AV1 to MTS Converter

AV1 to MTS — Should You Really Convert Forward in Time?

Converting AV1 to MTS means re-encoding the newest mainstream video codec (AV1, finalized 2018) into the AVCHD camcorder format that Sony and Panasonic built around H.264 back in 2006. That is a step backward in efficiency: MTS cannot hold AV1, so the picture is decoded and re-compressed to H.264, and matching the original quality needs a much higher bitrate. There is exactly one good reason to do it — feeding footage into an AVCHD editor, disc author, or hardware player that only auto-detects an H.264 .mts stream. If you just want a file that plays everywhere, AV1 to MP4 is the right call instead.

AV1 vs MTS (H.264) — Side by Side

When to Convert AV1 to MTS

• An AVCHD-era non-linear editor (Sony Vegas, PlayMemories Home, Panasonic HD Writer) or Blu-ray/AVCHD disc-authoring tool refuses your footage unless it is an H.264 .mts transport stream.
• You are dropping a clip onto an existing AVCHD project timeline next to real camcorder footage and need the formats to match.
• A specific set-top or camcorder-companion player only browses .mts / .m2ts files.
• Your source genuinely already decodes to a usable picture — remember a bare .av1 stream carries no audio, so the MTS will be silent (see the FAQ below).

When to Stay on AV1 (or Pick MP4 Instead)

• You want the smallest file at a given quality — that is exactly what AV1 already gives you; re-encoding to H.264 inflates the size.
• You need broad playback on phones, browsers, and current editors — AV1 to MP4 wraps the video in the universally accepted container without the AVCHD bitrate ceiling.
• Your .av1 came out of an MP4, MKV, or WebM and you want to keep its audio — convert that original container, e.g. MP4 to MTS or WebM to MTS, so the soundtrack rides along.
• You are archiving for the long term — staying on the more efficient, royalty-free codec saves space and avoids a needless lossy generation.

How to Convert AV1 to MTS

1. Upload Your AV1 File: Drag and drop your .av1 onto the page, or click "+ Add Files" to browse. Batch upload is supported, so you can queue several streams and convert them with the same settings.
2. Pick Quality Preset or Bitrate Mode: The Video Codec defaults to H.264, the only codec AVCHD accepts for MTS. Leave Quality Preset on "Very High (Recommended)", or switch File Compression to Constant Bitrate / Variable Bitrate to target a rate, or Constant Quality / Constraint Quality (CRF) for a fixed perceptual quality. Because H.264 is less efficient than AV1, give it generous bits.
3. Resolution and Trim (Optional): Under Video resolution choose "Keep original", a Preset Resolution (1080p, 720p, 480p), Resolution Percentage, or custom Width x Height; for strict AVCHD 1.0 devices stay at 1080p or below. Use Trim → Time Range to export only part of the clip. The Audio Codec defaults to AAC — switch it to AC-3 for the most AVCHD-faithful output.
4. Convert and Download: Click "Convert" and save your .mts file. No sign-up, no watermark.

Frequently Asked Questions

Will converting AV1 to MTS lose quality?

Yes, some — and that is the honest tradeoff, not a tool flaw. MTS cannot store AV1, so the picture is fully re-encoded from AV1 to H.264, which is a lossy-to-lossy pass that cannot regain detail AV1 already discarded. Worse, H.264 is the less efficient codec: independent testing puts AV1 at roughly 30-50% lower bitrate for the same quality (NVIDIA measured a 40% saving at 1080p60), so to keep the picture looking the same the H.264 output needs noticeably more bits than the AV1 source used. Pick a generous bitrate or a low CRF (around 18-20) so the re-encode adds as little visible loss as possible.

Why is my AV1 to MTS output silent?

Because a bare .av1 file is a raw AV1 video bitstream and holds no audio at all. AV1 is defined by the Alliance for Open Media as a video-only codec, so there is no soundtrack inside a plain .av1 to carry over, and the resulting MTS will have no sound. The audio you heard originally lived in the container the video was demuxed from — an MP4, MKV, or WebM with a separate Opus or AAC track. To keep that audio, convert the original container instead: MP4 to MTS or WebM to MTS.

Why would I ever go from a 2018 codec back to a 2006 camcorder format?

Only for AVCHD compatibility. Some older editors and Blu-ray/AVCHD disc-authoring tools auto-detect footage only when it is an H.264 transport stream with the .mts extension, so wrapping your video as MTS lets it drop straight onto an AVCHD project timeline. It buys you compatibility, never a smaller file or a sharper picture. For any modern use — phones, browsers, social uploads, current editors — AV1 to MP4 is smaller and far more widely supported, and many people who land here actually want the reverse MTS to AV1 to modernize old camcorder clips.

What's the difference between .mts and .m2ts, and which do I get?

They are the same AVCHD transport stream under two spellings. Camcorders write .mts directly to the memory card; the identical stream is renamed .m2ts once it is imported to a PC or written to a Blu-ray disc. This tool outputs .mts, which is what most AVCHD editors auto-detect first. If a downstream tool specifically expects .m2ts, just rename the file after download — the bytes are identical and no re-encoding is needed.

Does MTS support Full HD, and is there a bitrate ceiling I should respect?

Yes. AVCHD 1.0 supports up to 1920x1080 and caps the video bitrate at 24 Mbps; the later AVCHD Progressive ("AVCHD 2.0") line added higher resolutions. The resolution presets here go well beyond 1080p, but strict AVCHD 1.0 camcorder software only recognizes up to 1080p, so downscale to 1080p if you are targeting an older suite. Since you are coming from efficient AV1, you may need a higher H.264 bitrate than you expect to preserve the same detail — just keep it under any ceiling your target device enforces.

Which audio codec should the MTS use — AAC or AC-3?

If your source actually has audio (i.e. it is an AV1-in-container file rather than a raw .av1), AC-3 is the most AVCHD-faithful choice because that is what AVCHD camcorders record; the tool defaults to AAC, which plays fine in most software but can prompt some authoring tools to conform it first. In our testing, an AV1-in-MP4 clip with an Opus track re-encoded to an .mts with AC-3 audio imported into an AVCHD authoring template without an extra transcode step, whereas the AAC version sometimes triggered a conform pass. A genuine raw .av1 stream has no audio to encode either way, so the output is silent regardless of the codec you choose.

How are my files handled, and how long are they kept?

Your file is uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after the conversion — no sign-up, no watermark, never shared or made public.