зеркало из https://github.com/mozilla/gecko-dev.git
80 строки
2.2 KiB
C++
80 строки
2.2 KiB
C++
/*
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* Copyright 2015, Mozilla Foundation and contributors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "AnnexB.h"
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#include "BigEndian.h"
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#include <cstring>
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using mozilla::BigEndian;
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static const uint8_t kAnnexBDelimiter[] = { 0, 0, 0, 1 };
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/* static */ void
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AnnexB::ConvertFrameInPlace(std::vector<uint8_t>& aBuffer)
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{
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for (size_t i = 0; i < aBuffer.size() - 4 - sizeof(kAnnexBDelimiter) + 1; ) {
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uint32_t nalLen = BigEndian::readUint32(&aBuffer[i]);
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memcpy(&aBuffer[i], kAnnexBDelimiter, sizeof(kAnnexBDelimiter));
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i += nalLen + 4;
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}
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}
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static void
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ConvertParamSetToAnnexB(std::vector<uint8_t>::const_iterator& aIter,
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size_t aCount,
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std::vector<uint8_t>& aOutAnnexB)
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{
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for (size_t i = 0; i < aCount; i++) {
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aOutAnnexB.insert(aOutAnnexB.end(), kAnnexBDelimiter,
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kAnnexBDelimiter + sizeof(kAnnexBDelimiter));
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uint16_t len = BigEndian::readUint16(&*aIter); aIter += 2;
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aOutAnnexB.insert(aOutAnnexB.end(), aIter, aIter + len); aIter += len;
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}
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}
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/* static */ void
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AnnexB::ConvertConfig(const std::vector<uint8_t>& aBuffer,
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std::vector<uint8_t>& aOutAnnexB)
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{
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// Skip past irrelevant headers
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auto it = aBuffer.begin() + 5;
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if (it >= aBuffer.end()) {
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return;
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}
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size_t count = *(it++) & 31;
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// Check that we have enough bytes for the Annex B conversion
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// and the next size field. Bail if not.
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if (it + count * 2 >= aBuffer.end()) {
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return;
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}
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ConvertParamSetToAnnexB(it, count, aOutAnnexB);
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// Check that we have enough bytes for the Annex B conversion.
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count = *(it++);
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if (it + count * 2 > aBuffer.end()) {
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aOutAnnexB.clear();
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return;
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}
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ConvertParamSetToAnnexB(it, count, aOutAnnexB);
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}
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