diff --git a/src/H5Writer.cpp b/src/H5Writer.cpp
index dda4c98..6147b31 100644
--- a/src/H5Writer.cpp
+++ b/src/H5Writer.cpp
@@ -12,15 +12,13 @@ extern "C"
 
 using namespace std;
 
-H5Writer::H5Writer(const std::string& filename, const std::string& dataset_name, 
-            hsize_t frames_per_file, hsize_t initial_dataset_size, hsize_t dataset_increase_step) :
-    filename(filename), dataset_name(dataset_name), frames_per_file(frames_per_file), 
+H5Writer::H5Writer(const std::string& filename, hsize_t frames_per_file, hsize_t initial_dataset_size, hsize_t dataset_increase_step) :
+    filename(filename), frames_per_file(frames_per_file), 
     initial_dataset_size(initial_dataset_size), dataset_increase_step(dataset_increase_step)
 {
     #ifdef DEBUG_OUTPUT
         cout << "[H5Writer::H5Writer] Creating chunked writer"; 
         cout << " with filename " << filename;
-        cout << " and dataset_name " << dataset_name;
         cout << " and frames_per_file " << frames_per_file;
         cout << " and initial_dataset_size " << initial_dataset_size;
         cout << endl;
@@ -34,65 +32,138 @@ H5Writer::~H5Writer()
 
 void H5Writer::close_file()
 {
-    if (!is_file_open()) {
+    if (is_file_open()) {
+
+        #ifdef DEBUG_OUTPUT
+            cout << "[H5Writer::close_file] Closing file." << endl;
+        #endif
+
+        hsize_t min_frame_in_dataset = 0;
+        if (frames_per_file) {
+            min_frame_in_dataset = (current_frame_chunk - 1) * frames_per_file;
+        }
+
+        // max_data_index is relative to the current file.
+        hsize_t max_frame_in_dataset = max_data_index + min_frame_in_dataset;
+
+        // Frame indexing starts at 1 (for some reason).
+        auto image_nr_low = min_frame_in_dataset + 1;
+        auto image_nr_high = max_frame_in_dataset + 1;
+
+        #ifdef DEBUG_OUTPUT
+            cout << "[H5Writer::close_file] Setting datasets attribute image_nr_low=" << image_nr_low;
+            cout << " and image_nr_high=" << image_nr_high << endl;
+        #endif
+
+        for (const auto& dataset_map : datasets) {
+            auto dataset = dataset_map.second;
+
+            H5FormatUtils::compact_dataset(dataset, max_data_index);
+
+            H5FormatUtils::write_attribute(dataset, "image_nr_low", image_nr_low);
+            H5FormatUtils::write_attribute(dataset, "image_nr_high", image_nr_high);
+        }
+
+        file.close();
+
+    } else {
         #ifdef DEBUG_OUTPUT
             cout << "[H5Writer::close_file] Trying to close an already closed file." << endl;
         #endif
-
-        return;
     }
 
-    #ifdef DEBUG_OUTPUT
-        cout << "[H5Writer::close_file] Closing file." << endl;
-    #endif
-
-    H5FormatUtils::compact_dataset(dataset, max_frame_index);
-    
-    hsize_t min_frame_in_dataset = 0;
-    if (frames_per_file) {
-        min_frame_in_dataset = (current_frame_chunk - 1) * frames_per_file;
-    }
-
-    // max_frame_index is relative to the current file.
-    hsize_t max_frame_in_dataset = max_frame_index + min_frame_in_dataset;
-
-    // Frame indexing starts at 1 (for some reason).
-    auto image_nr_low = min_frame_in_dataset + 1;
-    auto image_nr_high = max_frame_in_dataset + 1;
-
-    #ifdef DEBUG_OUTPUT
-        cout << "[H5Writer::close_file] Setting dataset attribute image_nr_low=" << image_nr_low << " and image_nr_high=" << image_nr_high << endl;
-    #endif
-
-    H5FormatUtils::write_attribute(dataset, "image_nr_low", image_nr_low);
-    H5FormatUtils::write_attribute(dataset, "image_nr_high", image_nr_high);
-
     // Cleanup.
-    file.close();
+    datasets.clear();
+    datasets_current_size.clear();
+
     current_frame_chunk = 0;
-    current_dataset_size = 0;
-    max_frame_index = 0;
+    max_data_index = 0;
 }
 
-void H5Writer::write_frame_data(size_t frame_index, const size_t* frame_shape, size_t data_bytes_size, const char* data, const string& data_type, const string& endianness)
+void H5Writer::write_data(const string& dataset_name, const size_t data_index, const char* data,
+    const std::vector<size_t>& data_shape, const size_t data_bytes_size, const string& data_type, const string& endianness)
 {
     // Define the ofset of the currently received image in the file.
-    hsize_t relative_frame_index = prepare_storage_for_frame(frame_index, frame_shape, data_type, endianness);
+    hsize_t relative_data_index = prepare_storage_for_data(dataset_name, data_index, data_shape, data_type, endianness);
 
-    // Define where to write values in the dataset.
-    const hsize_t offset[] = {relative_frame_index, 0, 0};
+    // Define the offset where to write the data.
+    size_t data_rank = data_shape.size();
+    hsize_t offset[data_rank+1];
+    
+    offset[0] = relative_data_index;
+    for (uint index=0; index<data_rank; ++index) {
+        offset[index+1] = 0;
+    }
+
+    // No compression for now.
     uint32_t filters = 0;
+
+    const auto& dataset = datasets.at(dataset_name);
     
     if( H5DOwrite_chunk(dataset.getId(), H5P_DEFAULT, filters, offset, data_bytes_size, data) )
     {
         stringstream error_message;
-        error_message << "Error while writing chunk to file at offset " << relative_frame_index << "." << endl;
+        error_message << "Error while writing dataset " << dataset_name << " chunk to file at offset ";
+        error_message << relative_data_index << "." << endl;
 
         throw invalid_argument( error_message.str() );
     }
 }
 
-void H5Writer::create_file(const size_t* frame_shape, hsize_t frame_chunk, const string& type, const string& endianness) 
+void H5Writer::create_dataset(const string& dataset_name, const vector<size_t>& data_shape, 
+    const string& data_type, const string& endianness)
+{
+    // TODO: Create folder if it does not exist.
+
+    // Number of dimensions in each data point.
+    const size_t data_rank = data_shape.size();
+    // The +1 dimension is to account for the sequence of data points (time).
+    const hsize_t dataset_rank = data_rank + 1;
+
+    hsize_t dataset_dimension[dataset_rank];
+    hsize_t max_dataset_dimension[dataset_rank];
+    hsize_t dataset_chunking[dataset_rank];
+    
+    dataset_dimension[0] = initial_dataset_size;
+    // This dataset can be resized without limits. 
+    max_dataset_dimension[0] = H5S_UNLIMITED;
+    // Chunking is always set to a single data point.
+    dataset_chunking[0] = 1;
+
+    for (size_t index=0; index<data_rank; ++index) {
+        dataset_dimension[index+1] = data_shape[index];
+        max_dataset_dimension[index+1] = data_shape[index];
+        dataset_chunking[index+1] = data_shape[index];
+    }
+
+    H5::DataSpace dataspace(dataset_rank, dataset_dimension, max_dataset_dimension);
+
+    #ifdef DEBUG_OUTPUT
+        cout << "[H5Writer::create_dataset] Creating dataspace of size (";
+        for (hsize_t i=0; i<dataset_rank; ++i) {
+            cout << dataset_dimension[i] << ",";
+        }
+        cout << ")" << endl;
+    #endif
+
+    H5::DSetCreatPropList dataset_properties;
+    dataset_properties.setChunk(dataset_rank, dataset_chunking);
+    
+    H5::AtomType dataset_data_type(H5FormatUtils::get_dataset_data_type(data_type));
+
+    if (endianness == "big") {
+        dataset_data_type.setOrder(H5T_ORDER_BE);
+    } else {
+        dataset_data_type.setOrder(H5T_ORDER_LE);
+    }
+
+    auto dataset = file.createDataSet(dataset_name.c_str(), dataset_data_type, dataspace, dataset_properties);
+    
+    datasets.insert({dataset_name, dataset});
+    datasets_current_size.insert({dataset_name, initial_dataset_size});
+}
+
+void H5Writer::create_file(hsize_t frame_chunk) 
 {
 
     if (file.getId() != -1) {
@@ -118,43 +189,10 @@ void H5Writer::create_file(const size_t* frame_shape, hsize_t frame_chunk, const
         cout << "[H5Writer::create_file] Creating filename " << target_filename << endl;
     #endif
 
-    // TODO: Create folder if it does not exist.
-
-    file = H5::H5File( target_filename.c_str(), H5F_ACC_TRUNC );
+    file = H5::H5File(target_filename.c_str(), H5F_ACC_TRUNC);
     
-    hsize_t dataset_rank = 3;
-    const hsize_t dataset_dimension[] = {initial_dataset_size, frame_shape[0], frame_shape[1]};
-    const hsize_t max_dataset_dimension[] = {H5S_UNLIMITED, frame_shape[0], frame_shape[1]};
-    H5::DataSpace dataspace(dataset_rank, dataset_dimension, max_dataset_dimension);
-
-    #ifdef DEBUG_OUTPUT
-        cout << "[H5Writer::create_file] Creating dataspace of size (";
-        for (hsize_t i=0; i<dataset_rank; ++i) {
-            cout << dataset_dimension[i] << ",";
-        }
-        cout << ")" << endl;
-    #endif
-
-    // Set chunking to single image.
-    H5::DSetCreatPropList dataset_properties;
-    const hsize_t dataset_chunking[] = {1, frame_shape[0], frame_shape[1]};
-    dataset_properties.setChunk(dataset_rank, dataset_chunking);
-    
-    H5::AtomType data_type(H5FormatUtils::get_dataset_data_type(type));
-
-    if (endianness == "big") {
-        data_type.setOrder(H5T_ORDER_BE);
-    } else {
-        data_type.setOrder(H5T_ORDER_LE);
-    }
-
-    // Take into account initial size, set chunking.
-    dataset = file.createDataSet(dataset_name.c_str(), data_type, dataspace, dataset_properties);
-
-    // New file created - update global values.
+    // New file created - set this files chunk number.
     current_frame_chunk = frame_chunk;
-    current_dataset_size = initial_dataset_size;
-
 }
 
 bool H5Writer::is_file_open() 
@@ -162,44 +200,54 @@ bool H5Writer::is_file_open()
     return (file.getId() != -1);
 }
 
-hsize_t H5Writer::prepare_storage_for_frame(size_t frame_index, const size_t* frame_shape, const string& data_type, const string& endianness) 
+hsize_t H5Writer::prepare_storage_for_data(const string& dataset_name, const size_t data_index, const std::vector<size_t>& data_shape,
+     const string& data_type, const string& endianness) 
 {
-
-    hsize_t relative_frame_index = frame_index;
+    hsize_t relative_data_index = data_index;
 
     // Check if we have to create a new file.
     if (frames_per_file) {
-        hsize_t frame_chunk = (frame_index / frames_per_file) + 1;
+        hsize_t frame_chunk = (data_index / frames_per_file) + 1;
 
         // This frames does not go into this file.
         if (frame_chunk != current_frame_chunk) {
-            create_file(frame_shape, frame_chunk, data_type, endianness);
+            create_file(frame_chunk);
         }
 
-        // Make the frame_index relative to this chunk (file).
-        relative_frame_index = frame_index - ((frame_chunk - 1) * frames_per_file);
+        // Make the data_index relative to this chunk (file).
+        relative_data_index = data_index - ((frame_chunk - 1) * frames_per_file);
     }
 
     #ifdef DEBUG_OUTPUT
-        cout << "[H5Writer::prepare_storage_for_frame] Received frame index " << frame_index << " and processed as relative frame index " << relative_frame_index << endl;
+        cout << "[H5Writer::prepare_storage_for_data] Received frame index " << data_index << " and processed as relative frame index " << relative_data_index << endl;
     #endif
 
     // Open the file if needed.
     if (!is_file_open()) {
-        create_file(frame_shape, 0, data_type, endianness);
+        create_file();
     }
 
+    // Create the dataset if we don't have it yet.
+    if (datasets.find(dataset_name) == datasets.end()) {
+        create_dataset(dataset_name, data_shape, data_type, endianness);
+    }
+
+    hsize_t current_dataset_size = datasets_current_size.at(dataset_name);
+
     // Expand the dataset if needed.
-    if (relative_frame_index > current_dataset_size) {
-        current_dataset_size = H5FormatUtils::expand_dataset(dataset, relative_frame_index, dataset_increase_step);
+    if (relative_data_index > current_dataset_size) {
+        auto dataset = datasets.at(dataset_name);
+
+        hsize_t new_dataset_size = H5FormatUtils::expand_dataset(dataset, relative_data_index, dataset_increase_step);
+        datasets_current_size[dataset_name] = new_dataset_size;
     }
 
     // Keep track of the max index in this file - needed for shrinking the dataset at the end.
-    if (relative_frame_index > max_frame_index) {
-        max_frame_index = relative_frame_index;
+    if (relative_data_index > max_data_index) {
+        max_data_index = relative_data_index;
     }
 
-    return relative_frame_index;
+    return relative_data_index;
 }
 
 H5::H5File& H5Writer::get_h5_file() 
diff --git a/src/H5Writer.hpp b/src/H5Writer.hpp
index 8090301..dd5d3a6 100644
--- a/src/H5Writer.hpp
+++ b/src/H5Writer.hpp
@@ -1,37 +1,42 @@
 #ifndef H5WRITER_H
 #define H5WRITER_H
 
-#include <map>
+#include <unordered_map>
+#include <memory>
+#include <vector>
 #include <H5Cpp.h>
 
 class H5Writer
 {
     // Initialized in constructor.
     const std::string filename;
-    const std::string dataset_name;
     hsize_t frames_per_file;
     hsize_t initial_dataset_size;
     hsize_t dataset_increase_step = 0;
 
     // State variables.
-    hsize_t max_frame_index = 0;
-    hsize_t current_dataset_size = 0;
+    hsize_t max_data_index = 0;
     hsize_t current_frame_chunk = 0;
 
     H5::H5File file;
-    H5::DataSet dataset;
+    std::unordered_map<std::string, H5::DataSet> datasets;
+    std::unordered_map<std::string, hsize_t> datasets_current_size;
     
-    hsize_t prepare_storage_for_frame(size_t frame_index, const size_t* frame_shape, const std::string& data_type, const std::string& endianness);
-    void create_file(const size_t* frame_shape, hsize_t frame_chunk, const std::string& data_type, const std::string& endianness);
+    hsize_t prepare_storage_for_data(const std::string& dataset_name, const size_t data_index, const std::vector<size_t>& data_shape, 
+        const std::string& data_type, const std::string& endianness);
+
+    void create_file(const hsize_t frame_chunk=0);
+
+    void create_dataset(const std::string& dataset_name, const std::vector<size_t>& data_shape, 
+        const std::string& data_type, const std::string& endianness);
 
     public:
-        H5Writer(const std::string& filename, const std::string& dataset_name, 
-            hsize_t frames_per_file=0, hsize_t initial_dataset_size=1000, hsize_t dataset_increase_step=1000);
-        ~H5Writer();
+        H5Writer(const std::string& filename, hsize_t frames_per_file=0, hsize_t initial_dataset_size=1000, hsize_t dataset_increase_step=1000);
+        virtual ~H5Writer();
         bool is_file_open();
         void close_file();
-        void write_frame_data(size_t frame_index, const size_t* frame_shape, size_t data_bytes_size, 
-            const char* data, const std::string& data_type, const std::string& endianness);
+        void write_data(const std::string& dataset_name, const size_t data_index, const char* data, const std::vector<size_t>& data_shape, 
+            const size_t data_bytes_size, const std::string& data_type, const std::string& endianness);
         H5::H5File& get_h5_file();
 };
 
diff --git a/src/ProcessManager.cpp b/src/ProcessManager.cpp
index 44c8605..36aba1f 100644
--- a/src/ProcessManager.cpp
+++ b/src/ProcessManager.cpp
@@ -17,7 +17,8 @@ namespace pt = boost::property_tree;
 
 void ProcessManager::write_h5(WriterManager& manager, const H5Format& format, RingBuffer& ring_buffer) 
 {
-    H5Writer writer(manager.get_output_file(), format.get_raw_frames_dataset_name());
+    H5Writer writer(manager.get_output_file());
+    auto raw_frames_dataset_name = format.get_raw_frames_dataset_name();
     
     // Run until the running flag is set or the ring_buffer is empty.  
     while(manager.is_running() || !ring_buffer.is_empty()) {
@@ -35,18 +36,16 @@ void ProcessManager::write_h5(WriterManager& manager, const H5Format& format, Ri
         }
 
         // Write image data.
-        writer.write_frame_data(received_data.first->frame_index, 
-                                received_data.first->frame_shape,
-                                received_data.first->frame_bytes_size, 
-                                received_data.second,
-                                received_data.first->type,
-                                received_data.first->endianness);
+        writer.write_data(raw_frames_dataset_name,
+                          received_data.first->frame_index, 
+                          received_data.second,
+                          received_data.first->frame_shape,
+                          received_data.first->frame_bytes_size, 
+                          received_data.first->type,
+                          received_data.first->endianness);
 
         ring_buffer.release(received_data.first->buffer_slot_index);
 
-        // Write header data.
-        writer.write_data();
-
         manager.written_frame(received_data.first->frame_index);
     }
 
@@ -186,7 +185,7 @@ shared_ptr<FrameMetadata> ProcessManager::read_json_header(pt::ptree& json_heade
     header_data->frame_index = json_header.get<uint64_t>("frame");
 
     for (const auto& item : json_header.get_child("shape")) {
-        header_data->frame_shape.insert(item.second.get_value<size_t>());
+        header_data->frame_shape.push_back(item.second.get_value<size_t>());
     }
 
     // Array 1.0 specified little endian as the default encoding.
diff --git a/src/ProcessManager.hpp b/src/ProcessManager.hpp
index 8b5ba6e..163d92b 100644
--- a/src/ProcessManager.hpp
+++ b/src/ProcessManager.hpp
@@ -19,5 +19,5 @@ namespace ProcessManager
         const std::string& header, const std::map<std::string, HEADER_DATA_TYPE>& header_data_type);
 
     boost::any get_value_from_json(const boost::property_tree::ptree& json_header, 
-        const string& value_name, const HEADER_DATA_TYPE data_type);
+        const std::string& value_name, const HEADER_DATA_TYPE data_type);
 };
\ No newline at end of file