3GPP to RMVB Converter

3GPP to RMVB: What This Tutorial Covers

RMVB is RealNetworks' RealMedia Variable Bitrate container, released in 2003 as the locally-stored counterpart to the constant-bitrate RealMedia format that RealPlayer streamed. It had a long second life as the distribution format for Asian film and drama releases, and there are still players, set-top boxes and archives that expect .rmvb and nothing else.

3GPP is the mobile side of the same era — ETSI 3GPP TS 26.244, the format GSM and UMTS handsets recorded to. Moving one into the other is a legacy-to-legacy conversion, and the RealVideo encoder has several hard behaviours that will surprise you if nobody says so first. This walk-through covers the controls that work, the ones that render but do nothing, and the resolution rules that decide whether your output is the right shape.

How to Convert 3GPP to RMVB

1. Upload Your 3GPP File: Drag the .3gpp onto the page or click "Add Files" to browse. Several files can be queued and converted with the same settings.
2. Choose a Video Codec: Video Codec offers RealVideo 1.0 (RV10), which the page opens on, and RealVideo 2.0 (RV20). The two are not interchangeable — RealVideo 1.0 has a frame-size ceiling that RealVideo 2.0 does not, described below.
3. Pick an Audio Codec and a Resolution: Audio Codec lists AAC, AC3 and RealAudio 1.0; pick one deliberately rather than relying on a preselection, because the page's audio default is contested between two rules and is not something to build on. Video resolution opens on Keep original, with Preset Resolutions, Resolution Percentage, Width, Height and Width x Height available — and on this target the preset route is the one that behaves.
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.

Walk-through: The Resolution Rules Are Unusual Here

RealVideo encoders were designed around 2000-era desktop playback, and the encoder profile in this pipeline reflects that. Three rules interact, and knowing them saves a confusing round trip.

The frame is capped at 640 x 480. That cap is applied to each axis independently. On Keep original a source larger than 640 x 480 has its width clipped to 640 and its height clipped to 480 with no aspect-ratio correction, so a 1280 x 720 source comes out 640 x 480 — a 16:9 picture squashed into a 4:3 frame. For 3GPP sources this rarely bites, because handset recordings are usually 176 x 144, 320 x 240 or 352 x 288 and sit comfortably under the cap. But if your 3GPP happens to hold a 720p H.264 track, it will.

Dimensions are rounded down to a multiple of 16. RealVideo codes in 16 x 16 macroblocks, so both axes are floored to a multiple of 16 before encoding. A 640 x 360 frame becomes 640 x 352; a 352 x 288 frame is already aligned and passes through unchanged. This is a small vertical crop in effect, and it is why an output can be a handful of lines shorter than you expected.

Preset Resolutions behave better than Keep original. Selecting a preset sets the height and lets the width follow the source aspect ratio, so 480p from a 16:9 source lands at 848 x 480 with the shape intact. Presets above 480p are capped down to 480 lines by the same 640 x 480 ceiling. If your source is bigger than the cap, choosing a preset is strictly better than leaving Keep original, because it preserves the aspect ratio instead of squashing it.

RealVideo 1.0 has a hard size limit that RealVideo 2.0 does not. The RV10 encoder refuses any frame of 4,096 macroblocks or more — that is roughly one megapixel. 1280 x 816 (4,080 macroblocks) encodes; 1024 x 1024 (exactly 4,096) fails outright, and so does anything approaching HD. RealVideo 2.0 has no equivalent ceiling. Since RealVideo 1.0 is what the page opens on, a large source plus Keep original is the combination to avoid — either switch to RealVideo 2.0 or set a Preset Resolution.

Which Compression Controls Actually Do Something

With a RealVideo codec selected, the File Compression panel is not the panel you would get on an H.264 target, even though it looks similar.

Constraint Quality is the trap. The control renders, you can type a Max bitrate into it, and the value is discarded before the encoder ever sees it — RealVideo 1.0 and 2.0 support a simple bitrate or a quantiser, not the buffer-based rate control that mode depends on. If you want a size ceiling, use Constant Bitrate or Specific file size.

There is also a bitrate ceiling worth knowing about. The RealMedia muxer has a packet-size limit of roughly 64 KB per frame, so the pipeline caps the video bitrate at a value derived from that limit and the source frame rate — around 5 Mbit/s at 30 fps. On a 3GPP source you will never come near it; asking for 20 Mbit/s simply gets you the cap instead.

3GPP and RMVB at a Glance

Common Errors and How to Fix Them

• "The conversion failed and I do not know why." If the source is large, this is almost certainly the RealVideo 1.0 macroblock limit. Switch Video Codec to RealVideo 2.0, or set a Preset Resolution at 480p or below.
• "My 16:9 video came out squashed into 4:3." The 640 x 480 cap applied per axis at Keep original. Use Preset Resolutions instead, which sets the height and derives the width from the source shape.
• "The output is a few pixels shorter than the source." Expected. Both dimensions are floored to a multiple of 16 for macroblock alignment, so 360 lines become 352.
• "I set a Max bitrate under Constraint Quality and nothing changed." That mode is discarded for RealVideo output. Use Constant Bitrate or Specific file size.
• "I asked for a very high bitrate and got something much lower." The RealMedia muxer's packet limit caps the rate. On a mobile-resolution source there is no useful bitrate anywhere near that ceiling anyway.
• "There is no audio." The source may have carried an AMR track that failed to decode, or no audio at all. Check the .3gpp in VLC first; if it is silent there, it is silent here.

When This Doesn't Work

RMVB is a proprietary format with no open specification, no browser support, and no current hardware ecosystem — RealNetworks moved on years ago. If the only reason you are here is that some player would not open your .3gpp, converting to RealMedia trades one obscure format for another. 3GPP to MP4 plays on phones, browsers, TVs, editors and media servers with no codec archaeology at all, and 3GPP to MKV is the right answer if you want a flexible container for archiving. Pick RMVB only when a specific device, player or pipeline names it. If you want the same container without the variable-bitrate designation, 3GPP to RM writes it under the classic extension.

Frequently Asked Questions

Should I pick RealVideo 1.0 or RealVideo 2.0?

RealVideo 2.0 unless you have a reason not to. RealVideo 1.0 is what the page opens on and it is fine for small mobile frames, but its encoder refuses anything of 4,096 macroblocks or more — about one megapixel — so a large source fails outright rather than being downscaled for you. RealVideo 2.0 has no such ceiling and is a later, more capable codec. RealVideo 1.0 is worth selecting only when you are feeding something that specifically wants the older stream type.

Why is my output 640 x 480 when my source was widescreen?

Because RealVideo output is capped at 640 x 480 and, on the Keep original setting, that cap is applied to each axis independently with no aspect correction. A 1280 x 720 frame becomes 640 x 480 and the picture is squeezed. The fix is to use Preset Resolutions instead — a preset sets the height and derives the width from the source's own aspect ratio, so 480p from a 16:9 source comes out 848 x 480 with the shape preserved.

Which audio codec should I choose?

Choose one explicitly rather than leaving it. The list is AAC, AC3 and RealAudio 1.0, and the page has two competing rules for what should be preselected, so the safe assumption is that nothing dependable is chosen for you. AAC is the right pick for anything you will play on a computer, and it handles music and speech alike. RealAudio 1.0 is a narrowband speech codec — mono at 8 kHz — appropriate only when you are feeding a genuinely old RealPlayer-era target that expects it. AC3 is worth it only if the destination is a receiver that wants Dolby Digital.

What is the difference between RM and RMVB?

The container is the same; the label describes the encoding strategy. RealMedia was designed around constant-bitrate streaming, where a fixed rate matters because the file is being delivered over a connection with a known bandwidth. RMVB was introduced in 2003 for files stored locally, where a variable bitrate spends more bits on complex scenes and fewer on simple ones for the same overall size. This page writes .rmvb; 3GPP to RM writes the identical container family under the older extension.

Why does the Max bitrate field under Constraint Quality do nothing?

Because the RealVideo encoders do not implement the buffer-based rate control that mode depends on. Constraint Quality works by setting a maximum bitrate together with a buffer size, and both parameters are removed from the encode for RV10 and RV20 output, because those encoders accept only a plain target bitrate or a quantiser. The control renders because it is shared with every other video target; on this one it has no effect. Use Constant Bitrate or Specific file size to constrain the result.

Why is the Constant Quality field labelled CRF when it uses a 1-31 scale?

Because the numeric control is shared with H.264-class codecs, where CRF is the right name and higher numbers mean worse quality on a 0-51 scale. RealVideo takes a quantiser instead, on a 1-31 scale where lower is better — the opposite direction. The control does genuinely work, so it is usable if you know what a quantiser is; the label just belongs to another codec family. If you are not deliberately setting one, stay on Quality Preset.

Will converting my 3GPP to RMVB make it look better?

No. This is a lossy re-encode of already-lossy footage into a codec from roughly the same era, and RealVideo 1.0 and 2.0 are both older designs than the H.264 many later 3GPP files carry. The realistic outcome is "the same picture or slightly worse, in a container a RealPlayer-era target will accept". If the picture quality is what you care about, keep the original and convert to 3GPP to MP4 instead.

Does the audio get re-encoded even if my 3GPP already has AAC?

Yes. There is no pass-through path on this conversion — both the video and the audio are decoded and compressed again, whatever they were. In practice most 3GPP recordings carry AMR-NB anyway, which RealMedia cannot hold, so a re-encode was always going to happen. If your source does contain a good AAC track and you want to keep it untouched, RMVB is not the right destination.

How are my uploads handled?

Your file is uploaded over an encrypted connection, decoded and re-encoded on our servers, and both the upload and the resulting .rmvb are deleted automatically after a few hours. Files are never shared or made public, and there is no sign-up, no watermark and no account required.