syntax_decoding.v

H.264标准解码器全部verilog源码

//--------------------------------------------------------------------------------------------------
// Design    : nova
// Author(s) : Ke Xu
// Email	   : [e-mail]
// File      : syntax_decoding.v
// Generated : May 23, 2005
// Copyright (C) 2008 Ke Xu                
//-------------------------------------------------------------------------------------------------
// Description 
// Decoding each sytax inside the bitstream
//-------------------------------------------------------------------------------------------------

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

module syntax_decoding (clk,reset_n,mb_num_h,mb_num_v,end_of_MB_DEC,pin_disable_DF,
	parser_state,nal_unit_state,seq_parameter_set_state,pic_parameter_set_state,
	slice_header_state,slice_data_state,mb_pred_state,sub_mb_pred_state,
	exp_golomb_decoding_output,BitStream_buffer_output,dependent_variable_decoding_output,mbPartIdx,
	
	nal_unit_type,start_code_prefix_found,
	deblocking_filter_control_present_flag,disable_deblocking_filter_idc,disable_DF,
	slice_alpha_c0_offset_div2,slice_beta_offset_div2,
	mb_skip_run,NumMbPart,NumSubMbPart,
	MBTypeGen_mbAddrA,MBTypeGen_mbAddrD,MBTypeGen_mbAddrB_reg,
	log2_max_frame_num_minus4,log2_max_pic_order_cnt_lsb_minus4,constrained_intra_pred_flag,
	num_ref_idx_active_override_flag,num_ref_idx_l0_active_minus1,
	slice_type,mb_type,mb_type_general,sub_mb_type,Intra16x16_predmode,intra_chroma_pred_mode,
	pic_init_qp_minus26,chroma_qp_index_offset,
	rem_intra4x4_pred_mode,prev_intra4x4_pred_mode_flag,mvd,mv_below8x8);
	input clk,reset_n;
	input [3:0] mb_num_h,mb_num_v;
	input end_of_MB_DEC; 
	input pin_disable_DF;
	input [1:0] parser_state;
	input [2:0] nal_unit_state;
	input [3:0] seq_parameter_set_state;
	input [3:0] pic_parameter_set_state;
	input [3:0] slice_header_state;
	input [3:0] slice_data_state;
	input [2:0] mb_pred_state;
	input [1:0] sub_mb_pred_state;
	input [15:0] BitStream_buffer_output;
	input [7:0] exp_golomb_decoding_output;
	input [9:0] dependent_variable_decoding_output;
	input [1:0] mbPartIdx; 
	
	output [4:0] nal_unit_type;
	output start_code_prefix_found;
	output deblocking_filter_control_present_flag;
	output [1:0] disable_deblocking_filter_idc;
	output disable_DF; 
	output [3:0] slice_alpha_c0_offset_div2;
	output [3:0] slice_beta_offset_div2;
	output [6:0] mb_skip_run;
	output [2:0] NumMbPart;
	output [2:0] NumSubMbPart;
	output [1:0] MBTypeGen_mbAddrA;
	output MBTypeGen_mbAddrD;
	output [21:0] MBTypeGen_mbAddrB_reg;
	output [3:0] log2_max_frame_num_minus4;
	output [3:0] log2_max_pic_order_cnt_lsb_minus4;
	output constrained_intra_pred_flag;
	output num_ref_idx_active_override_flag;
	output [2:0] num_ref_idx_l0_active_minus1;
	output [2:0] slice_type;
	output [4:0] mb_type;
	output [3:0] mb_type_general;
	output [1:0] Intra16x16_predmode;
	output [1:0] intra_chroma_pred_mode;
	output [1:0] sub_mb_type;
	output [5:0] pic_init_qp_minus26;
	output [4:0] chroma_qp_index_offset;
	output [2:0] rem_intra4x4_pred_mode;
	output prev_intra4x4_pred_mode_flag;
	output [7:0] mvd;
	output [3:0] mv_below8x8;
	//--------------------------
	//start_code_prefix
	//--------------------------
	reg start_code_prefix_found;
	always @ (parser_state or BitStream_buffer_output)
		if (parser_state == `start_code_prefix)
			begin
				if (BitStream_buffer_output == 16'b0000000000000001)
					start_code_prefix_found <= 1;
				else
					start_code_prefix_found <= 0;
			end
		else
			start_code_prefix_found <= 0;
	//--------------------------
	//nal_unit
	//--------------------------
	reg forbidden_zero_bit;
	reg [1:0] nal_ref_idc;
	reg [4:0] nal_unit_type_reg;
	wire [4:0] nal_unit_type;
	assign nal_unit_type = (nal_unit_state == `forbidden_zero_bit_2_nal_unit_type)? BitStream_buffer_output[12:8]:nal_unit_type_reg; 
	always @ (posedge clk)
		if (reset_n == 0)
			begin
				forbidden_zero_bit <= 0;
				nal_ref_idc        <= 0;
				nal_unit_type_reg  <= 0;
			end
		else if (nal_unit_state == `forbidden_zero_bit_2_nal_unit_type)
			begin
				forbidden_zero_bit <= BitStream_buffer_output[15];
				nal_ref_idc        <= BitStream_buffer_output[14:13];
				nal_unit_type_reg  <= nal_unit_type;
			end
	//--------------------------
	//seq_parameter_set
	//--------------------------
	reg [7:0] profile_idc;
	reg constraint_set0_flag,constraint_set1_flag,constraint_set2_flag,constraint_set3_flag;
	reg [3:0] reserved_zero_4bits;
	reg [7:0] level_idc;
	reg [4:0] seq_parameter_set_id_sps;
	reg [3:0] log2_max_frame_num_minus4;
	reg [1:0] pic_order_cnt_type;
	reg [3:0] log2_max_pic_order_cnt_lsb_minus4;
	reg [2:0] num_ref_frames; //however,we only support 1 reference frame currently
	reg gaps_in_frame_num_value_allowed_flag;
	reg [3:0] pic_width_in_mbs_minus1; 
	reg [3:0] pic_height_in_map_units_minus1;
	reg frame_mbs_only_flag;
	reg direct_8x8_inference_flag;
	reg frame_cropping_flag;
	reg vui_parameter_present_flag;
	always @ (posedge clk)
		if (reset_n == 0)
			begin
				profile_idc                          <= 0;
				constraint_set0_flag                 <= 0;
				constraint_set1_flag                 <= 0;		
				constraint_set2_flag                 <= 0;
				constraint_set3_flag                 <= 0;
				reserved_zero_4bits	                 <= 0;
				level_idc                            <= 0;
				seq_parameter_set_id_sps             <= 0;
				log2_max_frame_num_minus4            <= 0;
				pic_order_cnt_type                   <= 0;
				log2_max_pic_order_cnt_lsb_minus4    <= 0;
				num_ref_frames                       <= 0; 
				gaps_in_frame_num_value_allowed_flag <= 0;
				pic_width_in_mbs_minus1              <= 0; 
				pic_height_in_map_units_minus1       <= 0;
				frame_mbs_only_flag                  <= 0;
				direct_8x8_inference_flag            <= 0;
				frame_cropping_flag                  <= 0;
				vui_parameter_present_flag           <= 0;
			end
		else 
			case (seq_parameter_set_state)
				`fixed_header:
				begin
					profile_idc <= BitStream_buffer_output[15:8];
					constraint_set0_flag <= BitStream_buffer_output[7];
					constraint_set1_flag <= BitStream_buffer_output[6];
					constraint_set2_flag <= BitStream_buffer_output[5];
					constraint_set3_flag <= BitStream_buffer_output[4];
					reserved_zero_4bits  <= BitStream_buffer_output[3:0];
				end
				`level_idc_s                           :level_idc                            <= BitStream_buffer_output[15:8];
				`seq_parameter_set_id_sps_s            :seq_parameter_set_id_sps             <= exp_golomb_decoding_output[4:0];
				`log2_max_frame_num_minus4_s           :log2_max_frame_num_minus4            <= exp_golomb_decoding_output[3:0];
				`pic_order_cnt_type_s                  :pic_order_cnt_type                   <= exp_golomb_decoding_output[1:0];
				`log2_max_pic_order_cnt_lsb_minus4_s   :log2_max_pic_order_cnt_lsb_minus4    <= exp_golomb_decoding_output[3:0];
				`num_ref_frames_s                      :num_ref_frames                       <= exp_golomb_decoding_output[0];
				`gaps_in_frame_num_value_allowed_flag_s:gaps_in_frame_num_value_allowed_flag <= BitStream_buffer_output[15];
				`pic_width_in_mbs_minus1_s             :pic_width_in_mbs_minus1              <= exp_golomb_decoding_output[3:0];
				`pic_height_in_map_units_minus1_s      :pic_height_in_map_units_minus1       <= exp_golomb_decoding_output[3:0];
				`frame_mbs_only_flag_2_frame_cropping_flag:
				begin
					frame_mbs_only_flag       <= BitStream_buffer_output[15];
					direct_8x8_inference_flag <= BitStream_buffer_output[14];
					frame_cropping_flag       <= BitStream_buffer_output[13];
				end
				`vui_parameter_present_flag_s:vui_parameter_present_flag <= BitStream_buffer_output[15];
			endcase
	//--------------------------
	//pic_parameter_set
	//--------------------------
	reg [7:0] pic_parameter_set_id_pps;
	reg [4:0] seq_parameter_set_id_pps;
	reg entropy_coding_mode_flag;
	reg pic_order_present_flag;
	reg [2:0] num_slice_groups_minus1;
	reg [2:0] num_ref_idx_l0_active_minus1;
	reg [2:0] num_ref_idx_l1_active_minus1;
	reg weighted_pred_flag;
	reg [1:0] weighted_bipred_idc;
	reg [5:0] pic_init_qp_minus26,pic_init_qs_minus26;
	reg [4:0] chroma_qp_index_offset;
	reg deblocking_filter_control_present_flag;
	reg constrained_intra_pred_flag;
	reg redundant_pic_cnt_present_flag;
	always @ (posedge clk)
		if (reset_n == 0)
			begin
				pic_parameter_set_id_pps               <= 0;
				seq_parameter_set_id_pps               <= 0;
				entropy_coding_mode_flag               <= 0;
				pic_order_present_flag                 <= 0;
				num_slice_groups_minus1                <= 0;
				num_ref_idx_l0_active_minus1           <= 0;
				num_ref_idx_l1_active_minus1           <= 0;
				weighted_pred_flag                     <= 0;
				weighted_bipred_idc                    <= 0;
				pic_init_qp_minus26                    <= 0;
				pic_init_qs_minus26                    <= 0;
				chroma_qp_index_offset                 <= 0;
				deblocking_filter_control_present_flag <= 0;
				constrained_intra_pred_flag            <= 0;
				redundant_pic_cnt_present_flag         <= 0;
			end
		else 
			case (pic_parameter_set_state)
				`pic_parameter_set_id_pps_s:pic_parameter_set_id_pps <= exp_golomb_decoding_output[7:0];
				`seq_parameter_set_id_pps_s:seq_parameter_set_id_pps <= exp_golomb_decoding_output[4:0];
			 	`entropy_coding_mode_flag_2_pic_order_present_flag:
				begin
					entropy_coding_mode_flag <= BitStream_buffer_output[15];
					pic_order_present_flag   <= BitStream_buffer_output[14];
				end
			 	`num_slice_groups_minus1_s         :num_slice_groups_minus1 <= exp_golomb_decoding_output[2:0];
				`num_ref_idx_l0_active_minus1_pps_s:num_ref_idx_l0_active_minus1 <= exp_golomb_decoding_output[2:0];
				`num_ref_idx_l1_active_minus1_pps_s:num_ref_idx_l1_active_minus1 <= exp_golomb_decoding_output[2:0];
				`weighted_pred_flag_2_weighted_bipred_idc:
				begin
					weighted_pred_flag  <= BitStream_buffer_output[15];
					weighted_bipred_idc <= BitStream_buffer_output[14:13];
				end
				`pic_init_qp_minus26_s   :pic_init_qp_minus26 <= exp_golomb_decoding_output[5:0];
				`pic_init_qs_minus26_s   :pic_init_qs_minus26 <= exp_golomb_decoding_output[5:0];
				`chroma_qp_index_offset_s:chroma_qp_index_offset <= exp_golomb_decoding_output[4:0];
				`deblocking_filter_control_2_redundant_pic_cnt_present_flag:
				begin
					deblocking_filter_control_present_flag <= BitStream_buffer_output[15];
					constrained_intra_pred_flag            <= BitStream_buffer_output[14];
					redundant_pic_cnt_present_flag         <= BitStream_buffer_output[13];
				end
			endcase
	//--------------------------
	//slice_header
	//--------------------------
	reg first_mb_in_slice;
	reg [2:0] slice_type;
	reg [7:0] pic_parameter_set_id_slice_header;
	reg [3:0] frame_num;
	reg idr_pic_id;
	reg [9:0] pic_order_cnt_lsb;
	reg num_ref_idx_active_override_flag;
	reg [1:0] disable_deblocking_filter_idc;
	reg [3:0] slice_alpha_c0_offset_div2_dec;
	reg [3:0] slice_beta_offset_div2_dec;
	always @ (posedge clk)
		if (reset_n == 0)
			begin
				first_mb_in_slice                 <= 0;
				slice_type                        <= 0;
				pic_parameter_set_id_slice_header <= 0;
				frame_num                         <= 0;
				idr_pic_id                        <= 0;
				pic_order_cnt_lsb                 <= 0;
				num_ref_idx_active_override_flag  <= 0;
				disable_deblocking_filter_idc     <= 0;
				slice_alpha_c0_offset_div2_dec    <= 0;
				slice_beta_offset_div2_dec        <= 0;
			end
		else
			case (slice_header_state)
				`first_mb_in_slice_s                :first_mb_in_slice                 <= exp_golomb_decoding_output[0];
				`slice_type_s                       :slice_type                        <= exp_golomb_decoding_output[2:0];
				`pic_parameter_set_id_slice_header_s:pic_parameter_set_id_slice_header <= exp_golomb_decoding_output;
				`frame_num_s                        :frame_num                         <= dependent_variable_decoding_output[3:0];
				`idr_pic_id_s                       :idr_pic_id                        <= exp_golomb_decoding_output[0];
				`pic_order_cnt_lsb_s                :pic_order_cnt_lsb                 <= dependent_variable_decoding_output[9:0];
				`num_ref_idx_active_override_flag_s :num_ref_idx_active_override_flag  <= BitStream_buffer_output[15];
				//num_ref_idx_l0_active_minus1_slice_header_s:
				//slice_qp_delta_s:slice_qp_delta <= exp_golomb_decoding_output[5:0];
				`disable_deblocking_filter_idc_s    :disable_deblocking_filter_idc     <= exp_golomb_decoding_output[1:0];
				`slice_alpha_c0_offset_div2_s       :slice_alpha_c0_offset_div2_dec    <= exp_golomb_decoding_output[3:0];
				`slice_beta_offset_div2_s           :slice_beta_offset_div2_dec 	     <= exp_golomb_decoding_output[3:0];
				//slice_group_change_cycle_s:
			endcase
	
	wire [3:0] slice_alpha_c0_offset_div2;
	wire [3:0] slice_beta_offset_div2;
	assign slice_alpha_c0_offset_div2 = {4{deblocking_filter_control_present_flag}} & slice_alpha_c0_offset_div2_dec;
	assign slice_beta_offset_div2 	  = {4{deblocking_filter_control_present_flag}} & slice_beta_offset_div2_dec;
	
	reg sw_disable_DF;
	always @ (posedge clk)
		if (reset_n == 0)
			sw_disable_DF <= 0;
		else if (slice_header_state == `disable_deblocking_filter_idc_s && disable_deblocking_filter_idc == 1)
			sw_disable_DF <= 1;
		else
			sw_disable_DF <= 0;
			
	assign disable_DF = sw_disable_DF | pin_disable_DF; 
	//--------------------------
	//slice_data
	//--------------------------
	wire [6:0] mb_skip_run;
	reg [6:0] mb_skip_run_reg;