The file plays fine on your computer. But when You move it to your TV, send it to a client, or try uploading it to a platform, nothing works. No playback. No error message that actually helps. Just a blank screen or a generic “format not supported.”
Most video compatibility problems trace back to the same handful of formats. Old containers, unsupported codecs, platform-specific formats that never travelled well. Here are the eight most common offenders, what makes each one problematic, and how to get out of them fast.
Why Some Formats Cause More Problems Than Others
The file extension is not the whole story. A video file has two layers: the container and the codec. The container — MP4, AVI, MOV — is the wrapper. The codec — H.264, HEVC, ProRes — is how the actual video data is compressed inside it.
Two files with the same extension can behave completely differently on the same device because the codec inside is different. An MP4 with H.264 plays everywhere. An MP4 with ProRes fails on most devices outside professional software. The extension looks identical. The compatibility is not.
This is why some video files cause problems that feel random. They’re not. They follow a clear pattern once you know what to look for.
The 8 Problem Formats
1. AVI
What it is: AVI was Microsoft’s first video container, introduced with Video for Windows in 1992. It dominated desktop video through the DivX/Xvid era from 2000 to 2010.
Why it causes problems: AVI doesn’t natively support modern features like subtitles, multiple audio tracks, or advanced metadata. More critically, AVI has no progressive download capability. The entire file must download before playback can begin, making it unusable for web embedding. AVI files have the problem of not supporting modern video compression technologies such as H.264 or HEVC. The result: large files that can’t stream and increasingly fail to import into modern software.
Who still encounters it: Anyone with files from older Windows machines, archival drives, or footage from the early 2000s.
Convert to: MP4 H.264. Converting AVI to MP4 typically reduces file size by 50 to 80% with no visible quality loss.
2. WMV
What it is: Windows Media Video. A Microsoft proprietary format designed for streaming on Windows systems.
Why it causes problems: WMV’s compatibility with non-Windows systems is limited and quality can suffer due to compression. WMV is not very popular among Apple users — errors and compatibility issues arise when working with WMV on a Mac or any Apple device. Android does not support WMV natively. It won’t upload to most social media platforms and fails on smart TVs outside the Windows ecosystem.
Who still encounters it: Users with older corporate video libraries, Windows-based screen recordings, or presentations exported from older Microsoft software.
Convert to: MP4 H.264. If you still use WMV files, convert them to MP4 for better compatibility across all platforms.
3. FLV
What it is: Flash Video. Built for Adobe Flash Player, once the dominant web video format.
Why it causes problems: Adobe officially ended Flash support in 2020. Today most browsers and devices no longer support FLV playback without additional plugins. FLV has become largely obsolete. It’s been replaced by MP4 and WebM for web streaming. Reopening an old FLV file today typically requires VLC ora legacy codec pack.
Who still encounters it: Anyone digging through old downloads, eLearning archives, or video from early 2000s corporate intranets.
Convert to: MP4 H.264. There is no practical reason to keep footage in FLV in 2025.
4. MTS / AVCHD
What it is: The video format output by Sony, Panasonic, and Canon HD camcorders from the late 2000s and early 2010s.
Why it causes problems: MTS files are not standalone. They live inside a complex AVCHD folder structure — AVCHD/BDMV/STREAM. Move or rename individual files and the structure breaks. AVCHD is designed for Blu-ray disc storage and older camcorder software, not for today’s drag-and-drop workflows. Audio compatibility is a current active issue — users report missing audio or AC-3 audio errors when importing MTS files into Adobe Premiere Pro 2025 and other recent editing applications.
Who still encounters it: Anyone with footage from camcorders of that era — a significant volume of family and event video.
Convert to: MP4 H.264 with AAC audio. Keep the full AVCHD folder structure intact until conversion is complete.
5. MOV with ProRes Codec
What it is: MOV is Apple’s container format — generally reliable. ProRes is the codec that creates problems when it lives inside it.
Why it causes problems: ProRes is a professional editing codec, not a delivery codec. HEVC and ProRes videos recorded on iPhone or professional cameras frequently fail to play on Windows computers and non-Apple devices. ProRes MOV files fail on YouTube upload, most Android devices, and virtually all software outside professional post-production tools on Mac.
Who still encounters it: Editors working in Final Cut Pro, footage shot on professional cameras set to ProRes output, and anyone who received a “high quality” file from a production company.
Convert to: MP4 H.264 for delivery. Keep the ProRes file as the editing master — it’s the correct format for editing. It’s not the correct format for sharing.
6. HEVC / H.265
What it is: The successor to H.264. Better compression, smaller files, same visual quality. iPhones record in HEVC by default.
Why it causes problems: Support is inconsistent. Nearly 35% of Android devices don’t include hardware-accelerated HEVC decoding. Older Android models prompt a “video codec not supported” error when playing HEVC videos. The video containers available for HEVC on Android are also limited — you can’t view HEVC files saved in MOV, M4V, AVI, or 3GP on Android. Windows requires a separately installed codec pack for HEVC playback on older systems. After upgrading to Android 15, H.265 hardware decoding fails entirely on several MediaTek Dimensity devices.
Who still encounters it: Anyone who sent an iPhone video to an Android user and got a “can’t open this file” message back.
Convert to: MP4 H.264 for broad compatibility. Keep HEVC for storage where file size matters and you control the playback device.
7. 3GP / 3G2
What it is: A mobile video format developed for early-generation smartphones and low-bandwidth connections.
Why it causes problems: Low resolution by design — typically 176×144 or 320×240. Limited codec support on modern editing software. Poor audio quality. Most modern platforms don’t accept it for upload, and most media players handle it inconsistently.
Who still encounters it: Footage from early Nokia, Samsung, and Sony Ericsson phones. Video MMS messages from before smartphones. Archival footage from the mid-2000s.
Convert to: MP4 H.264. Quality improvement from AI upscaling is worth doing before archiving — the source resolution is low enough that an enhancement pass adds visible value.
8. WebM
What it is: Google’s open-source web video format, built for HTML5 browser playback.
Why it causes problems: WebM works well in modern web environments but lacks broad support outside Chrome-based browsers. It fails to import into most professional editing applications, doesn’t play natively on older devices, and is not accepted by most platform upload systems. It’s a web delivery format that doesn’t travel well outside that specific context.
Who still encounters it: Developers downloading web-embedded video, screen recordings from browser-based tools, and footage exported from certain online editors.
Convert to: MP4 H.264 for general use. WebM stays useful for web embedding — outside that context, convert it.
The Fastest Way to Convert Any of These
The answer in every case above is the same: MP4 with H.264 video codec and AAC audio. It plays on every device, imports into every editing application, and uploads to every platform without compatibility issues.
TotalMedia VideoConverter handles all eight formats listed. Add files individually or drop an entire folder — batch processing converts everything in one session with consistent settings. The Web Video tab includes YouTube and Vimeo presets that automatically apply the correct encoder, resolution, and bitrate for platform delivery. Custom settings give full control over encoder, resolution, frame rate, bitrate, and audio codec for professional delivery requirements.
Available as both a desktop application and a web app — no installation required for the browser version.
Quick Conversion Reference
| Format | Main Problem | Convert To | Priority |
| AVI | No streaming, large files, outdated codecs | MP4 H.264 | Medium |
| WMV | Fails on Mac, Android, and most platforms | MP4 H.264 | High |
| FLV | Flash is dead — no modern browser support | MP4 H.264 | Critical |
| MTS/AVCHD | Folder structure fragility, audio issues | MP4 H.264 | High |
| MOV ProRes | Fails on non-Apple devices and platforms | MP4 H.264 | High |
| HEVC/H.265 | Patchy device support, iPhone sharing issues | MP4 H.264 | Medium |
| 3GP/3G2 | Low resolution, poor modern compatibility | MP4 H.264 | Medium |
| WebM | Limited to Chrome-based browsers | MP4 H.264 | Medium |
Frequently Asked Questions
Most smart TVs require MP4 with H.264 and AAC audio for USB playback. Formats like AVI, WMV, MTS, and WebM often fail on TV firmware even when they play fine in VLC on a computer. Convert to MP4 H.264 before transferring to USB and the compatibility problem disappears.
For general delivery — yes. MP4 with H.264 is the universal standard that plays on every device, uploads to every platform, and imports into every editing application. For editing masters, ProRes or DNxHR are better choices. For archiving multi-track projects, MKV handles multiple audio and subtitle streams more cleanly. For delivery and sharing, MP4 H.264 is the right answer in almost every case.
Converting from one lossy format to another at a matching or higher bitrate is visually lossless in practice. The important variable is output bitrate. Legacy AVI, WMV, and FLV files are already compressed with lossy codecs — converting to MP4 H.264 at a high bitrate produces quality indistinguishable from the source. Converting at a lower bitrate than the original discards detail permanently.
iPhones record in HEVC by default — a format that nearly 35% of Android devices can’t hardware-decode. The file looks like a standard MP4 but the codec inside isn’t supported. Converting to MP4 H.264 before sharing, or switching iPhone recording to Most Compatible in Camera settings, resolves this entirely.
Batch processing. Drop the entire folder into TotalMedia VideoConverter, set your output format once, and convert all files simultaneously. For a mixed folder of legacy formats — AVI, WMV, MTS, FLV — batch conversion processes everything in one session with consistent output settings, rather than converting each file individually.