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ffmpeg / libavcodec / jpeglsdec.c @ 2d2b5a14

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/*
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 * JPEG-LS decoder
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 * Copyright (c) 2003 Michael Niedermayer
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 * Copyright (c) 2006 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
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 * JPEG-LS decoder.
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 */
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#include "avcodec.h"
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#include "get_bits.h"
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#include "golomb.h"
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#include "mathops.h"
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#include "mjpeg.h"
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#include "mjpegdec.h"
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#include "jpegls.h"
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#include "jpeglsdec.h"
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/*
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* Uncomment this to significantly speed up decoding of broken JPEG-LS
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* (or test broken JPEG-LS decoder) and slow down ordinary decoding a bit.
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*
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* There is no Golomb code with length >= 32 bits possible, so check and
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* avoid situation of 32 zeros, FFmpeg Golomb decoder is painfully slow
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* on this errors.
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*/
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//#define JLS_BROKEN
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/**
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 * Decode LSE block with initialization parameters
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 */
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int ff_jpegls_decode_lse(MJpegDecodeContext *s)
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{
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    int len, id;
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    /* XXX: verify len field validity */
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    len = get_bits(&s->gb, 16);
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    id = get_bits(&s->gb, 8);
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    switch(id){
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    case 1:
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        s->maxval= get_bits(&s->gb, 16);
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        s->t1= get_bits(&s->gb, 16);
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        s->t2= get_bits(&s->gb, 16);
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        s->t3= get_bits(&s->gb, 16);
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        s->reset= get_bits(&s->gb, 16);
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//        ff_jpegls_reset_coding_parameters(s, 0);
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        //FIXME quant table?
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        break;
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    case 2:
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    case 3:
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        av_log(s->avctx, AV_LOG_ERROR, "palette not supported\n");
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        return -1;
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    case 4:
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        av_log(s->avctx, AV_LOG_ERROR, "oversize image not supported\n");
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        return -1;
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    default:
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        av_log(s->avctx, AV_LOG_ERROR, "invalid id %d\n", id);
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        return -1;
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    }
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//    av_log(s->avctx, AV_LOG_DEBUG, "ID=%i, T=%i,%i,%i\n", id, s->t1, s->t2, s->t3);
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    return 0;
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}
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/**
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 * Get context-dependent Golomb code, decode it and update context
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 */
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static inline int ls_get_code_regular(GetBitContext *gb, JLSState *state, int Q){
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    int k, ret;
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    for(k = 0; (state->N[Q] << k) < state->A[Q]; k++);
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#ifdef JLS_BROKEN
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    if(!show_bits_long(gb, 32))return -1;
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#endif
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    ret = get_ur_golomb_jpegls(gb, k, state->limit, state->qbpp);
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    /* decode mapped error */
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    if(ret & 1)
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        ret = -((ret + 1) >> 1);
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    else
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        ret >>= 1;
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    /* for NEAR=0, k=0 and 2*B[Q] <= - N[Q] mapping is reversed */
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    if(!state->near && !k && (2 * state->B[Q] <= -state->N[Q]))
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        ret = -(ret + 1);
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    ret= ff_jpegls_update_state_regular(state, Q, ret);
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    return ret;
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}
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/**
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 * Get Golomb code, decode it and update state for run termination
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 */
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static inline int ls_get_code_runterm(GetBitContext *gb, JLSState *state, int RItype, int limit_add){
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    int k, ret, temp, map;
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    int Q = 365 + RItype;
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    temp=  state->A[Q];
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    if(RItype)
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        temp += state->N[Q] >> 1;
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    for(k = 0; (state->N[Q] << k) < temp; k++);
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#ifdef JLS_BROKEN
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    if(!show_bits_long(gb, 32))return -1;
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#endif
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    ret = get_ur_golomb_jpegls(gb, k, state->limit - limit_add - 1, state->qbpp);
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    /* decode mapped error */
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    map = 0;
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    if(!k && (RItype || ret) && (2 * state->B[Q] < state->N[Q]))
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        map = 1;
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    ret += RItype + map;
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    if(ret & 1){
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        ret = map - ((ret + 1) >> 1);
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        state->B[Q]++;
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    } else {
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        ret = ret >> 1;
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    }
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    /* update state */
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    state->A[Q] += FFABS(ret) - RItype;
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    ret *= state->twonear;
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    ff_jpegls_downscale_state(state, Q);
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    return ret;
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}
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/**
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 * Decode one line of image
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 */
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static inline void ls_decode_line(JLSState *state, MJpegDecodeContext *s, void *last, void *dst, int last2, int w, int stride, int comp, int bits){
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    int i, x = 0;
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    int Ra, Rb, Rc, Rd;
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    int D0, D1, D2;
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    while(x < w) {
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        int err, pred;
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        /* compute gradients */
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        Ra = x ? R(dst, x - stride) : R(last, x);
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        Rb = R(last, x);
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        Rc = x ? R(last, x - stride) : last2;
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        Rd = (x >= w - stride) ? R(last, x) : R(last, x + stride);
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        D0 = Rd - Rb;
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        D1 = Rb - Rc;
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        D2 = Rc - Ra;
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        /* run mode */
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        if((FFABS(D0) <= state->near) && (FFABS(D1) <= state->near) && (FFABS(D2) <= state->near)) {
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            int r;
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            int RItype;
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            /* decode full runs while available */
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            while(get_bits1(&s->gb)) {
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                int r;
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                r = 1 << ff_log2_run[state->run_index[comp]];
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                if(x + r * stride > w) {
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                    r = (w - x) / stride;
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                }
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                for(i = 0; i < r; i++) {
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                    W(dst, x, Ra);
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                    x += stride;
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                }
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                /* if EOL reached, we stop decoding */
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                if(r != (1 << ff_log2_run[state->run_index[comp]]))
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                    return;
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                if(state->run_index[comp] < 31)
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                    state->run_index[comp]++;
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                if(x + stride > w)
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                    return;
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            }
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            /* decode aborted run */
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            r = ff_log2_run[state->run_index[comp]];
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            if(r)
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                r = get_bits_long(&s->gb, r);
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            for(i = 0; i < r; i++) {
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                W(dst, x, Ra);
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                x += stride;
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            }
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            /* decode run termination value */
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            Rb = R(last, x);
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            RItype = (FFABS(Ra - Rb) <= state->near) ? 1 : 0;
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            err = ls_get_code_runterm(&s->gb, state, RItype, ff_log2_run[state->run_index[comp]]);
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            if(state->run_index[comp])
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                state->run_index[comp]--;
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            if(state->near && RItype){
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                pred = Ra + err;
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            } else {
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                if(Rb < Ra)
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                    pred = Rb - err;
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                else
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                    pred = Rb + err;
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            }
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        } else { /* regular mode */
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            int context, sign;
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            context = ff_jpegls_quantize(state, D0) * 81 + ff_jpegls_quantize(state, D1) * 9 + ff_jpegls_quantize(state, D2);
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            pred = mid_pred(Ra, Ra + Rb - Rc, Rb);
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            if(context < 0){
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                context = -context;
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                sign = 1;
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            }else{
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                sign = 0;
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            }
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            if(sign){
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                pred = av_clip(pred - state->C[context], 0, state->maxval);
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                err = -ls_get_code_regular(&s->gb, state, context);
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            } else {
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                pred = av_clip(pred + state->C[context], 0, state->maxval);
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                err = ls_get_code_regular(&s->gb, state, context);
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            }
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            /* we have to do something more for near-lossless coding */
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            pred += err;
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        }
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        if(state->near){
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            if(pred < -state->near)
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                pred += state->range * state->twonear;
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            else if(pred > state->maxval + state->near)
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                pred -= state->range * state->twonear;
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            pred = av_clip(pred, 0, state->maxval);
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        }
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        pred &= state->maxval;
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        W(dst, x, pred);
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        x += stride;
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    }
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}
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int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near, int point_transform, int ilv){
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    int i, t = 0;
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    uint8_t *zero, *last, *cur;
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    JLSState *state;
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    int off = 0, stride = 1, width, shift;
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    zero = av_mallocz(s->picture.linesize[0]);
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    last = zero;
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    cur = s->picture.data[0];
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    state = av_mallocz(sizeof(JLSState));
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    /* initialize JPEG-LS state from JPEG parameters */
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    state->near = near;
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    state->bpp = (s->bits < 2) ? 2 : s->bits;
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    state->maxval = s->maxval;
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    state->T1 = s->t1;
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    state->T2 = s->t2;
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    state->T3 = s->t3;
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    state->reset = s->reset;
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    ff_jpegls_reset_coding_parameters(state, 0);
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    ff_jpegls_init_state(state);
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    if(s->bits <= 8)
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        shift = point_transform + (8 - s->bits);
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    else
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        shift = point_transform + (16 - s->bits);
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//    av_log(s->avctx, AV_LOG_DEBUG, "JPEG-LS params: %ix%i NEAR=%i MV=%i T(%i,%i,%i) RESET=%i, LIMIT=%i, qbpp=%i, RANGE=%i\n",s->width,s->height,state->near,state->maxval,state->T1,state->T2,state->T3,state->reset,state->limit,state->qbpp, state->range);
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//    av_log(s->avctx, AV_LOG_DEBUG, "JPEG params: ILV=%i Pt=%i BPP=%i, scan = %i\n", ilv, point_transform, s->bits, s->cur_scan);
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    if(ilv == 0) { /* separate planes */
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        off = s->cur_scan - 1;
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        stride = (s->nb_components > 1) ? 3 : 1;
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        width = s->width * stride;
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        cur += off;
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        for(i = 0; i < s->height; i++) {
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            if(s->bits <= 8){
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                ls_decode_line(state, s, last, cur, t, width, stride, off,  8);
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                t = last[0];
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            }else{
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                ls_decode_line(state, s, last, cur, t, width, stride, off, 16);
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                t = *((uint16_t*)last);
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            }
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            last = cur;
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            cur += s->picture.linesize[0];
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            if (s->restart_interval && !--s->restart_count) {
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                align_get_bits(&s->gb);
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                skip_bits(&s->gb, 16); /* skip RSTn */
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            }
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        }
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    } else if(ilv == 1) { /* line interleaving */
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        int j;
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        int Rc[3] = {0, 0, 0};
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        memset(cur, 0, s->picture.linesize[0]);
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        width = s->width * 3;
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        for(i = 0; i < s->height; i++) {
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            for(j = 0; j < 3; j++) {
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                ls_decode_line(state, s, last + j, cur + j, Rc[j], width, 3, j, 8);
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                Rc[j] = last[j];
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                if (s->restart_interval && !--s->restart_count) {
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                    align_get_bits(&s->gb);
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                    skip_bits(&s->gb, 16); /* skip RSTn */
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                }
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            }
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            last = cur;
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            cur += s->picture.linesize[0];
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        }
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    } else if(ilv == 2) { /* sample interleaving */
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        av_log(s->avctx, AV_LOG_ERROR, "Sample interleaved images are not supported.\n");
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        av_free(state);
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        av_free(zero);
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        return -1;
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    }
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    if(shift){ /* we need to do point transform or normalize samples */
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        int x, w;
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        w = s->width * s->nb_components;
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        if(s->bits <= 8){
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            uint8_t *src = s->picture.data[0];
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            for(i = 0; i < s->height; i++){
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                for(x = off; x < w; x+= stride){
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                    src[x] <<= shift;
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                }
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                src += s->picture.linesize[0];
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            }
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        }else{
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            uint16_t *src = (uint16_t*) s->picture.data[0];
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            for(i = 0; i < s->height; i++){
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                for(x = 0; x < w; x++){
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                    src[x] <<= shift;
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                }
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                src += s->picture.linesize[0]/2;
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            }
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        }
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    }
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    av_free(state);
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    av_free(zero);
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    return 0;
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}
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AVCodec ff_jpegls_decoder = {
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    "jpegls",
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    AVMEDIA_TYPE_VIDEO,
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    CODEC_ID_JPEGLS,
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    sizeof(MJpegDecodeContext),
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    ff_mjpeg_decode_init,
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    NULL,
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    ff_mjpeg_decode_end,
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    ff_mjpeg_decode_frame,
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    CODEC_CAP_DR1,
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    .long_name = NULL_IF_CONFIG_SMALL("JPEG-LS"),
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};