Introducing Targets iBasso DX50 & iBasso DX90

The port to for this two targets has been entirely developped by Ilia Sergachev (alias Il or xzcc). His source
can be found at https://bitbucket.org/isergachev/rockbox . The few necesary modifications for the DX90 port
was done by headwhacker form head-fi.org. Unfortunately i could not try out the final state of the DX90 port.
The port is hosted on android (without java) as standalone app. The official Firmware is required to run this port.
Ilia did modify the source files for the "android" target in the rockbox source to make the DX port work. The work I did
was to separate the code for DX50 (&DX90) from the android target.
On this Target Ilia used source from tinyalsa from AOSP. I did not touch that part of the code because I do not understand it.
What else I changed from Ilias sources besides the separation from the target "android":
* removed a dirty hack to keep backlight off
* changed value battery meter to voltage battery meter
* made all plugins compile (named target as "standalone") and added keymaps
* i added the graphics for the manual but did not do anything else for the manual yet
* minor optimizations

known bugs:
* timers are slowed donw when playback is active (tinyalsa related?)
* some minor bugs

Things to do:
* The main prolem will be how to install the app correctly. A guy called DOC2008 added a CWM (by androtab.info) to the
  official firmware and Ilia made a CWM installation script and a dualboot selector (rbutils/ibassoboot, build with
  ndk-build). We will have to find a way to install rockbox in a proper way without breaking any copyrights.
  Maybe ADB is an option but it is not enable with OF by default. Patching the OF is probably the way to go.
* All the wiki and manual

to build:
needed: android ndk installed, android sdk installed with additional build-tools 19.1.0 installed

./tools/configure
select iBasso DX50 or iBasso DX90
make -j apk

the content of rockbox.zip/.rockbox needs to be copied to /system/rockbox/app_rockbox/rockbox/ (rockbox app not needed)
the content of libs/armeabi to /system/rockbox/lib/ (rockbox app needed)

The boot selector is needed as /system/bin/MangoPlayer and the iBasso app as /system/bin/MangoPlayer_original. There
is also the "vold" file. The one from OF does not work with DX50 rockbox (DX90 works!?), the one from Ilia is necessary.

Until we have found a proper way to install it, it can only be installed following the instructions of Ilia on his
bitbucket page, using the CWM-OF and his installation script package.

Change-Id: Ic4faaf84824c162aabcc08e492cee6e0068719d0
Reviewed-on: http://gerrit.rockbox.org/941
Tested: Chiwen Chang <rock1104.tw@yahoo.com.tw>
Reviewed-by: Michael Giacomelli <giac2000@hotmail.com>

1 files changed, 798 insertions, 0 deletions

diff --git a/rbutil/ibassoboot/jni/qdbmp.c b/rbutil/ibassoboot/jni/qdbmp.c
new file mode 100644
index 0000000000..fd1337277d
--- /dev/null
+++ b/rbutil/ibassoboot/jni/qdbmp.c
@@ -0,0 +1,798 @@
+#include "qdbmp.h"
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Bitmap header */
+typedef struct _BMP_Header
+{
+        USHORT          Magic;                          /* Magic identifier: "BM" */
+        UINT            FileSize;                       /* Size of the BMP file in bytes */
+        USHORT          Reserved1;                      /* Reserved */
+        USHORT          Reserved2;                      /* Reserved */
+        UINT            DataOffset;                     /* Offset of image data relative to the file's start */
+        UINT            HeaderSize;                     /* Size of the header in bytes */
+        UINT            Width;                          /* Bitmap's width */
+        UINT            Height;                         /* Bitmap's height */
+        USHORT          Planes;                         /* Number of color planes in the bitmap */
+        USHORT          BitsPerPixel;           /* Number of bits per pixel */
+        UINT            CompressionType;        /* Compression type */
+        UINT            ImageDataSize;          /* Size of uncompressed image's data */
+        UINT            HPixelsPerMeter;        /* Horizontal resolution (pixels per meter) */
+        UINT            VPixelsPerMeter;        /* Vertical resolution (pixels per meter) */
+        UINT            ColorsUsed;                     /* Number of color indexes in the color table that are actually used by the bitmap */
+        UINT            ColorsRequired;         /* Number of color indexes that are required for displaying the bitmap */
+} BMP_Header;
+
+
+/* Private data structure */
+struct _BMP
+{
+        BMP_Header      Header;
+        UCHAR*          Palette;
+        UCHAR*          Data;
+};
+
+
+/* Holds the last error code */
+static BMP_STATUS BMP_LAST_ERROR_CODE = 0;
+
+
+/* Error description strings */
+static const char* BMP_ERROR_STRING[] =
+{
+        "",
+        "General error",
+        "Could not allocate enough memory to complete the operation",
+        "File input/output error",
+        "File not found",
+        "File is not a supported BMP variant (must be uncompressed 8, 24 or 32 BPP)",
+        "File is not a valid BMP image",
+        "An argument is invalid or out of range",
+        "The requested action is not compatible with the BMP's type"
+};
+
+
+/* Size of the palette data for 8 BPP bitmaps */
+#define BMP_PALETTE_SIZE        ( 256 * 4 )
+
+
+
+/*********************************** Forward declarations **********************************/
+int             ReadHeader      ( BMP* bmp, FILE* f );
+int             WriteHeader     ( BMP* bmp, FILE* f );
+
+int             ReadUINT        ( UINT* x, FILE* f );
+int             ReadUSHORT      ( USHORT *x, FILE* f );
+
+int             WriteUINT       ( UINT x, FILE* f );
+int             WriteUSHORT     ( USHORT x, FILE* f );
+
+
+
+
+
+
+/*********************************** Public methods **********************************/
+
+
+/**************************************************************
+        Creates a blank BMP image with the specified dimensions
+        and bit depth.
+**************************************************************/
+BMP* BMP_Create( UINT width, UINT height, USHORT depth )
+{
+        BMP*    bmp;
+        int             bytes_per_pixel = depth >> 3;
+        UINT    bytes_per_row;
+
+        if ( height <= 0 || width <= 0 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+                return NULL;
+        }
+
+        if ( depth != 8 && depth != 24 && depth != 32 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_FILE_NOT_SUPPORTED;
+                return NULL;
+        }
+
+
+        /* Allocate the bitmap data structure */
+        bmp = calloc( 1, sizeof( BMP ) );
+        if ( bmp == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
+                return NULL;
+        }
+
+
+        /* Set header' default values */
+        bmp->Header.Magic                               = 0x4D42;
+        bmp->Header.Reserved1                   = 0;
+        bmp->Header.Reserved2                   = 0;
+        bmp->Header.HeaderSize                  = 40;
+        bmp->Header.Planes                              = 1;
+        bmp->Header.CompressionType             = 0;
+        bmp->Header.HPixelsPerMeter             = 0;
+        bmp->Header.VPixelsPerMeter             = 0;
+        bmp->Header.ColorsUsed                  = 0;
+        bmp->Header.ColorsRequired              = 0;
+
+
+        /* Calculate the number of bytes used to store a single image row. This is always
+        rounded up to the next multiple of 4. */
+        bytes_per_row = width * bytes_per_pixel;
+        bytes_per_row += ( bytes_per_row % 4 ? 4 - bytes_per_row % 4 : 0 );
+
+
+        /* Set header's image specific values */
+        bmp->Header.Width                               = width;
+        bmp->Header.Height                              = height;
+        bmp->Header.BitsPerPixel                = depth;
+        bmp->Header.ImageDataSize               = bytes_per_row * height;
+        bmp->Header.FileSize                    = bmp->Header.ImageDataSize + 54 + ( depth == 8 ? BMP_PALETTE_SIZE : 0 );
+        bmp->Header.DataOffset                  = 54 + ( depth == 8 ? BMP_PALETTE_SIZE : 0 );
+
+
+        /* Allocate palette */
+        if ( bmp->Header.BitsPerPixel == 8 )
+        {
+                bmp->Palette = (UCHAR*) calloc( BMP_PALETTE_SIZE, sizeof( UCHAR ) );
+                if ( bmp->Palette == NULL )
+                {
+                        BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
+                        free( bmp );
+                        return NULL;
+                }
+        }
+        else
+        {
+                bmp->Palette = NULL;
+        }
+
+
+        /* Allocate pixels */
+        bmp->Data = (UCHAR*) calloc( bmp->Header.ImageDataSize, sizeof( UCHAR ) );
+        if ( bmp->Data == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
+                free( bmp->Palette );
+                free( bmp );
+                return NULL;
+        }
+
+
+        BMP_LAST_ERROR_CODE = BMP_OK;
+
+        return bmp;
+}
+
+
+/**************************************************************
+        Frees all the memory used by the specified BMP image.
+**************************************************************/
+void BMP_Free( BMP* bmp )
+{
+        if ( bmp == NULL )
+        {
+                return;
+        }
+
+        if ( bmp->Palette != NULL )
+        {
+                free( bmp->Palette );
+        }
+
+        if ( bmp->Data != NULL )
+        {
+                free( bmp->Data );
+        }
+
+        free( bmp );
+
+        BMP_LAST_ERROR_CODE = BMP_OK;
+}
+
+
+/**************************************************************
+        Reads the specified BMP image file.
+**************************************************************/
+BMP* BMP_ReadFile( const char* filename )
+{
+        BMP*    bmp;
+        FILE*   f;
+
+        if ( filename == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+                return NULL;
+        }
+
+
+        /* Allocate */
+        bmp = calloc( 1, sizeof( BMP ) );
+        if ( bmp == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
+                return NULL;
+        }
+
+
+        /* Open file */
+        f = fopen( filename, "rb" );
+        if ( f == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_FILE_NOT_FOUND;
+                free( bmp );
+                return NULL;
+        }
+
+
+        /* Read header */
+        if ( ReadHeader( bmp, f ) != BMP_OK || bmp->Header.Magic != 0x4D42 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_FILE_INVALID;
+                fclose( f );
+                free( bmp );
+                return NULL;
+        }
+
+
+        /* Verify that the bitmap variant is supported */
+        if ( ( bmp->Header.BitsPerPixel != 32 && bmp->Header.BitsPerPixel != 24 && bmp->Header.BitsPerPixel != 8 )
+                || bmp->Header.CompressionType != 0 || bmp->Header.HeaderSize != 40 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_FILE_NOT_SUPPORTED;
+                fclose( f );
+                free( bmp );
+                return NULL;
+        }
+
+
+        /* Allocate and read palette */
+        if ( bmp->Header.BitsPerPixel == 8 )
+        {
+                bmp->Palette = (UCHAR*) malloc( BMP_PALETTE_SIZE * sizeof( UCHAR ) );
+                if ( bmp->Palette == NULL )
+                {
+                        BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
+                        fclose( f );
+                        free( bmp );
+                        return NULL;
+                }
+
+                if ( fread( bmp->Palette, sizeof( UCHAR ), BMP_PALETTE_SIZE, f ) != BMP_PALETTE_SIZE )
+                {
+                        BMP_LAST_ERROR_CODE = BMP_FILE_INVALID;
+                        fclose( f );
+                        free( bmp->Palette );
+                        free( bmp );
+                        return NULL;
+                }
+        }
+        else    /* Not an indexed image */
+        {
+                bmp->Palette = NULL;
+        }
+
+
+        /* Allocate memory for image data */
+        bmp->Data = (UCHAR*) malloc( bmp->Header.ImageDataSize );
+        if ( bmp->Data == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
+                fclose( f );
+                free( bmp->Palette );
+                free( bmp );
+                return NULL;
+        }
+
+
+        /* Read image data */
+        if ( fread( bmp->Data, sizeof( UCHAR ), bmp->Header.ImageDataSize, f ) != bmp->Header.ImageDataSize )
+        {
+                BMP_LAST_ERROR_CODE = BMP_FILE_INVALID;
+                fclose( f );
+                free( bmp->Data );
+                free( bmp->Palette );
+                free( bmp );
+                return NULL;
+        }
+
+
+        fclose( f );
+
+        BMP_LAST_ERROR_CODE = BMP_OK;
+
+        return bmp;
+}
+
+
+/**************************************************************
+        Writes the BMP image to the specified file.
+**************************************************************/
+void BMP_WriteFile( BMP* bmp, const char* filename )
+{
+        FILE*   f;
+
+        if ( filename == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+                return;
+        }
+
+
+        /* Open file */
+        f = fopen( filename, "wb" );
+        if ( f == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_FILE_NOT_FOUND;
+                return;
+        }
+
+
+        /* Write header */
+        if ( WriteHeader( bmp, f ) != BMP_OK )
+        {
+                BMP_LAST_ERROR_CODE = BMP_IO_ERROR;
+                fclose( f );
+                return;
+        }
+
+
+        /* Write palette */
+        if ( bmp->Palette )
+        {
+                if ( fwrite( bmp->Palette, sizeof( UCHAR ), BMP_PALETTE_SIZE, f ) != BMP_PALETTE_SIZE )
+                {
+                        BMP_LAST_ERROR_CODE = BMP_IO_ERROR;
+                        fclose( f );
+                        return;
+                }
+        }
+
+
+        /* Write data */
+        if ( fwrite( bmp->Data, sizeof( UCHAR ), bmp->Header.ImageDataSize, f ) != bmp->Header.ImageDataSize )
+        {
+                BMP_LAST_ERROR_CODE = BMP_IO_ERROR;
+                fclose( f );
+                return;
+        }
+
+
+        BMP_LAST_ERROR_CODE = BMP_OK;
+        fclose( f );
+}
+
+
+/**************************************************************
+        Returns the image's width.
+**************************************************************/
+UINT BMP_GetWidth( BMP* bmp )
+{
+        if ( bmp == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+                return -1;
+        }
+
+        BMP_LAST_ERROR_CODE = BMP_OK;
+
+        return ( bmp->Header.Width );
+}
+
+
+/**************************************************************
+        Returns the image's height.
+**************************************************************/
+UINT BMP_GetHeight( BMP* bmp )
+{
+        if ( bmp == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+                return -1;
+        }
+
+        BMP_LAST_ERROR_CODE = BMP_OK;
+
+        return ( bmp->Header.Height );
+}
+
+
+/**************************************************************
+        Returns the image's color depth (bits per pixel).
+**************************************************************/
+USHORT BMP_GetDepth( BMP* bmp )
+{
+        if ( bmp == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+                return -1;
+        }
+
+        BMP_LAST_ERROR_CODE = BMP_OK;
+
+        return ( bmp->Header.BitsPerPixel );
+}
+
+
+/**************************************************************
+        Populates the arguments with the specified pixel's RGB
+        values.
+**************************************************************/
+void BMP_GetPixelRGB( BMP* bmp, UINT x, UINT y, UCHAR* r, UCHAR* g, UCHAR* b )
+{
+        UCHAR*  pixel;
+        UINT    bytes_per_row;
+        UCHAR   bytes_per_pixel;
+
+        if ( bmp == NULL || x < 0 || x >= bmp->Header.Width || y < 0 || y >= bmp->Header.Height )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+        }
+        else
+        {
+                BMP_LAST_ERROR_CODE = BMP_OK;
+
+                bytes_per_pixel = bmp->Header.BitsPerPixel >> 3;
+
+                /* Row's size is rounded up to the next multiple of 4 bytes */
+                bytes_per_row = bmp->Header.ImageDataSize / bmp->Header.Height;
+
+                /* Calculate the location of the relevant pixel (rows are flipped) */
+                pixel = bmp->Data + ( ( bmp->Header.Height - y - 1 ) * bytes_per_row + x * bytes_per_pixel );
+
+
+                /* In indexed color mode the pixel's value is an index within the palette */
+                if ( bmp->Header.BitsPerPixel == 8 )
+                {
+                        pixel = bmp->Palette + *pixel * 4;
+                }
+
+                /* Note: colors are stored in BGR order */
+                if ( r )        *r = *( pixel + 2 );
+                if ( g )        *g = *( pixel + 1 );
+                if ( b )        *b = *( pixel + 0 );
+        }
+}
+
+
+/**************************************************************
+        Sets the specified pixel's RGB values.
+**************************************************************/
+void BMP_SetPixelRGB( BMP* bmp, UINT x, UINT y, UCHAR r, UCHAR g, UCHAR b )
+{
+        UCHAR*  pixel;
+        UINT    bytes_per_row;
+        UCHAR   bytes_per_pixel;
+
+        if ( bmp == NULL || x < 0 || x >= bmp->Header.Width || y < 0 || y >= bmp->Header.Height )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+        }
+
+        else if ( bmp->Header.BitsPerPixel != 24 && bmp->Header.BitsPerPixel != 32 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
+        }
+
+        else
+        {
+                BMP_LAST_ERROR_CODE = BMP_OK;
+
+                bytes_per_pixel = bmp->Header.BitsPerPixel >> 3;
+
+                /* Row's size is rounded up to the next multiple of 4 bytes */
+                bytes_per_row = bmp->Header.ImageDataSize / bmp->Header.Height;
+
+                /* Calculate the location of the relevant pixel (rows are flipped) */
+                pixel = bmp->Data + ( ( bmp->Header.Height - y - 1 ) * bytes_per_row + x * bytes_per_pixel );
+
+                /* Note: colors are stored in BGR order */
+                *( pixel + 2 ) = r;
+                *( pixel + 1 ) = g;
+                *( pixel + 0 ) = b;
+        }
+}
+
+
+/**************************************************************
+        Gets the specified pixel's color index.
+**************************************************************/
+void BMP_GetPixelIndex( BMP* bmp, UINT x, UINT y, UCHAR* val )
+{
+        UCHAR*  pixel;
+        UINT    bytes_per_row;
+
+        if ( bmp == NULL || x < 0 || x >= bmp->Header.Width || y < 0 || y >= bmp->Header.Height )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+        }
+
+        else if ( bmp->Header.BitsPerPixel != 8 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
+        }
+
+        else
+        {
+                BMP_LAST_ERROR_CODE = BMP_OK;
+
+                /* Row's size is rounded up to the next multiple of 4 bytes */
+                bytes_per_row = bmp->Header.ImageDataSize / bmp->Header.Height;
+
+                /* Calculate the location of the relevant pixel */
+                pixel = bmp->Data + ( ( bmp->Header.Height - y - 1 ) * bytes_per_row + x );
+
+
+                if ( val )      *val = *pixel;
+        }
+}
+
+
+/**************************************************************
+        Sets the specified pixel's color index.
+**************************************************************/
+void BMP_SetPixelIndex( BMP* bmp, UINT x, UINT y, UCHAR val )
+{
+        UCHAR*  pixel;
+        UINT    bytes_per_row;
+
+        if ( bmp == NULL || x < 0 || x >= bmp->Header.Width || y < 0 || y >= bmp->Header.Height )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+        }
+
+        else if ( bmp->Header.BitsPerPixel != 8 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
+        }
+
+        else
+        {
+                BMP_LAST_ERROR_CODE = BMP_OK;
+
+                /* Row's size is rounded up to the next multiple of 4 bytes */
+                bytes_per_row = bmp->Header.ImageDataSize / bmp->Header.Height;
+
+                /* Calculate the location of the relevant pixel */
+                pixel = bmp->Data + ( ( bmp->Header.Height - y - 1 ) * bytes_per_row + x );
+
+                *pixel = val;
+        }
+}
+
+
+/**************************************************************
+        Gets the color value for the specified palette index.
+**************************************************************/
+void BMP_GetPaletteColor( BMP* bmp, UCHAR index, UCHAR* r, UCHAR* g, UCHAR* b )
+{
+        if ( bmp == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+        }
+
+        else if ( bmp->Header.BitsPerPixel != 8 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
+        }
+
+        else
+        {
+                if ( r )        *r = *( bmp->Palette + index * 4 + 2 );
+                if ( g )        *g = *( bmp->Palette + index * 4 + 1 );
+                if ( b )        *b = *( bmp->Palette + index * 4 + 0 );
+
+                BMP_LAST_ERROR_CODE = BMP_OK;
+        }
+}
+
+
+/**************************************************************
+        Sets the color value for the specified palette index.
+**************************************************************/
+void BMP_SetPaletteColor( BMP* bmp, UCHAR index, UCHAR r, UCHAR g, UCHAR b )
+{
+        if ( bmp == NULL )
+        {
+                BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
+        }
+
+        else if ( bmp->Header.BitsPerPixel != 8 )
+        {
+                BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
+        }
+
+        else
+        {
+                *( bmp->Palette + index * 4 + 2 ) = r;
+                *( bmp->Palette + index * 4 + 1 ) = g;
+                *( bmp->Palette + index * 4 + 0 ) = b;
+
+                BMP_LAST_ERROR_CODE = BMP_OK;
+        }
+}
+
+
+/**************************************************************
+        Returns the last error code.
+**************************************************************/
+BMP_STATUS BMP_GetError()
+{
+        return BMP_LAST_ERROR_CODE;
+}
+
+
+/**************************************************************
+        Returns a description of the last error code.
+**************************************************************/
+const char* BMP_GetErrorDescription()
+{
+        if ( BMP_LAST_ERROR_CODE > 0 && BMP_LAST_ERROR_CODE < BMP_ERROR_NUM )
+        {
+                return BMP_ERROR_STRING[ BMP_LAST_ERROR_CODE ];
+        }
+        else
+        {
+                return NULL;
+        }
+}
+
+
+
+
+
+/*********************************** Private methods **********************************/
+
+
+/**************************************************************
+        Reads the BMP file's header into the data structure.
+        Returns BMP_OK on success.
+**************************************************************/
+int     ReadHeader( BMP* bmp, FILE* f )
+{
+        if ( bmp == NULL || f == NULL )
+        {
+                return BMP_INVALID_ARGUMENT;
+        }
+
+        /* The header's fields are read one by one, and converted from the format's
+        little endian to the system's native representation. */
+        if ( !ReadUSHORT( &( bmp->Header.Magic ), f ) )                 return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.FileSize ), f ) )                return BMP_IO_ERROR;
+        if ( !ReadUSHORT( &( bmp->Header.Reserved1 ), f ) )             return BMP_IO_ERROR;
+        if ( !ReadUSHORT( &( bmp->Header.Reserved2 ), f ) )             return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.DataOffset ), f ) )              return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.HeaderSize ), f ) )              return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.Width ), f ) )                   return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.Height ), f ) )                  return BMP_IO_ERROR;
+        if ( !ReadUSHORT( &( bmp->Header.Planes ), f ) )                return BMP_IO_ERROR;
+        if ( !ReadUSHORT( &( bmp->Header.BitsPerPixel ), f ) )  return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.CompressionType ), f ) ) return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.ImageDataSize ), f ) )   return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.HPixelsPerMeter ), f ) ) return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.VPixelsPerMeter ), f ) ) return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.ColorsUsed ), f ) )              return BMP_IO_ERROR;
+        if ( !ReadUINT( &( bmp->Header.ColorsRequired ), f ) )  return BMP_IO_ERROR;
+
+        return BMP_OK;
+}
+
+
+/**************************************************************
+        Writes the BMP file's header into the data structure.
+        Returns BMP_OK on success.
+**************************************************************/
+int     WriteHeader( BMP* bmp, FILE* f )
+{
+        if ( bmp == NULL || f == NULL )
+        {
+                return BMP_INVALID_ARGUMENT;
+        }
+
+        /* The header's fields are written one by one, and converted to the format's
+        little endian representation. */
+        if ( !WriteUSHORT( bmp->Header.Magic, f ) )                     return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.FileSize, f ) )            return BMP_IO_ERROR;
+        if ( !WriteUSHORT( bmp->Header.Reserved1, f ) )         return BMP_IO_ERROR;
+        if ( !WriteUSHORT( bmp->Header.Reserved2, f ) )         return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.DataOffset, f ) )          return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.HeaderSize, f ) )          return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.Width, f ) )                       return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.Height, f ) )                      return BMP_IO_ERROR;
+        if ( !WriteUSHORT( bmp->Header.Planes, f ) )            return BMP_IO_ERROR;
+        if ( !WriteUSHORT( bmp->Header.BitsPerPixel, f ) )      return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.CompressionType, f ) )     return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.ImageDataSize, f ) )       return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.HPixelsPerMeter, f ) )     return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.VPixelsPerMeter, f ) )     return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.ColorsUsed, f ) )          return BMP_IO_ERROR;
+        if ( !WriteUINT( bmp->Header.ColorsRequired, f ) )      return BMP_IO_ERROR;
+
+        return BMP_OK;
+}
+
+
+/**************************************************************
+        Reads a little-endian unsigned int from the file.
+        Returns non-zero on success.
+**************************************************************/
+int     ReadUINT( UINT* x, FILE* f )
+{
+        UCHAR little[ 4 ];      /* BMPs use 32 bit ints */
+
+        if ( x == NULL || f == NULL )
+        {
+                return 0;
+        }
+
+        if ( fread( little, 4, 1, f ) != 1 )
+        {
+                return 0;
+        }
+
+        *x = ( little[ 3 ] << 24 | little[ 2 ] << 16 | little[ 1 ] << 8 | little[ 0 ] );
+
+        return 1;
+}
+
+
+/**************************************************************
+        Reads a little-endian unsigned short int from the file.
+        Returns non-zero on success.
+**************************************************************/
+int     ReadUSHORT( USHORT *x, FILE* f )
+{
+        UCHAR little[ 2 ];      /* BMPs use 16 bit shorts */
+
+        if ( x == NULL || f == NULL )
+        {
+                return 0;
+        }
+
+        if ( fread( little, 2, 1, f ) != 1 )
+        {
+                return 0;
+        }
+
+        *x = ( little[ 1 ] << 8 | little[ 0 ] );
+
+        return 1;
+}
+
+
+/**************************************************************
+        Writes a little-endian unsigned int to the file.
+        Returns non-zero on success.
+**************************************************************/
+int     WriteUINT( UINT x, FILE* f )
+{
+        UCHAR little[ 4 ];      /* BMPs use 32 bit ints */
+
+        little[ 3 ] = (UCHAR)( ( x & 0xff000000 ) >> 24 );
+        little[ 2 ] = (UCHAR)( ( x & 0x00ff0000 ) >> 16 );
+        little[ 1 ] = (UCHAR)( ( x & 0x0000ff00 ) >> 8 );
+        little[ 0 ] = (UCHAR)( ( x & 0x000000ff ) >> 0 );
+
+        return ( f && fwrite( little, 4, 1, f ) == 1 );
+}
+
+
+/**************************************************************
+        Writes a little-endian unsigned short int to the file.
+        Returns non-zero on success.
+**************************************************************/
+int     WriteUSHORT( USHORT x, FILE* f )
+{
+        UCHAR little[ 2 ];      /* BMPs use 16 bit shorts */
+
+        little[ 1 ] = (UCHAR)( ( x & 0xff00 ) >> 8 );
+        little[ 0 ] = (UCHAR)( ( x & 0x00ff ) >> 0 );
+
+        return ( f && fwrite( little, 2, 1, f ) == 1 );
+}
+