mirror of
https://gitee.com/openharmony/third_party_ffmpeg
synced 2024-11-24 19:59:46 +00:00
120 lines
2.7 KiB
C
120 lines
2.7 KiB
C
/*
|
|
* MQ-coder encoder
|
|
* Copyright (c) 2007 Kamil Nowosad
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* MQ-coder encoder
|
|
* @file
|
|
* @author Kamil Nowosad
|
|
*/
|
|
|
|
#include "mqc.h"
|
|
|
|
static void byteout(MqcState *mqc)
|
|
{
|
|
retry:
|
|
if (*mqc->bp == 0xff){
|
|
mqc->bp++;
|
|
*mqc->bp = mqc->c >> 20;
|
|
mqc->c &= 0xfffff;
|
|
mqc->ct = 7;
|
|
} else if ((mqc->c & 0x8000000)){
|
|
(*mqc->bp)++;
|
|
mqc->c &= 0x7ffffff;
|
|
goto retry;
|
|
} else{
|
|
mqc->bp++;
|
|
*mqc->bp = mqc->c >> 19;
|
|
mqc->c &= 0x7ffff;
|
|
mqc->ct = 8;
|
|
}
|
|
}
|
|
|
|
static void renorme(MqcState *mqc)
|
|
{
|
|
do{
|
|
mqc->a += mqc->a;
|
|
mqc->c += mqc->c;
|
|
if (!--mqc->ct)
|
|
byteout(mqc);
|
|
} while (!(mqc->a & 0x8000));
|
|
}
|
|
|
|
static void setbits(MqcState *mqc)
|
|
{
|
|
int tmp = mqc->c + mqc->a;
|
|
mqc->c |= 0xffff;
|
|
if (mqc->c >= tmp)
|
|
mqc->c -= 0x8000;
|
|
}
|
|
|
|
void ff_mqc_initenc(MqcState *mqc, uint8_t *bp)
|
|
{
|
|
ff_mqc_init_contexts(mqc);
|
|
mqc->a = 0x8000;
|
|
mqc->c = 0;
|
|
mqc->bp = bp-1;
|
|
mqc->bpstart = bp;
|
|
mqc->ct = 12 + (*mqc->bp == 0xff);
|
|
}
|
|
|
|
void ff_mqc_encode(MqcState *mqc, uint8_t *cxstate, int d)
|
|
{
|
|
int qe;
|
|
|
|
qe = ff_mqc_qe[*cxstate];
|
|
mqc->a -= qe;
|
|
if ((*cxstate & 1) == d){
|
|
if (!(mqc->a & 0x8000)){
|
|
if (mqc->a < qe)
|
|
mqc->a = qe;
|
|
else
|
|
mqc->c += qe;
|
|
*cxstate = ff_mqc_nmps[*cxstate];
|
|
renorme(mqc);
|
|
} else
|
|
mqc->c += qe;
|
|
} else{
|
|
if (mqc->a < qe)
|
|
mqc->c += qe;
|
|
else
|
|
mqc->a = qe;
|
|
*cxstate = ff_mqc_nlps[*cxstate];
|
|
renorme(mqc);
|
|
}
|
|
}
|
|
|
|
int ff_mqc_length(MqcState *mqc)
|
|
{
|
|
return mqc->bp - mqc->bpstart;
|
|
}
|
|
|
|
int ff_mqc_flush(MqcState *mqc)
|
|
{
|
|
setbits(mqc);
|
|
mqc->c = mqc->c << mqc->ct;
|
|
byteout(mqc);
|
|
mqc->c = mqc->c << mqc->ct;
|
|
byteout(mqc);
|
|
if (*mqc->bp != 0xff)
|
|
mqc->bp++;
|
|
return mqc->bp - mqc->bpstart;
|
|
}
|