inter_pred_pipeline.v

a H.264/AVC Baseline Decoder

//--------------------------------------------------------------------------------------------------
// Design    : nova
// Author(s) : Ke Xu
// Email	   : [e-mail]
// File      : Inter_pred_pipeline.v
// Generated : Oct 4, 2005
// Copyright (C) 2008 Ke Xu                
//-------------------------------------------------------------------------------------------------
// Description 
// Inter prediction pipeline
//-------------------------------------------------------------------------------------------------
// Revise log 
// 1.July 23,2006
// Change the ext_frame_RAM from async read to sync read.Therefore,blk4x4_inter_preload_counter has to +1 for all the cases
//-------------------------------------------------------------------------------------------------

// synopsys translate_off
`include "timescale.v"
// synopsys translate_on
`include "nova_defines.v"

module Inter_pred_pipeline (clk,reset_n,
	mb_num_h,mb_num_v,trigger_blk4x4_inter_pred,blk4x4_rec_counter,mb_type_general_bit3,
	mv_is16x16,mv_below8x8,
	mvx_CurrMb0,mvx_CurrMb1,mvx_CurrMb2,mvx_CurrMb3,
	mvy_CurrMb0,mvy_CurrMb1,mvy_CurrMb2,mvy_CurrMb3,
	Inter_pix_copy0,Inter_pix_copy1,Inter_pix_copy2,Inter_pix_copy3,
	LPE0_out,LPE1_out,LPE2_out,LPE3_out,
	CPE0_out,CPE1_out,CPE2_out,CPE3_out,
	
	mv_below8x8_curr,blk4x4_inter_preload_counter,blk4x4_inter_calculate_counter,Inter_chroma2x2_counter,
	end_of_one_blk4x4_inter,IsInterLuma,IsInterChroma,Is_InterChromaCopy,
	xInt_addr_unclip,xInt_org_unclip_1to0,pos_FracL,xFracC,yFracC,
	Inter_pred_out0,Inter_pred_out1,Inter_pred_out2,Inter_pred_out3,Inter_blk4x4_pred_output_valid,
	ref_frame_RAM_rd,ref_frame_RAM_rd_addr);
	input clk;
	input reset_n;
	input [3:0] mb_num_h,mb_num_v;
	input trigger_blk4x4_inter_pred;
	input [4:0] blk4x4_rec_counter;
	input mb_type_general_bit3;
	input mv_is16x16;
	input [3:0] mv_below8x8;
	input [31:0] mvx_CurrMb0,mvx_CurrMb1,mvx_CurrMb2,mvx_CurrMb3;
	input [31:0] mvy_CurrMb0,mvy_CurrMb1,mvy_CurrMb2,mvy_CurrMb3;
	input [7:0] Inter_pix_copy0,Inter_pix_copy1,Inter_pix_copy2,Inter_pix_copy3;
	input [7:0] LPE0_out,LPE1_out,LPE2_out,LPE3_out;
	input [7:0] CPE0_out,CPE1_out,CPE2_out,CPE3_out;
	
	output mv_below8x8_curr;
	output [5:0] blk4x4_inter_preload_counter;
	output [3:0] blk4x4_inter_calculate_counter;
	output [1:0] Inter_chroma2x2_counter;
	output end_of_one_blk4x4_inter;
	output IsInterLuma,IsInterChroma;
	output Is_InterChromaCopy;
	output [8:0] xInt_addr_unclip;
	output [1:0] xInt_org_unclip_1to0;
	output [3:0] pos_FracL;
	output [2:0] xFracC,yFracC;
	output [7:0] Inter_pred_out0,Inter_pred_out1,Inter_pred_out2,Inter_pred_out3;
	output [1:0] Inter_blk4x4_pred_output_valid;	//2'b01:luma output valid	2'b10:chroma output valid
	output ref_frame_RAM_rd;
	output [13:0] ref_frame_RAM_rd_addr;
	
	reg [5:0] blk4x4_inter_preload_counter;
	reg [3:0] blk4x4_inter_calculate_counter;
	reg mv_below8x8_curr;
	reg [7:0] Inter_pred_out0,Inter_pred_out1,Inter_pred_out2,Inter_pred_out3;
	reg [1:0] Inter_blk4x4_pred_output_valid;
	wire ref_frame_RAM_rd; 
	wire IsInterLuma;
	wire IsInterChroma;
	wire [1:0] xFracL;
	wire [1:0] yFracL;
	wire [2:0] xFracC;
	wire [2:0] yFracC;
	wire [13:0] ref_frame_RAM_rd_addr;
		
	assign IsInterLuma   = (!mb_type_general_bit3 && blk4x4_rec_counter < 16)? 1'b1:1'b0;
	assign IsInterChroma = (!mb_type_general_bit3 && blk4x4_rec_counter > 15)? 1'b1:1'b0;
	//-------------------------------------------------------------------------
	//mv_below8x8_curr for each 2x2 Inter Chroma prediction
	//-------------------------------------------------------------------------	
	always @ (IsInterLuma or IsInterChroma or blk4x4_rec_counter[3:0] or mv_below8x8)
		if (IsInterLuma)
			case (blk4x4_rec_counter[3:2])
				2'b00:mv_below8x8_curr <= mv_below8x8[0];
				2'b01:mv_below8x8_curr <= mv_below8x8[1];
				2'b10:mv_below8x8_curr <= mv_below8x8[2];
				2'b11:mv_below8x8_curr <= mv_below8x8[3];
			endcase
		else if (IsInterChroma)
			case (blk4x4_rec_counter[1:0])
				2'b00:mv_below8x8_curr <= mv_below8x8[0];
				2'b01:mv_below8x8_curr <= mv_below8x8[1];
				2'b10:mv_below8x8_curr <= mv_below8x8[2];
				2'b11:mv_below8x8_curr <= mv_below8x8[3];
			endcase
		else
			mv_below8x8_curr <= 0;
	//----------------------------------------------------------------------------------------
	//Inter_chroma2x2_counter to guide the prediction of 2x2 chroma blocks
	//2'b11 -> 2'b10 -> 2'b01 -> 2'b00
	//----------------------------------------------------------------------------------------
	reg [1:0] Inter_chroma2x2_counter;		
	always @ (posedge clk)
		if (reset_n == 1'b0)
			Inter_chroma2x2_counter <= 0;
		//mv_below8x8_curr == 1'b1 includes the condition that "blk4x4_rec_counter > 15"
		else if (IsInterChroma && trigger_blk4x4_inter_pred && mv_below8x8_curr)
			Inter_chroma2x2_counter <= 2'b11;
		else if	(blk4x4_inter_calculate_counter == 4'd1 && Inter_chroma2x2_counter != 0)
			Inter_chroma2x2_counter <= Inter_chroma2x2_counter - 1;
	
	//----------------------------------------------------------------------------------------
	//trigger_blk2x2_inter_pred:only for chroma 2x2 decoding
	//We introduce this additional signal since we need Inter_chroma2x2_counter to update 
	//one cycle before blk4x4_inter_calculate_counter
	//----------------------------------------------------------------------------------------
	reg trigger_blk2x2_inter_pred;
	always @ (posedge clk)
		if (reset_n == 1'b0)
			trigger_blk2x2_inter_pred <= 0;
		else if ((IsInterChroma && trigger_blk4x4_inter_pred && mv_below8x8_curr) || 
			(blk4x4_inter_calculate_counter == 4'd1 && Inter_chroma2x2_counter != 0))
			trigger_blk2x2_inter_pred <= 1'b1;
		else
			trigger_blk2x2_inter_pred <= 1'b0; 
	//----------------------------------------------------------------------------------------
	//Inter motion vector for current 4x4 luma/chroma block or 2x2 chroma block
	//	Inter_blk_mvx,Inter_blk_mvy
	//----------------------------------------------------------------------------------------
	reg [7:0] Inter_blk_mvx,Inter_blk_mvy;
	always @ (blk4x4_rec_counter or mv_below8x8_curr or Inter_chroma2x2_counter 
	   	or IsInterLuma or IsInterChroma or mv_is16x16  
		or mvx_CurrMb0 or mvx_CurrMb1 or mvx_CurrMb2 or mvx_CurrMb3
		or mvy_CurrMb0 or mvy_CurrMb1 or mvy_CurrMb2 or mvy_CurrMb3)
		//Inter luma
		if (IsInterLuma)
			begin
				if (mv_is16x16)
					begin	Inter_blk_mvx <= mvx_CurrMb0[7:0];  Inter_blk_mvy <= mvy_CurrMb0[7:0]; end
				else
					case (mv_below8x8_curr)
						1'b0:
						case (blk4x4_rec_counter[3:2])
							2'b00:begin	Inter_blk_mvx <= mvx_CurrMb0[7:0];  Inter_blk_mvy <= mvy_CurrMb0[7:0]; end
							2'b01:begin	Inter_blk_mvx <= mvx_CurrMb1[7:0];  Inter_blk_mvy <= mvy_CurrMb1[7:0]; end
							2'b10:begin	Inter_blk_mvx <= mvx_CurrMb2[7:0];  Inter_blk_mvy <= mvy_CurrMb2[7:0]; end
							2'b11:begin	Inter_blk_mvx <= mvx_CurrMb3[7:0];  Inter_blk_mvy <= mvy_CurrMb3[7:0]; end
						 endcase
						 1'b1:
						case (blk4x4_rec_counter)
							0 :begin Inter_blk_mvx <= mvx_CurrMb0[7:0];  Inter_blk_mvy <= mvy_CurrMb0[7:0];   end
							1 :begin Inter_blk_mvx <= mvx_CurrMb0[15:8]; Inter_blk_mvy <= mvy_CurrMb0[15:8];  end
							2 :begin Inter_blk_mvx <= mvx_CurrMb0[23:16];Inter_blk_mvy <= mvy_CurrMb0[23:16]; end
							3 :begin Inter_blk_mvx <= mvx_CurrMb0[31:24];Inter_blk_mvy <= mvy_CurrMb0[31:24]; end
							4 :begin Inter_blk_mvx <= mvx_CurrMb1[7:0];  Inter_blk_mvy <= mvy_CurrMb1[7:0];   end
							5 :begin Inter_blk_mvx <= mvx_CurrMb1[15:8]; Inter_blk_mvy <= mvy_CurrMb1[15:8];  end
							6 :begin Inter_blk_mvx <= mvx_CurrMb1[23:16];Inter_blk_mvy <= mvy_CurrMb1[23:16]; end
							7 :begin Inter_blk_mvx <= mvx_CurrMb1[31:24];Inter_blk_mvy <= mvy_CurrMb1[31:24]; end
							8 :begin Inter_blk_mvx <= mvx_CurrMb2[7:0];  Inter_blk_mvy <= mvy_CurrMb2[7:0];   end
							9 :begin Inter_blk_mvx <= mvx_CurrMb2[15:8]; Inter_blk_mvy <= mvy_CurrMb2[15:8];  end
							10:begin Inter_blk_mvx <= mvx_CurrMb2[23:16];Inter_blk_mvy <= mvy_CurrMb2[23:16]; end
							11:begin Inter_blk_mvx <= mvx_CurrMb2[31:24];Inter_blk_mvy <= mvy_CurrMb2[31:24]; end
							12:begin Inter_blk_mvx <= mvx_CurrMb3[7:0];  Inter_blk_mvy <= mvy_CurrMb3[7:0];   end
							13:begin Inter_blk_mvx <= mvx_CurrMb3[15:8]; Inter_blk_mvy <= mvy_CurrMb3[15:8];  end
							14:begin Inter_blk_mvx <= mvx_CurrMb3[23:16];Inter_blk_mvy <= mvy_CurrMb3[23:16]; end
							15:begin Inter_blk_mvx <= mvx_CurrMb3[31:24];Inter_blk_mvy <= mvy_CurrMb3[31:24]; end
							default:begin Inter_blk_mvx <= 0;Inter_blk_mvy <= 0; end
						endcase
					endcase
			end
		//Inter chroma
		else if (IsInterChroma)
			begin
				if (mv_is16x16)
					begin	Inter_blk_mvx <= mvx_CurrMb0[7:0];  Inter_blk_mvy <= mvy_CurrMb0[7:0]; end
				else	
					case (blk4x4_rec_counter[1:0])
						2'b00:
						if (mv_below8x8_curr)	//chroma2x2 prediction
							case (Inter_chroma2x2_counter)
								3:begin Inter_blk_mvx <= mvx_CurrMb0[7:0];  Inter_blk_mvy <= mvy_CurrMb0[7:0];   end
								2:begin Inter_blk_mvx <= mvx_CurrMb0[15:8]; Inter_blk_mvy <= mvy_CurrMb0[15:8];  end
								1:begin Inter_blk_mvx <= mvx_CurrMb0[23:16];Inter_blk_mvy <= mvy_CurrMb0[23:16]; end
								0:begin Inter_blk_mvx <= mvx_CurrMb0[31:24];Inter_blk_mvy <= mvy_CurrMb0[31:24]; end
							endcase
						else 				//chroma 4x4 prediction
							begin Inter_blk_mvx <= mvx_CurrMb0[7:0];  Inter_blk_mvy <= mvy_CurrMb0[7:0];   end
						2'b01:
						if (mv_below8x8_curr)	//need chroma2x2 prediction
							case (Inter_chroma2x2_counter)
								3:begin Inter_blk_mvx <= mvx_CurrMb1[7:0];  Inter_blk_mvy <= mvy_CurrMb1[7:0];   end
								2:begin Inter_blk_mvx <= mvx_CurrMb1[15:8]; Inter_blk_mvy <= mvy_CurrMb1[15:8];  end
								1:begin Inter_blk_mvx <= mvx_CurrMb1[23:16];Inter_blk_mvy <= mvy_CurrMb1[23:16]; end
								0:begin Inter_blk_mvx <= mvx_CurrMb1[31:24];Inter_blk_mvy <= mvy_CurrMb1[31:24]; end
							endcase
						else 				//chroma 4x4 prediction
							begin Inter_blk_mvx <= mvx_CurrMb1[7:0];  Inter_blk_mvy <= mvy_CurrMb1[7:0];   end
						2'b10:
						if (mv_below8x8_curr)	//chroma2x2 prediction
							case (Inter_chroma2x2_counter)
								3:begin Inter_blk_mvx <= mvx_CurrMb2[7:0];  Inter_blk_mvy <= mvy_CurrMb2[7:0];   end
								2:begin Inter_blk_mvx <= mvx_CurrMb2[15:8]; Inter_blk_mvy <= mvy_CurrMb2[15:8];  end
								1:begin Inter_blk_mvx <= mvx_CurrMb2[23:16];Inter_blk_mvy <= mvy_CurrMb2[23:16]; end
								0:begin Inter_blk_mvx <= mvx_CurrMb2[31:24];Inter_blk_mvy <= mvy_CurrMb2[31:24]; end
							endcase
						else 				//chroma 4x4 prediction
							begin Inter_blk_mvx <= mvx_CurrMb2[7:0];  Inter_blk_mvy <= mvy_CurrMb2[7:0];   end
						2'b11:
						if (mv_below8x8_curr)	//chroma2x2 prediction
							case (Inter_chroma2x2_counter)
								3:begin Inter_blk_mvx <= mvx_CurrMb3[7:0];  Inter_blk_mvy <= mvy_CurrMb3[7:0];   end
								2:begin Inter_blk_mvx <= mvx_CurrMb3[15:8]; Inter_blk_mvy <= mvy_CurrMb3[15:8];  end
								1:begin Inter_blk_mvx <= mvx_CurrMb3[23:16];Inter_blk_mvy <= mvy_CurrMb3[23:16]; end
								0:begin Inter_blk_mvx <= mvx_CurrMb3[31:24];Inter_blk_mvy <= mvy_CurrMb3[31:24]; end
							endcase
						else 				//chroma 4x4 prediction
							begin Inter_blk_mvx <= mvx_CurrMb3[7:0];  Inter_blk_mvy <= mvy_CurrMb3[7:0];   end
					endcase
			end
		else
			begin Inter_blk_mvx <= 0;  Inter_blk_mvy <= 0;   end
	//----------------------------------------------------------------------------------------
	//Describes the offset of each blk4x4 inside a MB
	//----------------------------------------------------------------------------------------
	// xOffset = 0  for 0,2,8, 10	yOffset = 0  for 0, 1, 4, 5
	// xOffset = 4  for 1,3,9, 11	yOffset = 4  for 2, 3, 6, 7
	// xOffset = 8  for 4,6,12,14	yOffset = 8  for 8, 9, 12,13
	// xOffset = 12 for 5,7,13,15	yOffset = 12 for 10,11,14,15
	reg [3:0] xOffsetL,yOffsetL;
	always @ (IsInterLuma or mv_below8x8_curr or blk4x4_rec_counter[2] or blk4x4_rec_counter[0])
		if (IsInterLuma)
			begin
				if (!mv_below8x8_curr)
					xOffsetL <= (blk4x4_rec_counter[2])? 4'd8:4'd0;
				else
					case ({blk4x4_rec_counter[2],blk4x4_rec_counter[0]})
						2'b00:xOffsetL <= 4'd0;
						2'b01:xOffsetL <= 4'd4;
						2'b10:xOffsetL <= 4'd8;
						2'b11:xOffsetL <= 4'd12;
					endcase
			end
		else
			xOffsetL <= 0;
			
	always @ (IsInterLuma or mv_below8x8_curr or blk4x4_rec_counter[3] or blk4x4_rec_counter[1])
		if (IsInterLuma)
			begin
				if (!mv_below8x8_curr)
					yOffsetL <= (blk4x4_rec_counter[3])? 4'd8:4'd0;
				else
					case ({blk4x4_rec_counter[3],blk4x4_rec_counter[1]})
						2'b00:yOffsetL <= 4'd0;
						2'b01:yOffsetL <= 4'd4;
						2'b10:yOffsetL <= 4'd8;
						2'b11:yOffsetL <= 4'd12;
					endcase