1 files changed, 196 insertions, 0 deletions
diff --git a/media/libstagefright/ESDS.cpp b/media/libstagefright/ESDS.cpp
new file mode 100644
index 0000000..53b92a0
--- /dev/null
+++ b/media/libstagefright/ESDS.cpp
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2009 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 <media/stagefright/ESDS.h>
+
+#include <string.h>
+
+namespace android {
+
+ESDS::ESDS(const void *data, size_t size)
+    : mData(new uint8_t[size]),
+      mSize(size),
+      mInitCheck(NO_INIT),
+      mDecoderSpecificOffset(0),
+      mDecoderSpecificLength(0) {
+    memcpy(mData, data, size);
+
+    mInitCheck = parse();
+}
+
+ESDS::~ESDS() {
+    delete[] mData;
+    mData = NULL;
+}
+
+status_t ESDS::InitCheck() const {
+    return mInitCheck;
+}
+
+status_t ESDS::getCodecSpecificInfo(const void **data, size_t *size) const {
+    if (mInitCheck != OK) {
+        return mInitCheck;
+    }
+
+    *data = &mData[mDecoderSpecificOffset];
+    *size = mDecoderSpecificLength;
+
+    return OK;
+}
+
+status_t ESDS::skipDescriptorHeader(
+        size_t offset, size_t size,
+        uint8_t *tag, size_t *data_offset, size_t *data_size) const {
+    if (size == 0) {
+        return ERROR_MALFORMED;
+    }
+
+    *tag = mData[offset++];
+    --size;
+
+    *data_size = 0;
+    bool more;
+    do {
+        if (size == 0) {
+            return ERROR_MALFORMED;
+        }
+
+        uint8_t x = mData[offset++];
+        --size;
+
+        *data_size = (*data_size << 7) | (x & 0x7f);
+        more = (x & 0x80) != 0;
+    }
+    while (more);
+
+    if (*data_size > size) {
+        return ERROR_MALFORMED;
+    }
+
+    *data_offset = offset;
+
+    return OK;
+}
+
+status_t ESDS::parse() {
+    uint8_t tag;
+    size_t data_offset;
+    size_t data_size;
+    status_t err =
+        skipDescriptorHeader(0, mSize, &tag, &data_offset, &data_size);
+
+    if (err != OK) {
+        return err;
+    }
+
+    if (tag != kTag_ESDescriptor) {
+        return ERROR_MALFORMED;
+    }
+
+    return parseESDescriptor(data_offset, data_size);
+}
+
+status_t ESDS::parseESDescriptor(size_t offset, size_t size) {
+    if (size < 3) {
+        return ERROR_MALFORMED;
+    }
+
+    offset += 2;  // skip ES_ID
+    size -= 2;
+
+    unsigned streamDependenceFlag = mData[offset] & 0x80;
+    unsigned URL_Flag = mData[offset] & 0x40;
+    unsigned OCRstreamFlag = mData[offset] & 0x20;
+
+    ++offset;
+    --size;
+
+    if (streamDependenceFlag) {
+        offset += 2;
+        size -= 2;
+    }
+
+    if (URL_Flag) {
+        if (offset >= size) {
+            return ERROR_MALFORMED;
+        }
+        unsigned URLlength = mData[offset];
+        offset += URLlength + 1;
+        size -= URLlength + 1;
+    }
+
+    if (OCRstreamFlag) {
+        offset += 2;
+        size -= 2;
+    }
+    
+    if (offset >= size) {
+        return ERROR_MALFORMED;
+    }
+
+    uint8_t tag;
+    size_t sub_offset, sub_size;
+    status_t err = skipDescriptorHeader(
+            offset, size, &tag, &sub_offset, &sub_size);
+
+    if (err != OK) {
+        return err;
+    }
+
+    if (tag != kTag_DecoderConfigDescriptor) {
+        return ERROR_MALFORMED;
+    }
+
+    err = parseDecoderConfigDescriptor(sub_offset, sub_size);
+
+    return err;
+}
+
+status_t ESDS::parseDecoderConfigDescriptor(size_t offset, size_t size) {
+    if (size < 13) {
+        return ERROR_MALFORMED;
+    }
+
+    offset += 13;
+    size -= 13;
+
+    if (size == 0) {
+        mDecoderSpecificOffset = 0;
+        mDecoderSpecificLength = 0;
+        return OK;
+    }
+
+    uint8_t tag;
+    size_t sub_offset, sub_size;
+    status_t err = skipDescriptorHeader(
+            offset, size, &tag, &sub_offset, &sub_size);
+
+    if (err != OK) {
+        return err;
+    }
+
+    if (tag != kTag_DecoderSpecificInfo) {
+        return ERROR_MALFORMED;
+    }
+
+    mDecoderSpecificOffset = sub_offset;
+    mDecoderSpecificLength = sub_size;
+
+    return OK;
+}
+
+}  // namespace android
+