split jpeg_ls into jpeglsdec, jpeglsenc and jpegls

Originally committed as revision 9021 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 361 insertions, 0 deletions

diff --git a/libavcodec/jpeglsdec.c b/libavcodec/jpeglsdec.c
new file mode 100644
index 0000000000..0d2b35858b
--- /dev/null
+++ b/libavcodec/jpeglsdec.c
@@ -0,0 +1,361 @@
+/*
+ * JPEG-LS decoder
+ * Copyright (c) 2003 Michael Niedermayer
+ * Copyright (c) 2006 Konstantin Shishkov
+ *
+ * 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
+ */
+
+/**
+ * @file jpeglsdec.c
+ * JPEG-LS decoder.
+ */
+
+#include "avcodec.h"
+#include "bitstream.h"
+#include "golomb.h"
+#include "mjpeg.h"
+#include "jpegls.h"
+#include "jpeglsdec.h"
+
+
+/*
+* Uncomment this to significantly speed up decoding of broken JPEG-LS
+* (or test broken JPEG-LS decoder) and slow down ordinary decoding a bit.
+*
+* There is no Golomb code with length >= 32 bits possible, so check and
+* avoid situation of 32 zeros, FFmpeg Golomb decoder is painfully slow
+* on this errors.
+*/
+//#define JLS_BROKEN
+
+
+/**
+ * Decode LSE block with initialization parameters
+ */
+int ff_jpegls_decode_lse(MJpegDecodeContext *s)
+{
+    int len, id;
+
+    /* XXX: verify len field validity */
+    len = get_bits(&s->gb, 16);
+    id = get_bits(&s->gb, 8);
+
+    switch(id){
+    case 1:
+        s->maxval= get_bits(&s->gb, 16);
+        s->t1= get_bits(&s->gb, 16);
+        s->t2= get_bits(&s->gb, 16);
+        s->t3= get_bits(&s->gb, 16);
+        s->reset= get_bits(&s->gb, 16);
+
+//        ff_jpegls_reset_coding_parameters(s, 0);
+        //FIXME quant table?
+        break;
+    case 2:
+    case 3:
+        av_log(s->avctx, AV_LOG_ERROR, "palette not supported\n");
+        return -1;
+    case 4:
+        av_log(s->avctx, AV_LOG_ERROR, "oversize image not supported\n");
+        return -1;
+    default:
+        av_log(s->avctx, AV_LOG_ERROR, "invalid id %d\n", id);
+        return -1;
+    }
+//    av_log(s->avctx, AV_LOG_DEBUG, "ID=%i, T=%i,%i,%i\n", id, s->t1, s->t2, s->t3);
+
+    return 0;
+}
+
+/**
+ * Get context-dependent Golomb code, decode it and update context
+ */
+static inline int ls_get_code_regular(GetBitContext *gb, JLSState *state, int Q){
+    int k, ret;
+
+    for(k = 0; (state->N[Q] << k) < state->A[Q]; k++);
+
+#ifdef JLS_BROKEN
+    if(!show_bits_long(gb, 32))return -1;
+#endif
+    ret = get_ur_golomb_jpegls(gb, k, state->limit, state->qbpp);
+
+    /* decode mapped error */
+    if(ret & 1)
+        ret = -((ret + 1) >> 1);
+    else
+        ret >>= 1;
+
+    /* for NEAR=0, k=0 and 2*B[Q] <= - N[Q] mapping is reversed */
+    if(!state->near && !k && (2 * state->B[Q] <= -state->N[Q]))
+        ret = -(ret + 1);
+
+    ret= ff_jpegls_update_state_regular(state, Q, ret);
+
+    return ret;
+}
+
+/**
+ * Get Golomb code, decode it and update state for run termination
+ */
+static inline int ls_get_code_runterm(GetBitContext *gb, JLSState *state, int RItype, int limit_add){
+    int k, ret, temp, map;
+    int Q = 365 + RItype;
+
+    temp=  state->A[Q];
+    if(RItype)
+        temp += state->N[Q] >> 1;
+
+    for(k = 0; (state->N[Q] << k) < temp; k++);
+
+#ifdef JLS_BROKEN
+    if(!show_bits_long(gb, 32))return -1;
+#endif
+    ret = get_ur_golomb_jpegls(gb, k, state->limit - limit_add - 1, state->qbpp);
+
+    /* decode mapped error */
+    map = 0;
+    if(!k && (RItype || ret) && (2 * state->B[Q] < state->N[Q]))
+        map = 1;
+    ret += RItype + map;
+
+    if(ret & 1){
+        ret = map - ((ret + 1) >> 1);
+        state->B[Q]++;
+    } else {
+        ret = ret >> 1;
+    }
+
+    /* update state */
+    state->A[Q] += FFABS(ret) - RItype;
+    ret *= state->twonear;
+    ff_jpegls_downscale_state(state, Q);
+
+    return ret;
+}
+
+/**
+ * Decode one line of image
+ */
+static inline void ls_decode_line(JLSState *state, MJpegDecodeContext *s, void *last, void *dst, int last2, int w, int stride, int comp, int bits){
+    int i, x = 0;
+    int Ra, Rb, Rc, Rd;
+    int D0, D1, D2;
+
+    while(x < w) {
+        int err, pred;
+
+        /* compute gradients */
+        Ra = x ? R(dst, x - stride) : R(last, x);
+        Rb = R(last, x);
+        Rc = x ? R(last, x - stride) : last2;
+        Rd = (x >= w - stride) ? R(last, x) : R(last, x + stride);
+        D0 = Rd - Rb;
+        D1 = Rb - Rc;
+        D2 = Rc - Ra;
+        /* run mode */
+        if((FFABS(D0) <= state->near) && (FFABS(D1) <= state->near) && (FFABS(D2) <= state->near)) {
+            int r;
+            int RItype;
+
+            /* decode full runs while available */
+            while(get_bits1(&s->gb)) {
+                int r;
+                r = 1 << ff_log2_run[state->run_index[comp]];
+                if(x + r * stride > w) {
+                    r = (w - x) / stride;
+                }
+                for(i = 0; i < r; i++) {
+                    W(dst, x, Ra);
+                    x += stride;
+                }
+                /* if EOL reached, we stop decoding */
+                if(r != (1 << ff_log2_run[state->run_index[comp]]))
+                    return;
+                if(state->run_index[comp] < 31)
+                    state->run_index[comp]++;
+                if(x + stride > w)
+                    return;
+            }
+            /* decode aborted run */
+            r = ff_log2_run[state->run_index[comp]];
+            if(r)
+                r = get_bits_long(&s->gb, r);
+            for(i = 0; i < r; i++) {
+                W(dst, x, Ra);
+                x += stride;
+            }
+
+            /* decode run termination value */
+            Rb = R(last, x);
+            RItype = (FFABS(Ra - Rb) <= state->near) ? 1 : 0;
+            err = ls_get_code_runterm(&s->gb, state, RItype, ff_log2_run[state->run_index[comp]]);
+            if(state->run_index[comp])
+                state->run_index[comp]--;
+
+            if(state->near && RItype){
+                pred = Ra + err;
+            } else {
+                if(Rb < Ra)
+                    pred = Rb - err;
+                else
+                    pred = Rb + err;
+            }
+        } else { /* regular mode */
+            int context, sign;
+
+            context = ff_jpegls_quantize(state, D0) * 81 + ff_jpegls_quantize(state, D1) * 9 + ff_jpegls_quantize(state, D2);
+            pred = mid_pred(Ra, Ra + Rb - Rc, Rb);
+
+            if(context < 0){
+                context = -context;
+                sign = 1;
+            }else{
+                sign = 0;
+            }
+
+            if(sign){
+                pred = av_clip(pred - state->C[context], 0, state->maxval);
+                err = -ls_get_code_regular(&s->gb, state, context);
+            } else {
+                pred = av_clip(pred + state->C[context], 0, state->maxval);
+                err = ls_get_code_regular(&s->gb, state, context);
+            }
+
+            /* we have to do something more for near-lossless coding */
+            pred += err;
+        }
+        if(state->near){
+            if(pred < -state->near)
+                pred += state->range * state->twonear;
+            else if(pred > state->maxval + state->near)
+                pred -= state->range * state->twonear;
+            pred = av_clip(pred, 0, state->maxval);
+        }
+
+        pred &= state->maxval;
+        W(dst, x, pred);
+        x += stride;
+    }
+}
+
+int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near, int point_transform, int ilv){
+    int i, t = 0;
+    uint8_t *zero, *last, *cur;
+    JLSState *state;
+    int off = 0, stride = 1, width, shift;
+
+    zero = av_mallocz(s->picture.linesize[0]);
+    last = zero;
+    cur = s->picture.data[0];
+
+    state = av_mallocz(sizeof(JLSState));
+    /* initialize JPEG-LS state from JPEG parameters */
+    state->near = near;
+    state->bpp = (s->bits < 2) ? 2 : s->bits;
+    state->maxval = s->maxval;
+    state->T1 = s->t1;
+    state->T2 = s->t2;
+    state->T3 = s->t3;
+    state->reset = s->reset;
+    ff_jpegls_reset_coding_parameters(state, 0);
+    ff_jpegls_init_state(state);
+
+    if(s->bits <= 8)
+        shift = point_transform + (8 - s->bits);
+    else
+        shift = point_transform + (16 - s->bits);
+
+//    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);
+//    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);
+    if(ilv == 0) { /* separate planes */
+        off = s->cur_scan - 1;
+        stride = (s->nb_components > 1) ? 3 : 1;
+        width = s->width * stride;
+        cur += off;
+        for(i = 0; i < s->height; i++) {
+            if(s->bits <= 8){
+                ls_decode_line(state, s, last, cur, t, width, stride, off,  8);
+                t = last[0];
+            }else{
+                ls_decode_line(state, s, last, cur, t, width, stride, off, 16);
+                t = *((uint16_t*)last);
+            }
+            last = cur;
+            cur += s->picture.linesize[0];
+
+            if (s->restart_interval && !--s->restart_count) {
+                align_get_bits(&s->gb);
+                skip_bits(&s->gb, 16); /* skip RSTn */
+            }
+        }
+    } else if(ilv == 1) { /* line interleaving */
+        int j;
+        int Rc[3] = {0, 0, 0};
+        memset(cur, 0, s->picture.linesize[0]);
+        width = s->width * 3;
+        for(i = 0; i < s->height; i++) {
+            for(j = 0; j < 3; j++) {
+                ls_decode_line(state, s, last + j, cur + j, Rc[j], width, 3, j, 8);
+                Rc[j] = last[j];
+
+                if (s->restart_interval && !--s->restart_count) {
+                    align_get_bits(&s->gb);
+                    skip_bits(&s->gb, 16); /* skip RSTn */
+                }
+            }
+            last = cur;
+            cur += s->picture.linesize[0];
+        }
+    } else if(ilv == 2) { /* sample interleaving */
+        av_log(s->avctx, AV_LOG_ERROR, "Sample interleaved images are not supported.\n");
+        av_free(state);
+        av_free(zero);
+        return -1;
+    }
+
+    if(shift){ /* we need to do point transform or normalize samples */
+        int x, w;
+
+        w = s->width * s->nb_components;
+
+        if(s->bits <= 8){
+            uint8_t *src = s->picture.data[0];
+
+            for(i = 0; i < s->height; i++){
+                for(x = off; x < w; x+= stride){
+                    src[x] <<= shift;
+                }
+                src += s->picture.linesize[0];
+            }
+        }else{
+            uint16_t *src = (uint16_t*) s->picture.data[0];
+
+            for(i = 0; i < s->height; i++){
+                for(x = 0; x < w; x++){
+                    src[x] <<= shift;
+                }
+                src += s->picture.linesize[0]/2;
+            }
+        }
+    }
+    av_free(state);
+    av_free(zero);
+
+    return 0;
+}