Convert MTS to HEVC — Free Online Tool
Convert MTS camcorder footage (AVCHD with H.264 video) to HEVC/H.265 format, dramatically reducing file size while preserving visual quality. HEVC's superior compression makes it ideal for archiving high-definition camcorder recordings at roughly half the bitrate of the original H.264 stream.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your MTS 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
This conversion re-encodes the H.264 video stream from the AVCHD/MTS container using the libx265 encoder, outputting a raw HEVC bitstream file. Unlike a simple remux, the video is fully re-encoded — every frame is decoded and recompressed using H.265's more efficient compression algorithms. The AC-3 or AAC audio track from the MTS file is not carried into the raw .hevc output, as the HEVC bitstream format is a video-only container with no audio or subtitle support. The default CRF of 28 for libx265 is calibrated to produce visual quality roughly equivalent to CRF 23 in H.264, meaning you get comparable image fidelity at a significantly smaller file size.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary — the open-source multimedia processing engine that handles decoding the AVCHD/MTS input and re-encoding it as HEVC. |
-i input.mts
|
Specifies the input MTS file — an AVCHD Transport Stream from a Sony or Panasonic camcorder, containing an H.264 video stream and AC-3 or AAC audio. |
-c:v libx265
|
Selects the libx265 software encoder to re-encode the H.264 video from the MTS file into HEVC/H.265, enabling the compression efficiency gains that make this conversion worthwhile. |
-crf 28
|
Sets the Constant Rate Factor for the libx265 encoder to 28, which is the default quality level calibrated to produce visual quality roughly equivalent to H.264 at CRF 23 — similar fidelity to your original AVCHD footage at a much lower bitrate. |
-x265-params log-level=error
|
Passes a parameter directly to the x265 encoder to suppress its verbose per-frame logging output, so only genuine encoding errors are printed — this does not affect the quality or content of the HEVC output. |
output.hevc
|
Defines the output as a raw HEVC bitstream file (.hevc), a video-only elementary stream with no container, audio tracks, or metadata from the original MTS recording. |
Common Use Cases
- Archiving years of Sony or Panasonic camcorder AVCHD footage to save storage space on NAS drives or cold storage, without visually perceptible quality loss
- Preparing 1080p or 4K AVCHD camcorder clips for editing in a workflow that accepts raw HEVC bitstreams, reducing I/O load on slower drives
- Compressing large MTS vacation or event recordings before storing them on cloud services where storage costs are based on gigabytes used
- Extracting and re-encoding the video track from MTS footage to share highly compressed clips with collaborators who need small file sizes for review
- Converting AVCHD footage from legacy Sony or Panasonic camcorders into a more future-proof HEVC format for long-term digital preservation
- Benchmarking or testing HEVC encoding quality settings against the original H.264 AVCHD source to determine the optimal CRF for a specific archival project
Frequently Asked Questions
No. The .hevc output format is a raw video bitstream container and does not support audio tracks. The AC-3 or AAC audio present in your MTS/AVCHD file will be dropped during this conversion. If you need to retain the audio, consider converting to a container format like MKV or MP4 instead, which can carry both the H.265 video stream and the original audio.
The CRF scale is not directly comparable between H.264 and H.265 encoders. Due to HEVC's superior compression efficiency, a CRF of 28 with libx265 produces visual quality roughly equivalent to CRF 23 with libx264. This means you get similar-looking results at a significantly smaller file size — typically 40–50% smaller than the original AVCHD H.264 stream at equivalent quality.
In most cases, the resulting HEVC file will be 40–60% smaller than the original MTS source at equivalent visual quality. The exact reduction depends on the complexity of your footage — static scenes with low motion compress more aggressively than fast-moving or high-detail content. AVCHD MTS files from camcorders typically record at fixed bitrates around 17–28 Mbps for 1080p, while the re-encoded HEVC output at CRF 28 will adapt its bitrate based on scene complexity, often landing well below the original.
Yes. The CRF (Constant Rate Factor) value controls the quality-to-file-size tradeoff. Lower CRF values (e.g., 18–22) produce higher quality at larger file sizes, while higher values (e.g., 30–35) produce smaller files with more compression artifacts. For archival purposes where quality is paramount, CRF 18–22 is recommended. The valid range for libx265 is 0 (lossless) to 51 (lowest quality), with 28 as the default for this tool.
The single-file command shown works for one file at a time, but you can adapt it for batch processing using a shell loop. On Linux or macOS, run: `for f in *.mts; do ffmpeg -i "$f" -c:v libx265 -crf 28 -x265-params log-level=error "${f%.mts}.hevc"; done`. On Windows Command Prompt, use: `for %f in (*.mts) do ffmpeg -i "%f" -c:v libx265 -crf 28 -x265-params log-level=error "%~nf.hevc"`. This is especially useful for archiving large collections of AVCHD camcorder footage in one pass.
This flag suppresses the verbose per-frame encoding statistics that libx265 outputs by default, showing only actual errors. It has no effect on the quality or content of the output file — it purely reduces terminal noise during encoding. You can safely remove it if you want to see detailed encoding progress information, such as per-frame QP values and bitrate statistics, which can be useful for diagnosing quality issues.
Technical Notes
The MTS/AVCHD format uses an MPEG-2 Transport Stream container with H.264 (AVC) video and either AC-3 or AAC audio, recorded at fixed bitrates by Sony and Panasonic camcorders. Converting to a raw HEVC bitstream (.hevc) means the output is a pure video elementary stream — no container wrapping, no audio, no subtitle support, and no metadata such as creation timestamps or GPS coordinates that some camcorders embed in the MTS stream. The libx265 encoder used here is a software encoder and will be significantly slower than the original camcorder's hardware H.264 encoder; expect encoding times of 0.1–0.3x real-time speed in a browser via WebAssembly, depending on your device's CPU. For files larger than 1GB — common with extended AVCHD recordings — the displayed FFmpeg command is particularly valuable, as running it locally with native FFmpeg will be 5–10x faster than the WebAssembly version. Note that HEVC playback support varies: while modern devices handle H.265 natively, some older software and platforms may require a container like MP4 or MKV rather than a raw .hevc bitstream for reliable playback.