Merge branch 'fz' of github.com:m-holger/qpdf into fz

2 files changed, 58 insertions, 45 deletions

diff --git a/libqpdf/Pl_TIFFPredictor.cc b/libqpdf/Pl_TIFFPredictor.cc
index 51594d11..ec477049 100644
--- a/libqpdf/Pl_TIFFPredictor.cc
+++ b/libqpdf/Pl_TIFFPredictor.cc
@@ -3,12 +3,9 @@
 #include <qpdf/BitStream.hh>
 #include <qpdf/BitWriter.hh>
 #include <qpdf/QTC.hh>
-#include <qpdf/QUtil.hh>
 
 #include <climits>
-#include <cstring>
 #include <stdexcept>
-#include <vector>
 
 Pl_TIFFPredictor::Pl_TIFFPredictor(
     char const* identifier,
@@ -22,7 +19,7 @@ Pl_TIFFPredictor::Pl_TIFFPredictor(
     columns(columns),
     samples_per_pixel(samples_per_pixel),
     bits_per_sample(bits_per_sample),
-    pos(0)
+    p_next(getNext())
 {
     if (samples_per_pixel < 1) {
         throw std::runtime_error("TIFFPredictor created with invalid samples_per_pixel");
@@ -35,71 +32,83 @@ Pl_TIFFPredictor::Pl_TIFFPredictor(
         throw std::runtime_error("TIFFPredictor created with invalid columns value");
     }
     this->bytes_per_row = bpr & UINT_MAX;
-    this->cur_row = QUtil::make_shared_array<unsigned char>(this->bytes_per_row);
-    memset(this->cur_row.get(), 0, this->bytes_per_row);
 }
 
 void
 Pl_TIFFPredictor::write(unsigned char const* data, size_t len)
 {
-    size_t left = this->bytes_per_row - this->pos;
-    size_t offset = 0;
-    while (len >= left) {
+    auto end = data + len;
+    auto row_end = data + (bytes_per_row - cur_row.size());
+    while (row_end <= end) {
         // finish off current row
-        memcpy(this->cur_row.get() + this->pos, data + offset, left);
-        offset += left;
-        len -= left;
+        cur_row.insert(cur_row.end(), data, row_end);
+        data = row_end;
+        row_end += bytes_per_row;
 
         processRow();
 
         // Prepare for next row
-        memset(this->cur_row.get(), 0, this->bytes_per_row);
-        left = this->bytes_per_row;
-        this->pos = 0;
+        cur_row.clear();
     }
-    if (len) {
-        memcpy(this->cur_row.get() + this->pos, data + offset, len);
-    }
-    this->pos += len;
+
+    cur_row.insert(cur_row.end(), data, end);
 }
 
 void
 Pl_TIFFPredictor::processRow()
 {
     QTC::TC("libtests", "Pl_TIFFPredictor processRow", (action == a_decode ? 0 : 1));
-    BitWriter bw(this->getNext());
-    BitStream in(this->cur_row.get(), this->bytes_per_row);
-    std::vector<long long> prev;
-    for (unsigned int i = 0; i < this->samples_per_pixel; ++i) {
-        long long sample = in.getBitsSigned(this->bits_per_sample);
-        bw.writeBitsSigned(sample, this->bits_per_sample);
-        prev.push_back(sample);
-    }
-    for (unsigned int col = 1; col < this->columns; ++col) {
-        for (unsigned int i = 0; i < this->samples_per_pixel; ++i) {
-            long long sample = in.getBitsSigned(this->bits_per_sample);
-            long long new_sample = sample;
-            if (action == a_encode) {
-                new_sample -= prev[i];
-                prev[i] = sample;
-            } else {
-                new_sample += prev[i];
-                prev[i] = new_sample;
+    previous.assign(samples_per_pixel, 0);
+    if (bits_per_sample != 8) {
+        BitWriter bw(p_next);
+        BitStream in(cur_row.data(), cur_row.size());
+        for (unsigned int col = 0; col < this->columns; ++col) {
+            for (auto& prev: previous) {
+                long long sample = in.getBitsSigned(this->bits_per_sample);
+                long long new_sample = sample;
+                if (action == a_encode) {
+                    new_sample -= prev;
+                    prev = sample;
+                } else {
+                    new_sample += prev;
+                    prev = new_sample;
+                }
+                bw.writeBitsSigned(new_sample, this->bits_per_sample);
+            }
+        }
+        bw.flush();
+    } else {
+        out.clear();
+        auto next = cur_row.begin();
+        auto cr_end = cur_row.end();
+        auto pr_end = previous.end();
+
+        while (next != cr_end) {
+            for (auto prev = previous.begin(); prev != pr_end && next != cr_end; ++prev, ++next) {
+                long long sample = *next;
+                long long new_sample = sample;
+                if (action == a_encode) {
+                    new_sample -= *prev;
+                    *prev = sample;
+                } else {
+                    new_sample += *prev;
+                    *prev = new_sample;
+                }
+                out.push_back(static_cast<unsigned char>(255U & new_sample));
             }
-            bw.writeBitsSigned(new_sample, this->bits_per_sample);
         }
+        p_next->write(out.data(), out.size());
     }
-    bw.flush();
 }
 
 void
 Pl_TIFFPredictor::finish()
 {
-    if (this->pos) {
+    if (!cur_row.empty()) {
         // write partial row
+        cur_row.insert(cur_row.end(), bytes_per_row - cur_row.size(), 0);
         processRow();
     }
-    this->pos = 0;
-    memset(this->cur_row.get(), 0, this->bytes_per_row);
-    getNext()->finish();
+    cur_row.clear();
+    p_next->finish();
 }
diff --git a/libqpdf/qpdf/Pl_TIFFPredictor.hh b/libqpdf/qpdf/Pl_TIFFPredictor.hh
index 21757593..276ed54d 100644
--- a/libqpdf/qpdf/Pl_TIFFPredictor.hh
+++ b/libqpdf/qpdf/Pl_TIFFPredictor.hh
@@ -6,6 +6,8 @@
 
 #include <qpdf/Pipeline.hh>
 
+#include<vector>
+
 class Pl_TIFFPredictor: public Pipeline
 {
   public:
@@ -31,8 +33,10 @@ class Pl_TIFFPredictor: public Pipeline
     unsigned int bytes_per_row;
     unsigned int samples_per_pixel;
     unsigned int bits_per_sample;
-    std::shared_ptr<unsigned char> cur_row;
-    size_t pos;
+    std::vector<unsigned char> cur_row;
+    std::vector<long long> previous;
+    std::vector<unsigned char> out;
+    Pipeline* p_next;
 };
 
 #endif // PL_TIFFPREDICTOR_HH