First release

node_modules/@videojs/vhs-utils/src/containers.js

@@ -0,0 +1,172 @@
+import {toUint8, bytesMatch} from './byte-helpers.js';
+import {findBox} from './mp4-helpers.js';
+import {findEbml, EBML_TAGS} from './ebml-helpers.js';
+import {getId3Offset} from './id3-helpers.js';
+import {findH264Nal, findH265Nal} from './nal-helpers.js';
+
+const CONSTANTS = {
+  // "webm" string literal in hex
+  'webm': toUint8([0x77, 0x65, 0x62, 0x6d]),
+
+  // "matroska" string literal in hex
+  'matroska': toUint8([0x6d, 0x61, 0x74, 0x72, 0x6f, 0x73, 0x6b, 0x61]),
+
+  // "fLaC" string literal in hex
+  'flac': toUint8([0x66, 0x4c, 0x61, 0x43]),
+
+  // "OggS" string literal in hex
+  'ogg': toUint8([0x4f, 0x67, 0x67, 0x53]),
+
+  // ac-3 sync byte, also works for ec-3 as that is simply a codec
+  // of ac-3
+  'ac3': toUint8([0x0b, 0x77]),
+
+  // "RIFF" string literal in hex used for wav and avi
+  'riff': toUint8([0x52, 0x49, 0x46, 0x46]),
+
+  // "AVI" string literal in hex
+  'avi': toUint8([0x41, 0x56, 0x49]),
+
+  // "WAVE" string literal in hex
+  'wav': toUint8([0x57, 0x41, 0x56, 0x45]),
+
+  // "ftyp3g" string literal in hex
+  '3gp': toUint8([0x66, 0x74, 0x79, 0x70, 0x33, 0x67]),
+
+  // "ftyp" string literal in hex
+  'mp4': toUint8([0x66, 0x74, 0x79, 0x70]),
+
+  // "styp" string literal in hex
+  'fmp4': toUint8([0x73, 0x74, 0x79, 0x70]),
+
+  // "ftyp" string literal in hex
+  'mov': toUint8([0x66, 0x74, 0x79, 0x70, 0x71, 0x74])
+};
+
+const _isLikely = {
+  aac(bytes) {
+    const offset = getId3Offset(bytes);
+
+    return bytesMatch(bytes, [0xFF, 0x10], {offset, mask: [0xFF, 0x16]});
+  },
+
+  mp3(bytes) {
+    const offset = getId3Offset(bytes);
+
+    return bytesMatch(bytes, [0xFF, 0x02], {offset, mask: [0xFF, 0x06]});
+  },
+
+  webm(bytes) {
+    const docType = findEbml(bytes, [EBML_TAGS.EBML, EBML_TAGS.DocType])[0];
+
+    // check if DocType EBML tag is webm
+    return bytesMatch(docType, CONSTANTS.webm);
+  },
+
+  mkv(bytes) {
+    const docType = findEbml(bytes, [EBML_TAGS.EBML, EBML_TAGS.DocType])[0];
+
+    // check if DocType EBML tag is matroska
+    return bytesMatch(docType, CONSTANTS.matroska);
+  },
+
+  mp4(bytes) {
+    return !_isLikely['3gp'](bytes) && !_isLikely.mov(bytes) &&
+      (bytesMatch(bytes, CONSTANTS.mp4, {offset: 4}) ||
+       bytesMatch(bytes, CONSTANTS.fmp4, {offset: 4}));
+  },
+  mov(bytes) {
+    return bytesMatch(bytes, CONSTANTS.mov, {offset: 4});
+  },
+  '3gp'(bytes) {
+    return bytesMatch(bytes, CONSTANTS['3gp'], {offset: 4});
+  },
+  ac3(bytes) {
+    const offset = getId3Offset(bytes);
+
+    return bytesMatch(bytes, CONSTANTS.ac3, {offset});
+  },
+
+  ts(bytes) {
+    if (bytes.length < 189 && bytes.length >= 1) {
+      return bytes[0] === 0x47;
+    }
+
+    let i = 0;
+
+    // check the first 376 bytes for two matching sync bytes
+    while (i + 188 < bytes.length && i < 188) {
+      if (bytes[i] === 0x47 && bytes[i + 188] === 0x47) {
+        return true;
+      }
+      i += 1;
+    }
+
+    return false;
+  },
+
+  flac(bytes) {
+    const offset = getId3Offset(bytes);
+
+    return bytesMatch(bytes, CONSTANTS.flac, {offset});
+  },
+  ogg(bytes) {
+    return bytesMatch(bytes, CONSTANTS.ogg);
+  },
+  avi(bytes) {
+    return bytesMatch(bytes, CONSTANTS.riff) &&
+      bytesMatch(bytes, CONSTANTS.avi, {offset: 8});
+  },
+  wav(bytes) {
+    return bytesMatch(bytes, CONSTANTS.riff) &&
+      bytesMatch(bytes, CONSTANTS.wav, {offset: 8});
+  },
+  'h264'(bytes) {
+    // find seq_parameter_set_rbsp
+    return findH264Nal(bytes, 7, 3).length;
+  },
+  'h265'(bytes) {
+    // find video_parameter_set_rbsp or seq_parameter_set_rbsp
+    return findH265Nal(bytes, [32, 33], 3).length;
+  }
+};
+
+// get all the isLikely functions
+// but make sure 'ts' is above h264 and h265
+// but below everything else as it is the least specific
+const isLikelyTypes = Object.keys(_isLikely)
+  // remove ts, h264, h265
+  .filter((t) => t !== 'ts' && t !== 'h264' && t !== 'h265')
+  // add it back to the bottom
+  .concat(['ts', 'h264', 'h265']);
+
+// make sure we are dealing with uint8 data.
+isLikelyTypes.forEach(function(type) {
+  const isLikelyFn = _isLikely[type];
+
+  _isLikely[type] = (bytes) => isLikelyFn(toUint8(bytes));
+});
+
+// export after wrapping
+export const isLikely = _isLikely;
+
+// A useful list of file signatures can be found here
+// https://en.wikipedia.org/wiki/List_of_file_signatures
+export const detectContainerForBytes = (bytes) => {
+  bytes = toUint8(bytes);
+
+  for (let i = 0; i < isLikelyTypes.length; i++) {
+    const type = isLikelyTypes[i];
+
+    if (isLikely[type](bytes)) {
+      return type;
+    }
+  }
+
+  return '';
+};
+
+// fmp4 is not a container
+export const isLikelyFmp4MediaSegment = (bytes) => {
+  return findBox(bytes, ['moof']).length > 0;
+};