Convert dashcam video to MP4

Dashcams fall into three camps, and which one yours is in decides how the conversion goes. Most mainstream cameras record H.264 video - the same compression your phone uses - and a growing number offer H.265 (HEVC) to fit more hours on the card. Those files are usually .MP4 or .MOV already, and when they won't play, the problem is the wrapper or a missing piece of the file rather than the video itself. Some cameras let you pick MPEG transport stream (.TS) instead of MP4 in their settings - VIOFO is the best-known example - because a .TS file survives a sudden power cut far better (more on that below). Budget and older cameras record Motion JPEG inside an .AVI: every frame stored as a separate photo, which makes the files enormous. See Codecs vs containers if the difference between the file type and the compression inside is new to you.

For H.264 and HEVC footage, Wave copies the video into a fresh MP4 wrapper without touching a single frame. The picture is bit-for-bit identical to what the camera recorded, which matters when the footage is evidence: number plates, road markings, and the timestamp overlay stay exactly as sharp as the original. Wave also puts the file's index at the front of the MP4 so it previews instantly in email, cloud storage, and insurer upload portals. For Motion JPEG footage, Wave decodes each photo-frame and re-encodes it as H.264 through your browser's WebCodecs encoder. That is a real re-encode, so there is a very small quality cost, but the file usually ends up 10-20x smaller - a 3-minute clip that was 1.5 GB as Motion JPEG lands around 100 MB as H.264.

The most stressful dashcam problem is a clip from the moment of a crash that refuses to open. An MP4 file keeps its index - the table of contents that tells a player where every frame lives - in a block that is only written when recording stops cleanly. If the impact or a battery disconnect cuts power mid-clip, that block never gets written and the file looks corrupted to every player. Wave can't rebuild a missing index, because the information isn't there to read. The open-source tool untrunc can, by borrowing the structure from a healthy clip recorded by the same camera with the same settings. This is also why some cameras offer .TS recording: transport streams have no single index to lose, so a power cut costs you a second or two at the very end instead of the whole clip. If you rely on your dashcam for evidence and it offers .TS, it's worth switching. How to repair a corrupted MP4 walks through the repair step by step.

A few practical details. Front and rear cameras almost always save separate files, usually marked F and R in the filename, so convert each one you need. Loop recording splits driving into 1, 3, or 5 minute segments; Wave converts one file at a time, and Merge MP4 explains how to join consecutive segments into one video. Impact-triggered clips are typically locked into a separate folder (often named Event, EMR, or Protected) so loop recording can't overwrite them - check there first. Timestamps and speed readouts burned into the picture survive any conversion because they are part of the image. GPS tracks are different: cameras store them as a hidden data track inside the file or as a separate .gpx or .nmea file, and Wave keeps only video, audio, and text subtitle tracks, so use your camera maker's viewer app when you need the map. Always keep the original file and the memory card untouched, and send the converted MP4 as a copy: if a claim is disputed, the unmodified original is what matters.