feat(codec): changes to handle muxer/browser/video/audio support separately (#10)

BREAKING CHANGE: parseCodecs output has been changed. It now returns an object that can have an audio or video property, depending on the codecs found. Those properties are object that contain type. and details. Type being the codec name and details being codec specific information usually with a leading period.

BREAKING CHANGE: `audioProfileFromDefault` has been renamed to `codecsFromDefault` and now returns all output from `parseCodecs` not just audio or audio profile.

Author: brandonocasey

src/codecs.js

@@ -1,3 +1,20 @@
+import window from 'global/window';
+
+const regexs = {
+  // to determine mime types
+  mp4: /^(av0?1|avc0?[1234]|vp0?9|flac|opus|mp3|mp4a|mp4v)/,
+  webm: /^(vp0?[89]|av0?1|opus|vorbis)/,
+  ogg: /^(vp0?[89]|theora|flac|opus|vorbis)/,
+
+  // to determine if a codec is audio or video
+  video: /^(av0?1|avc0?[1234]|vp0?[89]|hvc1|hev1|theora|mp4v)/,
+  audio: /^(mp4a|flac|vorbis|opus|ac-[34]|ec-3|alac|mp3)/,
+
+  // mux.js support regex
+  muxerVideo: /^(avc0?1)/,
+  muxerAudio: /^(mp4a)/
+};
+
 /**
  * Replace the old apple-style `avc1.<dd>.<dd>` codec string with the standard
  * `avc1.<hhhhhh>`
@@ -66,31 +83,32 @@ export const mapLegacyAvcCodecs = function(codecString) {
  * Parses a codec string to retrieve the number of codecs specified, the video codec and
  * object type indicator, and the audio profile.
  *
- * @param {string} [codecs]
+ * @param {string} [codecString]
  *        The codec string to parse
  * @return {ParsedCodecInfo}
  *         Parsed codec info
  */
-export const parseCodecs = function(codecs = '') {
-  const result = {
-    codecCount: 0
-  };
+export const parseCodecs = function(codecString = '') {
+  const codecs = codecString.split(',');
+  const result = {};
 
-  result.codecCount = codecs.split(',').length;
-  result.codecCount = result.codecCount || 2;
+  codecs.forEach(function(codec) {
+    codec = codec.trim();
 
-  // parse the video codec
-  const parsed = (/(^|\s|,)+(avc[13]|vp09|av01)([^ ,]*)/i).exec(codecs);
+    ['video', 'audio'].forEach(function(name) {
+      const match = regexs[name].exec(codec.toLowerCase());
 
-  if (parsed) {
-    result.videoCodec = parsed[2];
-    result.videoObjectTypeIndicator = parsed[3];
-  }
+      if (!match || match.length <= 1) {
+        return;
+      }
+
+      // maintain codec case
+      const type = codec.substring(0, match[1].length);
+      const details = codec.replace(type, '');
 
-  // parse the last field of the audio codec
-  result.audioProfile =
-    (/(^|\s|,)+mp4a.[0-9A-Fa-f]+\.([0-9A-Fa-f]+)/i).exec(codecs);
-  result.audioProfile = result.audioProfile && result.audioProfile[2];
+      result[name] = {type, details};
+    });
+  });
 
   return result;
 };
@@ -106,7 +124,7 @@ export const parseCodecs = function(codecs = '') {
  * @return {ParsedCodecInfo}
  *         Parsed codec info
  */
-export const audioProfileFromDefault = (master, audioGroupId) => {
+export const codecsFromDefault = (master, audioGroupId) => {
   if (!master.mediaGroups.AUDIO || !audioGroupId) {
     return null;
   }
@@ -122,9 +140,59 @@ export const audioProfileFromDefault = (master, audioGroupId) => {
 
     if (audioType.default && audioType.playlists) {
       // codec should be the same for all playlists within the audio type
-      return parseCodecs(audioType.playlists[0].attributes.CODECS).audioProfile;
+      return parseCodecs(audioType.playlists[0].attributes.CODECS);
     }
   }
 
   return null;
 };
+
+export const isVideoCodec = (codec = '') => regexs.video.test(codec.trim().toLowerCase());
+export const isAudioCodec = (codec = '') => regexs.audio.test(codec.trim().toLowerCase());
+
+export const getMimeForCodec = (codecString) => {
+  if (!codecString || typeof codecString !== 'string') {
+    return;
+  }
+  const codecs = codecString
+    .toLowerCase()
+    .split(',')
+    .map((c) => translateLegacyCodec(c.trim()));
+
+  // default to video type
+  let type = 'video';
+
+  // only change to audio type if the only codec we have is
+  // audio
+  if (codecs.length === 1 && isAudioCodec(codecs[0])) {
+    type = 'audio';
+  }
+
+  // default the container to mp4
+  let container = 'mp4';
+
+  // every codec must be able to go into the container
+  // for that container to be the correct one
+  if (codecs.every((c) => regexs.mp4.test(c))) {
+    container = 'mp4';
+  } else if (codecs.every((c) => regexs.webm.test(c))) {
+    container = 'webm';
+  } else if (codecs.every((c) => regexs.ogg.test(c))) {
+    container = 'ogg';
+  }
+
+  return `${type}/${container};codecs="${codecString}"`;
+};
+
+export const browserSupportsCodec = (codecString = '') => window.MediaSource &&
+  window.MediaSource.isTypeSupported &&
+  window.MediaSource.isTypeSupported(getMimeForCodec(codecString)) || false;
+
+export const muxerSupportsCodec = (codecString = '') => codecString.toLowerCase().split(',').every((codec) => {
+  codec = codec.trim();
+
+  return regexs.muxerVideo.test(codec) || regexs.muxerAudio.test(codec);
+});
+
+export const DEFAULT_AUDIO_CODEC = 'mp4a.40.2';
+export const DEFAULT_VIDEO_CODEC = 'avc1.4d400d';