Hi friends,
I'm developing a Ground Station and a feture of this station is show the
FlightGear screen (simulating a embbeded camera), then i choose to use the
jpg-httpd option, but the same show only a piece of screen (left-bottom), is
too slow to acquire this image and after less than 1 minute the memory increase
until fill complete RAM and swap to harddisk.
Reading the code I could see that the jpg-http processing seems to be
unfinished ?? Am I right ?
Then I did rewrite the jpg-httpd.h and jpg-httpd.cxx modules (method void
HttpdImageChannel :: foundTerminator( void )) to do a better image streaming,
using the complete image size specified in JpgFactory -> init( int width, int
height ); (call in jpg-httpd.h).
The memory leak was fixed and the performance is tooooooo fast comparing with
the old method.
I want contribute with this code because I believe that is a good idea and
could be used by other projects that uses FlightGear.
Leidson Campos
[EMAIL PROTECTED]
Java Universal Messenger
See the code bellow (maked by //[Leidson<] at start and //[Leidson>] at end
Changes in jpg-httpd.hxx module:
class HttpdImageChannel : public netChat
{
netBuffer buffer ;
trJpgFactory *JpgFactory;
public:
HttpdImageChannel() : buffer(512) {
setTerminator("\r\n");
JpgFactory = new trJpgFactory();
// This is a terrible hack but it can't be initialized until
// after OpenGL is up an running
//[Leidson<]
JpgFactory -> init( 700, 400 );
//[Leidson>]
}
.
.
.
Changes in jpg-httpd.cpp module:
#include <Main/fg_props.hxx>
#include <Main/globals.hxx>
#include "jpg-httpd.hxx"
//[Leidson<]
#define __MAX_HTTP_BLOCK_SIZE 4096
#define __MAX_STRING_SIZE 2048
#define __TIMEOUT_COUNT 5
#define __HTTP_GET_STRING "GET "
//[Leidson>]
SG_USING_STD(string);
.
.
.
.
// Handle http GET requests (rewrite)
//[Leidson<]
void HttpdImageChannel :: foundTerminator( void ) {
closeWhenDone();
char szTemp[256];
char szResponse[__MAX_STRING_SIZE];
char *pRequest = buffer.getData();
int nStep = 0;
int nBytesSent = 0;
int nTimeoutCount = 0;
int nBufferCount = 0;
int nImageLen;
int nBlockSize;
if ( strstr( pRequest, __HTTP_GET_STRING ) != NULL ) {
printf( "<<<<<<<<< HTTP Request : %s\n", pRequest );
nImageLen = JpgFactory -> render();
nBlockSize = ( nImageLen < __MAX_HTTP_BLOCK_SIZE ? nImageLen :
__MAX_HTTP_BLOCK_SIZE );
if( nImageLen ) {
strcpy( szResponse, "HTTP/1.1 200 OK" );
strcat( szResponse, getTerminator() );
strcat( szResponse, "Content-Type: image/jpeg" );
strcat( szResponse, getTerminator() );
printf( "info->numbytes = %d\n", nImageLen );
sprintf( szTemp, "Content-Length: %d", nImageLen );
strcat( szResponse, szTemp );
strcat( szResponse, getTerminator() );
strcat( szResponse, "Connection: close" );
strcat( szResponse, getTerminator() );
strcat( szResponse, getTerminator() );
if( getHandle() == -1 ) {
printf( "<<<<<<<<< Invalid socket handle. Ignoring
request.\n" );
buffer.remove();
printf( "<<<<<<<<< End of image Transmission.\n" );
return;
}
if( send( ( char * ) szResponse, strlen( szResponse ) )
<= 0 ) {
printf( "<<<<<<<<< Error to send HTTP response.
Ignoring request.\n" );
buffer.remove();
printf( "<<<<<<<<< End of image Transmission.\n" );
return;
}
/*
* Send block with size defined by __MAX_HTTP_BLOCK_SIZE
*/
while( nStep <= nImageLen ) {
nBufferCount++;
if( getHandle() == -1 ) {
printf( "<<<<<<<<< Invalid socket handle.
Ignoring request.\n" );
break;
}
nBytesSent = send( ( char * ) JpgFactory -> data() +
nStep, nBlockSize );
if( nBytesSent <= 0 ) {
if( nTimeoutCount == __TIMEOUT_COUNT ) {
printf( "<<<<<<<<< Timeout reached. Exiting
before end of image transmission.\n" );
nTimeoutCount = 0;
break;
}
printf( "<<<<<<<<< Zero bytes sent.\n" );
sleep( 1 );
nTimeoutCount++;
continue;
}
printf( ">>>>>>>>> (%d) BLOCK STEP %d - IMAGELEN %d -
BLOCKSIZE %d - SENT %d\n", nBufferCount, nStep, nImageLen, nBlockSize,
nBytesSent );
/*
* Calculate remaining image.
*/
if( ( nStep + nBlockSize ) >= nImageLen ) {
nBlockSize = ( nImageLen - nStep );
nStep += nBlockSize;
}
nStep += nBytesSent;
nTimeoutCount = 0;
usleep( 1000 );
}
printf( "<<<<<<<<< End of image Transmission.\n" );
} else {
printf( "!!! NO IMAGE !!!\n\tinfo -> numbytes = %d\n", nImageLen );
}
/*
* Release JPEG buffer.
*/
JpgFactory -> destroy();
}
buffer.remove();
}
//[Leidson>]
-------------------------------------------------------------------------
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