- From: Pierre-Anthony Lemieux <pal@sandflow.com>
- Date: Mon, 22 Oct 2012 12:45:57 -0700
- To: public-html-media@w3.org
Per the suggested process in our last call, below is a question re: choice of 'double' as the type for timestampOffset. Has this topic been considered before? Thanks, -- Pierre Time offsets and durations within media streams, e.g. to specify splice points, are often expressed in multiples of video frame or audio sample durations. These durations are typically rational numbers, e.g. 1/24, 1001/30000, 1/48000, etc. Many container formats (ISO BMFF, MXF...) express durations and offsets as rationals, e.g. as integer multiples of a rational timescale expressed as the ratio between an integer numerator and an integer denominator. Can timestampOffset (as a double) exactly represent such rational time offsets? For example, (double) ((1/24)*17) < 17*1/24 < (double) (17/24) -- at least in Win32 python. Accuracy can be important when a splice point needs to fall on a specific frame boundary or when comparing timestampOffsets.
Received on Monday, 22 October 2012 19:46:47 UTC