HDR, HEVC and MP4: what each one tells you

01. Separate the box, the encoding and the color.

Container packages tracks, codec encodes pictures, and HDR or SDR describes color and brightness handling. — A concept diagram, not a file inspection or an App screenshot.

Label	What it describes	What it cannot promise
MP4	The container holding tracks	A specific codec or SDR color
HEVC / H.265	The video compression codec	That the video is HDR
HDR	High dynamic range color handling	That every player displays it correctly

The filename is a starting clue. It is not a full description of the streams inside. A player has to support the actual encoding and color information as well as the container.

MDN explains choosing codecs together with a container. YouTube’s HDR requirements separately list containers, codecs and color metadata.

02. Match the change to the actual problem.

For opening errors check codec and container; for color problems check HDR support; for rejected uploads check every destination limit. — Start with the symptom. More than one constraint can apply to the same file.

The file will not open

Check the receiving app’s supported formats. H.264 video with AAC audio in MP4 is a common compatibility choice, but the destination may also restrict resolution, frame rate or file size.

It opens, but the colors look wrong

Check HDR handling in the player and display. If the destination needs SDR, use an actual HDR-to-SDR conversion. Changing the extension or merely rewriting color tags is not tone mapping.

A website refuses the upload

Read its exact error. Codec, container, duration and upload size are separate checks. A color conversion does not guarantee that an oversized file will be accepted.

For example, an HDR HEVC MOV sent to an SDR-only H.264 MP4 workflow needs both suitable color conversion and re-encoding. An SDR HEVC file may need only the codec compatibility conversion. Keep the source copy in either case.

03. Export once, then test the real destination.

Write down the requirement.
Choose the actual destination settings before converting. If it supports the original HDR file correctly, conversion may be unnecessary.
Keep the original.
Make a separate sharing copy. Re-encoding can discard detail, and an SDR copy does not replace an HDR master.
Check playback and upload.
Test the copy in the receiving app. Check color, audio, orientation, duration and file size. A successful export alone does not prove compatibility.

On Mac, QuickTime Player offers a native H.264 export path for HEVC media. Apple documents the Greater Compatibility option. Treat that as a codec workflow; do not assume it verifies every HDR-to-SDR requirement.

App facts checked against the US listing, version 1.0.6 on October 25, 2026. VideoFix is made by Space Sheep Studio.