mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
136 lines
3.2 KiB
136 lines
3.2 KiB
/* |
|
* 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 <string.h> |
|
|
|
#include "libavutil/avassert.h" |
|
#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); |
|
} |
|
} |
|
|
|
static int 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; |
|
} |
|
|
|
int ff_mqc_flush_to(MqcState *mqc, uint8_t *dst, int *dst_len) |
|
{ |
|
MqcState mqc2 = *mqc; |
|
mqc2.bpstart= |
|
mqc2.bp = dst; |
|
*mqc2.bp = *mqc->bp; |
|
mqc_flush(&mqc2); |
|
*dst_len = mqc2.bp - dst; |
|
if (mqc->bp < mqc->bpstart) { |
|
av_assert1(mqc->bpstart - mqc->bp == 1); |
|
av_assert1(*dst_len > 0); |
|
av_assert1(mqc->bp[0] == 0 && dst[0] == 0); |
|
(*dst_len) --; |
|
memmove(dst, dst+1, *dst_len); |
|
return mqc->bp - mqc->bpstart + 1 + *dst_len; |
|
} |
|
return mqc->bp - mqc->bpstart + *dst_len; |
|
}
|
|
|