Did I find mamory leak in Generic Image Decoder (GID) ?

[reinkor <reinkor@gmail.com>]

Dear All,

I tried out GID (Generic Image Decoder) from

http://sourceforge.net/projects/gen-img-dec/

The point was to read jpeg-images from my Ada program
"wrapped" in a function:

  function  read_jpg(cfile_jpg : String) return image1.imgc_t;

The source code is below. However, this function seems to eat memory
during (say 200) repeated calls to it (large images, 2000x1800 pixels each).

I did something very very stupid ?

reinert

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

Here is the actual code:

with Ada.Streams.Stream_IO;
use Ada.Streams.Stream_IO;

with Ada.Characters.Latin_1;

with Interfaces.C;
with Interfaces.C.Strings;

with system;
with Ada.Unchecked_Conversion;
with Interfaces;

with GID;
with Ada.Calendar;
with Ada.Characters.Handling;           use Ada.Characters.Handling;
with Ada.Text_IO;                       use Ada.Text_IO;
with Ada.Unchecked_Deallocation;

with Text_IO; use Text_IO;




package body file_handling3 is

  package Int_Io is new Text_IO.Integer_Io (Integer);
  use Int_Io;

  use Interfaces;

  type Byte_Array is array(Integer range <>) of Unsigned_8;
  type p_Byte_Array is access Byte_Array;
  procedure Dispose is new Ada.Unchecked_Deallocation(Byte_Array, p_Byte_Array);


  img_buf: p_Byte_Array := null;

  procedure Free_buf is new Ada.Unchecked_Deallocation(Object => Byte_Array, Name => p_Byte_Array);

  procedure Load_raw_image(
    image : in out GID.Image_descriptor;
    buffer: in out p_Byte_Array;
    next_frame: out Ada.Calendar.Day_Duration
  )
  is
    subtype Primary_color_range is Unsigned_8;
    image_width : constant Positive:= GID.Pixel_Width(image);
    image_height: constant Positive:= GID.Pixel_height(image);
    idx: Natural;
    --
    procedure Set_X_Y (x, y: Natural) is
    begin
      idx:= 3 * (x + image_width * (image_height - 1 - y));
    end Set_X_Y;
    --
    procedure Put_Pixel (
      red, green, blue : Primary_color_range;
      alpha            : Primary_color_range
    )
    is
    pragma Warnings(off, alpha); -- alpha is just ignored
    begin
      buffer(idx..idx+2):= (red, green, blue);
      idx:= idx + 3;
      -- ^ GID requires us to look to next pixel on the right for next time.
    end Put_Pixel;

    stars: Natural:= 0;
    procedure Feedback(percents: Natural) is
      so_far: constant Natural:= percents / 5;
    begin
      for i in stars+1..so_far loop
        Put( Standard_Error, '*');
      end loop;
      stars:= so_far;
    end Feedback;

    procedure Load_image is
      new GID.Load_image_contents(
        Primary_color_range, Set_X_Y,
        Put_Pixel, Feedback, GID.fast
      );

  begin
    Dispose(buffer);
    buffer:= new Byte_Array(0..3 * image_width * image_height - 1);
    Load_image(image, next_frame);
  end Load_raw_image;



 function read_jpg(cfile_jpg : String) return image1.imgc_t is
    f: Ada.Streams.Stream_IO.File_Type;
    i: GID.Image_descriptor;
    name : String := cfile_jpg;
    up_name: constant String:= To_Upper(name);
    next_frame, current_frame: Ada.Calendar.Day_Duration:= 0.0;
    isx,isy : Integer;
 begin

    Open(f, In_File, name);
    GID.Load_image_header(
      i,
      Stream(f).all,
      try_tga =>
        name'Length >= 4 and then
        up_name(up_name'Last-3..up_name'Last) = ".TGA"
    );
    Load_raw_image(i, img_buf, next_frame);
    Close(f);
    isx := GID.Pixel_Width(i);
    isy := GID.Pixel_Height(i);
    New_line;
    Put(" isx,isy: ");Put(Integer'Image(isx));Put(Integer'Image(isy));
    New_line;

    declare
      img1 : image1.imgc_t(1..isx,1..isy) := (others => (others => image1.Black));
      Index : Positive;
    begin
      Index := img_buf'First;
      for j in img1'Range (2) loop
          for i in img1'Range (1) loop
              img1(i,isy - j + 1).red   := image1.Short_I(img_buf (Index + 0));
              img1(i,isy - j + 1).green := image1.Short_I(img_buf (Index + 1));
              img1(i,isy - j + 1).blue  := image1.Short_I(img_buf (Index + 2));
              Index := Index + 3;
          end loop;
      end loop;
      Free_buf(img_buf);

      return img1;
    end;
 end read_jpg;

end file_handling3;