Output FRAME-RATE according to spec

[daveisfera]

See https://datatracker.ietf.org/doc/html/rfc8216#section-4.3.4.2

[mauricioabreu]

Hello, @daveisfera thank you for contributing.

Reading the spec, it is not clear that it SHOULD be rounded to three decimal places. I understand the spec as saying it SHOULD not have more than three decimal places

https://developer.apple.com/documentation/http-live-streaming/hls-authoring-specification-for-apple-devices#Video

1.18. Video on Demand (VOD) content SHOULD use a natural frame rate for the content. Frame rates 23.976, 24, 25, 29.97, 30, 50, 59.94, and 60 fps are supported.

What is your opinion? cc @leandromoreira

[daveisfera]

Hello, @daveisfera thank you for contributing.

Reading the spec, it is not clear that it SHOULD be rounded to three decimal places. I understand the spec as saying it SHOULD not have more than three decimal places

https://developer.apple.com/documentation/http-live-streaming/hls-authoring-specification-for-apple-devices#Video

1.18. Video on Demand (VOD) content SHOULD use a natural frame rate for the content. Frame rates 23.976, 24, 25, 29.97, 30, 50, 59.94, and 60 fps are supported.

The Apple document is definitely worth considering but the official spec reads:

The value is a decimal-floating-point describing the maximum frame rate for all the video in the Variant Stream, rounded to three decimal places.

[mauricioabreu]

@daveisfera I read the spec, but I didn't understand that as mandatory. 25 == 25,000

IMHO, Apple says that because in case the FPS has decimal places, it SHOULD have at most 3 decimal places.

[daveisfera]

Ya, I can definitely see that. I was interpreting it to mean that there should always be 3 decimal places, but that's not what's actually stated there and the trailing 0s could be left off

[mauricioabreu]

That's fine, @daveisfera. IMHO, specs are really hard to interpret.
I'm actually happy you took the time to open a pull request to solve a problem, even if it turned out not to be a problem at all.

Thank you for contributing to the m3u8 lib.