diff options
Diffstat (limited to 'libavcodec/mqcenc.c')
-rw-r--r-- | libavcodec/mqcenc.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/libavcodec/mqcenc.c b/libavcodec/mqcenc.c new file mode 100644 index 0000000000..97d352be44 --- /dev/null +++ b/libavcodec/mqcenc.c @@ -0,0 +1,119 @@ +/* + * 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; +} |