feat(BREAKING): use bigint for 64 bit ints if needed and available. #383
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| @@ -581,8 +582,8 @@ traf = function(track) { | |||
| 0x00, 0x00, 0x00, 0x00 // default_sample_flags | |||
| ])); | |||
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| upperWordBaseMediaDecodeTime = Math.floor(track.baseMediaDecodeTime / (UINT32_MAX + 1)); | |||
| lowerWordBaseMediaDecodeTime = Math.floor(track.baseMediaDecodeTime % (UINT32_MAX + 1)); | |||
| upperWordBaseMediaDecodeTime = Math.floor(track.baseMediaDecodeTime / (MAX_UINT32)); | |||
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We subtracted 1 from it at the top, only to minus 1 later...
| @@ -87,52 +88,55 @@ timescale = function(init) { | |||
| * fragment, in seconds | |||
| */ | |||
| startTime = function(timescale, fragment) { | |||
| var trafs, baseTimes, result; | |||
| var trafs, result; | |||
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This code was all kinds of weird. We create an empty array twice to map over another array of trafs?? Then we map over all tfhd/tfdt and parse them, but only take the first? It's all kinds of nuts.
I switched it so that we loop over all trafs, and only grab the lowest time that we find (which is what we ultimately did later in the code). Furthermore we only look for one tfhd and one tfdt as there will only ever be one, and we ignored other in the old code anyway.
| seconds = baseTime / scale; | ||
| } | ||
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| if (seconds < Number.MAX_SAFE_INTEGER) { |
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if converting it to the appropriate scale, brings it below the threshold to be a bigInt bring it back to a number.
| @@ -403,7 +404,7 @@ QUnit.test('can parse a moov', function(assert) { | |||
| flags: new Uint8Array([0, 0, 0]), | |||
| edits: [{ | |||
| segmentDuration: 0, | |||
| mediaTime: 1152921504606847000, | |||
| mediaTime: BigInt('0x1000000000000000'), | |||
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This number was 100% wrong before and relying on consistent (but incorrect) rounding in javascript.
brandonocasey
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Stop reading numbers imprecisely by using bigint (if needed).
EDIT: the only way I can see this being non-breaking is if we add an option to the function to use bigint if available, but i'm not sure if that is worth it.