iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
First find out whether the audio is out of sync by roughly the same amount throughout the stream or whether the mismatch grows over time. A fixed offset usually calls for aligning input start times; growing drift points instead to timestamp or clock problems that may need timestamp-based audio resampling compensation. There is no reliable one-command fix without knowing your inputs and how their clocks work.
Identify whether the mismatch is fixed or growing
Compare audio and video near the start, then at several later points. Use a recognizable sound and its matching visual event, such as a clap or a word with a clear mouth movement. Note the direction and approximate size of the mismatch each time.
- About the same offset throughout: investigate an initial offset or different input start times.
- The offset increases or decreases: investigate timestamps, sample-rate timing, or clocks that do not run at the same rate.
- The sync changes suddenly: look for missing, irregular, or discontinuous timestamps, input interruptions, and warnings in the FFmpeg log.
These patterns help narrow the diagnosis; they do not prove a particular root cause. Avoid changing several timing options at once, or you will not know which change helped.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Repair Windows errors before they cause bigger problems3Scan for outdated or missing drivers - takes under a minuteCollect the details that determine the fix
- Save the exact command and build information. Record the FFmpeg version/build and complete command line. Remove the private YouTube stream key before sharing logs or command output.
- Inspect the input streams. Use local FFmpeg tools such as
ffprobeto examine audio and video start times, time bases, audio sample rate, video frame rate, and any timestamp warnings. Compare the inputs, not just the final output. - Determine how the inputs are clocked. Establish whether audio and video come from one media file or device, or from separate real-time inputs. For separate sources, find out whether their timestamps derive from a shared clock.
- Repeat the sync check later. Record whether the offset stays steady, changes gradually, or jumps. Keep the test conditions and logs so you can compare each change.
FFmpeg’s online documentation is regenerated nightly and corresponds to its newest revision, so option behavior and availability should be checked against the documentation for your installed build when troubleshooting an existing setup.
#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
Correct a steady start-time offset
FFmpeg’s -itsoffset applies an offset to timestamps for an input. A positive value delays that input. Put the option before the -i it applies to. For example, if you have confirmed that a separate audio input needs to start 250 milliseconds later, the relevant pattern is:
-itsoffset 0.250 -i AUDIO_INPUT
AUDIO_INPUT is a placeholder, not a literal input name. Keep the rest of your known-working command intact, then check sync at the beginning and later in the stream. If the audio needs to move earlier, determine the appropriate adjustment for that input and verify the result rather than blindly applying a positive delay.
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
-isync is another start-time alignment option: it offsets a target input using the start-time difference from a reference input. FFmpeg says expected results assume both inputs derive their timestamps from the same clock source. Do not use it as a general drift correction for independent clocks.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Address drift that accumulates over time
If the mismatch grows, shifting an input’s start time alone will only move the initial alignment; it will not correct a continuing difference in timing. Investigate whether timestamps are valid and continuous and whether audio and video sources share a clock.
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.
FFmpeg’s audio resampler supports timestamp-based stretching, squeezing, filling, and trimming. Its async option is disabled by default. async=1 enables filling and trimming; larger values set the maximum sample compensation per second. The documentation also describes first_pts for padding or trimming at stream start and min_comp as a threshold for compensation.
There is no universal async value to recommend without the source timing and the installed FFmpeg build. Inspect the actual timestamps, consult that build’s resampler documentation, and test a controlled change. Confirm both initial sync and sync later in the stream. If timestamps are missing or discontinuous, investigate that input problem rather than masking it with an arbitrary compensation value.
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
Check video timing without changing it blindly
The video frame mode affects how FFmpeg handles frame timestamps. FFmpeg documents -fps_mode passthrough as forwarding frame timestamps, while cfr duplicates or drops frames to reach a requested constant frame rate. Muxers can also modify timestamps.
Changing frame mode or requesting a different frame rate can alter video timing; it is not automatically an audio-drift fix. Preserve the timing behavior your workflow needs unless the diagnosis shows that video timestamps are the problem. Avoid treating legacy -vsync changes or arbitrary frame-rate conversions as a generic cure.
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
Avoid fixes that cannot repair relative sync
- Shifting all output timestamps uniformly: this preserves relative audio/video timing differences, so it does not by itself repair an existing mismatch.
- Increasing a queue or buffer: muxer interleaving and buffering affect packet output behavior; they are not a general correction for accumulating drift.
- Changing multiple timing flags together: this obscures cause and effect and can introduce a new mismatch.
Verify the change on a test stream
- Keep an untouched copy of the working command and note the one change being tested.
- Use a private or otherwise appropriate test stream and check audio/video alignment near the beginning and at multiple later points.
- Review the FFmpeg log for timestamp warnings, dropped or duplicated frames, and input interruptions. A successful connection to YouTube does not establish that timing is correct.
- If the change improves one point but worsens another, restore the previous command and revisit the clock and timestamp diagnosis.
- Once the result is stable, save the tested command without exposing the stream key.
Or let it run in the cloud
If the underlying goal is keeping uploaded video live on YouTube rather than diagnosing a live FFmpeg input pipeline, StreamNeo is a different approach: upload a recording or build a playlist, add your YouTube stream key, and go live. It plays uploaded videos, not a camera feed, and it streams to YouTube only.
- Nothing has to stay on at home: the stream runs in the cloud.
- Uploaded video streams as made, up to 4K 60fps, at one price per slot rather than quality tiers.
- It automatically recovers if YouTube drops the stream.
- The first day is free with no card. The Monthly price is $9.99 per month.
For a YouTube stream made with FFmpeg, use the diagnostic steps above; to try cloud looping for uploaded videos, start with StreamNeo’s free first day.
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.
