Talk:Program-specific information

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Table Syntax CRC

I'm wondering if the description of "CRC32" in the "Table syntax section" shouldn't be clarified a bit, currently it's just a link to the general definition of CRC32. This... doesn't work for anyone just doing the generic IEEE CRC32 that comes with most languages. Some pages I ran into trying to clear this up:

The polynomial used in transport streams is the MSB variant, where most implementations use the LSB variant: https://stackoverflow.com/questions/36622511/check-crc32-in-transport-stream-pat-section-c-sharp
The algorithm may not be standard, it's described as a "left shifting (not reflected) CRC along with the CRC polynomial 0x104C11DB7 and initial CRC value of 0xFFFFFFFF, and not post complemented" (as per "Annex A of ISO/IEC 13818-1"): https://stackoverflow.com/questions/54339800/how-to-modify-crc-32-to-crc-32-mpeg-2

FWIW I was able to adapt the sample code in that second page and get a successful match where I wasn't getting one before. --Odysseus (talk) 05:55, 23 March 2021 (UTC)[reply]