amps of the Scarlett 3rd Gen. A switchable Air mode will add extra clarity to your acoustic instruments when recording with your Solo 3rd Gen
- Get the perfect guitar and vocal take with - With two high-headroom instrument inputs to plug in your guitar or bass so that they shine through. Capture your voice and instruments without any unwanted clipping or distortion thanks to our Gain Halos
- Studio quality recording for your music & podcasts - Achieve pro sounding recordings with Scarlett 3rd Gen’s high-performance converters enabling you to record and mix at up to 24-bit/192kHz. Your recordings will retain all of their sonic qualities
- Low-noise for crystal clear listening - 2 low-noise balanced outputs provide clean audio playback with 3rd Gen. Hear all the nuances of your tracks or music from Spotify, Apple & Amazon Music. Plug-in headphones for private listening in high-fidelity
- Everything in the box: Includes Pro Tools Intro+, Ableton Live Lite, Cubase LE, and Hitmaker Expansion: a suite of essential effects, powerful software instruments, and easy-to-use mastering tools
For a timestamp-aware check, FFplay can report audio/video synchronization drift in its statistics. Use the observation to compare the beginning with a later point rather than relying on one playback impression. FFplay’s master-clock setting is primarily a debugging control, not a general repair. See the FFplay documentation.
Check whether separate inputs share a clock
If audio and video are captured by separate live inputs, find out whether their timestamps derive from the same clock. If timestamps have a meaningful common timebase and only the inputs’ starting times differ, FFmpeg’s -isync may help align their starts. FFmpeg documents it as offsetting the target input based on the inputs’ start-time difference and says expected results require timestamp sources derived from the same clock. A start offset is not a correction for a clock-rate mismatch that accumulates over a long run.
Rank #2
- The new generation of the songwriter's interface: Plug in your mic and guitar and let Scarlett Solo 4th Gen bring big studio sound to wherever you make music
- Studio-quality sound: With a huge 120dB dynamic range, the newest generation of Scarlett uses the same converters as Focusrite’s flagship interfaces, found in the world's biggest studios
- Find your signature sound: Scarlett 4th Gen's improved Air mode lifts vocals and guitars to the front of the mix, adding musical presence and rich harmonic drive to your recordings
- All you need to record, mix and master your music: Includes industry-leading recording software and a full collection of record-making plugins
- Everything in the box: Includes Pro Tools Intro+, Ableton Live Lite, Cubase LE, and Hitmaker Expansion: a suite of essential effects, powerful software instruments, and easy-to-use mastering tools
Input options and ordering matter: verify -isync syntax and placement against the documentation for your installed FFmpeg version and command. Do not assume forcing wall-clock timestamps fixes a drifting source clock; timestamp options are not a general synchronization guarantee. Consult the FFmpeg command-line documentation and FFmpeg full documentation.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Test audio timestamp compensation with aresample
FFmpeg’s resampler describes async as “simple 1 parameter audio sync to timestamps using stretching, squeezing, filling and trimming.” Its documented default is 0, which means no compensation is applied. If audio samples are not matching valid timestamps, a controlled test with -af aresample=async=1 is reasonable.
Rank #3
- PLUG IN AND HEAR SOUND IN SECONDS - USB Type-A connector with a 3.5mm stereo headphone output and a separate 3.5mm mono microphone input. No drivers, no software, no external power - the adapter is USB bus-powered and is recognized as a standard USB audio device.
- WORKS ON WINDOWS, MAC AND LINUX - Driverless on Windows 98SE/ME/2000/XP/Server 2003/Vista/7/8, Linux and Mac OSX, and compliant with the USB Audio Device Class 1.0 specification, so any system that supports class-compliant USB audio will see it. Select it as the sound output and input device after plugging it in.
- TWO JACKS, TWO JOBS - The green jack is stereo OUT for headphones or powered speakers; the pink jack is mono microphone IN for a 3.5mm mic. It does NOT support 4-pole headsets on a single combo plug, it does NOT power passive speakers, and it does NOT add surround sound - it is a stereo 2-channel adapter.
- FOR LAPTOPS AND DESKTOPS THAT NEED AN AUDIO PORT BACK - Adds a headphone and mic port to a laptop, desktop, or mini PC whose onboard jack has failed or was never there. Managed and work-issued computers can block new USB audio devices by policy - check with your IT department before ordering for a company machine.
- SABRENT SUPPORT AND WARRANTY - What is in the box: one USB audio sound adapter. Backed by a 1-year limited warranty, extended to 2 years when you register within 90 days on the manufacturer's website.
The option’s value governs the maximum number of samples changed per second; a larger value allows more correction. The appropriate value depends on the measured error and source, so do not increase it blindly. Compare drift observations before and after the change, and listen for artifacts or discontinuities. The filter follows timestamps; it does not prove those timestamps are correct and may conceal an upstream timing problem. See the FFmpeg Resampler Documentation.
Match YouTube’s audio format, but do not mistake format for sync repair
YouTube’s live encoder recommendations specify 44.1 kHz for stereo audio and 48 kHz for 5.1 surround audio. Choose the rate that matches your channel layout and planned delivery, then run a sustained test. Sample-rate conversion is an output-format choice; by itself, it does not correct timestamp drift. YouTube also recommends testing with audio and movement similar to the planned stream. See YouTube’s live encoder settings.
Rank #4
- Podcast, Record, Live Stream, This Portable Audio Interface Covers it All - USB sound card for Mac or PC delivers 48kHz audio resolution for pristine recording every time
- Be ready for anything with this versatile M-AUDIO interface - Record guitar, vocals or line input signals with two combo XLR / Line / Instrument Inputs with phantom power
- Everything you Demand from an Audio Interface for Fuss-Free Monitoring - 1/4" headphone output and stereo 1/4" outputs for total monitoring flexibility; USB/Direct switch for zero latency monitoring
- Get the best out of your Microphones - M-Track Duo’s transparent Crystal Preamps guarantee optimal sound from all your microphones including condenser mics
- The MPC Production Experience - Includes MPC Beats Software complete with the essential production tools from Akai Professional
Use a controlled test to keep or reject a change
- Record the starting sync and note whether the audio leads or trails.
- Change one variable only: for example, test
aresample=async=1if timestamps and audio samples appear misaligned, or test start alignment if separate inputs share a clock. - Run long enough for the suspected drift to become measurable. Compare timestamp-aware observations at the start and later in the stream.
- Keep the change only if it stops accumulating drift without audible artifacts, discontinuities or unwanted latency changes.
FFmpeg’s online documentation is rolling. Check the installed build and its supported syntax before applying an option to a production stream.
Which approach fits which symptom?
| Approach | Use it when | What it changes | Important limit |
|---|---|---|---|
aresample=async=... |
Audio sample count does not keep up with meaningful timestamps | Stretches or squeezes audio, or fills or trims samples | Does not establish that timestamps are correct; can mask an upstream problem |
-isync |
Two live inputs have comparable timestamps but different starting times | Offsets one input by the start-time difference | Expected results require a shared clock; it does not continuously correct clock-rate mismatch |
| Output sample-rate configuration | You need to match the chosen YouTube delivery format | Converts or encodes audio at the selected rate | Correct format alone does not repair timestamp drift |
| Timestamp or clock-source correction | Inputs have faulty or independent timing | Addresses the underlying timebase or capture architecture | The appropriate action depends on the source and logs |
Troubleshoot common outcomes
The offset is already present when the stream starts
Check the inputs’ start times and timestamp relationship. If separate inputs share a clock and only their starts differ, investigate -isync using the correct input ordering and version-specific syntax. If they do not share a clock, start-time alignment alone may not hold over time.
Best Value
- The new generation of the artist's interface: Connect your mic to Scarlett's 4th Gen mic pres. Plug in your guitar. Fire up the included software. Start making your first big hit
- Studio-quality sound: With a huge 120dB dynamic range, the newest generation of Scarlett uses the same converters as Focusrite’s flagship interfaces, found in the world's biggest studios
- Never lose a great take: Scarlett 4th Gen's Auto Gain sets the perfect level for your mic or guitar, and Clip Safe prevents clipping, so you can focus on the music
- Find your signature sound: Air mode lifts vocals and guitars to the front of the mix, adding musical presence and rich harmonic drive to your recordings
- With Scarlett 4th Gen, you have all you need to record, mix and master your music: Includes industry-leading recording software and a full collection of record-making plugins
The offset keeps growing after alignment
Look for a clock-rate mismatch or timestamps that do not track the audio samples. A fixed start adjustment cannot correct accumulating error. Test aresample=async=1 only when there are meaningful timestamps to follow, and verify the result over a sustained run.
The stream is increasingly behind real time
Separate growing end-to-end latency from audio/video drift. Observe the stream’s timing and logs; changing an audio resampler or sample rate is not established as a fix for delivery latency.
Sync changes when playback moves to another device
Compare the same point in the stream on another player or device and note which path shows the issue. Do not alter production timing based on a single playback impression.
Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallThe audio sounds worse after enabling compensation
Revert the change if it introduces artifacts or discontinuities. Check the source timestamps and measured error before testing a different compensation value; higher values permit more samples to change per second, not necessarily a better result.
Or let it run in the cloud
If the meditation stream is a prerecorded video loop and the problem is keeping it running rather than diagnosing an FFmpeg capture chain, StreamNeo keeps an uploaded video or playlist live on YouTube from the cloud. Upload the video, add your YouTube stream key, and go live. Nothing has to stay on at home; each slot streams the upload as made, up to 4K 60fps, at one price per slot, with automatic recovery if YouTube drops the stream. The first day is free with no card. Monthly: $9.99 per month. Start your free day with StreamNeo.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
