HDCP works by having the source (e.g. the DVD player) encrypt the picture, then requiring an HDCP enabled display to decrypt it again. However, if an HDCP display receives an unencrypted source it will still display it, so your HDMI-equipped projector will display material whether it is encrypted or unencrypted

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In your case the DVD player is not HDCP capable so it will not encrypt the picture anyway.
You just need a DVI-to-HDMI cable and away you go!