Old Video File Formats:
AVI, WMV, FLV and More

Old Video File Formats at a Glance

“Convert here” means the video converters on this site accept the format. They output H.264 MP4 (CRF 23, AAC 192 kbps), up to 100 MB per file.

The Legacy Format Graveyard

The history of digital video is littered with abandoned formats. Three stand out for their once-dominant positions:

• AVI (Audio Video Interleave) — Microsoft, 1992. The first mainstream PC video format.
• WMV (Windows Media Video) — Microsoft, 1999. Microsoft's proprietary streaming format.
• FLV (Flash Video) — Macromedia/Adobe, 2002. The format that powered YouTube's first five years.

All three represent abandoned technology ecosystems. AVI lost to more efficient containers, WMV lost to cross-platform standards, and FLV died with Flash Player. Today, MP4 with H.264 has replaced all three as the universal video format.

Why AVI Is Obsolete

AVI (Audio Video Interleave) was Microsoft's first video container, introduced with Video for Windows in 1992. It dominated desktop video through the DivX/Xvid era (2000-2010), when nearly every downloaded video and DVD rip was an AVI file.

AVI is obsolete for several critical reasons:

• Large files: AVI usually holds older codecs such as Xvid or DivX, which need more bits than H.264 for the same picture, and its lack of proper timestamps makes B-frames awkward to store.
• Not built for the web: AVI keeps its index at the end of the file and browsers do not play it, so it is not used for web video.
• No modern browser plays AVI natively: Chrome, Firefox, Safari, and Edge all refuse AVI files. Zero web browser support.
• Fading codec support: AVI files made with old codecs such as Indeo or Cinepak often no longer play in current players.

Common sources of AVI files today: old camcorder recordings (DV/MiniDV), DVD rips from the 2000s, legacy surveillance camera systems, and old screen recording software like early Fraps. For a closer comparison with MP4, read AVI vs MP4 and why to convert AVI.

Why WMV Died

WMV (Windows Media Video) was Microsoft's attempt to dominate online video streaming in the early 2000s. It used Microsoft’s Windows Media Video codecs (WMV 9 was standardized as VC-1) inside an ASF (Advanced Systems Format) container, requiring Windows Media Player or a browser plugin for playback.

WMV failed for fundamental reasons:

• Windows-only: Mac and Linux users could not play WMV files without installing third-party software. In an increasingly multi-platform world, this was fatal.
• No mobile support: iOS never supported WMV. Android support was limited and inconsistent.
• DRM lock-in: WMV was heavily used for DRM-protected content (Windows Media DRM). This DRM system was eventually abandoned, leaving many purchased videos unplayable.
• No web browser support: WMV playback in browsers required plugins: ActiveX in Internet Explorer and a separate plugin for Firefox. When Chrome and Firefox removed plugin support, WMV became completely unplayable in browsers.
• VC-1 codec obsolescence: Microsoft's VC-1 codec (used in WMV) was competitive with H.264 and became a Blu-ray and HD DVD codec, but H.264 won almost everywhere else.

Common sources of WMV files today: old Windows Movie Maker exports, purchased videos with Windows Media DRM (now unplayable), corporate training videos from the 2000s, and early webcam recordings.

Why FLV Is Gone

FLV (Flash Video) was the format that made online video possible in the 2000s. YouTube, Vimeo, Dailymotion, and virtually every video-sharing site used FLV inside Flash Player embeds. At its peak, Adobe said Flash Player was installed on about 99% of internet-connected desktops.

FLV died because Flash Player died:

• Flash Player end of life: Adobe officially killed Flash Player on December 31, 2020. All major browsers removed Flash support. Without Flash Player, FLV files cannot play in any browser.
• Steve Jobs' 2010 letter: Apple's refusal to support Flash on iPhone (2007) and Steve Jobs' “Thoughts on Flash” letter (2010) were the beginning of the end. Mobile web without Flash proved that HTML5 video was the future.
• Security vulnerabilities: Flash Player was a constant source of zero-day exploits. Its removal improved web security dramatically.
• HTML5 <video> replacement: HTML5's native <video> element (with MP4/H.264) replaced everything Flash Video did, without requiring a plugin.

Common sources of FLV files today: old web video downloads, legacy content management systems, archived web pages, and old yt-dlp/youtube-dl downloads from the pre-MP4 era.

What You Gain by Converting to MP4

Converting any legacy format (AVI, WMV, or FLV) to MP4 with H.264 produces immediate benefits:

Smaller files

H.264 is dramatically more efficient than legacy codecs. Re-encoding an Xvid AVI, a VC-1 WMV, or a Sorenson/VP6 FLV to H.264 MP4 usually produces a smaller file for the same picture, though the exact saving depends on the source bitrate. The savings come from H.264's advanced motion compensation, B-frame prediction, and CABAC entropy coding.

Universal compatibility

H.264 MP4 plays on every device manufactured in the last 15 years. Every phone, tablet, computer, smart TV, gaming console, and web browser supports H.264 MP4 natively. No codec packs, no plugins, no third-party software needed.

Streaming support

MP4 with the faststart flag enables instant progressive playback. Web browsers can start playing the video before the entire file downloads. This is impossible with AVI, WMV, or FLV (without Flash Player).

Future-proofing

H.264 is an ISO/IEC standard with hardware decoding in nearly every phone, computer and TV. It will remain playable for decades. Legacy codec support (Xvid, VC-1, Sorenson) is actively being removed from modern operating systems.

Quality Preservation Tips

When converting legacy video to MP4, quality settings matter:

• CRF 20 for irreplaceable content: For home videos, family recordings, and content that cannot be re-obtained, use CRF 20 (or lower). This preserves maximum quality at a modest increase in file size compared to CRF 23.
• CRF 23 for general content: Our default setting. Produces quality indistinguishable from the source for most content, with excellent file size reduction.
• Do not exceed source quality: Legacy AVI/WMV/FLV files are already compressed with lossy codecs. Using a very low CRF (e.g., CRF 15) wastes space without improving quality — you cannot recover detail that the original codec already discarded.

Handling Interlaced Content

Old camcorder recordings and TV captures are often interlaced — each frame consists of two interleaved half-images (fields) that were designed for CRT televisions. On modern progressive displays (LCD, OLED), interlaced video shows characteristic horizontal lines during motion, called “combing artifacts.”

If your AVI file comes from a DV camcorder, VHS capture, or DVB recording, it is almost certainly interlaced. Our converter does not deinterlace, so run the yadif command below (or HandBrake’s Deinterlace filter) to get clean progressive video for modern screens.

The FFmpeg command for deinterlacing legacy content:

ffmpeg -i input.avi -vf yadif -c:v libx264 -crf 20 -c:a aac -b:a 192k output.mp4

This applies the yadif (Yet Another DeInterlacing Filter) to convert interlaced fields into progressive frames before encoding to H.264.

Tapes Are Not Files: VHS, Hi8 and MiniDV

Many “old video formats” are physical tapes. Analog tapes such as VHS, Betamax and Video8/Hi8 have to be played back and recorded with a USB video capture device before any software can convert them. Digital tapes such as MiniDV and Digital8 can be copied over FireWire, which usually produces DV-format AVI or MOV files; those convert to MP4 here like any other AVI.