111 lines
5.4 KiB
VHDL
111 lines
5.4 KiB
VHDL
----------------------------------------------------------------------------------
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-- Engineer: Mike Field <hamster@snap.net.nz>
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--
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-- Module Name: extract_audio_samples - Behavioral
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--
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-- Description: Extract audio data from the HDMI ADP data stream
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--
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------------------------------------------------------------------------------------
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-- The MIT License (MIT)
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--
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-- Copyright (c) 2015 Michael Alan Field
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--
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-- Permission is hereby granted, free of charge, to any person obtaining a copy
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-- of this software and associated documentation files (the "Software"), to deal
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-- in the Software without restriction, including without limitation the rights
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-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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-- copies of the Software, and to permit persons to whom the Software is
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-- furnished to do so, subject to the following conditions:
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--
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-- The above copyright notice and this permission notice shall be included in
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-- all copies or substantial portions of the Software.
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--
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-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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-- THE SOFTWARE.
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------------------------------------------------------------------------------------
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----- Want to say thanks? ----------------------------------------------------------
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------------------------------------------------------------------------------------
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--
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-- This design has taken many hours - with the industry metric of 30 lines
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-- per day, it is equivalent to about 6 months of work. I'm more than happy
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-- to share it if you can make use of it. It is released under the MIT license,
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-- so you are not under any onus to say thanks, but....
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--
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-- If you what to say thanks for this design how about trying PayPal?
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-- Educational use - Enough for a beer
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-- Hobbyist use - Enough for a pizza
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-- Research use - Enough to take the family out to dinner
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-- Commercial use - A weeks pay for an engineer (I wish!)
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--
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----------------------------------------------------------------------------------
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library IEEE;
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use IEEE.STD_LOGIC_1164.ALL;
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use IEEE.NUMERIC_STD.ALL;
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entity extract_audio_samples is
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Port ( clk : in STD_LOGIC;
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adp_data_valid : in STD_LOGIC;
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adp_header_bit : in STD_LOGIC;
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adp_frame_bit : in STD_LOGIC;
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adp_subpacket0_bits : in STD_LOGIC_VECTOR (1 downto 0);
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adp_subpacket1_bits : in STD_LOGIC_VECTOR (1 downto 0);
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adp_subpacket2_bits : in STD_LOGIC_VECTOR (1 downto 0);
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adp_subpacket3_bits : in STD_LOGIC_VECTOR (1 downto 0);
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audio_de : out STD_LOGIC;
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audio_channel : out STD_LOGIC_VECTOR (2 downto 0);
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audio_sample : out STD_LOGIC_VECTOR (23 downto 0)
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);
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end extract_audio_samples;
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architecture Behavioral of extract_audio_samples is
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signal header_bits : STD_LOGIC_VECTOR (31 downto 0);
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signal frame_bits : STD_LOGIC_VECTOR (31 downto 0);
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signal subpacket0_bits : STD_LOGIC_VECTOR (63 downto 0);
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signal subpacket1_bits : STD_LOGIC_VECTOR (63 downto 0);
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signal subpacket2_bits : STD_LOGIC_VECTOR (63 downto 0);
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signal subpacket3_bits : STD_LOGIC_VECTOR (63 downto 0);
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signal grab_other_channel : std_logic := '0';
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begin
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process(clk)
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begin
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if rising_edge(clk) then
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-----------------------------------------------
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-- Move the incoming bits into a shift register
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-----------------------------------------------
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header_bits <= adp_header_bit & header_bits(header_bits'high downto 1);
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frame_bits <= (adp_frame_bit and adp_data_valid) & frame_bits(frame_bits'high downto 1);
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subpacket0_bits <= adp_subpacket0_bits & subpacket0_bits(subpacket0_bits'high downto 2);
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subpacket1_bits <= adp_subpacket1_bits & subpacket1_bits(subpacket1_bits'high downto 2);
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subpacket2_bits <= adp_subpacket2_bits & subpacket2_bits(subpacket2_bits'high downto 2);
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subpacket3_bits <= adp_subpacket3_bits & subpacket3_bits(subpacket3_bits'high downto 2);
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audio_de <= '0';
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if grab_other_channel = '1' then
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audio_de <= header_bits(7);
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audio_channel <= "001";
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audio_sample <= subpacket0_bits(45 downto 22);
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grab_other_channel <= '0';
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end if;
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if frame_bits = x"FFFFFFFE" then
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------------------------------------------------
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-- Check the packet type as being audio samples
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------------------------------------------------
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if header_bits(7 downto 0) = x"02" then
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audio_de <= header_bits(8);
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audio_channel <= "000";
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audio_sample <= subpacket0_bits(23 downto 0);
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grab_other_channel <= '1';
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end if;
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end if;
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end if;
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end process;
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end Behavioral;
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