What is a .Y4M file?
Y4M stores raw uncompressed video, used to test and benchmark codecs.
- Did you know
- Y4M keeps video completely uncompressed so codec quality can be measured fairly.
- A Y4M file is structured as a short ASCII stream header followed by frames, each tagged with the literal word FRAME.
- Y4M was devised by the mjpegtools project to pipe raw YCbCr video between encoding tools.
- What Analyser reads
- Inspect streaming manifests and video containers: HLS/DASH/Smooth Streaming/HDS manifests and playlists; pro/broadcast MXF/GXF/LXF/DV; ASF/.dvr-ms and RealMedia; DivX/F4V/Insta360/GoPro proxies/GIFV; raw elementary streams (IVF, Y4M, MPEG-1/2, H.264/H.265 SPS, AV1 OBU); MPEG program/transport and PVR/DVB recordings; Windows Recorded TV, Ogg Media, NUT; DPX/Cineon/Dahua/.yuv identified.
- Depth of analysis
- .Y4M is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .Y4M file
- Drag a .Y4M file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.