@jxstjh/jhvideo/src/worker/decoder.worker.js

HTML5 jhvideo base on MPEG2-TS Stream Player

const MAXREQCOUNT = 100
const MINREQCOUNT = 10

const MAXREQCOUNT_LIVE = 50

//Decoder request.
const kInitDecoderReq = 0;
const kUninitDecoderReq = 1;
const kOpenDecoderReq = 2;
const kCloseDecoderReq = 3;
const kFeedDataReq = 4;
const kStartDecodingReq = 5;
const kPauseDecodingReq = 6;
const kSeekDecoderReq = 7;
const kClearDecoderReq = 8;

//Decoder response.
const kInitDecoderRsp = 0;
const kUninitDecoderRsp = 1;
const kOpenDecoderRsp = 2;
const kCloseDecoderRsp = 3;
const kVideoFrame = 4;
const kAudioFrame = 5;
const kStartDecodingRsp = 6;
const kPauseDecodingRsp = 7;
const kDecodeFinishedEvt = 8;
const kStartFeedingEvt = 9;
const kPauseFeedingEvt = 10;
const kDecodeErrorEvt = 11;
const kWamsLoadErrorEvt = 12;
const kAudioInfo = 13;

self.Module = {
    onRuntimeInitialized: function () {
        onWasmLoaded();
    }
};

var g_loadjs = true;

self.onmessage = function (evt) {
    if (!g_loadjs) {
        var objData = {
            t: kWamsLoadErrorEvt,
        };
        self.postMessage(objData);
        console.log("[ER] importScripts(libffmpeg.js)");
        return false;
    }
    if (!self.decoder) {
        console.log("[ER] Decoder not initialized!");
        return;
    }
    var req = evt.data;
    self.decoder.cacheAndProReq(req);
};

try {
    self.importScripts('libffmpeg.js');
} catch (e) {
    console.log(e)
    g_loadjs = false;
}

function Decoder() {
    this.coreLogLevel = 1;
    this.wasmLoaded = false;
    this.tmpReqQue = [];
    this.tmpDataQue = [];
    this.cacheBuffer = null;
    this.cacheSize = 0;
    this.decodeTimer = null;
    this.videoCallback = null;
    this.audioCallback = null;
    this.decoderID = 0;
    this.feedstatus = 0;
    this._frameDur = 40;
    this._startDec = 0;
    this._lastPts = 0;
    this._totalDur = 0;
    this._count = 0;
    this._speed = 1;
    this._inputCount = 0;
}

Decoder.prototype.initDecoder = function (chunkSize) {
    var ret = Module._initDecoder(this.coreLogLevel);
    if (0 == ret) {
        chunkSize = chunkSize || 65536;
        this.cacheBuffer = Module._malloc(chunkSize);
        this.cacheSize = chunkSize
    }
    var objData = {
        t: kInitDecoderRsp,
        e: ret
    };
    self.postMessage(objData);
};

Decoder.prototype.uninitDecoder = function () {
    var ret = Module._uninitDecoder();
    if (this.cacheBuffer != null) {
        Module._free(this.cacheBuffer);
        this.cacheBuffer = null;
        this.cacheSize = 0;
    }
};

Decoder.prototype.openDecoder = function (cd, islive) {
    var paramCount = 1, paramSize = 4;
    var paramByteBuffer = Module._malloc(paramCount * paramSize);
    var codeId = 3;
    if (cd == 9) {  //mpeg4
        codeId = 2;
    } else if (cd == 12) { //265
        codeId = 3;
    } else if (cd == 7) { //264
        codeId = 1;
    } else if (cd == 13) { //svac
        codeId = 4;
    } else if (cd == 14) { //mjpeg
        codeId = 5;
    } else if (cd == 15) { //mjpegb
        codeId = 6;
    }
    console.log('Decoder.openDecoder: code[', cd, '], codeId[', codeId, ']');
    var ret = Module._openDecoder(paramByteBuffer, codeId, 1, this.videoCallback, this.audioCallback);
    if (ret == 0) {
        var paramIntBuff = paramByteBuffer >> 2;
        var paramArray = Module.HEAP32.subarray(paramIntBuff, paramIntBuff + paramCount);
        this.decoderID = paramArray[0];
        this.islive = islive;

        // Send audio config to main thread
        var sampleRate = 8000;
        var channels = 1;
        var format = 1;  // 1 = 16-bit signed int
        try {
            if (typeof Module._getAudioSampleRate === 'function') {
                sampleRate = Module._getAudioSampleRate(this.decoderID);
            }
            if (typeof Module._getAudioChannels === 'function') {
                channels = Module._getAudioChannels(this.decoderID);
            }
            if (typeof Module._getAudioSampleFormat === 'function') {
                format = Module._getAudioSampleFormat(this.decoderID);
            }
        } catch (e) {
            // WASM module doesn't expose audio query functions, use defaults
        }
        self.postMessage({
            t: kAudioInfo,
            f: format,
            c: channels,
            r: sampleRate
        });
    }
    var objData = {
        t: kOpenDecoderRsp,
        e: ret
    };
    self.postMessage(objData);
    Module._free(paramByteBuffer);
};

Decoder.prototype.closeDecoder = function () {
    this.tmpDataQue = [];

    if (this.decodeTimer) {
        clearInterval(this.decodeTimer);
        this.decodeTimer = null;
    }

    var ret = Module._closeDecoder(this.decoderID);
    this.decoderID = 0
    var objData = {
        t: kCloseDecoderRsp,
        e: 0
    };
    self.postMessage(objData);
};

Decoder.prototype.startDecoding = function (speed, bdel) {
    if (this.decodeTimer) {
        clearInterval(this.decodeTimer);
    }
    if (typeof speed === 'number') {
        this._speed = speed;
    }
    if (bdel === true) {
        var dq = this.tmpDataQue;
        dq.splice(0, dq.length);
    }

    this.decodeTimer = setInterval(this.decode.bind(this), this._frameDur / this._speed);

};

Decoder.prototype.pauseDecoding = function () {
    if (this.decodeTimer) {
        clearInterval(this.decodeTimer);
        this.decodeTimer = null;
    }
};


Decoder.prototype.SeekDecoder = function (pts) {
    var dq = this.tmpDataQue;
    var del = 0;
    if (pts == -1) {
        dq.splice(0, dq.length);
    } else {
        for (var i = 0, len = dq.length; i < len; i++) {
            if (dq[i].k == 1) {
                if (dq[i].s < pts) {
                    del = i;
                } else if (dq[i].s = pts) {
                    del = i;
                    break;
                } else {
                    break;
                }
            }
        }
        if (del > 0) {
            dq.splice(0, del);
        }
    }

};

Decoder.prototype.decode = function () {
    if (this.feedstatus == 1 && this.tmpDataQue.length < MINREQCOUNT) {
        this.feedstatus = 0;
        self.postMessage({
            t: kStartFeedingEvt
        });
    }
    if (this.tmpDataQue.length > 0) {
        var dataReq = this.tmpDataQue.shift();
        this.decodeFrameData(dataReq.d, dataReq.s, dataReq.k);
    }

};

Decoder.prototype.decodeFrameData = function (data, pts, key) {
    var typedArray = data;
    if (typedArray.length > this.cacheSize) {
        Module._free(this.cacheBuffer);
        this.cacheSize = typedArray.length + 1000;
        this.cacheBuffer = Module._malloc(this.cacheSize);
    }
    Module.HEAPU8.set(typedArray, this.cacheBuffer);
    this._getFrame = false;
    var error = Module._decodeOnePacket(this.decoderID, this.cacheBuffer, typedArray.length, pts, pts);
    this._inputCount += 1;
    if (this._inputCount > 200) {
        self.postMessage({
            t: kDecodeErrorEvt
        });
        this._inputCount = 0;
        console.log("wasm deocdeError 200 times");
    } else {
        if (!this._getFrame && this.tmpDataQue.length > 0) {
            this.decode();
        }
    }
};

Decoder.prototype.processReq = function (req) {
    switch (req.t) {
        case kInitDecoderReq:
            this.initDecoder(req.s, req.c);
            break;
        case kUninitDecoderReq:
            this.uninitDecoder();
            break;
        case kOpenDecoderReq:
            this.openDecoder(req.cd, req.l);
            break;
        case kCloseDecoderReq:
            this.closeDecoder();
            break;
        case kStartDecodingReq:
            this.startDecoding(req.i, req.d);
            break;
        case kPauseDecodingReq:
            this.pauseDecoding();
            break;
        case kSeekDecoderReq:
            this.SeekDecoder(req.s);
            break;
        default:
    }
};

Decoder.prototype.cacheAndProReq = function (req) {
    if (req) {
        if (req.t === kFeedDataReq) {
            this.tmpDataQue.push(req);
            if (this._count >= 0) {
                var dif = req.s - this._lastPts,
                    frame = this._frameDur;
                this._totalDur += (dif <= 0 || dif >= 2000) ? frame : dif;
                if (this._count > 20) {
                    var val = this._totalDur / this._count;
                    if (frame - val > 3) {
                        this._frameDur = val;
                        this.startDecoding();
                        this._count = -1;
                    }
                }
            }
            this._lastPts = req.s;
            this._count++
            var dq = this.tmpDataQue;
            if (this.islive) {
                if (req.k == 1 && dq.length > MAXREQCOUNT_LIVE) {
                    dq.splice(0, dq.length - 1);
                }
            } else {
                if (this.feedstatus == 0 && this.tmpDataQue.length > MAXREQCOUNT) {
                    this.feedstatus = 1;
                    self.postMessage({
                        t: kPauseFeedingEvt
                    });
                } else if (this.feedstatus == 1 && this.tmpDataQue.length < MINREQCOUNT) {
                    this.feedstatus = 0;
                    self.postMessage({
                        t: kStartFeedingEvt
                    });
                }
            }

        } else {
            if (!this.wasmLoaded || this.tmpReqQue.length > 0) {
                this.tmpReqQue.push(req);
            } else {
                this.processReq(req);
            }
        }
    }
    if (this.wasmLoaded && this.tmpReqQue.length > 0) {
        var proReq = this.tmpReqQue.shift();
        this.processReq(proReq);
        if (this.tmpReqQue.length > 0) {
            setTimeout(this.cacheAndProReq, 0);
        }
    }
};

Decoder.prototype.onWasmLoaded = function () {
    this.wasmLoaded = true;

    var _this = this;
    this.videoCallback = Module.addFunction(function (y, yline, u, uline, v, vline, width, height, timestamp) {
        _this._inputCount = 0;
        _this._getFrame = true;
        var outArray = Module.HEAPU8.subarray(y, y + yline * height);
        var ydata = new Uint8Array(outArray);
        outArray = Module.HEAPU8.subarray(u, u + uline * height / 2);
        var udata = new Uint8Array(outArray);
        outArray = Module.HEAPU8.subarray(v, v + vline * height / 2);
        var vdata = new Uint8Array(outArray);
        var objData = {
            t: kVideoFrame,
            w: width,
            h: height,
            ly: yline,
            lu: uline,
            lv: vline,
            s: timestamp,
            y: ydata,
            u: udata,
            v: vdata
        };
        self.postMessage(objData, [objData.y.buffer], [objData.u.buffer], [objData.v.buffer]);
    });

    this.audioCallback = Module.addFunction(function (buff, size) {
        var outArray = Module.HEAPU8.subarray(buff, buff + size);
        var data = new Uint8Array(outArray);
        var objData = {
            t: kAudioFrame,
            d: data
        };
        self.postMessage(objData, [objData.d.buffer]);
    });

    this.cacheAndProReq();
};

self.decoder = new Decoder;


function onWasmLoaded() {
    if (self.decoder) {
        self.decoder.onWasmLoaded();
    } else {
        console.log("[ER] No decoder!");
    }
}