Problem With Global Structures

**Nils O. Selåsdal** · Sep 27 '06, 05:35 AM

Re: Problem With Global Structures

Harry wrote:

Good Day,
>
>
I am writing a code for the H.264 Video codec.I am using VC++
compiler,but programming is in c only.I have grouped the related global
variables under one structure in a header file called global.h.Like
this i have two three structures in global.h.
>
To initialise the structure members in global.h,I declared structure
variables in c files wherever the structure members are used.
>
For example
This is one of the structure in global.h
>
typedef struct
{
int YUV;
int img_height;
int img_width;
int intra_period;
int IntraPeriod;//period of I-frames
int SPPicturePeriod icity; // SP-Picture Periodicity (0=not used)
int BReferencePictu res; //Referenced B coded pictures (0=off, 1=on)
int start_frame_no_ in_this_IGOP;
int BitDepthLuma;
int BitDepthChroma;
int InterSearch16x1 6;
int InterSearch16x8 ;
int InterSearch8x16 ;
int InterSearch8x8;
int InterSearch8x4;
int InterSearch4x8;
int InterSearch4x4;
int Transform8x8Mod e;
int symbolMode;//Symbol mode (Entropy coding method: 0=UVLC, 1=CABAC)
int EnableIPCM;
int NoBframes;//no of b frames to be inserted
int UseHadamard;// Hadamard SymbolModeform (0=not used, 1=used)
int FrameSkip;//no of frames to be skipped
int RDopt;//2 means Fast High Complexity Mode\
}InputParameter s;
>
>
In the above structure,for example if i want to initialize the
img_width,img_h eight variables with some value in a c file where it is
used,for example call it encoder.c,I have declared structure variable
like as
>
InputParameters inputs,*input=& inputs;
>
Now i can initialize the variable in any of the following ways
>
inputs.img_widt h=176; (or) input->img_width=17 6;
inputs.img_heig ht=144; (or)input->img_height=144 ;

This is assignment not initialization, and needs to be done within a
function body.

If you want to initialize it:
InputParameters inputs = { 1,2,3,4 };

With C99, you can specify which members to initialize:
InputParameters inputs = { .img_width=176, .img_height=144 };

But i am getting the following error when i comile the c file,encoder.c
>
c:\documents and settings\hari\d esktop\enocoder \encoder.c(4) : error
C2143: syntax error : missing '{' before '.'
c:\documents and settings\hari\d esktop\enocoder \encoder.c(4) : error
C2059: syntax error : '.'
>
>
>
Can you suggest any other way for initailsing the structure member
variables direclty with some values.....
>
Thanks in advance
>

**Harry** · Sep 27 '06, 05:35 AM

Re: Problem With Global Structures

Nils O. Selåsdal wrote:

Harry wrote:

Good Day,

I am writing a code for the H.264 Video codec.I am using VC++
compiler,but programming is in c only.I have grouped the related global
variables under one structure in a header file called global.h.Like
this i have two three structures in global.h.

To initialise the structure members in global.h,I declared structure
variables in c files wherever the structure members are used.

For example
This is one of the structure in global.h

typedef struct
{
int YUV;
int img_height;
int img_width;
int intra_period;
int IntraPeriod;//period of I-frames
int SPPicturePeriod icity; // SP-Picture Periodicity (0=not used)
int BReferencePictu res; //Referenced B coded pictures (0=off, 1=on)
int start_frame_no_ in_this_IGOP;
int BitDepthLuma;
int BitDepthChroma;
int InterSearch16x1 6;
int InterSearch16x8 ;
int InterSearch8x16 ;
int InterSearch8x8;
int InterSearch8x4;
int InterSearch4x8;
int InterSearch4x4;
int Transform8x8Mod e;
int symbolMode;//Symbol mode (Entropy coding method: 0=UVLC, 1=CABAC)
int EnableIPCM;
int NoBframes;//no of b frames to be inserted
int UseHadamard;// Hadamard SymbolModeform (0=not used, 1=used)
int FrameSkip;//no of frames to be skipped
int RDopt;//2 means Fast High Complexity Mode\
}InputParameter s;

In the above structure,for example if i want to initialize the
img_width,img_h eight variables with some value in a c file where it is
used,for example call it encoder.c,I have declared structure variable
like as

InputParameters inputs,*input=& inputs;

Now i can initialize the variable in any of the following ways

inputs.img_widt h=176; (or) input->img_width=17 6;
inputs.img_heig ht=144; (or)input->img_height=144 ;

This is assignment not initialization, and needs to be done within a
function body.
>
If you want to initialize it:
InputParameters inputs = { 1,2,3,4 };
>
With C99, you can specify which members to initialize:
InputParameters inputs = { .img_width=176, .img_height=144 };
>

But i am getting the following error when i comile the c file,encoder.c

c:\documents and settings\hari\d esktop\enocoder \encoder.c(4) : error
C2143: syntax error : missing '{' before '.'
c:\documents and settings\hari\d esktop\enocoder \encoder.c(4) : error
C2059: syntax error : '.'

Can you suggest any other way for initailsing the structure member
variables direclty with some values.....

Thanks in advance

I know that this is the way to assign values to structrure member
variables,but if there are too many variables in the structure we can't
go on like...{2,6,7,. .......}....... what is wrong with my way of
assigning the initial values to the structure member variables

**Nils O. Selåsdal** · Sep 27 '06, 05:45 AM

Re: Problem With Global Structures

Harry wrote:

Nils O. Selåsdal wrote:

>Harry wrote:

>>Good Day,
>>>
>>>
>>I am writing a code for the H.264 Video codec.I am using VC++
>>compiler,bu t programming is in c only.I have grouped the related global
>>variables under one structure in a header file called global.h.Like
>>this i have two three structures in global.h.
>>>
>>To initialise the structure members in global.h,I declared structure
>>variables in c files wherever the structure members are used.
>>>
>>For example
>>This is one of the structure in global.h
>>>
>>typedef struct
>>{
>> int YUV;
>> int img_height;
>> int img_width;
>> int intra_period;
>> int IntraPeriod;//period of I-frames
>> int SPPicturePeriod icity; // SP-Picture Periodicity (0=not used)
>> int BReferencePictu res; //Referenced B coded pictures (0=off, 1=on)
>> int start_frame_no_ in_this_IGOP;
>> int BitDepthLuma;
>> int BitDepthChroma;
>> int InterSearch16x1 6;
>> int InterSearch16x8 ;
>> int InterSearch8x16 ;
>> int InterSearch8x8;
>> int InterSearch8x4;
>> int InterSearch4x8;
>> int InterSearch4x4;
>> int Transform8x8Mod e;
>> int symbolMode;//Symbol mode (Entropy coding method: 0=UVLC, 1=CABAC)
>> int EnableIPCM;
>> int NoBframes;//no of b frames to be inserted
>> int UseHadamard;// Hadamard SymbolModeform (0=not used, 1=used)
>> int FrameSkip;//no of frames to be skipped
>> int RDopt;//2 means Fast High Complexity Mode\
>>}InputParamet ers;
>>>
>>>
>>In the above structure,for example if i want to initialize the
>>img_width,img _height variables with some value in a c file where it is
>>used,for example call it encoder.c,I have declared structure variable
>>like as
>>>
>>InputParamete rs inputs,*input=& inputs;
>>>
>>Now i can initialize the variable in any of the following ways
>>>
>>inputs.img_wi dth=176; (or) input->img_width=17 6;
>>inputs.img_he ight=144; (or)input->img_height=144 ;

>This is assignment not initialization, and needs to be done within a
>function body.
>>
>If you want to initialize it:
>InputParameter s inputs = { 1,2,3,4 };
>>
>With C99, you can specify which members to initialize:
>InputParameter s inputs = { .img_width=176, .img_height=144 };
>>

>>But i am getting the following error when i comile the c file,encoder.c
>>>
>>c:\document s and settings\hari\d esktop\enocoder \encoder.c(4) : error
>>C2143: syntax error : missing '{' before '.'
>>c:\document s and settings\hari\d esktop\enocoder \encoder.c(4) : error
>>C2059: syntax error : '.'
>>>
>>>
>>>
>>Can you suggest any other way for initailsing the structure member
>>variables direclty with some values.....
>>>
>>Thanks in advance
>>>

>
>
I know that this is the way to assign values to structrure member
variables,but if there are too many variables in the structure we can't
go on like...{2,6,7,. .......}....... what is wrong with my way of
assigning the initial values to the structure member variables

There is nothing wrong with that, but as I said you need to do that
within a function body. It is unclear if your code tries to do that
at file scope - which is not legal. So, put that code in main, or
another function you call pretty quick..

As I also mentioned, provided you have a C99 compiler, you can
specify which members to initialize. I'm not sure this is supported
by Microsoft..

**Harry** · Sep 27 '06, 05:55 AM

Re: Problem With Global Structures

Nils O. Selåsdal wrote:

Harry wrote:

Nils O. Selåsdal wrote:

Harry wrote:
>Good Day,
>>
>>
>I am writing a code for the H.264 Video codec.I am using VC++
>compiler,but programming is in c only.I have grouped the related global
>variables under one structure in a header file called global.h.Like
>this i have two three structures in global.h.
>>
>To initialise the structure members in global.h,I declared structure
>variables in c files wherever the structure members are used.
>>
>For example
>This is one of the structure in global.h
>>
>typedef struct
>{
> int YUV;
> int img_height;
> int img_width;
> int intra_period;
> int IntraPeriod;//period of I-frames
> int SPPicturePeriod icity; // SP-Picture Periodicity (0=not used)
> int BReferencePictu res; //Referenced B coded pictures (0=off, 1=on)
> int start_frame_no_ in_this_IGOP;
> int BitDepthLuma;
> int BitDepthChroma;
> int InterSearch16x1 6;
> int InterSearch16x8 ;
> int InterSearch8x16 ;
> int InterSearch8x8;
> int InterSearch8x4;
> int InterSearch4x8;
> int InterSearch4x4;
> int Transform8x8Mod e;
> int symbolMode;//Symbol mode (Entropy coding method: 0=UVLC, 1=CABAC)
> int EnableIPCM;
> int NoBframes;//no of b frames to be inserted
> int UseHadamard;// Hadamard SymbolModeform (0=not used, 1=used)
> int FrameSkip;//no of frames to be skipped
> int RDopt;//2 means Fast High Complexity Mode\
>}InputParamete rs;
>>
>>
>In the above structure,for example if i want to initialize the
>img_width,img_ height variables with some value in a c file where it is
>used,for example call it encoder.c,I have declared structure variable
>like as
>>
>InputParameter s inputs,*input=& inputs;
>>
>Now i can initialize the variable in any of the following ways
>>
>inputs.img_wid th=176; (or) input->img_width=17 6;
>inputs.img_hei ght=144; (or)input->img_height=144 ;
This is assignment not initialization, and needs to be done within a
function body.
>
If you want to initialize it:
InputParameters inputs = { 1,2,3,4 };
>
With C99, you can specify which members to initialize:
InputParameters inputs = { .img_width=176, .img_height=144 };
>
>But i am getting the following error when i comile the c file,encoder..c
>>
>c:\documents and settings\hari\d esktop\enocoder \encoder.c(4) : error
>C2143: syntax error : missing '{' before '.'
>c:\documents and settings\hari\d esktop\enocoder \encoder.c(4) : error
>C2059: syntax error : '.'
>>
>>
>>
>Can you suggest any other way for initailsing the structure member
>variables direclty with some values.....
>>
>Thanks in advance
>>

I know that this is the way to assign values to structrure member
variables,but if there are too many variables in the structure we can't
go on like...{2,6,7,. .......}....... what is wrong with my way of
assigning the initial values to the structure member variables

>
There is nothing wrong with that, but as I said you need to do that
within a function body. It is unclear if your code tries to do that
at file scope - which is not legal. So, put that code in main, or
another function you call pretty quick..
>
>
As I also mentioned, provided you have a C99 compiler, you can
specify which members to initialize. I'm not sure this is supported
by Microsoft..

Thanks for your help dude

Problem With Global Structures

Problem With Global Structures

Comment

Comment

Comment

Comment