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Ace17

> You should just assign a different compression factor to the chroma channels instead [of subsampling chroma].

The good news is that we don't need to change the H.264 standard for this.

Supposing that:

- most of the already deployed embedded H.264 decoders support 4:4:4 profiles

- non-chroma-downsampled input content is available

Then, it's only a matter of changing encoder implementations to do exactly as you say.

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I'm pretty sure there is plenty of 444 content. Movies are likely filmed/edited at 444, they are provided to theaters at 444, but they are generally only made available to consumers at 420.

I believe the reason is that most hardware decoders sold to consumers do not support anything above 420. As Blu-rays and such are all currently 420, the chip makers don't have much incentive to support 444. It's a shame because your TV fully supports 444, and the difference can be huge on some content.

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