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-- Programmed by Jedidiah Barber
-- Released into the public domain
-- This program opens the file supplied as a command line argument. Except
-- rather than the usual libsndfile open procedure, it uses the standard Ada
-- library and libsndfile's virtual open. Then the program outputs the file
-- info and closes the file. No modifications are made.
with
Ada.Command_Line,
Ada.Directories,
Ada.Direct_IO,
Ada.Text_IO,
Interfaces,
Libsndfile.Virtual;
use type
Libsndfile.Count_Type;
procedure Virtual_IO_Example is
package ACom renames Ada.Command_Line;
package ADir renames Ada.Directories;
package DIO is new Ada.Direct_IO (Element_Type => Interfaces.Unsigned_8);
package TIO renames Ada.Text_IO;
Virtual_File : DIO.File_Type;
Current_Offset : Libsndfile.Count_Type := 0;
function My_Length
return Libsndfile.Count_Type is
begin
return Libsndfile.Count_Type (DIO.Size (Virtual_File));
end My_Length;
function My_Seek
(Offset : in Libsndfile.Count_Type;
Whence : in Libsndfile.Seek_From)
return Libsndfile.Count_Type is
begin
case Whence is
when Libsndfile.From_Start =>
Current_Offset := Offset;
when Libsndfile.From_Current =>
Current_Offset := Current_Offset + Offset;
when Libsndfile.From_End =>
Current_Offset := My_Length - 1 + Offset;
end case;
Current_Offset := Current_Offset mod My_Length;
return Current_Offset;
end My_Seek;
function My_Read
(Data : out Libsndfile.Raw_Data;
Bytes : in Libsndfile.Count_Type)
return Libsndfile.Count_Type
is
Item : Interfaces.Unsigned_8;
Data_Position : Integer := 1;
begin
while Data_Position <= Integer (Bytes) loop
DIO.Read (Virtual_File, Item, DIO.Count (1 + Current_Offset));
Data (Data_Position) := Item;
Data_Position := Data_Position + 1;
exit when Current_Offset + 1 > My_Length;
Current_Offset := Current_Offset + 1;
end loop;
return Libsndfile.Count_Type (Data_Position - 1);
end My_Read;
function My_Write
(Data : in Libsndfile.Raw_Data;
Bytes : in Libsndfile.Count_Type)
return Libsndfile.Count_Type
is
Item : Interfaces.Unsigned_8;
Data_Position : Integer := 1;
begin
while Data_Position <= Integer (Bytes) loop
Item := Data (Data_Position);
DIO.Write (Virtual_File, Item, DIO.Count (1 + Current_Offset));
Data_Position := Data_Position + 1;
exit when Current_Offset + 1 > My_Length;
Current_Offset := Current_Offset + 1;
end loop;
return Libsndfile.Count_Type (Data_Position - 1);
end My_Write;
function My_Tell
return Libsndfile.Count_Type is
begin
return Current_Offset + 1;
end My_Tell;
My_Info : Libsndfile.File_Info := Libsndfile.Blank_Info;
Test_File : Libsndfile.Virtual.Virtual_Sound_File;
begin
if ACom.Argument_Count < 1 then
TIO.Put_Line ("No filename provided");
ACom.Set_Exit_Status (ACom.Failure);
return;
end if;
if not ADir.Exists (ACom.Argument (1)) then
TIO.Put_Line ("File does not exist");
ACom.Set_Exit_Status (ACom.Failure);
return;
end if;
TIO.Put_Line ("Load file " & ACom.Argument (1));
DIO.Open (Virtual_File, DIO.In_File, ACom.Argument (1));
Test_File.Open
(Libsndfile.Read_Only,
My_Info,
My_Length'Unrestricted_Access,
My_Seek'Unrestricted_Access,
My_Read'Unrestricted_Access,
My_Write'Unrestricted_Access,
My_Tell'Unrestricted_Access);
TIO.New_Line;
TIO.Put_Line ("Open frame count:" &
Libsndfile.Count_Type'Image (Libsndfile.Frames (My_Info)));
TIO.Put_Line ("Open sample rate:" & Natural'Image (Libsndfile.Rate (My_Info)));
TIO.Put_Line ("Open channel count:" & Natural'Image (Libsndfile.Channels (My_Info)));
TIO.Put_Line ("Open major format: " &
Libsndfile.Major_Format'Image (Libsndfile.Major (My_Info)));
TIO.Put_Line ("Open minor format: " &
Libsndfile.Minor_Format'Image (Libsndfile.Minor (My_Info)));
TIO.Put_Line ("Open endianness: " &
Libsndfile.Endianness'Image (Libsndfile.Endian (My_Info)));
TIO.Put_Line ("Open section count:" & Natural'Image (Libsndfile.Sections (My_Info)));
TIO.Put_Line ("Open seekable: " & Boolean'Image (Libsndfile.Seekable (My_Info)));
TIO.New_Line;
Test_File.Close;
DIO.Close (Virtual_File);
TIO.Put_Line ("File closed");
end Virtual_IO_Example;
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