Old AVIs to 4K HDR: one player for thirty years of video

Published 28 October 2026 · 7 min read

Most video collections are a mix of decades: a DivX film from the early 2000s, a camcorder tape copied to DVD, a folder of phone clips, a 4K HDR film downloaded last week. AIX includes decoders for supported older and newer video formats, so no codec pack is required for those formats.

81 file types, decoders included

AIX Player recognises 81 video file types, and the decoders for the video inside them come with the app. Nothing else needs installing. If you are not sure whether a file is a container problem or a codec problem, the video formats page explains the difference.

The old ones

Old video brings old habits. TV recordings and DVDs are often interlaced, and AIX Player deinterlaces them automatically, so moving edges do not comb. Old DVD subtitles in .sub/.idx files and .smi and .ssa subtitle files load too. If an old AVI still refuses to open, the AVI troubleshooting guide covers the usual reasons.

The new ones

• Phone and camera video: MOV and MP4 with H.264 or HEVC (H.265), the format recent phones record in.
• Web video: WebM with VP8 or VP9, and AV1.
• Films and series: MKV with every audio and subtitle track inside it, plus Blu-ray streams as M2TS.
• Editing formats: ProRes and DNxHD.
• 10-bit and 4K SDR are free with no time limit; HDR such as HDR10 and HLG is part of AIX Pro with a free trial.

Small files and big ones

A two-minute phone clip and a three-hour 4K film take the same route. AIX Player has no resolution cap below 8K, so it plays up to 8K where your PC can decode it. Smooth playback depends on the streams, PC, drivers and sustained storage or network throughput.

Hardware decode is on by default and uses your graphics chip where it supports the video, falling back to the processor where it does not. If a big file stutters, the 4K stutter guide takes the causes in order.

Old soundtracks and new ones

The sound is decoded in the app too: MP3, AAC, AC-3 and E-AC-3, FLAC, ALAC, Opus, Vorbis, WMA and RealAudio’s Cook, and the other surround and lossless soundtracks of Blu-ray and DVD copies. AIX decodes supported surround soundtracks and routes them to a compatible output, using a downmix for stereo.

What it does not do

Honesty saves you time. Playlist files such as .asx and .wpl are not on the list, nor are Blu-ray .bdmv index files (open the M2TS streams instead), and teletext subtitles are not supported. A file that is damaged or only partly downloaded may stop early in any player.

Supported older and newer videos use the same player window and controls. If one does not, the unsupported codec guide shows how to find out why.