transmuxer.js 11 KB

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  1. var Stream = require('../utils/stream.js');
  2. var m2ts = require('../m2ts/m2ts.js');
  3. var codecs = require('../codecs/index.js');
  4. var AudioSegmentStream = require('./audio-segment-stream.js');
  5. var VideoSegmentStream = require('./video-segment-stream.js');
  6. var trackInfo = require('../mp4/track-decode-info.js');
  7. var isLikelyAacData = require('../aac/utils').isLikelyAacData;
  8. var AdtsStream = require('../codecs/adts');
  9. var AacStream = require('../aac/index');
  10. var clock = require('../utils/clock');
  11. var createPipeline = function createPipeline(object) {
  12. object.prototype = new Stream();
  13. object.prototype.init.call(object);
  14. return object;
  15. };
  16. var tsPipeline = function tsPipeline(options) {
  17. var pipeline = {
  18. type: 'ts',
  19. tracks: {
  20. audio: null,
  21. video: null
  22. },
  23. packet: new m2ts.TransportPacketStream(),
  24. parse: new m2ts.TransportParseStream(),
  25. elementary: new m2ts.ElementaryStream(),
  26. timestampRollover: new m2ts.TimestampRolloverStream(),
  27. adts: new codecs.Adts(),
  28. h264: new codecs.h264.H264Stream(),
  29. captionStream: new m2ts.CaptionStream(options),
  30. metadataStream: new m2ts.MetadataStream()
  31. };
  32. pipeline.headOfPipeline = pipeline.packet; // Transport Stream
  33. pipeline.packet.pipe(pipeline.parse).pipe(pipeline.elementary).pipe(pipeline.timestampRollover); // H264
  34. pipeline.timestampRollover.pipe(pipeline.h264); // Hook up CEA-608/708 caption stream
  35. pipeline.h264.pipe(pipeline.captionStream);
  36. pipeline.timestampRollover.pipe(pipeline.metadataStream); // ADTS
  37. pipeline.timestampRollover.pipe(pipeline.adts);
  38. pipeline.elementary.on('data', function (data) {
  39. if (data.type !== 'metadata') {
  40. return;
  41. }
  42. for (var i = 0; i < data.tracks.length; i++) {
  43. if (!pipeline.tracks[data.tracks[i].type]) {
  44. pipeline.tracks[data.tracks[i].type] = data.tracks[i];
  45. pipeline.tracks[data.tracks[i].type].timelineStartInfo.baseMediaDecodeTime = options.baseMediaDecodeTime;
  46. }
  47. }
  48. if (pipeline.tracks.video && !pipeline.videoSegmentStream) {
  49. pipeline.videoSegmentStream = new VideoSegmentStream(pipeline.tracks.video, options);
  50. pipeline.videoSegmentStream.on('timelineStartInfo', function (timelineStartInfo) {
  51. if (pipeline.tracks.audio && !options.keepOriginalTimestamps) {
  52. pipeline.audioSegmentStream.setEarliestDts(timelineStartInfo.dts - options.baseMediaDecodeTime);
  53. }
  54. });
  55. pipeline.videoSegmentStream.on('timingInfo', pipeline.trigger.bind(pipeline, 'videoTimingInfo'));
  56. pipeline.videoSegmentStream.on('data', function (data) {
  57. pipeline.trigger('data', {
  58. type: 'video',
  59. data: data
  60. });
  61. });
  62. pipeline.videoSegmentStream.on('done', pipeline.trigger.bind(pipeline, 'done'));
  63. pipeline.videoSegmentStream.on('partialdone', pipeline.trigger.bind(pipeline, 'partialdone'));
  64. pipeline.videoSegmentStream.on('endedtimeline', pipeline.trigger.bind(pipeline, 'endedtimeline'));
  65. pipeline.h264.pipe(pipeline.videoSegmentStream);
  66. }
  67. if (pipeline.tracks.audio && !pipeline.audioSegmentStream) {
  68. pipeline.audioSegmentStream = new AudioSegmentStream(pipeline.tracks.audio, options);
  69. pipeline.audioSegmentStream.on('data', function (data) {
  70. pipeline.trigger('data', {
  71. type: 'audio',
  72. data: data
  73. });
  74. });
  75. pipeline.audioSegmentStream.on('done', pipeline.trigger.bind(pipeline, 'done'));
  76. pipeline.audioSegmentStream.on('partialdone', pipeline.trigger.bind(pipeline, 'partialdone'));
  77. pipeline.audioSegmentStream.on('endedtimeline', pipeline.trigger.bind(pipeline, 'endedtimeline'));
  78. pipeline.audioSegmentStream.on('timingInfo', pipeline.trigger.bind(pipeline, 'audioTimingInfo'));
  79. pipeline.adts.pipe(pipeline.audioSegmentStream);
  80. } // emit pmt info
  81. pipeline.trigger('trackinfo', {
  82. hasAudio: !!pipeline.tracks.audio,
  83. hasVideo: !!pipeline.tracks.video
  84. });
  85. });
  86. pipeline.captionStream.on('data', function (caption) {
  87. var timelineStartPts;
  88. if (pipeline.tracks.video) {
  89. timelineStartPts = pipeline.tracks.video.timelineStartInfo.pts || 0;
  90. } else {
  91. // This will only happen if we encounter caption packets before
  92. // video data in a segment. This is an unusual/unlikely scenario,
  93. // so we assume the timeline starts at zero for now.
  94. timelineStartPts = 0;
  95. } // Translate caption PTS times into second offsets into the
  96. // video timeline for the segment
  97. caption.startTime = clock.metadataTsToSeconds(caption.startPts, timelineStartPts, options.keepOriginalTimestamps);
  98. caption.endTime = clock.metadataTsToSeconds(caption.endPts, timelineStartPts, options.keepOriginalTimestamps);
  99. pipeline.trigger('caption', caption);
  100. });
  101. pipeline = createPipeline(pipeline);
  102. pipeline.metadataStream.on('data', pipeline.trigger.bind(pipeline, 'id3Frame'));
  103. return pipeline;
  104. };
  105. var aacPipeline = function aacPipeline(options) {
  106. var pipeline = {
  107. type: 'aac',
  108. tracks: {
  109. audio: null
  110. },
  111. metadataStream: new m2ts.MetadataStream(),
  112. aacStream: new AacStream(),
  113. audioRollover: new m2ts.TimestampRolloverStream('audio'),
  114. timedMetadataRollover: new m2ts.TimestampRolloverStream('timed-metadata'),
  115. adtsStream: new AdtsStream(true)
  116. }; // set up the parsing pipeline
  117. pipeline.headOfPipeline = pipeline.aacStream;
  118. pipeline.aacStream.pipe(pipeline.audioRollover).pipe(pipeline.adtsStream);
  119. pipeline.aacStream.pipe(pipeline.timedMetadataRollover).pipe(pipeline.metadataStream);
  120. pipeline.metadataStream.on('timestamp', function (frame) {
  121. pipeline.aacStream.setTimestamp(frame.timeStamp);
  122. });
  123. pipeline.aacStream.on('data', function (data) {
  124. if (data.type !== 'timed-metadata' && data.type !== 'audio' || pipeline.audioSegmentStream) {
  125. return;
  126. }
  127. pipeline.tracks.audio = pipeline.tracks.audio || {
  128. timelineStartInfo: {
  129. baseMediaDecodeTime: options.baseMediaDecodeTime
  130. },
  131. codec: 'adts',
  132. type: 'audio'
  133. }; // hook up the audio segment stream to the first track with aac data
  134. pipeline.audioSegmentStream = new AudioSegmentStream(pipeline.tracks.audio, options);
  135. pipeline.audioSegmentStream.on('data', function (data) {
  136. pipeline.trigger('data', {
  137. type: 'audio',
  138. data: data
  139. });
  140. });
  141. pipeline.audioSegmentStream.on('partialdone', pipeline.trigger.bind(pipeline, 'partialdone'));
  142. pipeline.audioSegmentStream.on('done', pipeline.trigger.bind(pipeline, 'done'));
  143. pipeline.audioSegmentStream.on('endedtimeline', pipeline.trigger.bind(pipeline, 'endedtimeline'));
  144. pipeline.audioSegmentStream.on('timingInfo', pipeline.trigger.bind(pipeline, 'audioTimingInfo')); // Set up the final part of the audio pipeline
  145. pipeline.adtsStream.pipe(pipeline.audioSegmentStream);
  146. pipeline.trigger('trackinfo', {
  147. hasAudio: !!pipeline.tracks.audio,
  148. hasVideo: !!pipeline.tracks.video
  149. });
  150. }); // set the pipeline up as a stream before binding to get access to the trigger function
  151. pipeline = createPipeline(pipeline);
  152. pipeline.metadataStream.on('data', pipeline.trigger.bind(pipeline, 'id3Frame'));
  153. return pipeline;
  154. };
  155. var setupPipelineListeners = function setupPipelineListeners(pipeline, transmuxer) {
  156. pipeline.on('data', transmuxer.trigger.bind(transmuxer, 'data'));
  157. pipeline.on('done', transmuxer.trigger.bind(transmuxer, 'done'));
  158. pipeline.on('partialdone', transmuxer.trigger.bind(transmuxer, 'partialdone'));
  159. pipeline.on('endedtimeline', transmuxer.trigger.bind(transmuxer, 'endedtimeline'));
  160. pipeline.on('audioTimingInfo', transmuxer.trigger.bind(transmuxer, 'audioTimingInfo'));
  161. pipeline.on('videoTimingInfo', transmuxer.trigger.bind(transmuxer, 'videoTimingInfo'));
  162. pipeline.on('trackinfo', transmuxer.trigger.bind(transmuxer, 'trackinfo'));
  163. pipeline.on('id3Frame', function (event) {
  164. // add this to every single emitted segment even though it's only needed for the first
  165. event.dispatchType = pipeline.metadataStream.dispatchType; // keep original time, can be adjusted if needed at a higher level
  166. event.cueTime = clock.videoTsToSeconds(event.pts);
  167. transmuxer.trigger('id3Frame', event);
  168. });
  169. pipeline.on('caption', function (event) {
  170. transmuxer.trigger('caption', event);
  171. });
  172. };
  173. var Transmuxer = function Transmuxer(options) {
  174. var pipeline = null,
  175. hasFlushed = true;
  176. options = options || {};
  177. Transmuxer.prototype.init.call(this);
  178. options.baseMediaDecodeTime = options.baseMediaDecodeTime || 0;
  179. this.push = function (bytes) {
  180. if (hasFlushed) {
  181. var isAac = isLikelyAacData(bytes);
  182. if (isAac && (!pipeline || pipeline.type !== 'aac')) {
  183. pipeline = aacPipeline(options);
  184. setupPipelineListeners(pipeline, this);
  185. } else if (!isAac && (!pipeline || pipeline.type !== 'ts')) {
  186. pipeline = tsPipeline(options);
  187. setupPipelineListeners(pipeline, this);
  188. }
  189. hasFlushed = false;
  190. }
  191. pipeline.headOfPipeline.push(bytes);
  192. };
  193. this.flush = function () {
  194. if (!pipeline) {
  195. return;
  196. }
  197. hasFlushed = true;
  198. pipeline.headOfPipeline.flush();
  199. };
  200. this.partialFlush = function () {
  201. if (!pipeline) {
  202. return;
  203. }
  204. pipeline.headOfPipeline.partialFlush();
  205. };
  206. this.endTimeline = function () {
  207. if (!pipeline) {
  208. return;
  209. }
  210. pipeline.headOfPipeline.endTimeline();
  211. };
  212. this.reset = function () {
  213. if (!pipeline) {
  214. return;
  215. }
  216. pipeline.headOfPipeline.reset();
  217. };
  218. this.setBaseMediaDecodeTime = function (baseMediaDecodeTime) {
  219. if (!options.keepOriginalTimestamps) {
  220. options.baseMediaDecodeTime = baseMediaDecodeTime;
  221. }
  222. if (!pipeline) {
  223. return;
  224. }
  225. if (pipeline.tracks.audio) {
  226. pipeline.tracks.audio.timelineStartInfo.dts = undefined;
  227. pipeline.tracks.audio.timelineStartInfo.pts = undefined;
  228. trackInfo.clearDtsInfo(pipeline.tracks.audio);
  229. if (pipeline.audioRollover) {
  230. pipeline.audioRollover.discontinuity();
  231. }
  232. }
  233. if (pipeline.tracks.video) {
  234. if (pipeline.videoSegmentStream) {
  235. pipeline.videoSegmentStream.gopCache_ = [];
  236. }
  237. pipeline.tracks.video.timelineStartInfo.dts = undefined;
  238. pipeline.tracks.video.timelineStartInfo.pts = undefined;
  239. trackInfo.clearDtsInfo(pipeline.tracks.video); // pipeline.captionStream.reset();
  240. }
  241. if (pipeline.timestampRollover) {
  242. pipeline.timestampRollover.discontinuity();
  243. }
  244. };
  245. this.setRemux = function (val) {
  246. options.remux = val;
  247. if (pipeline && pipeline.coalesceStream) {
  248. pipeline.coalesceStream.setRemux(val);
  249. }
  250. };
  251. this.setAudioAppendStart = function (audioAppendStart) {
  252. if (!pipeline || !pipeline.tracks.audio || !pipeline.audioSegmentStream) {
  253. return;
  254. }
  255. pipeline.audioSegmentStream.setAudioAppendStart(audioAppendStart);
  256. }; // TODO GOP alignment support
  257. // Support may be a bit trickier than with full segment appends, as GOPs may be split
  258. // and processed in a more granular fashion
  259. this.alignGopsWith = function (gopsToAlignWith) {
  260. return;
  261. };
  262. };
  263. Transmuxer.prototype = new Stream();
  264. module.exports = Transmuxer;