Video Capturing

[Maqsood Alam]

My question is about video capturing through capture card

I want to know why do we have the following choices for picture size

1- For PAL systems
192 x 144
384 x 288
768 x 576
and

2- For NTSC systems
160 x 120
320 x 240
640 x 480

I have written the capture routines in VC++ using the VFW macros. There is a macro "capSetVideoFormat" which can be used to set the format of captured video data given in BITMAPINFOHEADER structure:

typedef struct tagBITMAPINFOHEADER{ // bmih
DWORD biSize;
LONG biWidth;
LONG biHeight;
WORD biPlanes;
WORD biBitCount
DWORD biCompression;
DWORD biSizeImage;
LONG biXPelsPerMeter;
LONG biYPelsPerMeter;
DWORD biClrUsed;
DWORD biClrImportant;
} BITMAPINFOHEADER;

If we set the width and height to any other value or interchange the sizes of PAL and NTSC system what will happen ?

Is there any restriction of size because of hardware ?

I want to be 100% sure to avoid incompatibilities arising out of use of different capture cards.

Regards
Maqsood Alam

[twfoo88]

hi,

i read that you have written a program for automatic
selection of PAL or NTSC more? I have an application
that'll capture from a PAL mode, but, when booted
up, the default mode is NTSC, do you know
how I can choose PAL mode in my program?

Thank you.

twfoo