Convert 3G2 to HEVC — Free Online Tool
Convert 3G2 video files from legacy CDMA mobile devices into HEVC (H.265) format, re-encoding the video stream with libx265 for dramatically smaller file sizes at comparable visual quality. HEVC's superior compression makes it ideal for archiving or repurposing old mobile footage without the bloat of the original low-bitrate 3G2 container.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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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
3G2 is a container format originally designed for CDMA mobile networks (Verizon, Sprint-era phones), typically storing H.264 or MJPEG video alongside AAC audio at constrained bitrates suited for cellular transmission. During this conversion, FFmpeg decodes the video stream from the 3G2 container and fully re-encodes it using the libx265 encoder, producing a raw HEVC bitstream (.hevc). The audio stream is dropped entirely in the output — HEVC (.hevc) is a raw video bitstream format with no container, meaning it carries only compressed video frames and has no mechanism for storing audio, subtitles, or metadata. The re-encoding process applies a CRF of 28, which is the x265 default and targets a visually efficient quality level, typically producing a file significantly smaller than the source 3G2 even when the original was already low-bitrate.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary — the open-source multimedia processing engine that handles decoding the 3G2 container, re-encoding the video with x265, and writing the raw HEVC bitstream output. |
-i input.3g2
|
Specifies the input file — a 3G2 container, the CDMA-era mobile multimedia format developed for 3GPP2 networks. FFmpeg will demux the container, exposing the video stream (typically H.264 or MJPEG) for decoding and re-encoding. |
-c:v libx265
|
Sets the video encoder to libx265, the open-source H.265/HEVC encoder. This triggers a full decode-and-reencode of the video stream from the 3G2 source rather than a simple remux, converting the original mobile-era codec to the modern HEVC standard. |
-crf 28
|
Sets the Constant Rate Factor for libx265 to 28, which is the encoder's default quality target. This value is calibrated to produce perceptually efficient results with x265 — it is not the same scale as the CRF 23 default used by libx264 in 3G2 encoding, but delivers comparable visual quality at a lower bitrate. |
-x265-params log-level=error
|
Passes an internal parameter string directly to the x265 encoder, suppressing its default verbose per-frame logging so only actual encoding errors are printed to the console. This does not affect the video quality or output file in any way. |
output.hevc
|
Specifies the output file as a raw .hevc elementary bitstream. This format contains only the encoded HEVC video frames with no container wrapper, meaning no audio, no metadata, and no timestamps — just the compressed video stream extracted from the original 3G2 file and re-encoded with x265. |
Common Use Cases
- Archiving old footage recorded on early 2000s CDMA smartphones (e.g., LG, Samsung CDMA models) into a modern, space-efficient format for long-term storage
- Stripping down a library of 3G2 clips from legacy devices to reduce storage footprint using HEVC's superior compression before re-muxing into a modern container like MKV or MP4
- Preparing the video-only stream from a 3G2 file for professional video editing workflows that import raw HEVC bitstreams, then handle audio separately
- Converting 3G2 footage to HEVC as an intermediate step before transcoding to a streaming-compatible format, leveraging x265's quality-per-bit advantage over the original codec
- Extracting and preserving the visual content of 3G2 files recorded on CDMA network devices when the audio track is corrupt, missing, or unnecessary for the end use
Frequently Asked Questions
No — audio is not preserved in this conversion. The .hevc output format is a raw video bitstream and has no container structure capable of holding audio tracks, subtitles, or metadata. Only the re-encoded video stream is written to the output file. If you need to keep the AAC or MP3 audio from your 3G2 file, you should target a container format like MP4 or MKV instead, which can hold both HEVC video and audio together.
The CRF scale is encoder-specific, not universal. The 3G2 source uses libx264, where CRF 23 is the default and represents a balanced quality target. For libx265 (H.265), CRF 28 is the equivalent default and produces visually comparable results to x264's CRF 23, because H.265 achieves the same perceptual quality at a lower bitrate. Using CRF 28 with x265 on typical 3G2 source footage will generally produce a smaller output file than the original while maintaining similar or better visual fidelity.
It depends on the original 3G2's codec and bitrate. If the 3G2 was encoded with H.264 (libx264), HEVC at CRF 28 will typically produce a file 30–50% smaller for equivalent quality. However, 3G2 files from old CDMA phones were often already heavily compressed at very low bitrates, so the size reduction may be less dramatic — and in some edge cases, re-encoding low-quality source footage at CRF 28 could produce a file of similar size if the encoder preserves detail the original discarded.
This flag suppresses the verbose per-frame encoding statistics that libx265 prints to the console by default, showing only actual errors. It has no effect on the output file quality or encoding behavior — it only affects what you see in the terminal. You can safely remove it if you want to see detailed x265 encoding progress, which can be useful for diagnosing encoding issues or monitoring quality settings on long conversions.
Yes — the CRF value in the command controls the quality-size tradeoff. For libx265, the CRF scale runs from 0 (lossless) to 51 (lowest quality). Lower values produce larger, higher-quality files: CRF 18 is considered near-visually-lossless for most content, while CRF 35 produces noticeably smaller files with more compression artifacts. For archiving 3G2 footage where the source is already low-resolution mobile video, a CRF between 24 and 30 is usually sufficient. Just replace the '28' in '-crf 28' with your preferred value.
The command as shown processes a single file, but you can adapt it for batch processing in a shell. On Linux or macOS, use: for f in *.3g2; do ffmpeg -i "$f" -c:v libx265 -crf 28 -x265-params log-level=error "${f%.3g2}.hevc"; done. On Windows Command Prompt: for %f in (*.3g2) do ffmpeg -i "%f" -c:v libx265 -crf 28 -x265-params log-level=error "%~nf.hevc". This is especially useful for processing large collections of old CDMA device recordings that exceed the 1GB browser tool limit.
Technical Notes
The .hevc output is a raw elementary bitstream — it contains no container wrapper, which means no audio, no timestamps, no metadata, and no chapter or subtitle support. This distinguishes it from .mp4 or .mkv files that happen to use HEVC video; raw .hevc files are primarily useful as intermediate files in professional workflows or for direct playback in media players that support raw bitstream decoding (such as VLC). The source 3G2 format was constrained by CDMA network transmission requirements, often encoding video at resolutions like 176x144 (QCIF) or 320x240 (QVGA) with H.264 at very low bitrates. Re-encoding such low-resolution, low-quality source material with x265 will not recover lost detail — the encoder can only compress what's there. The -x265-params flag uses x265's internal parameter string interface, which allows fine-grained control over the encoder beyond what standard FFmpeg flags expose. Lossless encoding is technically possible with libx265 using CRF 0, but this will produce very large files and is rarely appropriate for 3G2 source content that was already lossy-compressed. No metadata from the original 3G2 file (such as creation date or device model stored in the 3GPP2 container atoms) is carried into the raw HEVC output.