Convert DVR to 3GP — Free Online Tool
Convert DVR recordings to 3GP format for playback on mobile devices with limited storage and bandwidth. This tool re-encodes your DVR footage using H.264 video and AAC audio into the 3GP container, optimized for 3G mobile networks while preserving the core video content from surveillance or broadcast captures.
to
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
DVR files store video using H.264 (libx264) or MJPEG with AAC or MP3 audio inside a proprietary container tied to the recording device's firmware. Converting to 3GP requires fully re-encoding the content — the video stream is re-encoded with H.264 at CRF 23, and the audio is re-encoded to AAC at 64k bitrate, which is the standard low-bandwidth profile for 3GP. A scaling filter is also applied to ensure the output resolution has even dimensions (divisible by 2), a strict requirement of the 3GP container and H.264 codec. The result is a compact file playable on 3G-era mobile phones and compatible streaming platforms, though with reduced audio fidelity compared to the source due to the lower 64k bitrate target.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary, the open-source multimedia processing engine that handles reading the proprietary DVR container, decoding its video and audio streams, and re-encoding them into the 3GP output. |
-i input.dvr
|
Specifies the input DVR file. FFmpeg probes the DVR container to detect the internal video codec (H.264 or MJPEG) and audio codec (AAC or MP3) before beginning the conversion pipeline. |
-c:v libx264
|
Encodes the video output using the libx264 H.264 encoder, which is required to produce a valid 3GP file. Even if the source DVR already contains H.264 video, a full re-encode is necessary because the container format and streaming parameters must be rebuilt for 3GP compatibility. |
-c:a aac
|
Re-encodes the audio track to AAC, the standard audio codec for 3GP files. If the DVR source used MP3 audio, this transcodes it to AAC; if it was already AAC, the audio is still re-encoded to match the 3GP container's requirements and the specified 64k bitrate. |
-crf 23
|
Sets the Constant Rate Factor for H.264 video quality at 23, which is the default balanced setting. For DVR surveillance footage being downscaled to 3GP's mobile target, this provides acceptable sharpness without bloating the file — lower values like 18 would be noticeably higher quality but produce files larger than 3GP typically warrants. |
-b:a 64k
|
Targets an audio bitrate of 64 kilobits per second for the AAC output, matching 3GP's low-bandwidth design intent for 3G mobile networks. This is lower than typical DVR audio quality and will reduce clarity of speech and ambient sound in surveillance footage. |
-vf scale=trunc(iw/2)*2:trunc(ih/2)*2
|
Applies a video filter that rounds the output width and height down to the nearest even number. This is mandatory for 3GP with H.264, as the codec requires both dimensions to be divisible by 2 — DVR recordings from certain hardware may have odd-numbered resolutions that would otherwise cause the conversion to fail. |
output.3gp
|
Defines the output filename with the .3gp extension, which signals FFmpeg to use the 3GP muxer and write the re-encoded H.264 video and AAC audio into a 3GPP-compliant container ready for playback on mobile devices. |
Common Use Cases
- Sharing a clip from a DVR surveillance recording on an older mobile device that only supports 3GP playback
- Reducing a large DVR broadcast capture to a small 3GP file for transfer over a slow mobile data connection
- Archiving short segments of DVR security footage in a universally supported mobile format for field review on older handsets
- Preparing DVR footage for upload to legacy MMS or video messaging services that require 3GP format
- Converting DVR recordings to 3GP for embedding in mobile applications targeting low-bandwidth environments in developing regions
- Extracting a key clip from a DVR recording and compressing it to 3GP for quick sharing via Bluetooth between older phones
Frequently Asked Questions
Yes, substantially. DVR files recorded at broadcast or surveillance quality often carry higher bitrates than what 3GP targets. The 3GP output uses AAC audio at just 64k — much lower than a typical DVR audio track — and the H.264 video is constrained to a mobile-optimized profile. A DVR file of several hundred megabytes can compress to a fraction of that size, though the degree of reduction depends heavily on the original DVR resolution and frame rate.
The 3GP container combined with the H.264 codec requires that both the width and height of the video are divisible by 2. DVR recordings from certain surveillance or broadcast systems may capture at non-standard resolutions where one dimension is odd. The filter `scale=trunc(iw/2)*2:trunc(ih/2)*2` corrects this by rounding each dimension down to the nearest even number, preventing FFmpeg from throwing a 'width or height not divisible by 2' error without altering the visual content in any meaningful way.
Yes, this is a lossy-to-lossy conversion, so each re-encode introduces some generation loss. The video uses CRF 23, which is a reasonable quality level but noticeably lower than typical DVR master recordings. The audio drop to 64k AAC is more perceptible — dialogue and ambient audio will sound thinner than in the source. If you need higher audio quality in the 3GP output, you can adjust the `-b:a` flag to 96k or 128k using the FFmpeg command directly.
Modern smartphones have largely dropped native 3GP support from their default media apps, though Android still retains basic 3GP playback capability in many versions. iOS removed direct 3GP support years ago. For modern devices, you would typically be better served converting DVR footage to MP4 instead. The 3GP format is most practical for legacy 3G-era handsets or specialized mobile platforms that explicitly require it.
No. DVR files often embed proprietary metadata such as timestamp overlays, camera channel identifiers, and device-specific recording information within the container or as a secondary data stream. The 3GP format does not support these proprietary metadata structures, and FFmpeg will discard them during re-encoding. Visible timestamp overlays burned into the video frame itself will be preserved since they are part of the image data, but any separate metadata tracks will be lost.
Adjust the `-crf` value in the command. Lower CRF values produce higher quality and larger files — for example, `-crf 18` gives near-visually-lossless output while `-crf 35` or higher produces heavily compressed output suitable for very constrained storage. For 3GP's typical mobile use case, values between 26 and 32 strike a practical balance between watchable quality and small file size. You can also raise `-b:a` from 64k to 96k or 128k if the audio quality at default settings is insufficient.
Technical Notes
The DVR format is a proprietary container whose internal structure varies by manufacturer — some DVR devices produce files with H.264 video and AAC audio, while others use MJPEG with MP3. FFmpeg handles both combinations, but the re-encoding step to 3GP is always required since the container format itself changes entirely. The 3GP specification was defined by 3GPP for third-generation mobile networks and imposes strict constraints: resolution must have even dimensions, the H.264 profile should target Baseline or Main for maximum device compatibility, and audio bitrates are typically kept under 128k. The default 64k AAC audio bitrate reflects the bandwidth constraints 3GP was designed for, but it is audibly lossy for content with complex audio. The 3GP format does not support subtitles, chapters, or multiple audio tracks — any of these present in the DVR source will be silently dropped. Because DVR footage is already lossy-compressed, repeated re-encoding compounds generation loss each time, so you should work from the original DVR file rather than a previously converted copy whenever possible.