encoder-h261.cxx

mgcp协议源代码。支持多种编码：g711

/*encoder-h261.cc  (c) 1999-2000 Derek J Smithies ([e-mail])
 *                           Indranet Technologies ltd ([e-mail])
 *
 * This file is derived from vic, http://www-nrg.ee.lbl.gov/vic/
 * Their copyright notice is below.
 */
/*
 * Copyright (c) 1994-1995 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and the Network Research Group at
 *      Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
static const char rcsid[] =
    "@(#) $Header: /home/cvsroot/openh323/src/vic/encoder-h261.cxx,v 1.2 2000/02/04 05:16:23 craigs Exp $ (LBL)";

#include "encoder-h261.h"

H261Encoder::H261Encoder(Transmitter *T) : Encoder(T),
	bs_(0), bc_(0), 
        ngob_(12)
{
 	for (int q = 0; q < 32; ++q) {
		llm_[q] = 0;
		clm_[q] = 0;
	}
}

H261PixelEncoder:: H261PixelEncoder(Transmitter *T): H261Encoder(T)
{
	quant_required_ = 0;
	setq(10);
}

H261DCTEncoder::H261DCTEncoder(Transmitter *T) : H261Encoder(T) 
{
	quant_required_ = 1;
	setq(10);
}

/*
 * Set up the forward DCT quantization table for
 * INTRA mode operation.
 */
void
H261Encoder::setquantizers(int lq, int mq, int hq)
{
	int qt[64];
	if (lq > 31)
		lq = 31;
	if (lq <= 0)
		lq = 1;
	lq_ = lq;

	if (mq > 31)
		mq = 31;
	if (mq <= 0)
		mq = 1;
	mq_ = mq;

	if (hq > 31)
		hq = 31;
	if (hq <= 0)
		hq = 1;
	hq_ = hq;

	/*
	 * quant_required_ indicates quantization is not folded
	 * into fdct [because fdct is not performed]
	 */
	if (quant_required_ == 0) {
		/*
		 * Set the DC quantizer to 1, since we want to do this
		 * coefficient differently (i.e., the DC is rounded while
		 * the AC terms are truncated).
		 */
		qt[0] = 1;
		int i;
		for (i = 1; i < 64; ++i)
			qt[i] = lq_ << 1;
		fdct_fold_q(qt, lqt_);

		qt[0] = 1;
		for (i = 1; i < 64; ++i)
			qt[i] = mq_ << 1;
		fdct_fold_q(qt, mqt_);

		qt[0] = 1;
		for (i = 1; i < 64; ++i)
			qt[i] = hq_ << 1;
		fdct_fold_q(qt, hqt_);
	}
}

void
H261Encoder::setq(int q)
{
	setquantizers(q, q / 2, 1);
}

void
H261PixelEncoder::SetSize(int w, int h)
{
  if(width!=w){
	Encoder::SetSize(w, h);
	if (w == CIF_WIDTH && h == CIF_HEIGHT) {
		/* CIF */
		cif_ = 1;
		ngob_ = 12;
		bstride_ = 11;
		lstride_ = 16 * CIF_WIDTH - CIF_WIDTH / 2;
		cstride_ = 8 * 176 - 176 / 2;
		loffsize_ = 16;
		coffsize_ = 8;
		bloffsize_ = 1;
	} else if (w == QCIF_WIDTH && h == QCIF_HEIGHT) {
		/* QCIF */
		cif_ = 0;
		ngob_ = 6; /* not really number of GOBs, just loop limit */
		bstride_ = 0;
		lstride_ = 16 * QCIF_WIDTH - QCIF_WIDTH;
		cstride_ = 8 * 88 - 88;
		loffsize_ = 16;
		coffsize_ = 8;
		bloffsize_ = 1;
	} else {
		/*XXX*/
          PTRACE(0,"BAD GEOMETRY "<<w<<" x "<<h);
	  printf("H261PixelEncoder: H.261 bad geometry: %d x %d\n",w,h);
		exit(1);
	}
	u_int loff = 0;
	u_int coff = 0;
	u_int blkno = 0;
	for (u_int gob = 0; gob < ngob_; gob += 2) {
		loff_[gob] = loff;
		coff_[gob] = coff;
		blkno_[gob] = blkno;
		/* width of a GOB (these aren't ref'd in QCIF case) */
		loff_[gob + 1] = loff + 11 * 16;
		coff_[gob + 1] = coff + 11 * 8;
		blkno_[gob + 1] = blkno + 11;

		/* advance to next GOB row */
		loff += (16 * 16 * MBPERGOB) << cif_;
		coff += (8 * 8 * MBPERGOB) << cif_;
		blkno += MBPERGOB << cif_;
	}
  }//if(width!=w)
}

void
H261DCTEncoder::SetSize(int w, int h)
{

	Encoder::SetSize(w, h);
	if (w == CIF_WIDTH && h == CIF_HEIGHT) {
		/* CIF */
		cif_ = 1;
		ngob_ = 12;
		bstride_ = 11;
		lstride_ = - (11 * (64*BMB)) + 2 * 11 * 64 * BMB;
		cstride_ = - (11 * (64*BMB)) + 2 * 11 * 64 * BMB;
		loffsize_ = 64 * BMB;
		coffsize_ = 64 * BMB;
		bloffsize_ = 1;
	} else if (w == QCIF_WIDTH && h == QCIF_HEIGHT) {
		/* QCIF */
		cif_ = 0;
		ngob_ = 6; /* not really number of GOBs, just loop limit */
		bstride_ = 0;
		lstride_ = 0;
		cstride_ = 0;
		loffsize_ = 64 * BMB;
		coffsize_ = 64 * BMB;
		bloffsize_ = 1;
	} else {
		/*XXX*/
                printf("H261DCTEncoder: H.261 bad geometry: %d x %d\n",w,h);
		exit(1);
	}

	u_int gob;
	for (gob = 0; gob < ngob_; gob += 2) {

		if (gob != 0) {
			loff_[gob] = loff_[gob-2] +
				(MBPERGOB << cif_) * BMB * 64;
			coff_[gob] = coff_[gob-2] +
				(MBPERGOB << cif_) * BMB * 64;
			blkno_[gob] = blkno_[gob-2] +
				(MBPERGOB << cif_);
		} else {
			loff_[0] = 0;
			coff_[0] = loff_[0] + 4 * 64;	// 4 Y's
			blkno_[0] = 0;
		}

		loff_[gob + 1] = loff_[gob] + 11 * BMB * 64;
		coff_[gob + 1] = coff_[gob] + 11 * BMB * 64;
		blkno_[gob + 1] = blkno_[gob] + 11;
	}
}



/*
 * Make a map to go from a 12 bit dct value to an 8 bit quantized
 * 'level' number.  The 'map' includes both the quantizer (for the
 * dct encoder) and the perceptual filter 'threshhold' (for both
 * the pixel & dct encoders).  The first 4k of the map is for the
 * unfiltered coeff (the first 20 in zigzag order; roughly the
 * upper left quadrant) and the next 4k of the map are for the
 * filtered coef.
 */
char*
H261Encoder::make_level_map(int q, u_int fthresh)
{
	/* make the luminance map */
	char* lm = new char[0x2000];
	char* flm = lm + 0x1000;
	int i;
	lm[0] = 0;
	flm[0] = 0;
	q = quant_required_? q << 1 : 0;
	for (i = 1; i < 0x800; ++i) {
		u_int l = i;
		if (q)
			l /= q;
		lm[i] = l;
		lm[-i & 0xfff] = -l;

		if (l <= fthresh)
			l = 0;
		flm[i] = l;
		flm[-i & 0xfff] = -l;
	}
	return (lm);
}

/*
 * encode_blk:
 *	encode a block of DCT coef's
 */
void
H261Encoder::encode_blk(const short* blk, const char* lm)
{
	BB_INT bb = bb_;
	u_int nbb = nbb_;
	u_char* bc = bc_;

	/*
	 * Quantize DC.  Round instead of truncate.
	 */
	int dc = (blk[0] + 4) >> 3;

	if (dc <= 0)
		/* shouldn't happen with CCIR 601 black (level 16) */
		dc = 1;
	else if (dc > 254)
		dc = 254;
	else if (dc == 128)
		/* per Table 6/H.261 */
		dc = 255;
	/* Code DC */
	PUT_BITS(dc, 8, nbb, bb, bc);
	int run = 0;
	const u_char* colzag = &COLZAG[0];
	for (int zag; (zag = *++colzag) != 0; ) {
		if (colzag == &COLZAG[20])
			lm += 0x1000;
		int level = lm[((const u_short*)blk)[zag] & 0xfff];
		if (level != 0) {
			int val, nb;
			huffent* he;
			if (u_int(level + 15) <= 30 &&
			    (nb = (he = &hte_tc[((level&0x1f) << 6)|run])->nb))
				/* we can use a VLC. */
				val = he->val;
			else {
				 /* Can't use a VLC.  Escape it. */
				val = (1 << 14) | (run << 8) | (level & 0xff);
				nb = 20;
			}
			PUT_BITS(val, nb, nbb, bb, bc);
			run = 0;
		} else
			++run;
	}
	/* EOB */
	PUT_BITS(2, 2, nbb, bb, bc);

	bb_ = bb;
	nbb_ = nbb;
	bc_ = bc;
}

/*
 * H261PixelEncoder::encode_mb
 *	encode a macroblock given a set of input YUV pixels
 */
void
H261PixelEncoder::encode_mb(u_int mba, const u_char* frm,
			    u_int loff, u_int coff, int how)
{
	register int q;
	float* qt;
	if (how == CR_MOTION) {
		q = lq_;
		qt = lqt_;
	} else if (how == CR_BG) {
		q = hq_;
		qt = hqt_; 
	} else {
		/* must be at age threshold */
		q = mq_;
		qt = mqt_; 
	}

	/*
	 * encode all 6 blocks of the macro block to find the largest