RM to 3G2 Converter

Convert RM to 3G2

RM is RealNetworks' RealMedia container, the format that carried streaming video through the dial-up and early-broadband years. 3G2 is the 3GPP2 file format — the CDMA-side counterpart to 3GP, built on the same ISO base media structure that underpins MP4, and designed for handsets with very little decoding power and very little bandwidth.

Both formats are relics, which is the honest framing for this page. The reason to make a .3g2 today is almost never playback; it is that some specific piece of software, hardware or test rig demands the extension. Everything inside a .3g2 this converter writes is standard, so it will also play in VLC and anything FFmpeg-based. If general playback is the goal, RM to MP4 gives you the same video in a container nothing argues with.

The conversion is a full decode and re-encode. RealVideo and the codecs a 3G2 carries share nothing at the bitstream level, so there is no shortcut and one generation of loss is unavoidable.

How to Convert RM to 3G2

1. Upload Your RM File: Drag the .rm file onto the page or click "Add Files". Several clips can be queued and share the same settings. Uploads travel over an encrypted connection and are processed on our servers.
2. Confirm Video Codec: Video Codec opens on H.264, with H.263, MPEG-4 and Xvid as alternatives. Leave it on H.264 unless a specific device asked for something older — picking H.263 changes your frame size without asking, which the section below explains.
3. Check the Audio Codec Before You Convert: Audio Codec opens on AMR Narrow Band, with AMR Wide Band and AAC available. AMR is a speech codec and it forces the audio to mono at a fixed sample rate. If your RM file contains music, switch to AAC.
4. Set Compression, Resolution and Convert: Compression opens on Quality Preset at Very High (Recommended), alongside Specific file size, Constant Bitrate, Variable Bitrate, Constant Quality and Constraint Quality. Video resolution opens on Keep original. Click Convert and download. No sign-up, no watermark; files are deleted automatically after a few hours.

The Audio Default Is a Speech Codec — Know What It Does

AMR is Adaptive Multi-Rate, the narrowband codec built for GSM and CDMA voice calls. It is extremely efficient at what it does and completely unsuitable for anything else. Crucially, the sample rate and channel count are not yours to choose — they are properties of the codec, and the pipeline applies them regardless of what the source had:

We ran a 640×480 RealMedia clip with 44.1 kHz stereo audio through the default settings and probed the output: the audio came back as amr_nb at 8,000 Hz, one channel, around 12.8 kbit/s. The stereo image and everything above 4 kHz are gone, and no setting on the page brings them back — that is what choosing AMR means. It is exactly right for a spoken-word clip going to a legacy device and exactly wrong for anything musical.

If You Select H.263, the Frame Size Changes Underneath You

H.263 does not accept arbitrary picture sizes. It defines a small fixed set, and the pipeline enforces that by snapping the output to the largest legal size that fits inside your source — overriding whatever you chose under Video resolution, and without preserving the aspect ratio:

A 640×480 RealMedia clip converted with H.263 therefore comes out at 352×288, because 704×576 does not fit inside it. A 320×240 clip comes out at 176×144. If your source is widescreen, the snap ignores that entirely and the picture is squeezed into a 4:3-ish grid.

None of this happens on the default codec. We confirmed that a 640×480 source converted with H.264 stayed 640×480 with the resolution left on Keep original. Choose H.263 only when a device explicitly requires it, and expect the frame size in the table rather than the one you asked for.

Frequently Asked Questions

What is the difference between 3G2 and 3GP?

They come from different standards bodies for different mobile network families: 3GP is the 3GPP format used by GSM and UMTS handsets, and 3G2 is the 3GPP2 format used on CDMA2000 networks. Structurally they are near-identical, both being ISO base media containers in the same family as MP4, and both carry the same H.263, MPEG-4 and H.264 video. The practical differences are in which audio codecs each specification blesses and in the file's brand identifier. If a tool asked for one specifically, use that one; otherwise the choice rarely matters.

Why does my converted file sound so bad?

Because the default audio codec is AMR Narrow Band, which downmixes to mono and resamples to 8,000 Hz — telephone bandwidth. That is not a fault; it is the codec doing its job for the handsets 3G2 was designed around. Switch Audio Codec to AAC before converting and the audio keeps its sample rate and stereo image.

Will my 3G2 file play on a modern phone?

Probably, but not for the reason you think. Modern Android and iOS devices no longer care about 3G2 as a format; what they can play is the H.264 and AAC inside it, and most will happily open the file. The catch is that some apps and galleries filter by extension and will simply not offer to open a .3g2. If the target is a current phone, MP4 is the format that behaves predictably.

Should I choose H.264 or one of the older codecs?

H.264 unless something specific demands otherwise. It is far more efficient than H.263 or MPEG-4 Part 2, it does not impose fixed frame sizes, and the compression controls behave as labelled with it. Pick H.263 only for genuinely old hardware, accepting the frame-size snap described above. MPEG-4 and Xvid are both MPEG-4 Part 2 variants; on them the compression slider becomes a 1–31 quantiser scale where lower numbers mean better quality.

Why is the 3G2 file bigger than the RM file it came from?

Because the default preset is protecting the picture rather than the size. On H.264 the Very High preset resolves to a tight constant-quality target, and it tightens further on small frames because artifacts are more visible when there are fewer pixels to hide in — which is exactly the situation with a standard-definition RealMedia source. Step the preset down to Medium or Low, or switch File Compression to Specific file size and name a target.

What happens to the RealAudio track inside my RM file?

It is decoded and re-encoded. RealMedia files carry RealAudio in several flavours — the RealAudio 1.0 and 2.0 codecs, Cook, Sipro, ATRAC3 — along with more conventional codecs in later files, and whichever is present gets decoded and written out as AMR or AAC. Since the source was almost certainly a low-bitrate lossy stream, this is a lossy-to-lossy step and no bitrate you choose can recover what was already discarded.

Can I convert RMVB files on this page?

No — this page accepts .rm. RMVB is the variable-bitrate sibling of the same container and has its own page, with the same codec choices and the same behaviour. Either way the conversion is a full re-encode, because RealVideo has no relationship to H.264 or H.263 at the bitstream level.

How are my files handled while they are on your servers?

The .rm file is uploaded over an encrypted connection, converted on our servers, and both the upload and the finished .3g2 are deleted automatically after a few hours. There is no account to create, no watermark, and files are never shared or made public. If a RealMedia recording is long enough that uploading is the bottleneck, cut it first with the Video Cutter, which accepts .rm directly, and convert the shorter clip.