repositories / deb_ffmpeg.git / blame
| Commit | Line | Data |
|---|---|---|
| 2ba45a60 DM |
1 | /* |
| 2 | * MQ-coder encoder | |
| 3 | * Copyright (c) 2007 Kamil Nowosad | |
| 4 | * | |
| 5 | * This file is part of FFmpeg. | |
| 6 | * | |
| 7 | * FFmpeg is free software; you can redistribute it and/or | |
| 8 | * modify it under the terms of the GNU Lesser General Public | |
| 9 | * License as published by the Free Software Foundation; either | |
| 10 | * version 2.1 of the License, or (at your option) any later version. | |
| 11 | * | |
| 12 | * FFmpeg is distributed in the hope that it will be useful, | |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 15 | * Lesser General Public License for more details. | |
| 16 | * | |
| 17 | * You should have received a copy of the GNU Lesser General Public | |
| 18 | * License along with FFmpeg; if not, write to the Free Software | |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| 20 | */ | |
| 21 | ||
| 22 | /** | |
| 23 | * MQ-coder encoder | |
| 24 | * @file | |
| 25 | * @author Kamil Nowosad | |
| 26 | */ | |
| 27 | ||
| 28 | #include "mqc.h" | |
| 29 | ||
| 30 | static void byteout(MqcState *mqc) | |
| 31 | { | |
| 32 | retry: | |
| 33 | if (*mqc->bp == 0xff){ | |
| 34 | mqc->bp++; | |
| 35 | *mqc->bp = mqc->c >> 20; | |
| 36 | mqc->c &= 0xfffff; | |
| 37 | mqc->ct = 7; | |
| 38 | } else if ((mqc->c & 0x8000000)){ | |
| 39 | (*mqc->bp)++; | |
| 40 | mqc->c &= 0x7ffffff; | |
| 41 | goto retry; | |
| 42 | } else{ | |
| 43 | mqc->bp++; | |
| 44 | *mqc->bp = mqc->c >> 19; | |
| 45 | mqc->c &= 0x7ffff; | |
| 46 | mqc->ct = 8; | |
| 47 | } | |
| 48 | } | |
| 49 | ||
| 50 | static void renorme(MqcState *mqc) | |
| 51 | { | |
| 52 | do{ | |
| 53 | mqc->a += mqc->a; | |
| 54 | mqc->c += mqc->c; | |
| 55 | if (!--mqc->ct) | |
| 56 | byteout(mqc); | |
| 57 | } while (!(mqc->a & 0x8000)); | |
| 58 | } | |
| 59 | ||
| 60 | static void setbits(MqcState *mqc) | |
| 61 | { | |
| 62 | int tmp = mqc->c + mqc->a; | |
| 63 | mqc->c |= 0xffff; | |
| 64 | if (mqc->c >= tmp) | |
| 65 | mqc->c -= 0x8000; | |
| 66 | } | |
| 67 | ||
| 68 | void ff_mqc_initenc(MqcState *mqc, uint8_t *bp) | |
| 69 | { | |
| 70 | ff_mqc_init_contexts(mqc); | |
| 71 | mqc->a = 0x8000; | |
| 72 | mqc->c = 0; | |
| 73 | mqc->bp = bp-1; | |
| 74 | mqc->bpstart = bp; | |
| 75 | mqc->ct = 12 + (*mqc->bp == 0xff); | |
| 76 | } | |
| 77 | ||
| 78 | void ff_mqc_encode(MqcState *mqc, uint8_t *cxstate, int d) | |
| 79 | { | |
| 80 | int qe; | |
| 81 | ||
| 82 | qe = ff_mqc_qe[*cxstate]; | |
| 83 | mqc->a -= qe; | |
| 84 | if ((*cxstate & 1) == d){ | |
| 85 | if (!(mqc->a & 0x8000)){ | |
| 86 | if (mqc->a < qe) | |
| 87 | mqc->a = qe; | |
| 88 | else | |
| 89 | mqc->c += qe; | |
| 90 | *cxstate = ff_mqc_nmps[*cxstate]; | |
| 91 | renorme(mqc); | |
| 92 | } else | |
| 93 | mqc->c += qe; | |
| 94 | } else{ | |
| 95 | if (mqc->a < qe) | |
| 96 | mqc->c += qe; | |
| 97 | else | |
| 98 | mqc->a = qe; | |
| 99 | *cxstate = ff_mqc_nlps[*cxstate]; | |
| 100 | renorme(mqc); | |
| 101 | } | |
| 102 | } | |
| 103 | ||
| 104 | int ff_mqc_length(MqcState *mqc) | |
| 105 | { | |
| 106 | return mqc->bp - mqc->bpstart; | |
| 107 | } | |
| 108 | ||
| 109 | int ff_mqc_flush(MqcState *mqc) | |
| 110 | { | |
| 111 | setbits(mqc); | |
| 112 | mqc->c = mqc->c << mqc->ct; | |
| 113 | byteout(mqc); | |
| 114 | mqc->c = mqc->c << mqc->ct; | |
| 115 | byteout(mqc); | |
| 116 | if (*mqc->bp != 0xff) | |
| 117 | mqc->bp++; | |
| 118 | return mqc->bp - mqc->bpstart; | |
| 119 | } |