Subversion Repositories ima_adpcm_encoder

----------------------------------------------------------------------------------

-- Company:       VISENGI S.L. (www.visengi.com)

-- Engineer:      Victor Lopez Lorenzo (victor.lopez (at) visengi (dot) com)

-- 

-- Create Date:    19:34:36 04/November/2008

-- Project Name:   IMA ADPCM Encoder

-- Tool versions:  Xilinx ISE 9.2i

-- Description: 

--

-- Description: This project features a full-hardware sound compressor using the well known algorithm IMA ADPCM.

--              The core acts as a slave WISHBONE device. The output is perfectly compatible with any sound player

--              with the IMA ADPCM codec (included by default in every Windows). Includes a testbench that takes

--              an uncompressed PCM 16 bits Mono WAV file and outputs an IMA ADPCM compressed WAV file.

--              Compression ratio is fixed for IMA-ADPCM, being 4:1.

--

--

-- LICENSE TERMS: GNU GENERAL PUBLIC LICENSE Version 3

--

--     That is you may use it only in NON-COMMERCIAL projects.

--     You are only required to include in the copyrights/about section 

--     that your system contains a "IMA ADPCM Encoder (C) VISENGI S.L. under GPL license"

--     This holds also in the case where you modify the core, as the resulting core

--     would be a derived work.

--     Also, we would like to know if you use this core in a project of yours, just an email will do.

--

--    Please take good note of the disclaimer section of the GPL license, as we don't

--    take any responsability for anything that this core does.

----------------------------------------------------------------------------------

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity IMA_ADPCM_top is

   Port (  wb_clk_i : in std_logic;

           wb_rst_i : in std_logic;

           wb_cyc_i : in std_logic;

           wb_stb_i : in std_logic;

           wb_we_i  : in std_logic;

           wb_adr_i : in std_logic_vector(1 downto 0);

           wb_dat_i : in std_logic_vector(15 downto 0);

           wb_dat_o : out std_logic_vector(15 downto 0);

           wb_ack_o : out std_logic);

end IMA_ADPCM_top;

architecture Behavioral of IMA_ADPCM_top is

   component IMA_ADPCM_Encode port (

           clk : in  STD_LOGIC;

           reset : in  STD_LOGIC;

           PredictedValue_o : out std_logic_vector(15 downto 0);

           StepIndex_o : out std_logic_vector(6 downto 0);

           StateRDY : out std_logic;

                          sample : in std_logic_vector(15 downto 0); --don't change it while sample_rdy='1'

           sample_rdy : in std_logic; --lower it only when ADPCM_sample_rdy = '1'

                          ADPCM_sample : out std_logic_vector(3 downto 0);

           ADPCM_sample_rdy : out std_logic);

   end component;

        component WAV_header_rom port(

                addr0   : in  STD_LOGIC_VECTOR(5 downto 0);

                clk   : in  STD_LOGIC;

                datao0: out STD_LOGIC_VECTOR(7 downto 0));

        end component;

   signal WAV_addr : std_logic_vector(5 downto 0);

   signal WAV_data : std_logic_vector(7 downto 0);

   signal sample : std_logic_vector(15 downto 0);

   signal ADPCM_sample : std_logic_vector(3 downto 0);

   signal sample_rdy, ADPCM_sample_rdy : std_logic;

   signal soft_reset, isoft_reset : std_logic;

   signal iwb_ack_o : std_logic;

   -- IMPORTANT: Remember that flow control MUST be done externally (that is, if SamplesPerSec is set to 8000, then 8000 samples must be fed every second)

   -- The first 60 bytes of data correspond to the WAV header

   --

   --WISHBONE REGS' DESCRIPTION:

   --reg 0: Control(W: WRITES)/Status(R: READS)

   --    bit 15: (R) 0=finished, 1=compressing (W) 0=end file (if compressing), 1=start file compression

   --          clearing this bit while compressing doesn't immediately end it, because the current block must be finished (block size=256 bytes)

   --                the only thing that happens is that the next samples up to the end of the block (samples_per_block=505) will be zeros (silence).

   --    bit  1: (R) 1=ready for new input sample to be written on reg 3 (auto-cleared on write to reg 3), 0=processing last input sample

   --    bit  0: (R) 1=16 bits of output file are ready to be read on reg 3 (auto-cleared on read to reg 3), 0=processing next output word

   --reg 1: SamplesPerSec (i.e.: 8000, 22050, 32000, 44100, ...)

   --reg 2: SecondsToCompress (0 for undefined (max values will be used in file headers) -> the sound will be complete and reproducible but an "early EOF" or "damaged file" error may appear in player at the end of the sound)

   --reg 3: On writes: a 16 bit sample is expected - On reads: data lines will contain 16 bits of the compressed output file (only if reg(0)(0)='1'!!!)

      --output words of 16 bits should be read from MSB to LSB

   signal SamplesPerSec1, SecondsToCompress2, CompressedWord : std_logic_vector(15 downto 0);

   signal InputRDY, OutputRDY, OutputRDY_sync2, RDYOutput, FinishBlock : std_logic;

   signal StartCompressing, Compressing, EndCompression : std_logic;

   signal CompressedNibbles : integer range 0 to 4;

   signal WriteHeader, WriteHeader_sync2 : std_logic;

   signal WriteState, WriteState_sync2 : std_logic;

   signal BlockBytes : integer range 0 to 255;

   signal SecondsCompressed : std_logic_vector(15 downto 0);

   signal SamplesCompressed : std_logic_vector(15 downto 0);

   signal MSB, LoadROM : std_logic;

   signal SamplesInFile : std_logic_vector(31 downto 0);

        signal PredictedValue : std_logic_vector(15 downto 0);

        signal StepIndex : std_logic_vector(6 downto 0);

   signal StateRDY : std_logic;

   signal WriteStateLSWord : std_logic;

begin

   isoft_reset <= soft_reset or wb_rst_i;

   WAV_ROM: WAV_header_rom port map (

      addr0 => WAV_addr,

      clk => wb_clk_i,

      datao0 => WAV_data);

   IMA_ADPCM_Encoder : IMA_ADPCM_Encode port map (

      clk => wb_clk_i,

      reset => isoft_reset,

      PredictedValue_o => PredictedValue,

      StepIndex_o => StepIndex,

      StateRDY => StateRDY,

      sample => sample,

      sample_rdy => sample_rdy,

      ADPCM_sample => ADPCM_sample,

      ADPCM_sample_rdy => ADPCM_sample_rdy);

   Input_process : process (wb_clk_i, wb_rst_i)

      variable WaitW : std_logic;

   begin

      if (wb_rst_i = '1') then

         iwb_ack_o <= '0';

         wb_dat_o <= (others => '0');

         InputRDY <= '0';

         OutputRDY <= '0';

         OutputRDY_sync2 <= '0';

         SamplesPerSec1 <= (others => '0');

         SecondsToCompress2 <= (others => '0');

         Compressing <= '0';

         StartCompressing <= '0';

         WaitW := '0';

         soft_reset <= '0';

         sample <= (others => '0');

         sample_rdy <= '0';

      elsif (wb_clk_i = '1' and wb_clk_i'event) then

         OutputRDY_sync2 <= OutputRDY;

         soft_reset <= '0';

         iwb_ack_o <= wb_cyc_i and wb_stb_i and not iwb_ack_o;

         if (RDYOutput = '1') then OutputRDY <= '1'; end if;

         if (ADPCM_sample_rdy = '1') then

            sample_rdy <= '0';

            if (CompressedNibbles < 3 and WriteState = '0') then InputRDY <= '1'; end if;

         end if;

         if (OutputRDY_sync2 = '1' and OutputRDY = '0' and WriteState = '0' and WriteHeader = '0') then InputRDY <= '1'; end if;

         if (((OutputRDY_sync2 = '1' and OutputRDY = '0') or (WriteHeader_sync2 = '1' and WriteHeader = '0')) and WriteState = '1' and BlockBytes = 0 and WaitW = '0') then InputRDY <= '1'; WaitW := '1'; end if; --to write the block header one input sample is required

         if (WriteState_sync2 = '1' and WriteState = '0') then InputRDY <= '1'; WaitW := '0'; end if; --after writing the block header, ask for input sample

         if (EndCompression = '1') then Compressing <= '0'; end if;

         if (FinishBlock = '1') then

            sample <= x"0000";

            sample_rdy <= '1';

            InputRDY <= '0';

         end if;

         if (wb_cyc_i = '1' and wb_stb_i = '1') then

            case wb_adr_i is

               when "00" => --control/status

                  if (wb_we_i = '0') then --read = status

                     wb_dat_o <= (others => '0');

                     wb_dat_o(15) <= Compressing;

                     wb_dat_o(1) <= InputRDY;

                     wb_dat_o(0) <= OutputRDY;

                  else --write = control

                     StartCompressing <= wb_dat_i(15);

                     if (wb_dat_i(15) = '1' and Compressing = '0') then --start new operation?

                        soft_reset <= '1';

                        OutputRDY <= '0';

                        InputRDY <= '0'; --wait for WriteHeader

                        Compressing <= '1';

                     end if;

                  end if;

               when "11" => --data in/out

                  if (wb_we_i = '0') then --read = get compressed data

                     if (OutputRDY = '1') then

                        wb_dat_o <= CompressedWord;

                        OutputRDY <= '0';

                     end if;

                  else --write = put input sample

                     if (InputRDY = '1') then

                        if (FinishBlock = '0') then sample <= wb_dat_i; else sample <= x"0000"; end if;

                        sample_rdy <= '1';

                        InputRDY <= '0';

                     end if;

                  end if;

               when "01" => --SamplesPerSec

                  if (wb_we_i = '0') then --read

                     wb_dat_o <= SamplesPerSec1;

                  else --write

                     SamplesPerSec1 <= wb_dat_i;

                  end if;

               when "10" => --SecondsToCompress

                  if (wb_we_i = '0') then --read

                     wb_dat_o <= SecondsToCompress2;

                  else --write

                     SecondsToCompress2 <= wb_dat_i;

                  end if;

               when others =>

                  report "-----------> Wrong WB Address!" severity WARNING;

            end case;

         end if;

      end if;

   end process;

   wb_ack_o <= iwb_ack_o;

   Output_process : process (wb_clk_i, wb_rst_i)

      variable WaitADPCM : std_logic;

      variable WAV_data_to_write : std_logic_vector(7 downto 0);

   begin

      if (wb_rst_i = '1') then

         CompressedWord <= (others => '0');

         RDYOutput <= '0';

         WriteHeader <= '1';

         WriteHeader_sync2 <= '1';

         FinishBlock <= '0';

         BlockBytes <= 0;

         CompressedNibbles <= 0;

         EndCompression <= '0';

         MSB <= '1';

         LoadROM <= '1';

         WAV_addr <= (others => '0');

         WAV_data_to_write := (others => '0');

         SecondsCompressed <= (others => '0');

         SamplesCompressed <= (others => '0');

         WriteState <= '0';

         WriteState_sync2 <= '0';

         WriteStateLSWord  <= '0';

         WaitADPCM := '0';

      elsif (wb_clk_i = '1' and wb_clk_i'event) then

         WriteHeader_sync2 <= WriteHeader;

         WriteState_sync2 <= WriteState;

         if (WriteState_sync2 = '0' and WriteState = '1') then WaitADPCM := '1'; end if;

         EndCompression <= '0';

         RDYOutput <= '0';

         if (StartCompressing = '0' and Compressing = '1') then FinishBlock <= '1'; end if; --finish compression on end of current block!

         if (ADPCM_sample_rdy = '1' and WriteState = '0') then --because WriteState uses one ADPCM_sample_rdy to write its own header sample

            case CompressedNibbles is --little endian on each byte (byte 0:n1n0, byte 1:n3n2, ...)

               when 0 =>

                  CompressedWord(11 downto 8) <= ADPCM_sample;

                  CompressedNibbles <= CompressedNibbles + 1;

               when 1 =>

                  CompressedWord(15 downto 12) <= ADPCM_sample;

                  CompressedNibbles <= CompressedNibbles + 1;

               when 2 =>

                  CompressedWord(3 downto 0) <= ADPCM_sample;

                  CompressedNibbles <= CompressedNibbles + 1;

               when 3 =>

                  CompressedWord(7 downto 4) <= ADPCM_sample;

                  CompressedNibbles <= CompressedNibbles + 1;

                  if (BlockBytes /= 254) then

                     BlockBytes <= BlockBytes + 2;

                  else

                     BlockBytes <= 0;

                     WriteState <= '1';

                  end if;

               when others => --4 pending wb read of reg 3

                  CompressedNibbles <= CompressedNibbles;

            end case;

            if (SamplesCompressed = SamplesPerSec1) then

               if (SecondsCompressed = SecondsToCompress2) then

                  FinishBlock <= '1'; --finish compression on end of current block!

               else

                  SamplesCompressed <= (others => '0');

                  SecondsCompressed <= SecondsCompressed + 1;

               end if;

            else

               SamplesCompressed <= SamplesCompressed + 1;

            end if;

         end if;

         if (Compressing = '1' and EndCompression = '0') then

            if (CompressedNibbles = 4) then

               if (OutputRDY_sync2 = '1' and OutputRDY = '0') then

                  CompressedNibbles <= 0;

                  if (WriteStateLSWord  = '0' and BlockBytes = 4) then WriteState <= '0'; end if; --lower it (but not in the cycle it is risen!)

               else

                  if (OutputRDY = '0' and RDYOutput = '0') then RDYOutput <= '1'; end if;

               end if;

            else

               if (RDYOutput = '0' and OutputRDY = '0') then --get next nibble/s if last CompressedWord is read

                  if (FinishBlock = '1') then --finish compression on end of current block!

                     if (BlockBytes = 0) then

                        EndCompression <= '1'; --signal input process the end of the compression

                     end if;

                  else --normal operation

                     if (WriteHeader = '1') then --output WAV header

                        if (LoadROM = '0') then

                           LoadROM <= '1'; --give the ROM time to read a byte

                           if (WAV_addr = "111100") then --last header byte + 1

                              WAV_addr <= (others => '0');

                              WriteHeader <= '0';

                              WriteState <= '1';

                           end if;

                        else

                           WAV_addr <= WAV_addr + 1;

                           WAV_data_to_write := WAV_data; --by default times are for undefined in WAV header

                           case WAV_addr is --all data is little-endian!

                              when "000100" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(7 downto 0); end if; --LSB of file_size-8 (FF for undefined)

                              when "000101" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(15 downto 8); end if; --LSB2 of file_size-8 (FF for undefined)

                              when "000110" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(23 downto 16); end if; --MSB2 of file_size-8 (FF for undefined)

                              when "000111" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(31 downto 24); end if; --MSB of file_size-8 (7F for undefined)

                              when "011000" => WAV_data_to_write := SamplesPerSec1(7 downto 0); --LSB of SamplesPerSec

                              when "011001" => WAV_data_to_write := SamplesPerSec1(15 downto 8); --MSB of SamplesPerSec

                              when "011100" => WAV_data_to_write := SamplesPerSec1(8 downto 1); --LSB of AvgBytesPerSec : approx. SamplesPerSec/2

                              when "011101" => WAV_data_to_write := '0' & SamplesPerSec1(15 downto 9); --MSB of AvgBytesPerSec : approx. SamplesPerSec/2

                              when "110000" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(7 downto 0); end if; --LSB of SamplesPerChannelInFile (FF for undefined)

                              when "110001" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(15 downto 8); end if; --LSB2 of SamplesPerChannelInFile (FF for undefined)

                              when "110010" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(23 downto 16); end if; --MSB2 of SamplesPerChannelInFile (FF for undefined)

                              when "110011" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(31 downto 24); end if; --MSB of SamplesPerChannelInFile (7F for undefined)

                              when "111000" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(7 downto 0); end if; --LSB of file_size-60 (FF for undefined)

                              when "111001" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(15 downto 8); end if; --LSB2 of file_size-60 (FF for undefined)

                              when "111010" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(23 downto 16); end if; --MSB2 of file_size-60 (FF for undefined)

                              when "111011" => if (SecondsToCompress2 /= x"0000") then WAV_data_to_write := SamplesInFile(31 downto 24); end if; --MSB of file_size-60 (7F for undefined)

                              when others => null;

                           end case;

                           if (MSB = '1') then

                              CompressedWord(15 downto 8) <= WAV_data_to_write;

                           else

                              CompressedWord(7 downto 0) <= WAV_data_to_write;

                              CompressedNibbles <= 4; --signal word ready

                           end if;

                           MSB <= not MSB;

                           LoadROM <= '0';

                        end if;

                     else --output ADPCM data

                        if (WriteState = '1' and FinishBlock = '0') then --block header with state at the beginning and every 256 bytes

                           if (WaitADPCM = '1') then

                              if (ADPCM_sample_rdy = '1') then WaitADPCM := '0'; end if;

                           else

                              if (StateRDY = '1') then

                                 if (WriteStateLSWord  = '0') then --write first two bytes of state: PredictedValue

                                    CompressedWord <= PredictedValue(7 downto 0) & PredictedValue(15 downto 8); --little endian!

                                    BlockBytes <= 2;

                                    SamplesCompressed <= SamplesCompressed + 1;

                                 else --write second two bytes of state: StepIndex & x"00"

                                    CompressedWord <= '0' & StepIndex & x"00";

                                    --WriteState <= '0'; lower it only after Output written

                                    BlockBytes <= BlockBytes + 2;

                                 end if;

                                 WriteStateLSWord <= not WriteStateLSWord;

                                 CompressedNibbles <= 4; --signal word ready

                              end if;

                           end if;

                        else --data nibbles

                           null; --taken care of above

                        end if;

                     end if;

                  end if;

               end if;

            end if;

         else

            CompressedWord <= (others => '0');

            RDYOutput <= '0';

            WriteHeader <= '1';

            FinishBlock <= '0';

            BlockBytes <= 0;

            CompressedNibbles <= 0;

            EndCompression <= '0';

            MSB <= '1';

            LoadROM <= '1';

            WAV_addr <= (others => '0');

            SecondsCompressed <= (others => '0');

            SamplesCompressed <= (others => '0');

            WriteState <= '0';

            WriteStateLSWord  <= '0';

            WaitADPCM := '0';

         end if;

      end if;

   end process;

   process (wb_clk_i, wb_rst_i)

   begin

      if (wb_rst_i = '1') then

         SamplesInFile <= (others => '0');

      elsif (wb_clk_i = '1' and wb_clk_i'event) then

         --comment next lines to save up a lot of resources (multiplier),

         --but then use undefined number of seconds for compression!!

         --(to stop it just write 0 to the MSb of WB reg 0)

         --just be aware that final WAV file will play but at the end,

         --some players will display an error saying something like "Early EOF" or "Corrupted file".

         --if (Compressing = '1' and EndCompression = '0') then

            --SamplesInFile <= SamplesPerSec1 * SecondsToCompress2;

         --else

            if (LoadROM = '1') then

               if (WAV_addr = "000000") then --file_size-8=SamplesInFile/2+52

                  --file size calculation is approximate, unless you want to mess up with floats

                  --or you have a fixed sampling rate (and want to modify the source code of this process)

                  SamplesInFile <= (('0' & SamplesPerSec1(15 downto 1)) * SecondsToCompress2) + x"34";

                  --SamplesInFile <= '0' & (SamplesInFile(31 downto 1) + x"34");

               elsif (WAV_addr = "011101") then --get raw SamplesInFile

                  SamplesInFile <= SamplesPerSec1 * SecondsToCompress2;

               elsif (WAV_addr = "110100") then --file_size-60=SamplesInFile/2

                  SamplesInFile <= '0' & SamplesInFile(31 downto 1);

               end if;

            end if;

         --end if;

      end if;

   end process;

end Behavioral;