| /* |
| * 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(int32_t skip, int32_t cut) { |
| mFrontPadding = mSkip = skip; |
| mBackPadding = cut; |
| mWriteHead = 0; |
| mReadHead = 0; |
| mCapacity = cut + 4096; |
| mCutBuffer = new char[mCapacity]; |
| ALOGV("skipcutbuffer %d %d %d", skip, cut, mCapacity); |
| } |
| |
| SkipCutBuffer::~SkipCutBuffer() { |
| delete[] mCutBuffer; |
| } |
| |
| void SkipCutBuffer::submit(MediaBuffer *buffer) { |
| 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); |
| } |
| |
| void SkipCutBuffer::submit(const sp<ABuffer>& buffer) { |
| 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::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 |