C++ AP4_Sample::GetSize方法代码示例

/*----------------------------------------------------------------------
|   AP4_MarlinIpmpTrackDecrypter:GetProcessedSampleSize
+---------------------------------------------------------------------*/
AP4_Size 
AP4_MarlinIpmpTrackDecrypter::GetProcessedSampleSize(AP4_Sample& sample)
{
    // with CBC, we need to decrypt the last block to know what the padding was
    AP4_Size       encrypted_size = sample.GetSize()-AP4_AES_BLOCK_SIZE;
    AP4_DataBuffer encrypted;
    AP4_DataBuffer decrypted;
    AP4_Size       decrypted_size = AP4_CIPHER_BLOCK_SIZE;
    if (sample.GetSize() < 2*AP4_CIPHER_BLOCK_SIZE) {
        return 0;
    }
    AP4_Size offset = sample.GetSize()-2*AP4_CIPHER_BLOCK_SIZE;
    if (AP4_FAILED(sample.ReadData(encrypted, 2*AP4_CIPHER_BLOCK_SIZE, offset))) {
        return 0;
    }
    decrypted.Reserve(decrypted_size);
    m_Cipher->SetIV(encrypted.GetData());
    if (AP4_FAILED(m_Cipher->ProcessBuffer(encrypted.GetData()+AP4_CIPHER_BLOCK_SIZE, 
                                           AP4_CIPHER_BLOCK_SIZE,
                                           decrypted.UseData(), 
                                           &decrypted_size, 
                                           true))) {
        return 0;
    }
    unsigned int padding_size = AP4_CIPHER_BLOCK_SIZE-decrypted_size;
    return encrypted_size-padding_size;
}

/*----------------------------------------------------------------------
|   AP4_OmaDcfCbcSampleEncrypter::GetEncryptedSampleSize
+---------------------------------------------------------------------*/
AP4_Size
AP4_OmaDcfCbcSampleEncrypter::GetEncryptedSampleSize(AP4_Sample& sample)
{
    AP4_Size sample_size = sample.GetSize();
    AP4_Size padding_size = AP4_CIPHER_BLOCK_SIZE-(sample_size%AP4_CIPHER_BLOCK_SIZE);
    return sample_size+padding_size+AP4_CIPHER_BLOCK_SIZE+1;
}

/*----------------------------------------------------------------------
|   AP4_LinearReader::PopSample
+---------------------------------------------------------------------*/
bool
AP4_LinearReader::PopSample(Tracker*        tracker,
                            AP4_Sample&     sample,
                            AP4_DataBuffer& sample_data)
{
    SampleBuffer* head = NULL;
    if (AP4_SUCCEEDED(tracker->m_Samples.PopHead(head))) {
        assert(head->m_Sample);
        sample = *head->m_Sample;
        sample_data.SetData(head->m_Data.GetData(), head->m_Data.GetDataSize());
        assert(m_BufferFullness >= sample.GetSize());
        m_BufferFullness -= sample.GetSize();
        delete head;
        return true;
    }

    return false;
}

/*----------------------------------------------------------------------
|       AP4_IsmaTrackDecrypter::GetProcessedSampleSize
+---------------------------------------------------------------------*/
AP4_Size   
AP4_IsmaTrackDecrypter::GetProcessedSampleSize(AP4_Sample& sample)
{
    AP4_Size isma_header_size = 
        m_CipherParams->GetKeyIndicatorLength() +
        m_CipherParams->GetIvLength();
    if (m_CipherParams->GetSelectiveEncryption()) {
        isma_header_size++;
    }
    return sample.GetSize()-isma_header_size;
}

/*----------------------------------------------------------------------
|   AP4_Track::Clone
+---------------------------------------------------------------------*/
AP4_Track* 
AP4_Track::Clone(AP4_Result* result)
{
    AP4_SyntheticSampleTable* sample_table = new AP4_SyntheticSampleTable();
    
    // default return value
    if (result) *result = AP4_SUCCESS;
    
    // add clones of the sample descriptions to the new sample table
    for (unsigned int i=0; ;i++) {
        AP4_SampleDescription* sample_description = GetSampleDescription(i);
        if (sample_description == NULL) break;
        sample_table->AddSampleDescription(sample_description->Clone());
    }

    AP4_Sample  sample;
    AP4_Ordinal index = 0;
    while (AP4_SUCCEEDED(GetSample(index, sample))) {
        AP4_ByteStream* data_stream;
        data_stream = sample.GetDataStream();
        sample_table->AddSample(*data_stream,
                                sample.GetOffset(),
                                sample.GetSize(),
                                sample.GetDuration(),
                                sample.GetDescriptionIndex(),
                                sample.GetDts(),
                                sample.GetCtsDelta(),
                                sample.IsSync());
        AP4_RELEASE(data_stream); // release our ref, the table has kept its own ref.
        index++;
    }    
    
    // create the cloned track
    AP4_Track* clone = new AP4_Track(GetType(),
                                     sample_table,
                                     GetId(),
                                     GetMovieTimeScale(),
                                     GetDuration(),
                                     GetMediaTimeScale(),
                                     GetMediaDuration(),
                                     GetTrackLanguage(),
                                     GetWidth(),
                                     GetHeight());
                                     
    return clone;
}

/*----------------------------------------------------------------------
|   ShowSample
+---------------------------------------------------------------------*/
static void
ShowSample(AP4_Sample& sample, unsigned int index, AP4_SampleDecrypter* sample_decrypter)
{
    printf("[%06d] size=%6d duration=%6d", 
           index, 
           (int)sample.GetSize(), 
           (int)sample.GetDuration());
    printf(" offset=%10lld dts=%10lld cts=%10lld ", 
           sample.GetOffset(),
           sample.GetDts(), 
           sample.GetCts());
    if (sample.IsSync()) {
        printf(" [S] ");
    } else {
        printf("     ");
    }

    AP4_DataBuffer sample_data;
    sample.ReadData(sample_data);
    AP4_DataBuffer* data = &sample_data;
    
    AP4_DataBuffer decrypted_sample_data;
    if (sample_decrypter) {
        sample_decrypter->DecryptSampleData(sample_data, decrypted_sample_data);
        data = & decrypted_sample_data;
    }
    
    unsigned int show = data->GetDataSize();
    if (show > 12) show = 12; // max first 12 chars
    
    for (unsigned int i=0; i<show; i++) {
        printf("%02x", data->GetData()[i]);
    }
    if (show == data->GetDataSize()) {
        printf("\n");
    } else {
        printf("...\n");
    }
}

/*----------------------------------------------------------------------
|   AP4_Processor::TrackHandler::GetProcessedSampleSize
+---------------------------------------------------------------------*/
AP4_Size   
AP4_Processor::TrackHandler::GetProcessedSampleSize(AP4_Sample& sample)
{
    // default implementation: do no change the sample size
    return sample.GetSize();
}

/*----------------------------------------------------------------------
|   AP4_SampleTable::GenerateStblAtom
+---------------------------------------------------------------------*/
AP4_Result 
AP4_SampleTable::GenerateStblAtom(AP4_ContainerAtom*& stbl)
{
    // create the stbl container
    stbl = new AP4_ContainerAtom(AP4_ATOM_TYPE_STBL);

    // create the stsd atom
    AP4_StsdAtom* stsd = new AP4_StsdAtom(this);

    // create the stsz atom
    AP4_StszAtom* stsz = new AP4_StszAtom();

    // create the stsc atom
    AP4_StscAtom* stsc = new AP4_StscAtom();

    // create the stts atom
    AP4_SttsAtom* stts = new AP4_SttsAtom();

    // create the stss atom
    AP4_StssAtom* stss = new AP4_StssAtom();
    
    // declare the ctts atom (may be created later)
    AP4_CttsAtom* ctts = NULL;
    
    // start chunk table
    AP4_Ordinal             current_chunk_index              = 0;
    AP4_Size                current_chunk_size               = 0;
    AP4_Position            current_chunk_offset             = 0;
    AP4_Cardinal            current_samples_in_chunk         = 0;
    AP4_Ordinal             current_sample_description_index = 0;
    AP4_UI32                current_duration                 = 0;
    AP4_Cardinal            current_duration_run             = 0;
    AP4_UI32                current_cts_delta                = 0;
    AP4_Cardinal            current_cts_delta_run            = 0;
    AP4_Array<AP4_Position> chunk_offsets;

    // process all the samples
    bool         all_samples_are_sync = false;
    AP4_Cardinal sample_count = GetSampleCount();
    for (AP4_Ordinal i=0; i<sample_count; i++) {
        AP4_Sample sample;
        GetSample(i, sample);
        
        // update DTS table
        AP4_UI32 new_duration = sample.GetDuration();
        if (new_duration != current_duration && current_duration_run != 0) {
            // emit a new stts entry
            stts->AddEntry(current_duration_run, current_duration);
            
            // reset the run count
            current_duration_run = 0;
        } 
        ++current_duration_run;
        current_duration = new_duration;
        
        // update CTS table
        AP4_UI32 new_cts_delta = sample.GetCtsDelta();
        if (new_cts_delta != current_cts_delta && current_cts_delta_run != 0) {
            // create a ctts atom if we don't have one
            if (ctts == NULL) ctts = new AP4_CttsAtom();
            
            //emit a new ctts entry
            ctts->AddEntry(current_cts_delta_run, current_cts_delta);
            
            // reset the run count
            current_cts_delta_run = 0;
        }
        ++current_cts_delta_run;
        current_cts_delta = new_cts_delta;
        
        // add an entry into the stsz atom
        stsz->AddEntry(sample.GetSize());
        
        // update the sync sample table
        if (sample.IsSync()) {
            stss->AddEntry(i+1);
            if (i==0) all_samples_are_sync = true;
        } else {
            all_samples_are_sync = false;
        }
        
        // see in which chunk this sample is
        AP4_Ordinal chunk_index = 0;
        AP4_Ordinal position_in_chunk = 0;
        AP4_Result  result = GetSampleChunkPosition(i, chunk_index, position_in_chunk);
        if (AP4_SUCCEEDED(result)) {
            if (chunk_index != current_chunk_index && current_samples_in_chunk != 0) {
                // new chunk
                chunk_offsets.Append(current_chunk_offset);
                current_chunk_offset += current_chunk_size;

                stsc->AddEntry(1, 
                               current_samples_in_chunk,
                               current_sample_description_index+1);

                current_samples_in_chunk = 0;
                current_chunk_size       = 0;
//.........这里部分代码省略.........

/*----------------------------------------------------------------------
|   AP4_Processor::ProcessFragments
+---------------------------------------------------------------------*/
AP4_Result
AP4_Processor::ProcessFragments(AP4_MoovAtom*              moov, 
                                AP4_List<AP4_MoofLocator>& moofs, 
                                AP4_ContainerAtom*         mfra,
                                AP4_ByteStream&            input, 
                                AP4_ByteStream&            output)
{
    // FIXME: this only works for non-changing moofs 
 
    for (AP4_List<AP4_MoofLocator>::Item* item = moofs.FirstItem();
                                          item;
                                          item = item->GetNext()) {
        AP4_MoofLocator*   locator     = item->GetData();
        AP4_ContainerAtom* moof        = locator->m_Moof;
        AP4_UI64           moof_offset = locator->m_Offset;
        AP4_UI64           mdat_payload_offset = moof_offset+moof->GetSize()+8;
        AP4_MovieFragment* fragment    = new AP4_MovieFragment(moof);
        AP4_Sample         sample;
        AP4_DataBuffer     sample_data_in;
        AP4_DataBuffer     sample_data_out;
        AP4_Result         result;
    
        // process all the traf atoms
        AP4_Array<AP4_Processor::FragmentHandler*> handlers;
        for (;AP4_Atom* atom = moof->GetChild(AP4_ATOM_TYPE_TRAF, handlers.ItemCount());) {
            AP4_ContainerAtom* traf = AP4_DYNAMIC_CAST(AP4_ContainerAtom, atom);
            AP4_Processor::FragmentHandler* handler = CreateFragmentHandler(traf);
            if (handler) result = handler->ProcessFragment();
            handlers.Append(handler);
        }
             
        // write the moof
        AP4_UI64 moof_out_start = 0;
        output.Tell(moof_out_start);
        bool moof_has_changed = false;
        moof->Write(output);
            
        // process all track runs
        for (unsigned int i=0; i<handlers.ItemCount(); i++) {
            AP4_FragmentSampleTable* sample_table = NULL;
            AP4_Processor::FragmentHandler* handler = handlers[i];

            // get the track ID
            AP4_ContainerAtom* traf = AP4_DYNAMIC_CAST(AP4_ContainerAtom, moof->GetChild(AP4_ATOM_TYPE_TRAF, i));
            AP4_TfhdAtom* tfhd      = AP4_DYNAMIC_CAST(AP4_TfhdAtom, traf->GetChild(AP4_ATOM_TYPE_TFHD, i));
            
            // create a sample table object so we can read the sample data
            result = fragment->CreateSampleTable(moov, tfhd->GetTrackId(), &input, moof_offset, mdat_payload_offset, sample_table);
            if (AP4_FAILED(result)) return result;

            // compute the mdat size
            AP4_UI64 mdat_size = 0;
            for (unsigned int j=0; j<sample_table->GetSampleCount(); j++) {
                result = sample_table->GetSample(j, sample);
                if (AP4_FAILED(result)) return result;
                mdat_size += sample.GetSize();
            }
            
            // write an mdat header
            if (mdat_size > 0xFFFFFFFF-8) {
                // we don't support large mdat fragments
                return AP4_ERROR_OUT_OF_RANGE;
            }
            if (mdat_size) {
                output.WriteUI32((AP4_UI32)(8+mdat_size));
                output.WriteUI32(AP4_ATOM_TYPE_MDAT);
            }
            
#if defined(AP4_DEBUG)
            AP4_Position before;
            output.Tell(before);
#endif
            
            // write the mdat
            for (unsigned int j=0; j<sample_table->GetSampleCount(); j++) {
                result = sample_table->GetSample(j, sample);
                if (AP4_FAILED(result)) return result;
                sample.ReadData(sample_data_in);
                
                // process the sample data
                if (handler) {
                    result = handler->ProcessSample(sample_data_in, sample_data_out);
                    if (AP4_FAILED(result)) return result;

                    // write the sample data
                    result = output.Write(sample_data_out.GetData(), sample_data_out.GetDataSize());
                    if (AP4_FAILED(result)) return result;

                    // give the handler a chance to update the atoms
                    result = handler->FinishFragment();
                    if (AP4_SUCCEEDED(result)) moof_has_changed = true;
                } else {
                    // write the sample data (unmodified)
                    result = output.Write(sample_data_in.GetData(), sample_data_in.GetDataSize());
                    if (AP4_FAILED(result)) return result;
                }
            }
//.........这里部分代码省略.........

/*----------------------------------------------------------------------
|       AP4_SampleTable::GenerateStblAtom
+---------------------------------------------------------------------*/
AP4_Result 
AP4_SampleTable::GenerateStblAtom(AP4_ContainerAtom*& stbl)
{
    // create the stbl container
    stbl = DNew AP4_ContainerAtom(AP4_ATOM_TYPE_STBL);

    // create the stsd atom
    AP4_StsdAtom* stsd = DNew AP4_StsdAtom(this);

    // create the stsz atom
    AP4_StszAtom* stsz = DNew AP4_StszAtom();

    // create the stsc atom
    AP4_StscAtom* stsc = DNew AP4_StscAtom();

    // start chunk table
    AP4_Cardinal        samples_in_chunk = 0;
    AP4_Offset          current_chunk_offset = 0;
    AP4_Size            current_chunk_size = 0;
    AP4_Array<AP4_UI32> chunk_offsets;

    // process all the samples
    AP4_Cardinal sample_count = GetSampleCount();
    for (AP4_Ordinal i=0; i<sample_count; i++) {
        AP4_Sample sample;
        GetSample(i, sample);
        
        // add an entry into the stsz atom
        stsz->AddEntry(sample.GetSize());
        
        // adjust the current chunk info
        current_chunk_size += sample.GetSize();

        // count the sample
        samples_in_chunk++;
        if (samples_in_chunk == 10) {
            // new chunk
            chunk_offsets.Append(current_chunk_offset);
            stsc->AddEntry(1, 10, 1);
            samples_in_chunk = 0;

            // adjust the chunk offset
            current_chunk_offset += current_chunk_size;
            current_chunk_size = 0;
        }
    }

    // process any unfinished chunk
    if (samples_in_chunk != 0) {
        // new chunk
        chunk_offsets.Append(current_chunk_offset);
        stsc->AddEntry(1, samples_in_chunk, 1);
    }

    // create the stco atom
    AP4_StcoAtom* stco = DNew AP4_StcoAtom(&chunk_offsets[0], 
                                          chunk_offsets.ItemCount());

    // create the stts atom (for now, we assume sample of equal duration)
    AP4_SttsAtom* stts = DNew AP4_SttsAtom();
    stts->AddEntry(sample_count, 1000); // FIXME

    // attach the children of stbl
    stbl->AddChild(stsd);
    stbl->AddChild(stsz);
    stbl->AddChild(stsc);
    stbl->AddChild(stco);
    stbl->AddChild(stts);

    return AP4_SUCCESS;
}