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ffmpeg / libavcodec / rv30.c @ 42d6c3ba

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/*
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 * RV30 decoder
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 * Copyright (c) 2007 Konstantin Shishkov
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file rv30.c
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 * RV30 decoder
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 */
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#include "avcodec.h"
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#include "dsputil.h"
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#include "mpegvideo.h"
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#include "golomb.h"
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#include "rv34.h"
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#include "rv30data.h"
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static int rv30_parse_slice_header(RV34DecContext *r, GetBitContext *gb, SliceInfo *si)
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{
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    int mb_bits;
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    int w = r->s.width, h = r->s.height;
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    int mb_size;
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    memset(si, 0, sizeof(SliceInfo));
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    if(get_bits(gb, 3))
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        return -1;
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    si->type = get_bits(gb, 2);
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    if(si->type == 1) si->type = 0;
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    if(get_bits1(gb))
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        return -1;
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    si->quant = get_bits(gb, 5);
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    skip_bits1(gb);
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    si->pts = get_bits(gb, 13);
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    skip_bits(gb, r->rpr);
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    si->width  = w;
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    si->height = h;
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    mb_size = ((w + 15) >> 4) * ((h + 15) >> 4);
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    mb_bits = ff_rv34_get_start_offset(gb, mb_size);
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    si->start = get_bits(gb, mb_bits);
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    skip_bits1(gb);
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    return 0;
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}
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/**
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 * Decode 4x4 intra types array.
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 */
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static int rv30_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int8_t *dst)
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{
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    int i, j, k;
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    for(i = 0; i < 4; i++, dst += r->s.b4_stride - 4){
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        for(j = 0; j < 4; j+= 2){
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            int code = svq3_get_ue_golomb(gb) << 1;
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            if(code >= 81*2){
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                av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction code\n");
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                return -1;
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            }
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            for(k = 0; k < 2; k++){
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                int A = dst[-r->s.b4_stride] + 1;
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                int B = dst[-1] + 1;
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                *dst++ = rv30_itype_from_context[A * 90 + B * 9 + rv30_itype_code[code + k]];
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                if(dst[-1] == 9){
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                    av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction mode\n");
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                    return -1;
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                }
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            }
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        }
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    }
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    return 0;
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}
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/**
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 * Decode macroblock information.
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 */
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static int rv30_decode_mb_info(RV34DecContext *r)
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{
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    static const int rv30_p_types[6] = { RV34_MB_SKIP, RV34_MB_P_16x16, RV34_MB_P_8x8, -1, RV34_MB_TYPE_INTRA, RV34_MB_TYPE_INTRA16x16 };
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    static const int rv30_b_types[6] = { RV34_MB_SKIP, RV34_MB_B_DIRECT, RV34_MB_B_FORWARD, RV34_MB_B_BACKWARD, RV34_MB_TYPE_INTRA, RV34_MB_TYPE_INTRA16x16 };
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    MpegEncContext *s = &r->s;
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    GetBitContext *gb = &s->gb;
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    int code = svq3_get_ue_golomb(gb);
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    if(code > 11){
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        av_log(s->avctx, AV_LOG_ERROR, "Incorrect MB type code\n");
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        return -1;
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    }
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    if(code > 5){
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        av_log(s->avctx, AV_LOG_ERROR, "dquant needed\n");
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        code -= 6;
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    }
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    if(s->pict_type != FF_B_TYPE)
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        return rv30_p_types[code];
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    else
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        return rv30_b_types[code];
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}
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/**
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 * Initialize decoder.
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 */
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static av_cold int rv30_decode_init(AVCodecContext *avctx)
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{
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    RV34DecContext *r = avctx->priv_data;
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    r->rv30 = 1;
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    ff_rv34_decode_init(avctx);
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    if(avctx->extradata_size < 2){
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        av_log(avctx, AV_LOG_ERROR, "Extradata is too small.\n");
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        return -1;
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    }
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    r->rpr = (avctx->extradata[1] & 7) >> 1;
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    r->rpr = FFMIN(r->rpr + 1, 3);
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    r->parse_slice_header = rv30_parse_slice_header;
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    r->decode_intra_types = rv30_decode_intra_types;
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    r->decode_mb_info     = rv30_decode_mb_info;
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    r->luma_dc_quant_i = rv30_luma_dc_quant;
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    r->luma_dc_quant_p = rv30_luma_dc_quant;
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    return 0;
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}
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AVCodec rv30_decoder = {
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    "rv30",
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    CODEC_TYPE_VIDEO,
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    CODEC_ID_RV30,
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    sizeof(RV34DecContext),
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    rv30_decode_init,
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    NULL,
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    ff_rv34_decode_end,
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    ff_rv34_decode_frame,
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    CODEC_CAP_DR1 | CODEC_CAP_DELAY,
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    .long_name = NULL_IF_CONFIG_SMALL("RealVideo 3.0"),
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};