MX Player Audio Out Of Sync: How To Fix Lip Sync Problems

When MX Player’s audio and video drift apart, it can make even a great movie unwatchable. The good news is that most lip sync problems come from a handful of fixable causes: decoding mode conflicts, variable frame rate files, Bluetooth latency, damaged downloads, or device performance limits. This guide walks through practical, step by step fixes, starting with the simplest and moving to more technical solutions, so you can get back to smooth, properly synced playback.

1. Understand Why MX Player Gets Out Of Sync.

Lip sync issues usually happen because the audio clock and video clock are not progressing together. The player tries to keep them aligned, but certain conditions make that difficult.

1.1 The Most Common Causes

Here are the issues that most often create audio delay (audio late) or audio ahead (audio early):

• Bluetooth or wireless audio latency (headphones, speakers, soundbars) that adds delay outside the player.
• Hardware decoder quirks where your device’s hardware video decoding pipeline introduces timing drift.
• High bitrate or high resolution files that push the device too hard, causing dropped video frames and perceived desync.
• Variable frame rate (VFR) video (common with screen recordings and some phone camera files) that can confuse A/V timing.
• Corrupt downloads or damaged containers (MP4/MKV issues), where timestamps inside the file are inconsistent.
• Background load (heavy multitasking, battery saver modes, thermal throttling) that interrupts steady decoding.

1.2 Identify Whether Audio Is Early Or Late

Before you change settings, confirm the direction of the problem:

• Audio late: lips move first, then the words arrive afterward.
• Audio early: you hear words first, then the mouth movement follows.

This matters because some fixes add delay and some reduce it. Also note whether it happens only with Bluetooth, only with one file, or across all videos.

2. Quick Fixes You Can Try In Under 2 Minutes.

Start here. These resolve a large percentage of cases without changing advanced settings.

2.1 Pause, Seek, And Restart Playback

Temporary sync drift can happen after resuming from the background or after a network hiccup (for streamed files).

• Pause for 3 to 5 seconds, then press play.
• Seek forward 10 seconds, then seek back 10 seconds.
• Close the video and reopen it.

If the problem disappears until the next resume, the issue is likely state related rather than file corruption.

2.2 Restart MX Player And Reboot Your Device

A full reboot clears stuck audio routes, Bluetooth stack glitches, and memory pressure.

• Force close MX Player.
• Restart your phone or tablet.
• Test the same video again.

2.3 Disable Bluetooth To Rule Out Wireless Latency

Bluetooth audio is often delayed because the audio must be encoded, transmitted, buffered, and decoded. Some devices compensate well, others do not, and some combinations drift during playback.

• Play the same scene using your phone’s speakers or wired headphones.
• If lip sync is fixed when Bluetooth is off, you are dealing primarily with wireless latency rather than a broken video file.

3. Fix Audio Sync Inside MX Player (Player-Level Fixes).

If the desync is consistent (for example, always about 200 ms late), you can often correct it using MX Player’s built in audio delay controls and decoding settings.

3.1 Adjust Audio Delay (Lip Sync Offset)

MX Player includes an audio delay adjustment so you can shift audio earlier or later to match the video.

• If audio is late, adjust so audio plays earlier (negative delay).
• If audio is early, adjust so audio plays later (positive delay).

Practical tip: adjust in small steps, then replay a dialogue heavy scene (close ups are easiest to judge). If you need a huge offset (like more than 500 ms), the file or decoding pipeline is likely the real problem, and you should continue with the fixes below.

3.2 Switch Between HW And SW Decoding

Hardware decoding (HW) uses your device’s video decoding hardware, which is efficient but can be buggy for certain codecs, profiles, or containers. Software decoding (SW) is more compatible but uses more CPU.

• Try switching to SW decoder if HW decoding shows drift, stutter, or lip sync errors.
• If SW plays in sync but stutters, try HW+ (if available) or lower playback load (see Section 5).

If changing the decoder fixes sync instantly for the same file, you have identified the issue: it was timing behavior in the device’s hardware decode path.

3.3 Toggle Audio Track Or Video Track (If Available)

Some files include multiple audio tracks (different languages) or commentary tracks. Occasionally one track has bad timestamps.

• Switch to a different audio track and test sync.
• If the file has multiple video streams (rare), try the alternative stream.

If only one specific track is out of sync, the file’s track metadata is likely the culprit.

4. Fix The File (When Only Certain Videos Are Out Of Sync).

If MX Player works fine for most videos but one download is consistently out of sync, you should suspect the file itself. This is especially true if the video is out of sync on multiple players.

4.1 Confirm The Problem In Another Player

Test the exact same file in another reputable player on the same device.

• If it is out of sync everywhere, the file is likely authored incorrectly or damaged.
• If it is only out of sync in MX Player, focus on MX Player settings (decoding, audio delay) and device audio routing.

4.2 Re-Download Or Copy The File Again

Incomplete downloads and flaky transfers can create timestamp glitches. This happens more than people realize, especially with large MKV files.

• Delete the file and download it again from the original source.
• If transferred from a PC, try a different cable, different port, or a different transfer method.

If the re-downloaded version plays in sync, the original file was incomplete or corrupted.

4.3 Remux The Video (Rebuild The Container Without Re-encoding)

When timestamps inside the container are odd but the audio and video streams are fine, remuxing can fix sync without quality loss. This means you put the same audio and video into a fresh container (often MKV or MP4).

• Use a tool that can remux without re-encoding.
• After remuxing, test the new file in MX Player.

This is one of the best solutions when the file plays but drifts over time, or when seeking makes sync worse.

4.4 Convert Variable Frame Rate Videos To Constant Frame Rate

Variable frame rate is common in screen recordings, webcam captures, and some phone camera modes. Many players handle VFR well, but some combinations of VFR plus certain audio codecs can drift, especially on older devices.

• If the problem is a screen recording, try exporting it with constant frame rate.
• If you are comfortable with video tools, transcode to a constant frame rate format for maximum compatibility.

Converting VFR to CFR can be time consuming, but it is a strong fix for videos that slowly desync the longer they play.

5. Fix Device Performance And Playback Load (When Video Stutters Too).

Sometimes the audio is actually correct, but the video is dropping frames due to CPU, GPU, or thermal limits. That makes it look like lips are not matching speech.

5.1 Close Background Apps And Disable Heavy Overlays

If your device is under load, real time decoding can suffer.

• Close background apps, especially games, browsers with many tabs, and screen recorders.
• Disable picture-in-picture overlays you are not using.
• Temporarily disable VPNs that may affect network streaming stability.

5.2 Reduce Playback Complexity

Some settings increase processing requirements.

• Turn off video post-processing features (if enabled).
• Avoid extreme zoom modes that force additional scaling work.
• If the file is 4K on a midrange phone, try a 1080p version of the same content.

If performance improves and sync returns, the root cause was resource pressure rather than a timing bug.

5.3 Watch For Thermal Throttling

Phones can slow down when hot, which can cause video frame drops.

• If your device is warm, let it cool and try again.
• Avoid charging while playing very high bitrate video.

6. Fix Bluetooth And Audio Output Issues (Common With Headphones And Soundbars).

If the video is in sync on the phone speaker but not on Bluetooth, your main issue is output latency. Some of this is normal, but you can often reduce it.

6.1 Try A Different Bluetooth Codec Or Disable HD Audio

Some Bluetooth codecs increase buffering to improve quality, which can increase latency. Device support varies widely.

• If your device offers a “HD audio” toggle for the connected Bluetooth device, try turning it off and re-test.
• If you have developer options and know what you are doing, you can test different Bluetooth codec options and prioritize lower latency choices.

If turning off HD audio reduces delay, you have confirmed codec buffering as a major contributor.

6.2 Use Wired Audio Or Low Latency Hardware For Best Sync

For the most reliable lip sync, wired headphones or speakers avoid most transmission buffering. If you need wireless, hardware designed for low latency (and compatible device support) typically performs better.

• Test with wired headphones or a USB-C to 3.5 mm adapter if your phone supports it.
• If you use a TV or soundbar, check whether the TV has an audio delay setting and whether it is set correctly.

6.3 Reconnect The Bluetooth Device And Reset Audio Routing

Bluetooth stacks can get into a bad state where delay fluctuates.

• Disconnect Bluetooth, wait 10 seconds, reconnect.
• Forget the device and pair again if the problem persists.

7. Advanced Troubleshooting (When Nothing Else Works).

If you have tried decoder switches, audio delay, re-downloading, and Bluetooth testing, you may be dealing with a compatibility issue between the file’s codecs and your device’s capabilities.

7.1 Check The Codec And Container Details

Knowing what you are playing helps you choose the best fix. Key items include:

• Video codec (H.264/AVC, H.265/HEVC, VP9)
• Audio codec (AAC, MP3, AC-3, E-AC-3, DTS)
• Container (MP4, MKV)
• Frame rate type (constant vs variable)

If the audio codec is unusual for your device, software decoding or remuxing to a more compatible format may help.

7.2 Update MX Player And Your Android System Components

Player updates can fix decoder bugs, and system updates can fix media framework issues. Also, some Android components responsible for media playback get updated via the app ecosystem depending on device model.

• Update MX Player to the latest version available to you.
• Update your device OS if an update is available.

7.3 Reset MX Player Settings (If You Changed Many Things)

If you have toggled many options, it can be hard to remember what changed. A reset can return you to a known good baseline.

• Note any important preferences first (subtitles, gesture controls, default folders).
• Reset settings, then test the problematic file again.

8. Frequently Asked Questions About MX Player Lip Sync.

8.1 Why Is MX Player Out Of Sync Only With Bluetooth Headphones?

Bluetooth adds transmission and buffering delay that can vary by device, codec, and headset. If the same video is in sync on speakers but not on Bluetooth, your fix is usually to adjust audio delay, change Bluetooth codec settings, or use a lower latency audio path.

8.2 Why Does Sync Get Worse The Longer The Video Plays?

Progressive drift often points to timestamp or frame rate issues in the file, such as variable frame rate or a container with inconsistent timing data. Remuxing or converting to constant frame rate is often the most reliable long term fix.

8.3 Why Does Seeking Forward Make Audio Desync Worse?

Seeking stresses timestamp handling. If the file has imperfect indexing or damaged timestamps, jumping around can cause the audio and video to re-align incorrectly. Remuxing the file or re-downloading it commonly resolves this.

8.4 Is Hardware Decoding Always Better?

Hardware decoding is usually more power efficient and smoother, but it can be less compatible with edge cases. If you see lip sync issues, switching to software decoding is a legitimate troubleshooting step, especially for older phones or unusual video profiles.

8.5 What If The Video Is Fine On My PC But Not On My Phone?

PC players often have different decoders and more CPU headroom. On phones, hardware decode paths and performance limits are more likely to trigger stutter and timing drift. In that case, try software decoding, lower resolution files, or remuxing to a highly compatible format.

9. A Simple Step By Step Checklist (Do This In Order).

If you want the shortest path to a fix, follow this sequence:

1. Test the video on phone speakers (Bluetooth off) to isolate wireless latency.
2. Force close MX Player, reopen, and replay the same scene.
3. Adjust audio delay slightly to match lips.
4. Switch decoder: HW to SW (or try HW+ if available).
5. Try a different audio track if the file has one.
6. Re-download the file or re-transfer it from your PC.
7. Remux the file into a clean MKV or MP4 container.
8. If it is a screen recording, convert VFR to constant frame rate.

In practice, most users solve it by either adjusting audio delay (especially for Bluetooth) or changing the decoder mode (especially for device-specific hardware decoding issues).

Citations

• Android Developers documentation on audio and latency concepts. (Android Developers)
• Android Developers documentation on Bluetooth audio codecs and configuration options (background on codec and latency tradeoffs). (Android Open Source Project)
• FFmpeg documentation on remuxing (stream copy) concepts used to fix container timestamp issues. (FFmpeg)
• Variable frame rate overview and why it can complicate playback timing. (HandBrake Documentation)