Question

我创建了一个程序，该程序使用Bento4解密曲目，但是我坚持将文件写入磁盘。写加密轨道时，程序崩溃，因为加密和解密样本的大小不同。

此问题出在以下注释之后，位于FragmentedSampleReader :: ReadSample（）中的main.cpp中： //将初始化和数据写入解密的文件。

AP4_Result FragmentedSampleReader::ReadSample()
{
    AP4_Position pos_init, pos_after_sample;
    m_FragmentStream->Tell(pos_init);

    AP4_Result result;
    if (!m_codecHandler || !m_codecHandler->ReadNextSample(m_sample, m_sampleData))
    {
        bool useDecryptingDecoder = m_protectedDesc && (m_decrypterCaps.flags & SSD::SSD_DECRYPTER::SSD_CAPS::SSD_SECURE_PATH) != 0;
        bool decrypterPresent(m_decrypter != nullptr);

        if (AP4_FAILED(result = ReadNextSample(m_track->GetId(), m_sample, (m_decrypter || useDecryptingDecoder) ? m_encrypted : m_sampleData)))
        {
            if (result == AP4_ERROR_EOS)
            {
                if (dynamic_cast<AP4_DASHStream*>(m_FragmentStream)->waitingForSegment())
                    m_sampleData.SetDataSize(0);
                else
                    m_eos = true;
            }
            return result;
        }

        //Protection could have changed in ProcessMoof
        if (!decrypterPresent && m_decrypter != nullptr && !useDecryptingDecoder)
            m_encrypted.SetData(m_sampleData.GetData(), m_sampleData.GetDataSize());
        else if (decrypterPresent && m_decrypter == nullptr && !useDecryptingDecoder)
            m_sampleData.SetData(m_encrypted.GetData(), m_encrypted.GetDataSize());

        // Make sure that the decrypter is NOT allocating memory!
        // If decrypter and addon are compiled with different DEBUG / RELEASE
        // options freeing HEAP memory will fail.
        if (m_decrypter)
        {
            m_sampleData.Reserve(m_encrypted.GetDataSize() + 4096);
            result = m_decrypter->DecryptSampleData(m_poolId, m_encrypted, m_sampleData, NULL);
        }
        else if (useDecryptingDecoder)
        {
            m_sampleData.Reserve(m_encrypted.GetDataSize() + 1024);
            result = m_singleSampleDecryptor->DecryptSampleData(m_poolId, m_encrypted, m_sampleData, nullptr, 0, nullptr, nullptr);
        }
    }


    // Write initialisation & data into decrypted file
    std::vector<char> buffer;
    int pos_decrypted = file_decrypted_data.tellp();
    if(pos_decrypted < pos_init)
    {
        buffer.reserve(pos_init - pos_decrypted);
        file_fragment.seekg(pos_decrypted, std::ios::beg);
        file_fragment.read(buffer.data(), pos_init - pos_decrypted);
        file_decrypted_data.write(buffer.data(), pos_init - pos_decrypted);
    }

    m_FragmentStream->Tell(pos_after_sample);
    int metadata_length = pos_after_sample - m_sampleData.GetDataSize() - pos_init;

    buffer.reserve(metadata_length);
    file_fragment.seekg(pos_init, std::ios::beg);
    file_fragment.read(buffer.data(), metadata_length);

    file_decrypted_data.write(buffer.data(), metadata_length);
    file_decrypted_data.write((const char*)m_sampleData.GetData(), m_sampleData.GetDataSize());

    return result;
};

我有一个官方的git repo：https://github.com/x-hgg-x/video_decrypter

它给了我下面的错误。

std::bad_alloc error

C ++程序中的解密错误

0 个答案: