Convert HEVC to MTS — Free Online Tool
Convert HEVC/H.265 files to MTS (AVCHD) format by re-encoding the video stream from H.265 to H.264 using libx264 — the codec expected by AVCHD-compliant camcorder players and editing software. This is ideal for bringing highly-compressed H.265 footage into workflows built around Sony or Panasonic AVCHD compatibility.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your HEVC file here
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Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
HEVC (H.265) and MTS use different video codecs, so a full re-encode is required — this is not a simple remux. The H.265 video stream is decoded and then re-encoded to H.264 (libx264) at CRF 23, which is the standard quality level for visually transparent H.264 output. Because raw HEVC files typically carry no audio stream, the AAC audio track in the output will be empty or absent unless your source file contains audio. The output is wrapped in an MPEG-2 Transport Stream container (.mts), which is the standard AVCHD container used by Sony and Panasonic camcorders and recognized by broadcast and professional editing tools.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser version, this runs via FFmpeg.wasm (WebAssembly) entirely on your local machine — no data is sent to a server. |
-i input.hevc
|
Specifies the input file — a raw HEVC/H.265 bitstream. FFmpeg will demux and decode this H.265 video stream for re-encoding into the AVCHD-compatible H.264 codec. |
-c:v libx264
|
Re-encodes the video stream using the libx264 H.264 encoder. This is necessary because AVCHD (MTS) devices and software expect H.264 video, not the H.265 codec used in the source file. |
-c:a aac
|
Encodes the audio stream using the AAC codec, which is one of the two standard audio codecs in AVCHD alongside AC-3. If the source HEVC file contains no audio, this flag has no effect. |
-crf 23
|
Sets the Constant Rate Factor for the H.264 encode to 23, which is libx264's default and produces a good balance of visual quality and file size. Lower values increase quality and file size; higher values reduce both. |
-b:a 128k
|
Sets the AAC audio bitrate to 128 kilobits per second, which is a standard quality level for stereo AAC audio in AVCHD files — sufficient for voice and general video audio. |
output.mts
|
Defines the output filename with the .mts extension, which tells FFmpeg to wrap the H.264 video and AAC audio inside an MPEG-2 Transport Stream container — the standard format for AVCHD camcorder footage. |
Common Use Cases
- Importing H.265 footage from a modern mirrorless camera into older NLE software (like Sony Vegas or early Premiere versions) that only supports AVCHD/MTS project workflows
- Preparing H.265 encoded clips for playback on Sony or Panasonic camcorder-connected TVs or monitors that expect AVCHD-compliant MTS files
- Converting drone footage encoded in HEVC to MTS for compatibility with broadcast ingest systems that mandate MPEG-2 Transport Stream containers
- Downconverting H.265 archival video to the H.264-based MTS format for long-term storage in an AVCHD folder structure compatible with legacy authoring tools
- Sharing H.265 clips with a video production team whose shared storage and review pipeline is built around AVCHD MTS file handling
Frequently Asked Questions
Yes, there will be some quality loss because the H.265 video must be fully decoded and re-encoded as H.264 — two lossy compression stages applied to the same footage. The default CRF 23 setting produces high-quality H.264 output, but it will not be bit-for-bit identical to the source. H.264 is also inherently less compression-efficient than H.265, so the resulting MTS file will likely be larger than the original HEVC file at comparable visual quality.
MTS is the AVCHD container format, which was standardized by Sony and Panasonic around H.264 (AVC). While FFmpeg technically supports writing H.265 into an MTS container, AVCHD-compliant devices, cameras, and many editing applications only recognize H.264-encoded MTS files. Using the default libx264 codec ensures the output will be broadly compatible with AVCHD playback hardware and software.
Yes, FFmpeg will still produce a valid MTS file, but the AAC audio track may be empty or the tool may warn that no audio stream was found in the source. Many raw HEVC files (.hevc) are video-only streams and carry no audio. If you need audio in the output, you should first combine your HEVC file with an audio source before conversion, or add a silent audio track using FFmpeg's anullsrc filter.
Change the value after -crf to control H.264 quality. Lower numbers mean higher quality and larger files — CRF 18 is near-visually lossless for H.264, while CRF 28 produces smaller files with more visible compression. The default CRF 23 is a good balance for most use cases. For example: ffmpeg -i input.hevc -c:v libx264 -c:a aac -crf 18 -b:a 128k output.mts
Yes, on Linux or macOS you can loop over files in a shell: for f in *.hevc; do ffmpeg -i "$f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "${f%.hevc}.mts"; done. On Windows Command Prompt, use: for %f in (*.hevc) do ffmpeg -i "%f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "%~nf.mts". This is especially useful for large batches that exceed the 1GB browser limit.
The MTS container does support subtitles, but raw HEVC files do not carry subtitle or chapter data, so there is nothing to carry over in this conversion. If you are working with an HEVC stream that was previously extracted from a container with subtitles, you would need to re-mux the subtitle track separately — it will not be automatically included in this conversion workflow.
Technical Notes
The key technical challenge in this conversion is the generational quality loss from decoding H.265 and re-encoding to H.264. H.265 achieves its compression advantage through more advanced inter-frame prediction and transform coding, which H.264 cannot replicate — so the MTS output at CRF 23 will typically be 30–50% larger than the source HEVC file for equivalent perceptual quality. The MPEG-2 Transport Stream container (.mts) is designed for streaming and broadcast environments, which is why it supports features like multiple audio tracks, but it does not support chapter markers. HDR metadata (HDR10, HLG) present in H.265 sources will be lost during the H.264 re-encode unless tone-mapping filters are explicitly added to the FFmpeg command, since libx264 in standard mode targets SDR output. The -x265-params log-level=error flag from the input side is not carried into the output encoding; the libx264 encoder operates with its own defaults. For 4K HEVC sources being converted to MTS, note that AVCHD as a standard caps resolution at 1080p — while FFmpeg will technically write the file, strict AVCHD players may not recognize 4K MTS files as conformant.