codec.c

这是一个压缩解压包,用C语言进行编程的,里面有详细的源代码.

/**************************************************************************
 *
 *	XVID VFW FRONTEND
 *	codec
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *************************************************************************/

/**************************************************************************
 *
 *	History:
 *
 *	12.07.2002	num_threads
 *	23.06.2002	XVID_CPU_CHKONLY; loading speed up
 *	25.04.2002	ICDECOMPRESS_PREROLL
 *	17.04.2002	re-enabled lumi masking for 1st pass
 *	15.04.2002	updated cbr support
 *	04.04.2002	separated 2-pass code to 2pass.c
 *				interlacing support
 *				hinted ME support
 *	23.03.2002	daniel smith <[e-mail]>
 *				changed inter4v to only be in modes 5 or 6
 *				fixed null mode crash ?
 *				merged foxer's alternative 2-pass code
 *				added DEBUGERR output on errors instead of returning
 *	16.03.2002	daniel smith <[e-mail]>
 *				changed BITMAPV4HEADER to BITMAPINFOHEADER
 *					- prevents memcpy crash in compress_get_format()
 *				credits are processed in external 2pass mode
 *				motion search precision = 0 now effective in 2-pass
 *				modulated quantization
 *				added DX50 fourcc
 *	01.12.2001	inital version; (c)2001 peter ross <[e-mail]>
 *
 *************************************************************************/

#include <windows.h>
#include <vfw.h>
#include <stdio.h>
#include "vfwext.h"

#include <xvid.h>
#include "debug.h"
#include "codec.h"
#include "status.h"



static const int pmvfast_presets[7] = {
	0, 0, 0, 0,
	0 | XVID_ME_HALFPELREFINE16 | 0,
	0 | XVID_ME_HALFPELREFINE16 | 0 |
	XVID_ME_ADVANCEDDIAMOND16, XVID_ME_HALFPELREFINE16 | XVID_ME_EXTSEARCH16 |
	XVID_ME_HALFPELREFINE8 | 0 | XVID_ME_USESQUARES16
};



/*	return xvid compatbile colorspace,
	or XVID_CSP_NULL if failure
*/

static int get_colorspace(BITMAPINFOHEADER * hdr)
{
	/* rgb only: negative height specifies top down image */
	int rgb_flip = (hdr->biHeight < 0 ? 0 : XVID_CSP_VFLIP);

	switch(hdr->biCompression)
	{
	case BI_RGB :
		if (hdr->biBitCount == 16)
		{
			DPRINTF("RGB16 (RGB555)");
			return rgb_flip | XVID_CSP_RGB555;
		}
		if (hdr->biBitCount == 24) 
		{
			DPRINTF("RGB24");
			return rgb_flip | XVID_CSP_BGR;
		}
		if (hdr->biBitCount == 32) 
		{
			DPRINTF("RGB32");
			return rgb_flip | XVID_CSP_BGRA;
		}

		DPRINTF("unsupported BI_RGB biBitCount=%i", hdr->biBitCount);
		return XVID_CSP_NULL;

	case BI_BITFIELDS :
		if (hdr->biSize >= sizeof(BITMAPV4HEADER))
		{
			BITMAPV4HEADER * hdr4 = (BITMAPV4HEADER *)hdr;

			if (hdr4->bV4BitCount == 16 &&
				hdr4->bV4RedMask == 0x7c00 &&
				hdr4->bV4GreenMask == 0x3e0 &&
				hdr4->bV4BlueMask == 0x1f)
			{
				DPRINTF("RGB555");
				return rgb_flip | XVID_CSP_RGB555;
			}

			if(hdr4->bV4BitCount == 16 &&
				hdr4->bV4RedMask == 0xf800 &&
				hdr4->bV4GreenMask == 0x7e0 &&
				hdr4->bV4BlueMask == 0x1f)
			{
				DPRINTF("RGB565");
				return rgb_flip | XVID_CSP_RGB565;
			}

			DPRINTF("unsupported BI_BITFIELDS mode");
			return XVID_CSP_NULL;
		}
		
		DPRINTF("unsupported BI_BITFIELDS/BITMAPHEADER combination");
		return XVID_CSP_NULL;

	case FOURCC_I420 :
	case FOURCC_IYUV :
		DPRINTF("IYUY");
		return XVID_CSP_I420;

	case FOURCC_YV12 :
		DPRINTF("YV12");
		return XVID_CSP_YV12;
			
	case FOURCC_YUYV :
	case FOURCC_YUY2 :
		DPRINTF("YUY2");
		return XVID_CSP_YUY2;

	case FOURCC_YVYU :
		DPRINTF("YVYU");
		return XVID_CSP_YVYU;

	case FOURCC_UYVY :
		DPRINTF("UYVY");
		return XVID_CSP_UYVY;

	default :
		DPRINTF("unsupported colorspace %c%c%c%c", 
			hdr->biCompression&0xff,
			(hdr->biCompression>>8)&0xff,
			(hdr->biCompression>>16)&0xff,
			(hdr->biCompression>>24)&0xff);
		return XVID_CSP_NULL;
	}
}


/* compressor */


/* test the output format */

LRESULT compress_query(CODEC * codec, BITMAPINFO * lpbiInput, BITMAPINFO * lpbiOutput)
{
	BITMAPINFOHEADER * inhdr = &lpbiInput->bmiHeader;
	BITMAPINFOHEADER * outhdr = &lpbiOutput->bmiHeader;

	/* VFWEXT detection */
	if (inhdr->biCompression == VFWEXT_FOURCC) {
		return (ICM_USER+0x0fff);
	}

	if (get_colorspace(inhdr) == XVID_CSP_NULL) 
	{
		return ICERR_BADFORMAT;
	}

	if (lpbiOutput == NULL) 
	{
		return ICERR_OK;
	}

	if (inhdr->biWidth != outhdr->biWidth || inhdr->biHeight != outhdr->biHeight ||
		(outhdr->biCompression != FOURCC_XVID && outhdr->biCompression != FOURCC_DIVX && outhdr->biCompression != FOURCC_DX50))
	{
		return ICERR_BADFORMAT;
	}

	return ICERR_OK;
}


LRESULT compress_get_format(CODEC * codec, BITMAPINFO * lpbiInput, BITMAPINFO * lpbiOutput)
{
	BITMAPINFOHEADER * inhdr = &lpbiInput->bmiHeader;
	BITMAPINFOHEADER * outhdr = &lpbiOutput->bmiHeader;

	if (get_colorspace(inhdr) == XVID_CSP_NULL)
	{
		return ICERR_BADFORMAT;
	}

	if (lpbiOutput == NULL) 
	{
		return sizeof(BITMAPINFOHEADER);
	}

	memcpy(outhdr, inhdr, sizeof(BITMAPINFOHEADER));
	outhdr->biSize = sizeof(BITMAPINFOHEADER);
	outhdr->biSizeImage = compress_get_size(codec, lpbiInput, lpbiOutput);
	outhdr->biXPelsPerMeter = 0;
	outhdr->biYPelsPerMeter = 0;
	outhdr->biClrUsed = 0;
	outhdr->biClrImportant = 0;

	if (codec->config.fourcc_used == 0)
	{
		outhdr->biCompression = FOURCC_XVID;
	}
	else if (codec->config.fourcc_used == 1)
	{
		outhdr->biCompression = FOURCC_DIVX;
	}
	else
	{
		outhdr->biCompression = FOURCC_DX50;
	}

	return ICERR_OK;
}


LRESULT compress_get_size(CODEC * codec, BITMAPINFO * lpbiInput, BITMAPINFO * lpbiOutput)
{
	return 2 * lpbiOutput->bmiHeader.biWidth * lpbiOutput->bmiHeader.biHeight * 3;
}


LRESULT compress_frames_info(CODEC * codec, ICCOMPRESSFRAMES * icf)
{
#if 0
	DPRINTF("%i %i", icf->lStartFrame, icf->lFrameCount);
#endif
	codec->fincr = icf->dwScale;
	codec->fbase = icf->dwRate;
	return ICERR_OK;
}


static char type2char(int type)
{
	if (type==XVID_TYPE_IVOP)
		return 'I';
	if (type==XVID_TYPE_PVOP)
		return 'P';
	if (type==XVID_TYPE_BVOP)
		return 'B';
	return 'S';
}

static int vfw_debug(void *handle,
			 int opt,
			 void *param1,
			 void *param2)
{
	switch (opt) {
	case XVID_PLG_CREATE:
		*((void**)param2) = NULL;
	case XVID_PLG_INFO:
	case XVID_PLG_DESTROY:
	case XVID_PLG_BEFORE:
		return 0;

	case XVID_PLG_AFTER:
		{
			xvid_plg_data_t *data = (xvid_plg_data_t *) param1;

			/* We don't use DPRINTF here because it's active only for _DEBUG
			 * builds and that activates lot of other debug printfs. We only
			 * want these all the time */
			char buf[1024];
			sprintf(buf, "[%6i]   type=%c   Q:%2i   length:%6i",
					data->frame_num, 
					type2char(data->type),
					data->quant, 
					data->length);
			OutputDebugString(buf);

			return 0;
		}
	}

	return XVID_ERR_FAIL;
}

#define XVID_DLL_NAME "xvidcore.dll"

static int init_dll(CODEC* codec)
{
	if (codec->m_hdll != NULL)
		return 0;

	DPRINTF("init_dll");
	codec->m_hdll = LoadLibrary(XVID_DLL_NAME);
	if (codec->m_hdll == NULL) {
		DPRINTF("dll load failed");
		MessageBox(0, XVID_DLL_NAME " not found!","Error!", MB_ICONEXCLAMATION|MB_OK);
		return XVID_ERR_FAIL;
	}

	codec->xvid_global_func = (int (__cdecl *)(void *, int, void *, void *))GetProcAddress(codec->m_hdll, "xvid_global");
	if (codec->xvid_global_func == NULL) {
		MessageBox(0, "xvid_global() not found", "Error", 0);
		return XVID_ERR_FAIL;
	}

	codec->xvid_encore_func = (int (__cdecl *)(void *, int, void *, void *))GetProcAddress(codec->m_hdll, "xvid_encore");
	if (codec->xvid_encore_func == NULL) {
		MessageBox(0, "xvid_encore() not found", "Error", 0);
		return XVID_ERR_FAIL;
	}

	codec->xvid_decore_func = (int (__cdecl *)(void *, int, void *, void *))GetProcAddress(codec->m_hdll, "xvid_decore");
	if (codec->xvid_decore_func == NULL) {
		MessageBox(0, "xvid_decore() not found", "Error", 0);
		return XVID_ERR_FAIL;
	}

	codec->xvid_plugin_single_func = 
		(int (__cdecl *)(void *, int, void *, void *))(GetProcAddress(codec->m_hdll, "xvid_plugin_single"));
	codec->xvid_plugin_2pass1_func = 
		(int (__cdecl *)(void *, int, void *, void *))(GetProcAddress(codec->m_hdll, "xvid_plugin_2pass1"));
	codec->xvid_plugin_2pass2_func = 
		(int (__cdecl *)(void *, int, void *, void *))(GetProcAddress(codec->m_hdll, "xvid_plugin_2pass2"));
	codec->xvid_plugin_lumimasking_func = 
		(int (__cdecl *)(void *, int, void *, void *))(GetProcAddress(codec->m_hdll, "xvid_plugin_lumimasking"));
	codec->xvid_plugin_psnr_func = 
		(int (__cdecl *)(void *, int, void *, void *))(GetProcAddress(codec->m_hdll, "xvid_plugin_psnr"));

	return 0;
}

/* constant-quant zones for fixed quant encoding */
static void
prepare_cquant_zones(CONFIG * config) {
	
	int i = 0;
	if (config->num_zones == 0 || config->zones[0].frame != 0) {
		/* first zone does not start at frame 0 or doesn't exist */

		if (config->num_zones >= MAX_ZONES) config->num_zones--; /* we scrifice last zone */

		config->zones[config->num_zones].frame = 0;
		config->zones[config->num_zones].mode = RC_ZONE_QUANT;
		config->zones[config->num_zones].weight = 100;
		config->zones[config->num_zones].quant = config->desired_quant;
		config->zones[config->num_zones].type = XVID_TYPE_AUTO;
		config->zones[config->num_zones].greyscale = 0;
		config->zones[config->num_zones].chroma_opt = 0;
		config->zones[config->num_zones].bvop_threshold = 0;
		config->num_zones++;

		sort_zones(config->zones, config->num_zones, &i);
	}

	/* step 2: let's change all weight zones into quant zones */
	
	for(i = 0; i < config->num_zones; i++)
		if (config->zones[i].mode == RC_ZONE_WEIGHT) {
			config->zones[i].mode = RC_ZONE_QUANT;
			config->zones[i].quant = (100*config->desired_quant) / config->zones[i].weight;
		}
}

/* full first pass zones */