Subversion Repositories bluespec-h264

// The MIT License

// Copyright (c) 2006-2007 Massachusetts Institute of Technology

// Permission is hereby granted, free of charge, to any person obtaining a copy

// of this software and associated documentation files (the "Software"), to deal

// in the Software without restriction, including without limitation the rights

// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

// copies of the Software, and to permit persons to whom the Software is

// furnished to do so, subject to the following conditions:

// The above copyright notice and this permission notice shall be included in

// all copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

// THE SOFTWARE.

//**********************************************************************

// NAL unit unwrapper implementation

//----------------------------------------------------------------------

//

//

package mkNalUnwrap;

import H264Types::*;

import INalUnwrap::*;

import FIFO::*;

import Connectable::*;

import GetPut::*;

//-----------------------------------------------------------

// NAL Unwrapper Module

//-----------------------------------------------------------

module mkNalUnwrap( INalUnwrap );

   FIFO#(InputGenOT)  infifo    <- mkFIFO;

   FIFO#(NalUnwrapOT) outfifo   <- mkFIFO;

   Reg#(Bit#(8))      buffera   <- mkReg(0);

   Reg#(Bit#(8))      bufferb   <- mkReg(0);

   Reg#(Bit#(8))      bufferc   <- mkReg(0);

   Reg#(Bit#(2))      bufcount  <- mkReg(0);

   Reg#(Bit#(27))     zerocount <- mkReg(0);

   //-----------------------------------------------------------

   // Rules

   rule fillbuffer (bufcount<3

                    &&& infifo.first() matches tagged DataByte .dbyte);

      bufferc  <= bufferb;

      bufferb  <= buffera;

      buffera  <= dbyte;

      bufcount <= bufcount+1;

      infifo.deq();

   endrule

   rule newnalunit (bufcount==3

                    &&& infifo.first() matches tagged DataByte .dbyte

                    &&& ((bufferc==0 && bufferb==0 && buffera==1)

                         || (bufferc==0 && bufferb==0 && buffera==0 && dbyte==1)));

      zerocount <= 0;

      if(bufferc==0 && bufferb==0 && buffera==1)

         bufcount <= 0;

      else

         begin

            bufcount <= 0;

            infifo.deq();

         end

      outfifo.enq(NewUnit);

      $display("ccl1newunit");

   endrule

   rule remove3byte (bufcount==3

                     &&& infifo.first() matches tagged DataByte .dbyte

                     &&& (bufferc==0 && bufferb==0 && buffera==3 && dbyte<4));

      zerocount <= zerocount+2;

      bufcount  <= 0;

   endrule

   rule normalop (bufcount==3

                  &&& infifo.first() matches tagged DataByte .dbyte

                  &&& !(bufferc==0 && bufferb==0 && buffera==3 && dbyte<4)

                  &&& !((bufferc==0 && bufferb==0 && buffera==1)

                        || (bufferc==0 && bufferb==0 && buffera==0 && dbyte==1)));

      if(bufferc==0)

         begin

            zerocount <= zerocount+1;

            bufferc  <= bufferb;

            bufferb  <= buffera;

            buffera  <= dbyte;

            infifo.deq();

         end

      else if(zerocount==0)

         begin

            outfifo.enq(RbspByte (bufferc));

            $display("ccl1rbspbyte %h", bufferc);

            bufferc  <= bufferb;

            bufferb  <= buffera;

            buffera  <= dbyte;

            infifo.deq();

         end

      else

         begin

            zerocount <= zerocount-1;

            outfifo.enq(RbspByte (0));

            $display("ccl1rbspbyte 00");

         end

   endrule

   rule endfileop(infifo.first() matches tagged EndOfFile);

      case ( bufcount )

         3:

         begin

            if(bufferc==0 && bufferb==0 && buffera<4)

               begin

                  bufcount  <= 0;

                  zerocount <= 0;

               end

            else if(zerocount==0)

               begin

                  bufcount <= 2;

                  outfifo.enq(RbspByte (bufferc));

                  $display("ccl1rbspbyte %h", bufferc);

               end

            else

               begin

                  zerocount <= zerocount-1;

                  outfifo.enq(RbspByte (0));

                  $display("ccl1rbspbyte 00");

               end

         end

         2:

         begin

            bufcount  <= 1;

            if(!(bufferb==0 && buffera==0))

               outfifo.enq(RbspByte (bufferb));

               $display("ccl1rbspbyte %h", bufferb);

         end

         1:

         begin

            bufcount  <= 0;

            if(!(buffera==0))

               outfifo.enq(RbspByte (buffera));

               $display("ccl1rbspbyte %h", buffera);

         end

         0:

         begin

            infifo.deq();

            outfifo.enq(EndOfFile);

            $display("EndOfFile reached (NalUnwrap)");

         end

      endcase

   endrule

   interface Put ioin  = fifoToPut(infifo);

   interface Get ioout = fifoToGet(outfifo);

endmodule

endpackage