Move Codec2-related code from hardware/google/av

Test: None
Bug: 112362730
Change-Id: Ie2f8ff431d65c40333f267ab9877d47089adeea4
diff --git a/media/codec2/sfplugin/SkipCutBuffer.cpp b/media/codec2/sfplugin/SkipCutBuffer.cpp
new file mode 100644
index 0000000..5762440
--- /dev/null
+++ b/media/codec2/sfplugin/SkipCutBuffer.cpp
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "SkipCutBuffer"
+#include <utils/Log.h>
+
+#include <media/stagefright/foundation/ADebug.h>
+#include <media/stagefright/MediaBuffer.h>
+#include <media/stagefright/SkipCutBuffer.h>
+
+namespace android {
+
+SkipCutBuffer::SkipCutBuffer(size_t skip, size_t cut, size_t num16BitChannels) {
+
+    mWriteHead = 0;
+    mReadHead = 0;
+    mCapacity = 0;
+    mCutBuffer = nullptr;
+
+    if (num16BitChannels == 0 || num16BitChannels > INT32_MAX / 2) {
+        ALOGW("# channels out of range: %zu, using passthrough instead", num16BitChannels);
+        return;
+    }
+    size_t frameSize = num16BitChannels * 2;
+    if (skip > INT32_MAX / frameSize || cut > INT32_MAX / frameSize
+            || cut * frameSize > INT32_MAX - 4096) {
+        ALOGW("out of range skip/cut: %zu/%zu, using passthrough instead",
+                skip, cut);
+        return;
+    }
+    skip *= frameSize;
+    cut *= frameSize;
+
+    mFrontPadding = mSkip = skip;
+    mBackPadding = cut;
+    mCapacity = cut + 4096;
+    mCutBuffer = new (std::nothrow) char[mCapacity];
+    ALOGV("skipcutbuffer %zu %zu %d", skip, cut, mCapacity);
+}
+
+SkipCutBuffer::~SkipCutBuffer() {
+    delete[] mCutBuffer;
+}
+
+void SkipCutBuffer::submit(MediaBuffer *buffer) {
+    if (mCutBuffer == nullptr) {
+        // passthrough mode
+        return;
+    }
+
+    int32_t offset = buffer->range_offset();
+    int32_t buflen = buffer->range_length();
+
+    // drop the initial data from the buffer if needed
+    if (mFrontPadding > 0) {
+        // still data left to drop
+        int32_t to_drop = (buflen < mFrontPadding) ? buflen : mFrontPadding;
+        offset += to_drop;
+        buflen -= to_drop;
+        buffer->set_range(offset, buflen);
+        mFrontPadding -= to_drop;
+    }
+
+
+    // append data to cutbuffer
+    char *src = ((char*) buffer->data()) + offset;
+    write(src, buflen);
+
+
+    // the mediabuffer is now empty. Fill it from cutbuffer, always leaving
+    // at least mBackPadding bytes in the cutbuffer
+    char *dst = (char*) buffer->data();
+    size_t copied = read(dst, buffer->size());
+    buffer->set_range(0, copied);
+}
+
+template <typename T>
+void SkipCutBuffer::submitInternal(const sp<T>& buffer) {
+    if (mCutBuffer == nullptr) {
+        // passthrough mode
+        return;
+    }
+
+    int32_t offset = buffer->offset();
+    int32_t buflen = buffer->size();
+
+    // drop the initial data from the buffer if needed
+    if (mFrontPadding > 0) {
+        // still data left to drop
+        int32_t to_drop = (buflen < mFrontPadding) ? buflen : mFrontPadding;
+        offset += to_drop;
+        buflen -= to_drop;
+        buffer->setRange(offset, buflen);
+        mFrontPadding -= to_drop;
+    }
+
+
+    // append data to cutbuffer
+    char *src = (char*) buffer->data();
+    write(src, buflen);
+
+
+    // the mediabuffer is now empty. Fill it from cutbuffer, always leaving
+    // at least mBackPadding bytes in the cutbuffer
+    char *dst = (char*) buffer->base();
+    size_t copied = read(dst, buffer->capacity());
+    buffer->setRange(0, copied);
+}
+
+void SkipCutBuffer::submit(const sp<ABuffer>& buffer) {
+    submitInternal(buffer);
+}
+
+void SkipCutBuffer::submit(const sp<MediaCodecBuffer>& buffer) {
+    submitInternal(buffer);
+}
+
+void SkipCutBuffer::clear() {
+    mWriteHead = mReadHead = 0;
+    mFrontPadding = mSkip;
+}
+
+void SkipCutBuffer::write(const char *src, size_t num) {
+    int32_t sizeused = (mWriteHead - mReadHead);
+    if (sizeused < 0) sizeused += mCapacity;
+
+    // Everything must fit. Make sure the buffer is a little larger than needed,
+    // so there is no ambiguity as to whether mWriteHead == mReadHead means buffer
+    // full or empty
+    size_t available = mCapacity - sizeused - 32;
+    if (available < num) {
+        int32_t newcapacity = mCapacity + (num - available);
+        char * newbuffer = new char[newcapacity];
+        memcpy(newbuffer, mCutBuffer, mCapacity);
+        delete [] mCutBuffer;
+        mCapacity = newcapacity;
+        mCutBuffer = newbuffer;
+        ALOGV("reallocated buffer at size %d", newcapacity);
+    }
+
+    size_t copyfirst = (mCapacity - mWriteHead);
+    if (copyfirst > num) copyfirst = num;
+    if (copyfirst) {
+        memcpy(mCutBuffer + mWriteHead, src, copyfirst);
+        num -= copyfirst;
+        src += copyfirst;
+        mWriteHead += copyfirst;
+        CHECK_LE(mWriteHead, mCapacity);
+        if (mWriteHead == mCapacity) mWriteHead = 0;
+        if (num) {
+            memcpy(mCutBuffer, src, num);
+            mWriteHead += num;
+        }
+    }
+}
+
+size_t SkipCutBuffer::read(char *dst, size_t num) {
+    int32_t available = (mWriteHead - mReadHead);
+    if (available < 0) available += mCapacity;
+
+    available -= mBackPadding;
+    if (available <=0) {
+        return 0;
+    }
+    if (available < int32_t(num)) {
+        num = available;
+    }
+
+    size_t copyfirst = (mCapacity - mReadHead);
+    if (copyfirst > num) copyfirst = num;
+    if (copyfirst) {
+        memcpy(dst, mCutBuffer + mReadHead, copyfirst);
+        num -= copyfirst;
+        dst += copyfirst;
+        mReadHead += copyfirst;
+        CHECK_LE(mReadHead, mCapacity);
+        if (mReadHead == mCapacity) mReadHead = 0;
+        if (num) {
+            memcpy(dst, mCutBuffer, num);
+            mReadHead += num;
+        }
+    }
+    return available;
+}
+
+size_t SkipCutBuffer::size() {
+    int32_t available = (mWriteHead - mReadHead);
+    if (available < 0) available += mCapacity;
+    return available;
+}
+
+}  // namespace android