73 lines
1.8 KiB
C++
73 lines
1.8 KiB
C++
#include "H264Parser.h"
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#include <cstring>
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using namespace xop;
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Nal H264Parser::findNal(const uint8_t *data, uint32_t size)
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{
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Nal nal(nullptr, nullptr);
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if(size < 5)
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{
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return nal;
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}
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nal.second = const_cast<uint8_t*>(data) + (size-1);
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uint32_t startCode = 0;
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uint32_t pos = 0;
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uint8_t prefix[3] = {0};
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memcpy(prefix, data, 3);
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size -= 3;
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data += 2;
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while(size--)
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{
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if ((prefix[pos % 3] == 0) && (prefix[(pos + 1) % 3] == 0) && (prefix[(pos + 2) % 3] == 1))
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{
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if(nal.first == nullptr) // 00 00 01
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{
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nal.first = const_cast<uint8_t*>(data) + 1;
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startCode = 3;
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}
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else if(startCode == 3)
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{
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nal.second = const_cast<uint8_t*>(data) - 3;
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break;
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}
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}
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else if ((prefix[pos % 3] == 0) && (prefix[(pos + 1) % 3] == 0) && (prefix[(pos + 2) % 3] == 0))
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{
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if (*(data+1) == 0x01) // 00 00 00 01
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{
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if(nal.first == nullptr)
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{
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if(size >= 1)
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{
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nal.first = const_cast<uint8_t*>(data) + 2;
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}
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else
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{
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break;
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}
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startCode = 4;
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}
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else if(startCode == 4)
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{
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nal.second = const_cast<uint8_t*>(data) - 3;
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break;
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}
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}
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}
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prefix[(pos++) % 3] = *(++data);
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}
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if(nal.first == nullptr)
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nal.second = nullptr;
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return nal;
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}
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