[Openquicktime-users] reading the data extracted by the decoder

[<pv...@un...>]

Hi,
Hi,

I am trying to get a small example going to decode frames from a
quicktime movie. I have tried to create a JPEG-encoded video and I am
now trying to extract the frames from the movie. I am not sure the
creation of the movie succeeded, but I cannot read any other movie
available at the project website.

I ahve included part of the source code tor ead a frame, although no
values appear in the buffer. Wahat is the right way to extract the
values from the "decompress_row" buffer ?

	unsigned char **decompress_row = NULL, **transfer = NULL;
	RGB *clr = NULL; /* RGBA */	...

	video_width = quicktime_video_width( ( quicktime_t *)filmptr, n_video
);
	video_height = quicktime_video_height( ( quicktime_t *)filmptr, n_video
);	
	video_rate = quicktime_frame_rate( ( quicktime_t *)filmptr, n_video );
	video_pos = quicktime_video_position( ( quicktime_t *)filmptr, n_video
);
	
	decompress_row = ( unsigned char **)malloc( video_height * sizeof( char
*) );
	if( !decompress_row ){
		sprintf( errbuf, "Could not allocate frame row buffer" );
		status = IE_NOT_OK;
	}
	transfer = decompress_row;
	
	quicktime_reads_cmodel( ( quicktime_t *)filmptr, BC_RGBA8888, n_video
);
	
	clr = ImageOutData( img );
	
	for( i = 0; i < video_height; i++ ) {
		decompress_row[i] = ( unsigned char *)clr + i * video_width * 4;
	}
	
	quicktime_decode_video( ( quicktime_t *)filmptr, BC_RGBA8888,
decompress_row, n_video);
	
	for( y = 0; y < video_height; y++ ){
		for( x = 0; x < video_width; x++ ){
			Red( clr ) = *transfer[y]++;
			Green( clr ) = *transfer[y]++;
			Blue( clr ) = *transfer[y]++;
			Extra( clr ) = *transfer[y]++;
		
			printf( "%d\t%d\t%d\t%d\t%d\n", x, y, ( int )Red( clr ), ( int
)Green( clr ), ( int )Blue( clr ) );
			clr++;
		}
	}



Best regards,

Peter Van Osta

Union Biometrica N.V./S.A.
European Scientific Operations (ESO)
Cipalstraat 3
B-2440 Geel
Belgium
tel.: +32 (0)14 570 619
fax.: +32 (0)14 570 621

http://www.unionbio.com/

http://ourworld.compuserve.com/homepages/pvosta/cvwww.htm