avcodec/jpeg2000dec: Fix Selective arithmetic coding bypass and Multiple codeword segments

These 2 are highly related so they are in the same commit
Fixes part of Ticket4605
Fixes p0_04.j2k
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/jpeg2000.c

@@ -468,7 +468,7 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
                     cblk->zero      = 0;
                     cblk->lblock    = 3;
                     cblk->length    = 0;
-                    cblk->lengthinc = 0;
+                    memset(cblk->lengthinc, 0, sizeof(cblk->lengthinc));
                     cblk->npasses   = 0;
                 }
             }

libavcodec/jpeg2000.h

@@ -163,11 +163,15 @@ typedef struct Jpeg2000Cblk {
     uint8_t ninclpasses; // number coding of passes included in codestream
     uint8_t nonzerobits;
     uint16_t length;
-    uint16_t lengthinc;
+    uint16_t lengthinc[JPEG2000_MAX_PASSES];
+    uint8_t nb_lengthinc;
     uint8_t lblock;
     uint8_t zero;
     uint8_t data[8192];
-    Jpeg2000Pass passes[100];
+    int nb_terminations;
+    int nb_terminationsinc;
+    int data_start[JPEG2000_MAX_PASSES];
+    Jpeg2000Pass passes[JPEG2000_MAX_PASSES];
     uint16_t coord[2][2]; // border coordinates {{x0, x1}, {y0, y1}}
 } Jpeg2000Cblk; // code block
 
@@ -264,4 +268,21 @@ void ff_jpeg2000_reinit(Jpeg2000Component *comp, Jpeg2000CodingStyle *codsty);
 
 void ff_jpeg2000_cleanup(Jpeg2000Component *comp, Jpeg2000CodingStyle *codsty);
 
+static inline int needs_termination(int style, int passno) {
+    if (style & JPEG2000_CBLK_BYPASS) {
+        int type = passno % 3;
+        passno /= 3;
+        if (type == 0 && passno > 2)
+            return 2;
+        if (type == 2 && passno > 2)
+            return 1;
+        if (style & JPEG2000_CBLK_TERMALL) {
+            return passno > 2 ? 2 : 1;
+        }
+    }
+    if (style & JPEG2000_CBLK_TERMALL)
+        return 1;
+    return 0;
+}
+
 #endif /* AVCODEC_JPEG2000_H */

libavcodec/jpeg2000dec.c

@@ -764,6 +764,7 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s,
                                   int layno, uint8_t *expn, int numgbits)
 {
     int bandno, cblkno, ret, nb_code_blocks;
+    int cwsno;
 
     if (!(ret = get_bits(s, 1))) {
         jpeg2000_flush(s);
@@ -819,16 +820,32 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s,
             }
 
             cblk->lblock += llen;
-            if ((ret = get_bits(s, av_log2(newpasses) + cblk->lblock)) < 0)
-                return ret;
-            if (ret > sizeof(cblk->data)) {
-                avpriv_request_sample(s->avctx,
-                                      "Block with lengthinc greater than %"SIZE_SPECIFIER"",
-                                      sizeof(cblk->data));
-                return AVERROR_PATCHWELCOME;
-            }
-            cblk->lengthinc = ret;
-            cblk->npasses  += newpasses;
+
+            cblk->nb_lengthinc = 0;
+            cblk->nb_terminationsinc = 0;
+            do {
+                int newpasses1 = 0;
+
+                while (newpasses1 < newpasses) {
+                    newpasses1 ++;
+                    if (needs_termination(codsty->cblk_style, cblk->npasses + newpasses1 - 1)) {
+                        cblk->nb_terminationsinc ++;
+                        break;
+                    }
+                }
+
+                if ((ret = get_bits(s, av_log2(newpasses1) + cblk->lblock)) < 0)
+                    return ret;
+                if (ret > sizeof(cblk->data)) {
+                    avpriv_request_sample(s->avctx,
+                                        "Block with lengthinc greater than %"SIZE_SPECIFIER"",
+                                        sizeof(cblk->data));
+                    return AVERROR_PATCHWELCOME;
+                }
+                cblk->lengthinc[cblk->nb_lengthinc++] = ret;
+                cblk->npasses  += newpasses1;
+                newpasses -= newpasses1;
+            } while(newpasses);
         }
     }
     jpeg2000_flush(s);
@@ -847,18 +864,27 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s,
         nb_code_blocks = prec->nb_codeblocks_height * prec->nb_codeblocks_width;
         for (cblkno = 0; cblkno < nb_code_blocks; cblkno++) {
             Jpeg2000Cblk *cblk = prec->cblk + cblkno;
-            if (   bytestream2_get_bytes_left(&s->g) < cblk->lengthinc
-                || sizeof(cblk->data) < cblk->length + cblk->lengthinc + 2
-            ) {
-                av_log(s->avctx, AV_LOG_ERROR,
-                       "Block length %"PRIu16" or lengthinc %d is too large\n",
-                       cblk->length, cblk->lengthinc);
-                return AVERROR_INVALIDDATA;
-            }
+            for (cwsno = 0; cwsno < cblk->nb_lengthinc; cwsno ++) {
+                if (   bytestream2_get_bytes_left(&s->g) < cblk->lengthinc[cwsno]
+                    || sizeof(cblk->data) < cblk->length + cblk->lengthinc[cwsno] + 4
+                ) {
+                    av_log(s->avctx, AV_LOG_ERROR,
+                        "Block length %"PRIu16" or lengthinc %d is too large\n",
+                        cblk->length, cblk->lengthinc[cwsno]);
+                    return AVERROR_INVALIDDATA;
+                }
 
-            bytestream2_get_bufferu(&s->g, cblk->data + cblk->length, cblk->lengthinc);
-            cblk->length   += cblk->lengthinc;
-            cblk->lengthinc = 0;
+                bytestream2_get_bufferu(&s->g, cblk->data + cblk->length, cblk->lengthinc[cwsno]);
+                cblk->length   += cblk->lengthinc[cwsno];
+                cblk->lengthinc[cwsno] = 0;
+                if (cblk->nb_terminationsinc) {
+                    cblk->nb_terminationsinc--;
+                    cblk->nb_terminations++;
+                    cblk->data[cblk->length++] = 0xFF;
+                    cblk->data[cblk->length++] = 0xFF;
+                    cblk->data_start[cblk->nb_terminations] = cblk->length;
+                }
+            }
         }
     }
     return 0;
@@ -1012,7 +1038,7 @@ static void decode_sigpass(Jpeg2000T1Context *t1, int width, int height,
                         flags_mask &= ~(JPEG2000_T1_SIG_S | JPEG2000_T1_SIG_SW | JPEG2000_T1_SIG_SE);
                     if (ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + ff_jpeg2000_getsigctxno(t1->flags[y+1][x+1] & flags_mask, bandno))) {
                         int xorbit, ctxno = ff_jpeg2000_getsgnctxno(t1->flags[y+1][x+1], &xorbit);
-                        if (bpass_csty_symbol)
+                        if (t1->mqc.raw)
                              t1->data[y][x] = ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + ctxno) ? -mask : mask;
                         else
                              t1->data[y][x] = (ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + ctxno) ^ xorbit) ?
@@ -1116,9 +1142,11 @@ static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
                        int width, int height, int bandpos)
 {
     int passno = cblk->npasses, pass_t = 2, bpno = cblk->nonzerobits - 1, y;
-    int clnpass_cnt = 0;
+    int pass_cnt = 0;
     int bpass_csty_symbol           = codsty->cblk_style & JPEG2000_CBLK_BYPASS;
     int vert_causal_ctx_csty_symbol = codsty->cblk_style & JPEG2000_CBLK_VSC;
+    int term_cnt = 0;
+    int coder_type;
 
     av_assert0(width  <= JPEG2000_MAX_CBLKW);
     av_assert0(height <= JPEG2000_MAX_CBLKH);
@@ -1141,24 +1169,33 @@ static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
         switch(pass_t) {
         case 0:
             decode_sigpass(t1, width, height, bpno + 1, bandpos,
-                           bpass_csty_symbol && (clnpass_cnt >= 4),
+                           bpass_csty_symbol && (pass_cnt >= 3*3),
                            vert_causal_ctx_csty_symbol);
             break;
         case 1:
             decode_refpass(t1, width, height, bpno + 1);
             break;
         case 2:
+            av_assert2(!t1->mqc.raw);
             decode_clnpass(s, t1, width, height, bpno + 1, bandpos,
                            codsty->cblk_style & JPEG2000_CBLK_SEGSYM,
                            vert_causal_ctx_csty_symbol);
             break;
         }
+        if ((coder_type = needs_termination(codsty->cblk_style, pass_cnt))) {
+            if (term_cnt >= cblk->nb_terminations) {
+                av_log(s->avctx, AV_LOG_ERROR, "Missing needed termination \n");
+                return AVERROR_INVALIDDATA;
+            }
+            ff_mqc_initdec(&t1->mqc, cblk->data + cblk->data_start[++term_cnt], coder_type == 2, 0);
+        }
 
         pass_t++;
         if (pass_t == 3) {
             bpno--;
             pass_t = 0;
         }
+        pass_cnt ++;
     }
     return 0;
 }