Add support for partial bitstream decoding (#1407) (fixes #715)

Add a -allow-partial option to opj_decompress utility and a opj_decoder_set_strict_mode() option to the API

Co-authored-by: Chris Hafey <chafey@gmail.com>

1 files changed, 51 insertions, 14 deletions

diff --git a/src/lib/openjp2/t2.c b/src/lib/openjp2/t2.c
index 06603892..ebda0052 100644
--- a/src/lib/openjp2/t2.c
+++ b/src/lib/openjp2/t2.c
@@ -502,7 +502,6 @@ OPJ_BOOL opj_t2_decode_packets(opj_tcd_t* tcd,
                                     l_current_pi->precno, l_current_pi->layno, skip_packet ? "skipped" : "kept");
                 */
             }
-
             if (!skip_packet) {
                 l_nb_bytes_read = 0;
 
@@ -1378,6 +1377,7 @@ static OPJ_BOOL opj_t2_read_packet_data(opj_t2_t* p_t2,
     opj_tcd_cblk_dec_t* l_cblk = 00;
     opj_tcd_resolution_t* l_res =
         &p_tile->comps[p_pi->compno].resolutions[p_pi->resno];
+    OPJ_BOOL partial_buffer = OPJ_FALSE;
 
     OPJ_ARG_NOT_USED(p_t2);
     OPJ_ARG_NOT_USED(pack_info);
@@ -1397,6 +1397,12 @@ static OPJ_BOOL opj_t2_read_packet_data(opj_t2_t* p_t2,
         for (cblkno = 0; cblkno < l_nb_code_blocks; ++cblkno) {
             opj_tcd_seg_t *l_seg = 00;
 
+            // if we have a partial data stream, set numchunks to zero
+            // since we have no data to actually decode.
+            if (partial_buffer) {
+                l_cblk->numchunks = 0;
+            }
+
             if (!l_cblk->numnewpasses) {
                 /* nothing to do */
                 ++l_cblk;
@@ -1419,12 +1425,32 @@ static OPJ_BOOL opj_t2_read_packet_data(opj_t2_t* p_t2,
                 /* Check possible overflow (on l_current_data only, assumes input args already checked) then size */
                 if ((((OPJ_SIZE_T)l_current_data + (OPJ_SIZE_T)l_seg->newlen) <
                         (OPJ_SIZE_T)l_current_data) ||
-                        (l_current_data + l_seg->newlen > p_src_data + p_max_length)) {
-                    opj_event_msg(p_manager, EVT_ERROR,
-                                  "read: segment too long (%d) with max (%d) for codeblock %d (p=%d, b=%d, r=%d, c=%d)\n",
-                                  l_seg->newlen, p_max_length, cblkno, p_pi->precno, bandno, p_pi->resno,
-                                  p_pi->compno);
-                    return OPJ_FALSE;
+                        (l_current_data + l_seg->newlen > p_src_data + p_max_length) ||
+                        (partial_buffer)) {
+                    if (p_t2->cp->strict) {
+                        opj_event_msg(p_manager, EVT_ERROR,
+                                      "read: segment too long (%d) with max (%d) for codeblock %d (p=%d, b=%d, r=%d, c=%d)\n",
+                                      l_seg->newlen, p_max_length, cblkno, p_pi->precno, bandno, p_pi->resno,
+                                      p_pi->compno);
+                        return OPJ_FALSE;
+                    } else {
+                        opj_event_msg(p_manager, EVT_WARNING,
+                                      "read: segment too long (%d) with max (%d) for codeblock %d (p=%d, b=%d, r=%d, c=%d)\n",
+                                      l_seg->newlen, p_max_length, cblkno, p_pi->precno, bandno, p_pi->resno,
+                                      p_pi->compno);
+                        // skip this codeblock since it is a partial read
+                        partial_buffer = OPJ_TRUE;
+                        l_cblk->numchunks = 0;
+
+                        l_seg->numpasses += l_seg->numnewpasses;
+                        l_cblk->numnewpasses -= l_seg->numnewpasses;
+                        if (l_cblk->numnewpasses > 0) {
+                            ++l_seg;
+                            ++l_cblk->numsegs;
+                            break;
+                        }
+                        continue;
+                    }
                 }
 
 #ifdef USE_JPWL
@@ -1486,8 +1512,12 @@ static OPJ_BOOL opj_t2_read_packet_data(opj_t2_t* p_t2,
         ++l_band;
     }
 
-    *(p_data_read) = (OPJ_UINT32)(l_current_data - p_src_data);
-
+    // return the number of bytes read
+    if (partial_buffer) {
+        *(p_data_read) = p_max_length;
+    } else {
+        *(p_data_read) = (OPJ_UINT32)(l_current_data - p_src_data);
+    }
 
     return OPJ_TRUE;
 }
@@ -1549,11 +1579,18 @@ static OPJ_BOOL opj_t2_skip_packet_data(opj_t2_t* p_t2,
                 /* Check possible overflow then size */
                 if (((*p_data_read + l_seg->newlen) < (*p_data_read)) ||
                         ((*p_data_read + l_seg->newlen) > p_max_length)) {
-                    opj_event_msg(p_manager, EVT_ERROR,
-                                  "skip: segment too long (%d) with max (%d) for codeblock %d (p=%d, b=%d, r=%d, c=%d)\n",
-                                  l_seg->newlen, p_max_length, cblkno, p_pi->precno, bandno, p_pi->resno,
-                                  p_pi->compno);
-                    return OPJ_FALSE;
+                    if (p_t2->cp->strict) {
+                        opj_event_msg(p_manager, EVT_ERROR,
+                                      "skip: segment too long (%d) with max (%d) for codeblock %d (p=%d, b=%d, r=%d, c=%d)\n",
+                                      l_seg->newlen, p_max_length, cblkno, p_pi->precno, bandno, p_pi->resno,
+                                      p_pi->compno);
+                        return OPJ_FALSE;
+                    } else {
+                        opj_event_msg(p_manager, EVT_WARNING,
+                                      "skip: segment too long (%d) with max (%d) for codeblock %d (p=%d, b=%d, r=%d, c=%d)\n",
+                                      l_seg->newlen, p_max_length, cblkno, p_pi->precno, bandno, p_pi->resno,
+                                      p_pi->compno);
+                    }
                 }
 
 #ifdef USE_JPWL