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/*
* Copyright 2015, Mozilla Foundation and contributors
*
* 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 "AnnexB.h"
#include "BigEndian.h"
#include <cstring>
using mozilla::BigEndian;
static const uint8_t kAnnexBDelimiter[] = { 0, 0, 0, 1 };
/* static */ void
AnnexB::ConvertFrameInPlace(std::vector<uint8_t>& aBuffer)
{
for (size_t i = 0; i < aBuffer.size() - 4 - sizeof(kAnnexBDelimiter) + 1; ) {
uint32_t nalLen = BigEndian::readUint32(&aBuffer[i]);
memcpy(&aBuffer[i], kAnnexBDelimiter, sizeof(kAnnexBDelimiter));
i += nalLen + 4;
}
}
static void
ConvertParamSetToAnnexB(std::vector<uint8_t>::const_iterator& aIter,
size_t aCount,
std::vector<uint8_t>& aOutAnnexB)
{
for (size_t i = 0; i < aCount; i++) {
aOutAnnexB.insert(aOutAnnexB.end(), kAnnexBDelimiter,
kAnnexBDelimiter + sizeof(kAnnexBDelimiter));
uint16_t len = BigEndian::readUint16(&*aIter); aIter += 2;
aOutAnnexB.insert(aOutAnnexB.end(), aIter, aIter + len); aIter += len;
}
}
/* static */ void
AnnexB::ConvertConfig(const std::vector<uint8_t>& aBuffer,
std::vector<uint8_t>& aOutAnnexB)
{
// Skip past irrelevant headers
auto it = aBuffer.begin() + 5;
if (it >= aBuffer.end()) {
return;
}
size_t count = *(it++) & 31;
// Check that we have enough bytes for the Annex B conversion
// and the next size field. Bail if not.
if (it + count * 2 >= aBuffer.end()) {
return;
}
ConvertParamSetToAnnexB(it, count, aOutAnnexB);
// Check that we have enough bytes for the Annex B conversion.
count = *(it++);
if (it + count * 2 > aBuffer.end()) {
aOutAnnexB.clear();
return;
}
ConvertParamSetToAnnexB(it, count, aOutAnnexB);
}
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