AVCHD to RMVB Converter

AVCHD to RMVB: Every Output Lands at 640x480 or Smaller

RMVB is RealNetworks' RealMedia container with variable-bitrate RealVideo inside it — the format that carried an enormous amount of low-bandwidth video across Asia in the 2000s, and which still turns up in older media libraries and on set-top boxes of that era. It is a standard-definition format by construction, and the encoders behind it are period pieces.

That has one consequence you need to know before you upload anything: RealVideo output here is capped at 640 pixels wide and 480 pixels tall. A 1920x1080 AVCHD clip does not come out at 1080p, or at 720p, or at any HD size at all. The cap exists because the RealVideo 1.0 and 2.0 encoders and the RealMedia muxer both fall over at HD frame sizes, and it is what keeps this route working — but it also means the settings you choose interact in a way that is not obvious, and one of them will silently ruin your aspect ratio.

How to Convert AVCHD to RMVB

1. Upload Your AVCHD File: Drag the .avchd onto the page or click "+ Add Files". Only the .avchd extension is accepted here; several clips can be queued and all run with the same settings.
2. Set Video resolution to a Preset Resolution: Do this even though "Keep original" is what the page opens on, and even though your source is bigger than anything RealVideo can hold. The reason is in the walk-through below — Keep original produces a 640x480 file with the picture squashed, while any Preset Resolution keeps the shape correct.
3. Choose Video Codec and Audio Codec: Video Codec opens on RealVideo 1.0, with RealVideo 2.0 as the alternative; RV20 is the newer and more efficient of the two. Audio Codec offers AAC, AC3 and RealAudio 1.0, and you should pick one deliberately — nothing dependable is preselected, for the reason explained under the controls table.
4. Convert and Download: Click Convert and save the .rmvb. Files are uploaded over an encrypted connection, re-encoded on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.

Walk-through: Why "Keep original" Squashes 16:9 Into 4:3

The 640x480 ceiling is applied by clamping the width and the height independently. That is fine when the requested frame is already small, and destructive when it is not.

With Keep original selected, the pipeline starts from your source's real dimensions and clamps each one on its own:

• Width: min(1920, 640) = 640
• Height: min(1080, 480) = 480

Nothing recalculates the aspect ratio afterwards, so the entire 16:9 frame is compressed sideways into a 4:3 box. We measured this end to end: a 1920x1080 AVCHD clip on Keep original came out as a 640x480 RMVB with everybody in it visibly narrowed.

With a Preset Resolution the arithmetic is different, because a preset sets the height only and the width is derived from the source's own aspect ratio afterwards. The height is still clamped to 480, but the width then follows correctly:

• Choose 720p, 1080p or anything above 480p → clamped to a height of 480, width derived → 848x480, correct 16:9
• Choose 480p → 848x480, the same thing
• Choose 360p → 640x360
• Choose 240p → 432x240

All of these were produced from the same 1920x1080 source. The last small detail: RealVideo frames are floored to a multiple of 16, which is why the numbers land where they do rather than on round figures.

So the rule for this page is short — never leave Video resolution on Keep original for HD footage. Pick any preset. If you want the smallest sensible file from a camcorder clip, 360p or 240p are honest choices for a format that was designed for dial-up-era bandwidth in the first place.

Which Controls Actually Move the Output

The Audio Codec row needs an explanation. Two different rules in the option configuration both want to set the opening value on RMVB output — one nominates RealAudio 1.0, the other nominates AAC — and which of them wins depends on whether a video codec has been resolved at the moment the panel is built. Because the outcome is not stable, this page does not claim a default: open the list and choose. AAC is the sensible answer for anything you might want to play on a modern device, AC3 if a set-top box expects Dolby, and RealAudio 1.0 only for period authenticity, since it is fixed at 8 kHz mono and exactly 8 kbit/s — telephone quality, and audibly so.

AVCHD and RMVB Side by Side

The AVCHD figures above are as published in the official AVCHD format specification.

Frequently Asked Questions

Why can't I get a 720p or 1080p RMVB out of this?

Because the RealVideo encoders cannot produce one. RealVideo 1.0 refuses to initialise above 4,095 sixteen-pixel macroblocks, so the largest frames it will accept are around 1024x1008 or 1280x816 — 1280x720 is fine, and 1080p is not remotely close. RealVideo 2.0 gets further only to hit the RealMedia muxer's hard 64 KB per-packet limit, which an HD keyframe exceeds and which causes the muxer to drop the frame outright. The 640x480 ceiling this page applies is what stops those failures from reaching you. RMVB was designed in an era when 640x480 was a generous frame size, and there is no setting that changes that. If you want HD, AVCHD to MP4 is the conversion you actually want.

Should I choose RealVideo 1.0 or RealVideo 2.0?

RealVideo 2.0 unless you have a reason not to. RV20 is the later design and holds detail better at the low bitrates this format implies, and every player that reads RMVB reads it. RV10 is the value the page opens on and is worth choosing only for a very old device or authoring tool that specifically names RealVideo 1.0. Both are subject to the same 640x480 ceiling, the same multiple-of-16 frame rule and the same muxer packet limit, so the choice is purely about compression efficiency.

The Constant Quality field says CRF but the numbers only go to 31. Is it broken?

It is mislabelled, not broken. On RealVideo the pipeline emits a qscale rather than a CRF, and the slider is correctly ranged 1-31 for it, opening at 5. The convention is inverted from what "CRF" implies for H.264: on this scale lower is better quality and a larger file, with 1 as the best and 31 as the worst. The value it opens on, 5, is already a sensible high-quality setting for standard-definition material, so most people should leave it alone. The control that genuinely does nothing on this page is Constraint Quality, not this one.

Why does the Max bitrate box under Constraint Quality have no effect?

Because Constraint Quality works by setting a maximum rate and a buffer size, and the pipeline removes both of those parameters for RealVideo 1.0 and 2.0 — those encoders only accept a simple target bitrate or a quantiser, not the buffer-based rate control that Constraint Quality relies on. The field still renders because the control is shared across every video target on the site, but the number you type is discarded before the encoder runs. Use Constant Quality, Constant Bitrate or Specific file size instead.

What audio codec will I get if I don't touch the Audio Codec list?

That is exactly the situation this page cannot answer honestly, which is why it tells you to choose. Two different configuration rules both try to set the opening value on RMVB output — one nominating RealAudio 1.0 and the other AAC — and they resolve in different orders depending on whether a video codec has been settled when the panel is drawn. All three offered codecs mux correctly into RMVB, so the fix is a single click: AAC for general playability, AC3 for a Dolby-expecting set-top box, or RealAudio 1.0 for authenticity at 8 kHz mono and 8 kbit/s.

My camcorder files are .MTS. Is this the right page?

Only if the file is literally named .avchd, which is all this page accepts. No camcorder writes that extension — AVCHD clips are .MTS on the memory card and .M2TS once imported into a BDMV folder or onto a disc — so a .avchd has almost always been renamed by hand or produced by a converter. The bytes are the same transport stream either way, so renaming works, but MTS to RMVB and M2TS to RMVB already cover the names your camera uses.

Is RMVB different from RM, and does it matter which one I pick?

They are the same container. RM is RealNetworks' RealMedia file and RMVB is the same format written with a variable bitrate rather than a constant one — the extension was a labelling convention, not a separate specification, and the pipeline writes both through the same RealMedia muxer. Choose whichever extension the software or device on the other end is expecting; if you want the constant-bitrate spelling instead, AVCHD to RM is the same conversion under the other name.

Will converting to RMVB deinterlace 1080i camcorder footage?

No. There is no deinterlacing filter anywhere in this pipeline, at any setting. If your clips were recorded in a 1080i mode, each frame carries two fields captured a moment apart, and the combing on moving subjects is baked into the picture before RealVideo ever sees it. Because the frame is also being scaled down to 480 lines or fewer, the combing is resampled along with everything else and tends to show up as flicker or fringing rather than clean interlace lines. If it matters, deinterlace in a desktop editor before uploading.

How large a file can I convert, and how long do you keep it?

There is no fixed per-file cap on our side — upload size and connection speed are what limit you in practice, and AVCHD is heavy at up to 24 Mbit/s, so a long recording runs to several gigabytes before conversion starts. Setting a Start time and a Duration under Trim is much quicker than uploading a whole clip you only need a minute of. Everything you send travels over an encrypted connection, is converted on our servers, and both the upload and the output are deleted automatically after a few hours. Nothing is shared or made public, no account is required and no watermark is added.