Added jpeg streaming classes.

- Provides streaming operations for decompressing/compressing
  JPEG files.
- Allows pixel operations to be performed on large JPEG images
  without holding the entire bitmap in memory.

Change-Id: I597ddf282b59d2ba6d6bca4722208121e3728f94

1 files changed, 52 insertions, 0 deletions

diff --git a/jni_jpegstream/src/jerr_hook.cpp b/jni_jpegstream/src/jerr_hook.cpp
new file mode 100644
index 000000000..f8f864f78
--- /dev/null
+++ b/jni_jpegstream/src/jerr_hook.cpp
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#include "jerr_hook.h"
+#include "jni_defines.h"
+
+/**
+ * Replaces libjpeg's error_exit function, returns control to
+ * the point
+ */
+void ErrExit(j_common_ptr cinfo) {
+    ErrManager* mgr = reinterpret_cast<ErrManager*>(cinfo->err);
+    (*cinfo->err->output_message) (cinfo);
+    // Returns control to error handling in jpeg_writer
+    longjmp(mgr->setjmp_buf, 1);
+}
+
+/**
+ * Replaces libjpeg's output_message function, writes message
+ * to logcat's error log.
+ */
+void ErrOutput(j_common_ptr cinfo) {
+    ErrManager* mgr = reinterpret_cast<ErrManager*>(cinfo->err);
+    char buf[JMSG_LENGTH_MAX];
+    (*cinfo->err->format_message) (cinfo, buf);
+    buf[JMSG_LENGTH_MAX - 1] = '\0';  // Force null terminator
+    // Output error message in ndk logcat.
+    LOGE("%s\n", buf);
+}
+
+void SetupErrMgr(j_common_ptr cinfo, ErrManager* errMgr) {
+    jpeg_std_error(&(errMgr->mgr));
+    errMgr->mgr.error_exit = ErrExit;
+    errMgr->mgr.output_message = ErrOutput;
+    cinfo->err = reinterpret_cast<struct jpeg_error_mgr*>(errMgr);
+}
+
+