CONVERT
MTS → AAC
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Fast, secure MTS to AAC conversion. No registration required.
Setup: MTS is the AVCHD camcorder variant of the MPEG transport stream. Goal: an interchangeable AAC. A MTS to AAC conversion strips the video track from your MTS and keeps only the audio as a clean AAC file. KaijuConverter runs FFmpeg server-side so the audio stream is copied without re-encoding when the codecs allow, preserving the original bitrate and avoiding generational quality loss. In practice MTS is the AVCHD camcorder variant of the MPEG transport stream. On the other end, AAC is the Advanced Audio Codec, more efficient than MP3 and ubiquitous in modern streaming.
AVCHD Video
Source formatMTS (AVCHD) is a high-definition video format from Sony and Panasonic camcorders.
AAC Audio
Target formatAAC is a lossy audio codec that delivers better sound quality than MP3 at similar bitrates. It is the default audio format for Apple Music, YouTube, and most streaming services.
Why convert MTS to AAC
Audio takes a fraction of the space of the original MTS and plays on every device. Converting to AAC means a podcast-length recording drops from hundreds of megabytes to a handful, which matters on mobile data and in cloud storage bills.
HOW TO CONVERT
MTS → AAC
Upload the MTS
Drop the video file into the browser uploader. We only need the file itself — nothing about its origin is retained.
FFmpeg demuxes to AAC
The pipeline detects the audio stream inside the MTS container and remuxes (or re-encodes if formats differ) into AAC.
Download the AAC
Grab the extracted audio. Both MTS and AAC auto-delete within two hours.
Common Use Cases
Share across platforms
Send AAC files to anyone without worrying about whether they have the right software for MTS.
Embed in documents
Drop AAC output into Word, Google Docs, PowerPoint, Notion or a website without conversion warnings.
Optimize size
AAC often produces smaller files than MTS for web, email and storage.
Archive & future-proof
Store in a widely-supported format that will still open on future operating systems without legacy plugins.
MTS vs AAC — Strengths and limitations
What each format does best, and where it falls short.
MTS Strengths
- Native format for every AVCHD camcorder since 2006.
- H.264 compression — small files for high-def quality.
- Direct compatibility with iMovie, Premiere, Resolve, Final Cut.
- Carries Dolby Digital 5.1 audio on flagship camcorders.
Limitations
- Slow to decode — editors typically transcode for editing.
- Proprietary folder-structure conventions complicate direct import.
- Largely legacy as smartphones replaced dedicated camcorders.
AAC Strengths
- Better quality than MP3 at equal bitrate — the industry standard since 2000s.
- Universally supported on every smartphone, OS, and browser.
- Efficient on battery thanks to widespread hardware decoding.
- Scales from 8 kbps speech (HE-AACv2) to lossy-transparent 320 kbps.
- Five-channel + LFE surround support out of the box.
Limitations
- Patent-encumbered — encoders have licensing fees, which is why open alternatives (Opus, Vorbis) exist.
- Slightly more complex to encode than MP3.
- Raw .aac streams carry no seek index — tooling often prefers M4A/MP4 containers.
MTS vs AAC — Technical specifications
Side-by-side comparison of the technical details.
MTS
- MIME type
- video/mp2t
- Extension
- .mts
- Container
- BDAV MPEG-2 Transport Stream (192-byte packets)
- Video codecs
- H.264 (AVCHD Main/High Profile)
- Audio codecs
- AC-3 (Dolby Digital), LPCM
AAC
- MIME type
- audio/aac
- Extensions
- .aac, .m4a, .mp4 (container-dependent)
- Standard
- ISO/IEC 14496-3
- Variants
- AAC-LC, HE-AAC, HE-AACv2, AAC-LD, xHE-AAC
- Sample rates
- 8-96 kHz
| Specification | MTS | AAC |
|---|---|---|
| MIME type | video/mp2t | audio/aac |
| Extension | .mts | — |
| Container | BDAV MPEG-2 Transport Stream (192-byte packets) | — |
| Video codecs | H.264 (AVCHD Main/High Profile) | — |
| Audio codecs | AC-3 (Dolby Digital), LPCM | — |
| Extensions | — | .aac, .m4a, .mp4 (container-dependent) |
| Standard | — | ISO/IEC 14496-3 |
| Variants | — | AAC-LC, HE-AAC, HE-AACv2, AAC-LD, xHE-AAC |
| Sample rates | — | 8-96 kHz |
MTS vs AAC — Typical file sizes
Approximate file sizes for common scenarios.
MTS
- 1 min HD AVCHD (17 Mbps) ~130 MB
- 1 hour AVCHD Full HD ~8 GB
AAC
- Speech podcast (64 kbps) 1 MB/min
- 3-min music track (128 kbps) 3 MB
- 3-min music track (256 kbps) 6 MB
- Broadcast-quality 5.1 (384 kbps) 9 MB for 3 min
Quality & Compatibility
When the audio codec inside the MTS is directly writable into the AAC container, we stream-copy without re-encoding, which means the AAC is bit-for-bit the same audio data. If the codec differs (e.g. a MTS carrying AAC into a AAC that requires MP3), we re-encode at high default bitrate.
Tips for Best Results
- Keep the original MTS alongside the AAC — you may want to re-extract at different settings later.
- If the AAC sounds thin, the source MTS likely had a low-bitrate audio track; check the file metadata before blaming the converter.
- For YouTube-style rips, start with the highest-quality MTS you can download, not the smallest — audio quality scales with video file size even though you discard the video.
Frequently Asked Questions
Yes. The free tier accepts files up to 25 MB without registration, email capture or watermarks; paid plans go up to 2 GB. Paid plans raise the size cap, enable batch conversions and provide a REST API for automation, but nothing on the free tier is quality-limited — the output is exactly the same as on any paid plan.
Only if the audio codec inside MTS is not directly writable into the AAC container. When codecs match we stream-copy, producing a bit-exact AAC. When they differ, we re-encode at a high-quality default, so the perceptual loss is tiny for anything other than lossless-to-lossless mismatches.
Uploads run over HTTPS, files are processed in isolated containers, and both the source MTS and the AAC output are auto-deleted within two hours. No account is required, file contents are never logged, and KaijuConverter does not use uploads for AI training. The paid plan adds a signable data-processing agreement for regulated workflows.
No. The full MTS lands in our processing container, we demux the audio locally and then the container is destroyed. The video bytes never leave KaijuConverter infrastructure and auto-delete within two hours along with the original file.
Most files finish in well under a minute. Small images and documents are typically ready in a few seconds; large video or audio files scale roughly with duration. Upload speed from your network is usually the dominant factor, not server time.
Yes. The Advanced options let you set start and end times in HH:MM:SS, so you can extract a single chapter, a specific quote or a clean sample instead of the full duration of the MTS.
Related comparisons
See these formats side by side to understand which fits your use case best.
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Read guideSecure & Private Conversion
Your files are encrypted during transfer, processed in isolated containers, and automatically deleted within 60 minutes. We never read, share, or store your data.