Convert AVI to MTS (AVCHD) online for free. Prepare video for Blu-ray authoring and HD camcorder workflows.

How to Convert AVI to MTS Online

1. Upload Your AVI File: Drag and drop or click "Add Files" to select one or more.avi files. Batch conversion is supported and everything stays on our servers.
2. Pick Video Codec and Quality Preset: Default Video Codec for MTS output is H.264 — the codec required by the AVCHD specification. Quality Preset defaults to "Very High (Recommended)"; choose Highest for archival masters or Medium for smaller files. For finer control switch File Compression to Specific File Size, Constant Bitrate (target 17–24 Mbps for 1080p AVCHD 1.0), Variable Bitrate, Constant Quality (CRF 18–23), or Constraint Quality.
3. Set Audio Codec and Resolution (Optional): Default Audio Codec is AAC. Switch to AC3 (Dolby Digital) if the file is destined for Blu-ray authoring or for AVCHD-folder ingest into legacy camcorder software — AC3 is the standard for both. Under Video Resolution, keep the original or pick a Preset Resolution (1920×1080, 1440×1080, 1280×720) that matches an AVCHD-spec frame size.
4. Trim and Convert: Optionally set Trim to Time Range with Start Time and Duration to extract a segment. Click Convert and download. No sign-up, no watermark, no sign-up.

Why Convert AVI to MTS?

AVI is Microsoft's video container, introduced with Video for Windows in November 1992. MTS is the on-camcorder file extension for AVCHD, a transport-stream-based HD format jointly developed by Sony and Panasonic in 2006 and used by Canon HF/HG, Panasonic HDC/AG, Sony HDR/NEX/HXR, and JVC GZ camcorders. Converting AVI to MTS re-wraps legacy footage into a container that AVCHD-aware editors and Blu-ray authoring tools recognize.

• Blu-ray disc authoring — The Blu-ray spec mandates H.264 or MPEG-2 video with AC3, LPCM, or DTS audio in an MPEG transport stream. MTS with H.264 + AC3 drops cleanly into authoring tools like multiAVCHD or DVDStyler without a re-encode pass.
• Camcorder folder ingest — Many older Sony Handycam and Panasonic HDC playback utilities expect a BDMV/STREAM/*.MTS folder structure. An MTS file can be placed there for playback or NLE detection through the camcorder importer.
• Legacy NLE workflows — Sony Vegas Pro 9+, Pinnacle Studio, and older Adobe Premiere Elements builds historically had reliable MTS importers but flaky AVI codec detection (DivX/Xvid pack required). Converting up-front avoids the codec-pack dependency.
• Broadcast and IPTV pipelines — The MPEG transport stream wrapper carries PCR timestamps and PAT/PMT tables for stream multiplexing, which AVI's RIFF wrapper lacks. Useful for ATSC test playout, set-top box testing, and IPTV middleware.
• Error-resilient archival on flash media — Transport streams interleave 188-byte packets so a localized read error trashes one packet, not the whole file. AVI's index sits at the file end; index corruption can render an otherwise-good AVI unplayable.
• Modern codec without changing your editor — If your AVI uses Xvid or DivX (MPEG-4 Part 2), re-encoding to H.264 inside an MTS often yields a smaller file at the same perceptual quality.

AVI vs MTS — Format Comparison

File Compression Mode Quick Guide

Frequently Asked Questions

Should I pick AC3 or AAC for the audio?

AC3 (Dolby Digital) if the file is going to a Blu-ray authoring tool, AVCHD camcorder folder, or any pipeline that requires the AVCHD spec. AAC if you only need an MTS-wrapped H.264 file for general playback or upload — AAC is more efficient at low bitrates but isn't part of the AVCHD spec, so some authoring tools and older standalone players may reject it. The xconvert default is AAC; switch to AC3 under Audio Codec for AVCHD-strict outputs.

Will Sony Vegas Pro import the converted MTS directly?

Vegas Pro 9 and later add native AVCHD support, but importer reliability varies by H.264 profile and frame rate. If Vegas refuses the file or shows red frames, the safest workflow is to convert to AVI/DNxHD or MPEG-2 instead — that's the long-standing Vegas troubleshooting recipe. For most modern Vegas builds, an MTS using H.264 Main Profile, 1920×1080 at 23.976/29.97/59.94, with AC3 audio imports cleanly. Try AVI to MOV if you specifically need a QuickTime-friendly intermediate.

What's the difference between MTS and M2TS?

Both wrap the same H.264 + AC3/LPCM payload. MTS is what the camcorder writes to the SD card. M2TS is what the camcorder produces after import via its companion software (PMB, PlayMemories) — the M2TS variant adds a 4-byte timestamp prefix per 188-byte transport packet, used by Blu-ray players for accurate seeking. xconvert outputs MTS; if you specifically need.m2ts use AVI to M2TS.

Why is my AVI file not accepted?

The.avi extension is required, and the container must be valid RIFF/AVI. Some "AVI" files from older webcams or DVR firmware are non-standard (truncated index, missing idx1 chunk, or wrapped MJPEG that no longer matches the codec FourCC). If upload fails, try opening the file in VLC and re-saving as AVI first, or convert via AVI to MP4 which has more permissive AVI parsing.

What bitrate should I use for 1080p MTS?

For AVCHD 1.0 spec compliance, target 17–24 Mbit/s constant bitrate at 1920×1080. AVCHD 2.0 raises the ceiling to 28 Mbit/s and adds 1080p50/60. If spec compliance doesn't matter and you just want a good-looking H.264 file in an MTS wrapper, CRF 20–22 with H.264 High Profile produces near-transparent quality at roughly 8–15 Mbit/s for typical content.

Can I keep the original audio track without re-encoding?

Not in this converter — audio is re-encoded to the codec you choose under Audio Codec. If your source AVI already has AAC or AC3 audio at a reasonable bitrate, the re-encode is essentially a transparent pass; the size delta is small. If you need a true stream-copy workflow, that's a desktop-tool job (ffmpeg -c:a copy).

Will the conversion change my video resolution or frame rate?

Resolution is preserved unless you explicitly change it under Video Resolution (Original is the default). Frame rate is preserved from the source. If the source is interlaced AVI (rare but possible from older DV-AVI captures) and you need progressive output, switch the resolution preset to a 1080p or 720p progressive value and the encoder will deinterlace.

Does MTS play on my phone or smart TV?

Modern smart TVs from Samsung, LG, and Sony generally play MTS files from a USB drive. Phones are hit-or-miss: most Android players (VLC, MX Player) handle MTS, while iOS Files and the stock Photos app will not preview MTS — you'd want MP4 instead. For phone-friendly output use MTS to MP4 on the resulting file, or skip the MTS step and convert AVI directly to MP4.

Is there a file size limit?

XConvert processes files on its servers and deletes them automatically after a few hours. Multi-gigabyte AVI files work but encoding time scales linearly. To shrink the input first, run Compress AVI before the conversion. To shrink the output, run Compress MTS afterward.