A quick translation of h264-stream

Map over H264Stream from action script and get it passing JSLint. There are still plenty of pieces which are definitely busted. Stub ExpGolomb out for now.

src/exp-golomb.js

@@ -0,0 +1,141 @@
+(function() {
+
+window.videojs.hls.ExpGolomb = function() {};
+
+/*
+      public class ExpGolomb
+    {
+        private var workingData:ByteArray;
+        private var workingWord:uint;
+        private var workingbBitsAvailable:uint;
+
+        public function ExpGolomb(pData:ByteArray)
+        {
+            workingData = pData;
+            workingData.position = 0;
+            loadWord();
+        }
+
+        public function length():uint
+        {
+            return ( 8 * workingData.length );
+        }
+
+        public function bitsAvailable():uint
+        {
+            return ( 8 * workingData.bytesAvailable ) + workingbBitsAvailable;
+        }
+
+        private function loadWord():void
+        {
+            workingWord = 0; workingbBitsAvailable = 0;
+            switch( workingData.bytesAvailable )
+            {
+                case 0: workingbBitsAvailable = 0; break;
+                default: // not 0, but greater than 4
+                case 4: workingWord =                        workingData.readUnsignedByte(); workingbBitsAvailable  = 8;
+                case 3: workingWord = ( workingWord << 8 ) | workingData.readUnsignedByte(); workingbBitsAvailable += 8;
+                case 2: workingWord = ( workingWord << 8 ) | workingData.readUnsignedByte(); workingbBitsAvailable += 8;
+                case 1: workingWord = ( workingWord << 8 ) | workingData.readUnsignedByte(); workingbBitsAvailable += 8;
+            }
+
+            workingWord <<= (32 - workingbBitsAvailable);
+        }
+
+        public function skipBits(size:int):void
+        {
+            if ( workingbBitsAvailable > size )
+            {
+                workingWord          <<= size;
+                workingbBitsAvailable -= size;
+            }
+            else
+            {
+                size -= workingbBitsAvailable;
+                var skipBytes:int = size / 8;
+
+                size                 -= ( skipBytes * 8 );
+                workingData.position += skipBytes;
+
+                loadWord();
+
+                workingWord          <<= size;
+                workingbBitsAvailable -= size;
+            }
+        }
+
+        public function readBits(size:int):uint
+        {
+//            if ( 32 < size )
+//                throw new Error("Can not read more than 32 bits at a time");
+
+            var bits:uint     = ( workingbBitsAvailable < size ?  workingbBitsAvailable : size);
+            var valu:uint     = workingWord >>> (32 - bits);
+
+            workingbBitsAvailable -= bits;
+            if ( 0 < workingbBitsAvailable )
+                workingWord <<= bits;
+            else
+                loadWord();
+
+            bits = size - bits;
+            if ( 0 < bits )
+                return valu << bits | readBits( bits );
+            else
+                return valu;
+        }
+
+        private function skipLeadingZeros():uint
+        {
+            for( var clz:uint = 0 ; clz < workingbBitsAvailable ; ++clz )
+            {
+                if( 0 != ( workingWord & ( 0x80000000 >>> clz ) ) )
+                {
+                    workingWord          <<= clz;
+                    workingbBitsAvailable -= clz;
+                    return clz;
+                }
+            }
+
+            loadWord(); // we exhausted workingWord and still have not found a 1
+            return clz + skipLeadingZeros();
+        }
+
+        public function skipUnsignedExpGolomb():void
+        {
+            skipBits(1 + skipLeadingZeros() );
+        }
+
+        public function skipExpGolomb():void
+        {
+            skipBits(1 + skipLeadingZeros() );
+        }
+
+        public function readUnsignedExpGolomb():uint
+        {
+            var clz:uint = skipLeadingZeros();
+            return readBits(clz+1) - 1;
+        }
+
+        public function readExpGolomb():int
+        {
+            var valu:int = readUnsignedExpGolomb();
+            if ( 0x01 & valu ) // the number is odd if the low order bit is set
+                return (1 + valu) >>> 1; // add 1 to make it even, and devide by 2
+            else
+                return -1 * (valu >>> 1); // devide by two then make it negative
+        }
+
+        // Some convenience functions
+        public function readBoolean():Boolean
+        {
+            return 1 == readBits(1);
+        }
+
+        public function readUnsignedByte():int
+        {
+            return readBits(8);
+        }
+    }
+*/
+})();

src/h264-stream.js

@@ -7,9 +7,428 @@
  */
 
 (function(window) {
+  var
+    ExpGolomb = window.videojs.hls.ExpGolomb,
+    FlvTag = window.videojs.hls.FlvTag,
+    H264ExtraData = function() {
+      var
+        sps = [], // :Array
+        pps = []; // :Array
 
-window.videojs.hls.H264Stream = function(){
-  this.tags = [];
-};
+      this.addSPS = function() { // :ByteArray
+        var tmp = new Uint8Array(); // :ByteArray
+        sps.push(tmp);
+        return tmp;
+      };
 
+      this.addPPS = function() { // :ByteArray
+        var tmp = new Uint8Array(); // :ByteArray
+        pps.push(tmp);
+        return tmp;
+      };
+
+      this.extraDataExists = function() { // :Boolean
+        return 0 < sps.length;
+      };
+
+      // (sizeOfScalingList:int, expGolomb:ExpGolomb):void
+      this.scaling_list = function(sizeOfScalingList, expGolomb) {
+        var
+          lastScale = 8, // :int
+          nextScale = 8, // :int
+          j,
+          delta_scale; // :int
+
+        for (j = 0; j < sizeOfScalingList; ++j) {
+          if (0 !== nextScale) {
+            delta_scale = expGolomb.readExpGolomb();
+            nextScale = (lastScale + delta_scale + 256) % 256;
+            //useDefaultScalingMatrixFlag = ( j = = 0 && nextScale = = 0 )
+          }
+
+          lastScale = (nextScale === 0) ? lastScale : nextScale;
+          // scalingList[ j ] = ( nextScale == 0 ) ? lastScale : nextScale;
+          // lastScale = scalingList[ j ]
+        }
+      };
+
+      this.getSps0Rbsp = function() { // :ByteArray
+        // remove emulation bytes. Is this nesessary? is there ever emulation bytes in the SPS?
+        var
+          sps0 = sps[0],// :ByteArray = sps[0];
+          s, // :uint
+          e, // :uint
+          rbsp, // :ByteArray
+          o; // :uint
+
+        sps0.position      = 1;
+        s = sps0.position;
+        e = sps0.bytesAvailable - 2;
+        rbsp = new Uint8Array(); // new ByteArray();
+
+        for (o = s ; o < e ;) {
+          if (3 !== sps0[o + 2]) {
+            o += 3;
+          } else if (0 !== sps0[o + 1]) {
+            o += 2;
+          } else if (0 !== sps0[o + 0]) {
+            o += 1;
+          } else { // found emulation bytess
+            rbsp.writeShort(0x0000);
+
+            if ( o > s ) {
+              // If there are bytes to write, write them
+              sps0.readBytes( rbsp, rbsp.length, o-s );
+            }
+
+            // skip the emulation bytes
+            sps0.position += 3;
+            o = s = sps0.position;
+          }
+        }
+
+        // copy any remaining bytes
+        sps0.readBytes(rbsp, rbsp.length);
+        sps0.position = 0;
+        return rbsp;
+      };
+
+      //(pts:uint):FlvTag
+      this.metaDataTag = function(pts) {
+        var
+          tag = new FlvTag(FlvTag.METADATA_TAG), // :FlvTag
+          expGolomb, // :ExpGolomb
+          profile_idc, // :int
+          chroma_format_idc, // :int
+          imax, // :int
+          i, // :int
+
+          pic_order_cnt_type, // :int
+          num_ref_frames_in_pic_order_cnt_cycle, // :uint
+
+          pic_width_in_mbs_minus1, // :int
+          pic_height_in_map_units_minus1, // :int
+        
+          frame_mbs_only_flag, // :int
+          frame_cropping_flag, // :Boolean
+
+          frame_crop_left_offset, // :int
+          frame_crop_right_offset, // :int
+          frame_crop_top_offset, // :int
+          frame_crop_bottom_offset, // :int
+
+          width,
+          height;
+
+          tag.dts = pts;
+          tag.pts = pts;
+          expGolomb = new ExpGolomb(this.getSps0Rbsp());
+
+        profile_idc = expGolomb.readUnsignedByte(); // :int = expGolomb.readUnsignedByte(); // profile_idc u(8)
+        expGolomb.skipBits(16);// constraint_set[0-5]_flag, u(1), reserved_zero_2bits u(2), level_idc u(8)
+        expGolomb.skipUnsignedExpGolomb(); // seq_parameter_set_id
+
+        if (profile_idc === 100 ||
+            profile_idc === 110 ||
+            profile_idc === 122 ||
+            profile_idc === 244 ||
+            profile_idc === 44 ||
+            profile_idc === 83 ||
+            profile_idc === 86 ||
+            profile_idc === 118 ||
+            profile_idc === 128) {
+          chroma_format_idc = expGolomb.readUnsignedExpGolomb();
+          if (3 === chroma_format_idc) {
+            expGolomb.skipBits(1); // separate_colour_plane_flag
+          }
+          expGolomb.skipUnsignedExpGolomb(); // bit_depth_luma_minus8
+          expGolomb.skipUnsignedExpGolomb(); // bit_depth_chroma_minus8
+          expGolomb.skipBits(1); // qpprime_y_zero_transform_bypass_flag
+          if ( expGolomb.readBoolean() ) { // seq_scaling_matrix_present_flag
+            imax = (chroma_format_idc !== 3) ? 8 : 12;
+            for (i = 0 ; i < imax ; ++i) {
+              if (expGolomb.readBoolean()) { // seq_scaling_list_present_flag[ i ]
+                if (i < 6) {
+                  this.scaling_list(16, expGolomb);
+                } else {
+                  this.scaling_list(64, expGolomb);
+                }
+              }
+            }
+          }
+        }
+
+        expGolomb.skipUnsignedExpGolomb(); // log2_max_frame_num_minus4
+        pic_order_cnt_type = expGolomb.readUnsignedExpGolomb();
+
+        if ( 0 === pic_order_cnt_type ) {
+          expGolomb.readUnsignedExpGolomb(); //log2_max_pic_order_cnt_lsb_minus4
+        } else if ( 1 === pic_order_cnt_type ) {
+          expGolomb.skipBits(1); // delta_pic_order_always_zero_flag
+          expGolomb.skipExpGolomb(); // offset_for_non_ref_pic
+          expGolomb.skipExpGolomb(); // offset_for_top_to_bottom_field
+          num_ref_frames_in_pic_order_cnt_cycle = expGolomb.readUnsignedExpGolomb();
+          for(i = 0 ; i < num_ref_frames_in_pic_order_cnt_cycle ; ++i) {
+            expGolomb.skipExpGolomb(); // offset_for_ref_frame[ i ]
+          }
+        }
+
+        expGolomb.skipUnsignedExpGolomb(); // max_num_ref_frames
+        expGolomb.skipBits(1); // gaps_in_frame_num_value_allowed_flag
+        pic_width_in_mbs_minus1 = expGolomb.readUnsignedExpGolomb();
+        pic_height_in_map_units_minus1 = expGolomb.readUnsignedExpGolomb();
+
+        frame_mbs_only_flag = expGolomb.readBits(1);
+        if (0 === frame_mbs_only_flag) {
+          expGolomb.skipBits(1); // mb_adaptive_frame_field_flag
+        }
+
+        expGolomb.skipBits(1); // direct_8x8_inference_flag
+        frame_cropping_flag = expGolomb.readBoolean();
+        if (frame_cropping_flag) {
+          frame_crop_left_offset = expGolomb.readUnsignedExpGolomb();
+          frame_crop_right_offset = expGolomb.readUnsignedExpGolomb();
+          frame_crop_top_offset = expGolomb.readUnsignedExpGolomb();
+          frame_crop_bottom_offset = expGolomb.readUnsignedExpGolomb();
+        }
+
+        width = ((pic_width_in_mbs_minus1 +1)*16) - frame_crop_left_offset*2 - frame_crop_right_offset*2;
+        height = ((2 - frame_mbs_only_flag)* (pic_height_in_map_units_minus1 +1) * 16) - (frame_crop_top_offset * 2) - (frame_crop_bottom_offset * 2);
+
+        tag.writeMetaDataDouble("videocodecid", 7);
+        tag.writeMetaDataDouble("width", width);
+        tag.writeMetaDataDouble("height", height);
+        // tag.writeMetaDataDouble("videodatarate", 0 );
+        // tag.writeMetaDataDouble("framerate", 0);
+
+        return tag;
+      };
+
+      // (pts:uint):FlvTag
+      this.extraDataTag = function(pts) {
+        var
+          i,
+          tag = new FlvTag(FlvTag.VIDEO_TAG,true);
+
+        tag.dts = pts;
+        tag.pts = pts;
+
+        tag.writeByte(0x01);// version
+        tag.writeByte(sps[0][1]);// profile
+        tag.writeByte(sps[0][2]);// compatibility
+        tag.writeByte(sps[0][3]);// level
+        tag.writeByte(0xFC | 0x03); // reserved (6 bits), NULA length size - 1 (2 bits)
+        tag.writeByte(0xE0 | 0x01 ); // reserved (3 bits), num of SPS (5 bits)
+        tag.writeShort( sps[0].length ); // data of SPS
+        tag.writeBytes( sps[0] ); // SPS
+
+        tag.writeByte( pps.length ); // num of PPS (will there ever be more that 1 PPS?)
+        for (i = 0 ; i < pps.length ; ++i) {
+          tag.writeShort(pps[i].length); // 2 bytes for length of PPS
+          tag.writeBytes(pps[i]); // data of PPS
+        }
+
+        return tag;
+      };
+    };
+
+  window.videojs.hls.H264Stream = function() {
+    var
+      tags = [],
+
+      next_pts, // :uint;
+      next_dts, // :uint;
+      pts_delta = -1, // :int
+
+      h264Frame, // :FlvTag
+
+      oldExtraData = new H264ExtraData(), // :H264ExtraData
+      newExtraData = new H264ExtraData(), // :H264ExtraData
+  
+      nalUnitType = -1, // :int
+
+      state; // :uint;
+  
+    this.tags = [];
+
+    //(pts:uint, dts:uint, dataAligned:Boolean):void
+    this.setNextTimeStamp = function(pts, dts, dataAligned) {
+      if (0>pts_delta) {
+        // We assume the very first pts is less than 0x8FFFFFFF (max signed 
+        // int32)
+        pts_delta = pts;
+      }
+
+      // We could end up with a DTS less than 0 here. We need to deal with that!
+      next_pts = pts - pts_delta;
+      next_dts = dts - pts_delta;
+
+      // If data is aligned, flush all internal buffers
+      if (dataAligned) {
+        this.finishFrame();
+      }
+    };
+
+    this.finishFrame = function() {
+      if (null !== h264Frame) {
+        // Push SPS before EVERY IDR frame fo seeking
+        if (newExtraData.extraDataExists()) {
+          oldExtraData = newExtraData;
+          newExtraData = new H264ExtraData();
+        }
+
+        if(true === h264Frame.keyFrame) {
+          // Push extra data on every IDR frame in case we did a stream change + seek
+          tags.push( oldExtraData.metaDataTag (h264Frame.pts) );
+          tags.push( oldExtraData.extraDataTag(h264Frame.pts) );
+        }
+
+        h264Frame.endNalUnit();
+        tags.push(h264Frame);
+      }
+
+      h264Frame = null;
+      nalUnitType = -1;
+      state = 0;
+    };
+
+    // (pData:ByteArray, o:int, l:int):void
+    this.writeBytes = function(pData, o, l) {
+      var
+        nalUnitSize, // :uint
+        s, // :uint
+        e, // :uint
+        t; // :int
+
+      if (0 >= l) {
+        return;
+      }
+      switch (state) {
+      default:
+        state = 1;
+        break;
+      case 0:
+        state = 1;
+        break;
+        /*--------------------------------------------------------------------------------------------------------------------*/
+      case 1: // We are looking for overlaping start codes
+        if (1 >= pData[o]) {
+          nalUnitSize = (null === h264Frame) ? 0 : h264Frame.nalUnitSize();
+          if (1 <= nalUnitSize && 0 === h264Frame.negIndex(1)) {
+            // ?? ?? 00 | O[01] ?? ??
+            if (1 === pData[o] && 2 <= nalUnitSize && 0 === h264Frame.negIndex(2) ) {
+              // ?? 00 00 : 01
+              if (3 <= nalUnitSize && 0 === h264Frame.negIndex(3)) {
+                h264Frame.length -= 3; // 00 00 00 : 01
+              } else {
+                h264Frame.length -= 2; // 00 00 : 01
+              }
+              
+              state = 3;
+              return this.writeBytes(pData, o + 1, l - 1);
+            }
+
+            if (1 < l && 0 === pData[o] && 1 === pData[o + 1]) {
+              // ?? 00 | 00 01
+              if (2 <= nalUnitSize && 0 === h264Frame.negIndex(2)) {
+                h264Frame.length -= 2; // 00 00 : 00 01
+              } else {
+                h264Frame.length -= 1; // 00 : 00 01
+              }
+              
+              state = 3;
+              return this.writeBytes(pData, o + 2, l - 2);
+            }
+
+            if (2 < l && 0 === pData[o] && 0 === pData[o + 1]  && 1 === pData[o + 2]) {
+              // 00 | 00 00 01
+              h264Frame.length -= 1;
+              state = 3;
+              return this.writeBytes(pData, o + 3, l - 3);
+            }
+          }
+        }
+        // allow fall through if the above fails, we may end up checking a few
+        // bytes a second time. But that case will be VERY rare
+        state = 2;
+        break;
+      case 2: // Look for start codes in pData
+        s = o; // s = Start
+        e = s + l; // e = End
+        for (t = e - 3 ; o < t ;) {
+          if (1 < pData[o + 2]) {
+            o += 3; // if pData[o+2] is greater than 1, there is no way a start code can begin before o+3
+          } else if (0 !== pData[o + 1]) {
+              o += 2;
+          } else if (0 !== pData[o]) {
+              o += 1;
+          } else {
+            // If we get here we have 00 00 00 or 00 00 01
+            if (1 === pData[o + 2]) {
+              if (o > s) {
+                h264Frame.writeBytes(pData, s, o - s);
+              }
+              state = 3; o += 3;
+              return this.writeBytes(pData, o, e - o);
+            }
+
+            if (4 <= e-o && 0 === pData[o + 2] && 1 === pData[o + 3]) {
+              if (o > s) {
+                h264Frame.writeBytes(pData, s, o - s);
+              }
+              state = 3;
+              o += 4;
+              return this.writeBytes(pData, o, e - o);
+            }
+
+            // We are at the end of the buffer, or we have 3 NULLS followed by something that is not a 1, eaither way we can step forward by at least 3
+            o += 3;
+          }
+        }
+
+        // We did not find any start codes. Try again next packet
+        state = 1;
+        h264Frame.writeBytes( pData, s, l );
+        return;
+        /*--------------------------------------------------------------------------------------------------------------------*/
+      case 3: // The next byte is the first byte of a NAL Unit
+        if (null !== h264Frame) {
+          switch (nalUnitType) {
+            // We are still operating on the previous NAL Unit
+          case  7:
+            h264Frame.endNalUnit(newExtraData.addSPS());
+            break;
+          case  8:
+            h264Frame.endNalUnit(newExtraData.addPPS());
+            break;
+          case  5:
+            h264Frame.keyFrame = true;
+            h264Frame.endNalUnit();
+            break;
+          default:
+            h264Frame.endNalUnit();
+            break;
+          }
+        }
+
+        nalUnitType = pData[o] & 0x1F;
+        if ( null != h264Frame && 9 === nalUnitType ) {
+          this.finishFrame(); // We are starting a new access unit. Flush the previous one
+        }
+
+        // finishFrame may render h264Frame null, so we must test again
+        if ( null === h264Frame )
+        {
+          h264Frame = new FlvTag(FlvTag.VIDEO_TAG);
+          h264Frame.pts = next_pts;
+          h264Frame.dts = next_dts;
+        }
+
+        h264Frame.startNalUnit();
+        state = 2; // We know there will not be an overlapping start code, so we can skip that test
+        return this.writeBytes(pData, o, l);
+        /*--------------------------------------------------------------------------------------------------------------------*/
+      } // switch
+    };
+  };
 })(this);