流媒体/Mpeg4/MP4

开发平台：
Visual C++

VideoBuffer.cpp：源码内容
							/**************************************************************************************
 *                                                                                    *
 * This application contains code from OpenDivX and is released as a "Larger Work"    *
 * under that license. Consistant with that license, this application is released     *
 * under the GNU General Public License.                                              *
 *                                                                                    *
 * The OpenDivX license can be found at: http://www.projectmayo.com/opendivx/docs.php *
 * The GPL can be found at: http://www.gnu.org/copyleft/gpl.html                      *
 *                                                                                    *
 * Copyright (c) 2001 - Project Mayo                                                  *
 *                                                                                    *
 * Authors: Damien Chavarria <adrc at projectmayo.com>                                *
 *                                                                                    *
 **************************************************************************************/
#include "VideoBuffer.h"
/*
 * Class functions
 */
/*
 * Constructor
 */
VideoBuffer::VideoBuffer(AviDecaps *decaps, Codec *codec)
{
	unsigned int i;
	this->input_buffer = NULL;
	if(decaps != NULL || codec != NULL) {
		this->decaps = decaps;
		this->codec  = codec;
		this->input_buffer = (char *) malloc(VIDEO_BUFFER_SIZE);
		for(i=0; i < 1/*BUFFER_SIZE*/; i++) {
	
			this->frames[i] = (char *) malloc(decaps->Width()*decaps->Height()*4);
			memset(this->frames[i], 0, decaps->Width()*decaps->Height()*4);
		}
		this->frame_size = decaps->Width()*decaps->Height()*3;
		this->free_slots = BUFFER_SIZE;
		//this->mutex = CreateMutex (NULL, FALSE, NULL);
		this->running = 0;
		this->mode    = VIDEO_BUFFER_INACTIVE;
	}
}
VideoBuffer::~VideoBuffer()
{
}
DWORD WINAPI FillThread(LPVOID lpData)
{
	VideoBuffer *videoBuffer;
	videoBuffer = (VideoBuffer *) lpData;
	if(videoBuffer == NULL)
		return 0;
	while(videoBuffer->running) {
		Sleep(2);
	
		if(videoBuffer->free_slots > 0) {
			long frame_size = 0;
			WaitForSingleObject(videoBuffer->mutex, INFINITE);
			if( (BUFFER_SIZE - videoBuffer->free_slots - 1) > 0) {
				memcpy(videoBuffer->frames[BUFFER_SIZE - videoBuffer->free_slots],
					   videoBuffer->frames[BUFFER_SIZE - videoBuffer->free_slots - 1],
					   videoBuffer->frame_size);
			}
			/*
			 * Do Decomp here
			 */
			
			frame_size = videoBuffer->decaps->NextVideoFrame(videoBuffer->input_buffer);
				
			if(frame_size == -2) {
				/*
				 * We're at the end of the file
				 */
					
			    ReleaseMutex(videoBuffer->mutex);
				return 0;
			}
			videoBuffer->codec->Decompress(videoBuffer->input_buffer, 
										   frame_size, 
										   videoBuffer->frames[BUFFER_SIZE - videoBuffer->free_slots]);
			videoBuffer->free_slots--;
			ReleaseMutex(videoBuffer->mutex);
		}
	}
	return 0;
}
void VideoBuffer::Start()
{
	/*
	 * First fill our buffer
	 *
	 */
	this->free_slots = BUFFER_SIZE;
	this->running    = 1;
	if(mode == VIDEO_BUFFER_ACTIVE) {
		
		//this->fillThread = CreateThread( NULL, 0, FillThread, (LPVOID) this, 0, &this->id );
		//SetThreadPriority(this->fillThread, THREAD_PRIORITY_ABOVE_NORMAL);
	}
}
void VideoBuffer::Stop()
{
	this->running = 0;
	//TerminateThread(this->fillThread, 0);
	unsigned int i;
	if(this->input_buffer != NULL)
		free(this->input_buffer);
	for(i=0; i < 1/*BUFFER_SIZE*/; i++) {
	
		if(this->frames[i] != NULL)
			free(this->frames[i]);
	}
}
char *VideoBuffer::GiveMeAFrame()
{
	unsigned int i;
	switch(this->mode) {
	case VIDEO_BUFFER_ACTIVE:
		if(this->input_buffer && this->free_slots < BUFFER_SIZE) {
			long frame_size = 0;
			char *temp;
			temp = this->frames[0];
			//WaitForSingleObject(this->mutex, INFINITE);
			for(i=0; i < BUFFER_SIZE - 1; i++) {
			
				this->frames[i] = this->frames[i+1];
			}
			this->frames[BUFFER_SIZE - 1] = temp;
			this->free_slots++;
			//ReleaseMutex(this->mutex);
			return this->frames[0];
		}
		else {
			
			
		
			/*
			 * Shouldn't happen
			 */
			return NULL; //this->frames[0];
		}
		break;
	case VIDEO_BUFFER_INACTIVE:
		long frame_size = 0;
		/*
		 * Do Decomp here
		 */
			
		frame_size = this->decaps->NextVideoFrame(this->input_buffer);
				
		if(frame_size == -2) {
			/*
			 * We're at the end of the file
			 */
					
			return NULL;
		}
		this->codec->Decompress(this->input_buffer, 
			 				    frame_size, 
							    this->frames[0]);
		break;
	}
	return this->frames[0];
}
void VideoBuffer::Drop()
{
	unsigned int i;
	long frame_size = 0;
	switch(this->mode) {
	case VIDEO_BUFFER_INACTIVE:
		/*
		 * Do Decomp here
		 */
			
		frame_size = this->decaps->NextVideoFrame(this->input_buffer);
				
		if(frame_size == -2) {
			/*
			 * We're at the end of the file
			 */
				
			return;
		}
		this->codec->Drop(this->input_buffer, 
			 			  frame_size, 
						  this->frames[0]);
		break;
	case VIDEO_BUFFER_ACTIVE:
		break;
	}
}

						