Hacker News: asdcplib

New comment by asdcplib in "SMPTE Makes Its Standards Freely Accessible"

asdcplib — Sat, 20 Jun 2026 19:32:32 +0000

Once upon a time, acquiring a standard involved writing to a far away address and then waiting "six to eight weeks" for a paper document to show up in your mailbox. By 1995 (when internet access became common) SMPTE was seventy years old. Certain, uh, expectations had become concretized by then, and it took considerable time and effort to overcome those.

New comment by asdcplib in "SMPTE Makes Its Standards Freely Accessible"

asdcplib — Sat, 20 Jun 2026 19:18:48 +0000

>can anyone pin point the significance of making this entirely Free?

It's critical for data encodings (codecs, metadata,) because without free standards developers will attempt to reverse engineer from sample files, resulting in poor interoperability and causing chaos for those implementers that actually do bother to acquire and read the spec.

New comment by asdcplib in "SMPTE Makes Its Standards Freely Accessible"

asdcplib — Sat, 20 Jun 2026 19:08:07 +0000

This is mostly true, with some exceptions. The Digital Cinema standards (428, 429, 430, etc.) were in fact developed in conference rooms and on whiteboards. It was a greenfield application with no incumbent formats.

New comment by asdcplib in "How encryption for Cinema Movies works"

asdcplib — Mon, 21 Apr 2025 15:57:21 +0000

Hi, asdcplib author here (mentioned in the article.) Excellent writeup of DCP and related tech. FYI the colorspace of an SDR DCP MXF file is X'Y'Z' with gamma 2.6 (see SMPTE 428-1.) Other MXF formats (i.e., not cinema) use a wide variety of colorspaces. Despite the huge range of XYZ, DCP image files are usually constrained to code values that fall within P3 (again, SDR.) The HDR applications are more interesting.

Upon reading the comments: • DCP is a B2B format. DCP usage is licensed by contract, not EULA. Please keep these important differences in mind when commenting on DRM. • Decrypt, decode, color processing, watermark occurs in FPGA. If you think that sounds hard, remember that all of this tech was originally deployed 20 years ago. Moore's law has made our lives much easier since! • Frame-by-frame encipherment, rather than whole stream, better supports random access and the famous tobacco intermissions popular in the EU.