Task 014: .ADT File Format
Task 014: .ADT File Format
The .ADT file extension is associated with multiple formats, each tied to specific applications, and no single, universally accepted specification exists for all .ADT files. Based on available information, the primary uses of the .ADT extension include:
- ACT! Document Template (Swiftpage Act! CRM): A template for creating word processing documents with a consistent layout, often stored in a Microsoft Compound Document format.
- World of Warcraft Map File (Blizzard Entertainment): Game map tiles stored within .MPQ archives, containing terrain and object data.
- ADTS Audio File: Audio files in the Audio Data Transport Stream format, containing audio frames for streaming.
- Advantage Database Server Table (ADS): A proprietary database table format for storing structured data.
- Alphacam Diecut Tool Data: Data files for CAD/CAM woodworking software.
- Asterix DataSet Transformation: Configuration data for telecommunication equipment.
- Advanced Dental Tracker / Advanced Data Table: Structured medical data, often for patient records.
Since the task does not specify which .ADT format to target and no comprehensive file system-level specification is publicly available for any of these formats, I’ll focus on the Advantage Database Server (ADS) .ADT format, as it’s a proprietary database format with some documented characteristics and is commonly referenced in data-related contexts. The ADS .ADT format is used for database tables and is managed exclusively by the Advantage Database Server, making it a reasonable choice for a file system-oriented task.
1. Properties of the .ADT File Format (Advantage Database Server)
The ADS .ADT format is a proprietary database table format, and its intrinsic file system properties are derived from limited public documentation and general database file characteristics. The following properties are inferred based on available information and typical database file structures:
- File Extension:
.adt - File Type: Binary, proprietary database table format.
- Storage Structure: Structured data stored in tables with records and fields, using an indexing mechanism for record access.
- Header: Contains metadata such as table schema (field names, types, and sizes), record count, and file version.
- Data Records: Fixed or variable-length records storing data in predefined fields (e.g., character, numeric, date, memo).
- Indexes: Associated index files (often .ADI) for efficient data retrieval.
- File Size: Variable, depending on the number of records and field types; typically grows with data volume.
- Encoding: Binary encoding, not human-readable, specific to the Advantage Database Server.
- Access Method: Sequential or indexed access via the Advantage Database Server; not directly compatible with other xBase tools.
- Concurrency: Supports multi-user access with locking mechanisms for data integrity.
- Path Location: Typically stored in a database directory, configurable by the application.
- Associated Files: May include .ADI (index) and .ADM (memo) files for complete table functionality.
- Proprietary Nature: Cannot be opened by other xBase tools or standard database applications without ADS.
Note: Exact specifications (e.g., byte-level structure, header format) are not publicly documented, as the ADS .ADT format is proprietary. The properties above are generalized based on database file conventions and references to ADS .ADT files.
Challenges and Assumptions
- Lack of Public Specification: No detailed, public byte-level specification for ADS .ADT files exists in the provided references or general web searches. The proprietary nature limits access to structural details.
- Assumption for Coding: Since exact decoding requires proprietary knowledge, the following classes will simulate handling an .ADT file by assuming a simplified structure: a header with metadata (e.g., field count, field types) followed by records. The classes will open, read, write, and print these assumed properties, focusing on file system-level interaction (e.g., file path, size, basic metadata).
- Simplified Model: We’ll assume the .ADT file has a header (e.g., 512 bytes with field count and record count) and a data section with records (e.g., fixed-length records of 100 bytes each). This is a placeholder structure for demonstration, as the actual format is proprietary.
2. Python Class for .ADT File Handling
import os
import struct
class ADTFile:
def __init__(self, filepath):
self.filepath = filepath
self.header_size = 512 # Assumed header size in bytes
self.record_size = 100 # Assumed record size in bytes
self.properties = {}
def read(self):
"""Read and decode the .ADT file, storing properties."""
try:
with open(self.filepath, 'rb') as f:
# Read header (simulated: field count, record count)
header_data = f.read(self.header_size)
if len(header_data) < self.header_size:
raise ValueError("File too small to contain valid header")
# Decode header (assume 4-byte integers for field and record counts)
field_count, record_count = struct.unpack('<II', header_data[:8])
self.properties = {
'file_extension': '.adt',
'file_path': self.filepath,
'file_size': os.path.getsize(self.filepath),
'file_type': 'Advantage Database Table',
'field_count': field_count,
'record_count': record_count,
'header_size': self.header_size,
'record_size': self.record_size
}
# Read sample record (first 100 bytes of data section)
f.seek(self.header_size)
sample_record = f.read(self.record_size)
self.properties['sample_record'] = sample_record.hex()[:32] + '...' if sample_record else 'N/A'
except FileNotFoundError:
print(f"Error: File {self.filepath} not found")
except Exception as e:
print(f"Error reading file: {e}")
def write(self, field_count=10, record_count=100):
"""Write a new .ADT file with simulated header and empty records."""
try:
with open(self.filepath, 'wb') as f:
# Write header (simulated)
header_data = struct.pack('<II', field_count, record_count)
header_data += b'\x00' * (self.header_size - len(header_data))
f.write(header_data)
# Write empty records
for _ in range(record_count):
f.write(b'\x00' * self.record_size)
self.properties['file_size'] = os.path.getsize(self.filepath)
print(f"File {self.filepath} written successfully")
except Exception as e:
print(f"Error writing file: {e}")
def print_properties(self):
"""Print all file properties to console."""
for key, value in self.properties.items():
print(f"{key}: {value}")
# Example usage
if __name__ == "__main__":
adt = ADTFile("sample.adt")
adt.write() # Create a sample file
adt.read()
adt.print_properties()
Explanation:
- Assumptions: The class assumes a simple .ADT structure with a 512-byte header (containing field count and record count as 4-byte integers) and 100-byte records. This is a placeholder due to the lack of a public specification.
- Read: Opens the file in binary mode, reads the header, decodes field and record counts, and extracts a sample record as hex.
- Write: Creates a new .ADT file with a simulated header and empty records.
- Print: Displays properties like file path, size, and assumed metadata.
- Limitations: Without the actual ADS specification, this is a simplified model. Real .ADT files require the Advantage Database Server for proper handling.
3. Java Class for .ADT File Handling
import java.io.*;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.HashMap;
import java.util.Map;
public class ADTFile {
private String filepath;
private int headerSize = 512; // Assumed header size in bytes
private int recordSize = 100; // Assumed record size in bytes
private Map<String, Object> properties = new HashMap<>();
public ADTFile(String filepath) {
this.filepath = filepath;
}
public void read() {
try (RandomAccessFile file = new RandomAccessFile(filepath, "r")) {
// Read header
byte[] headerData = new byte[headerSize];
int bytesRead = file.read(headerData);
if (bytesRead < headerSize) {
throw new IOException("File too small to contain valid header");
}
// Decode header (assume 4-byte integers for field and record counts)
ByteBuffer buffer = ByteBuffer.wrap(headerData).order(ByteOrder.LITTLE_ENDIAN);
int fieldCount = buffer.getInt();
int recordCount = buffer.getInt();
// Store properties
properties.put("file_extension", ".adt");
properties.put("file_path", filepath);
properties.put("file_size", new File(filepath).length());
properties.put("file_type", "Advantage Database Table");
properties.put("field_count", fieldCount);
properties.put("record_count", recordCount);
properties.put("header_size", headerSize);
properties.put("record_size", recordSize);
// Read sample record
file.seek(headerSize);
byte[] sampleRecord = new byte[recordSize];
file.read(sampleRecord);
StringBuilder hex = new StringBuilder();
for (int i = 0; i < Math.min(16, sampleRecord.length); i++) {
hex.append(String.format("%02x", sampleRecord[i]));
}
properties.put("sample_record", hex.length() > 0 ? hex + "..." : "N/A");
} catch (FileNotFoundException e) {
System.out.println("Error: File " + filepath + " not found");
} catch (IOException e) {
System.out.println("Error reading file: " + e.getMessage());
}
}
public void write(int fieldCount, int recordCount) {
try (RandomAccessFile file = new RandomAccessFile(filepath, "rw")) {
// Write header
ByteBuffer buffer = ByteBuffer.allocate(headerSize).order(ByteOrder.LITTLE_ENDIAN);
buffer.putInt(fieldCount).putInt(recordCount);
file.write(buffer.array());
// Write empty records
byte[] emptyRecord = new byte[recordSize];
for (int i = 0; i < recordCount; i++) {
file.write(emptyRecord);
}
properties.put("file_size", new File(filepath).length());
System.out.println("File " + filepath + " written successfully");
} catch (IOException e) {
System.out.println("Error writing file: " + e.getMessage());
}
}
public void printProperties() {
for (Map.Entry<String, Object> entry : properties.entrySet()) {
System.out.println(entry.getKey() + ": " + entry.getValue());
}
}
public static void main(String[] args) {
ADTFile adt = new ADTFile("sample.adt");
adt.write(10, 100); // Create a sample file
adt.read();
adt.printProperties();
}
}
Explanation:
- Assumptions: Similar to Python, assumes a header with field and record counts and fixed-size records.
- Read: Uses
RandomAccessFilefor binary reading, decoding the header withByteBufferin little-endian order. - Write: Creates a new file with a header and empty records.
- Print: Outputs properties to the console.
- Limitations: Simplified due to proprietary format; real .ADT files require ADS-specific libraries.
4. JavaScript Class for .ADT File Handling
const fs = require('fs').promises;
const path = require('path');
class ADTFile {
constructor(filepath) {
this.filepath = filepath;
this.headerSize = 512; // Assumed header size in bytes
this.recordSize = 100; // Assumed record size in bytes
this.properties = {};
}
async read() {
try {
const fileBuffer = await fs.readFile(this.filepath);
if (fileBuffer.length < this.headerSize) {
throw new Error('File too small to contain valid header');
}
// Decode header (assume 4-byte integers for field and record counts)
const view = new DataView(fileBuffer.buffer);
const fieldCount = view.getInt32(0, true); // Little-endian
const recordCount = view.getInt32(4, true);
// Store properties
const stats = await fs.stat(this.filepath);
this.properties = {
file_extension: '.adt',
file_path: this.filepath,
file_size: stats.size,
file_type: 'Advantage Database Table',
field_count: fieldCount,
record_count: recordCount,
header_size: this.headerSize,
record_size: this.recordSize,
sample_record: fileBuffer.slice(this.headerSize, this.headerSize + this.recordSize)
.toString('hex').slice(0, 32) + '...' || 'N/A'
};
} catch (error) {
console.error(`Error reading file: ${error.message}`);
}
}
async write(fieldCount = 10, recordCount = 100) {
try {
const buffer = Buffer.alloc(this.headerSize + recordCount * this.recordSize);
buffer.writeInt32LE(fieldCount, 0); // Write field count
buffer.writeInt32LE(recordCount, 4); // Write record count
// Rest of header and records are zero-filled
await fs.writeFile(this.filepath, buffer);
this.properties.file_size = (await fs.stat(this.filepath)).size;
console.log(`File ${this.filepath} written successfully`);
} catch (error) {
console.error(`Error writing file: ${error.message}`);
}
}
printProperties() {
for (const [key, value] of Object.entries(this.properties)) {
console.log(`${key}: ${value}`);
}
}
}
// Example usage
(async () => {
const adt = new ADTFile('sample.adt');
await adt.write();
await adt.read();
adt.printProperties();
})();
Explanation:
- Assumptions: Same simplified structure as above.
- Read: Uses Node.js
fs.promisesfor asynchronous file reading, decoding the header withDataView. - Write: Creates a new file with a header and zero-filled records.
- Print: Logs properties to the console.
- Limitations: Node.js-specific; browser-based JavaScript would require different file handling (e.g., File API).
5. C Class for .ADT File Handling
C does not have classes, so we’ll use a struct and functions to emulate class-like behavior.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define HEADER_SIZE 512
#define RECORD_SIZE 100
typedef struct {
char* filepath;
long file_size;
char* file_extension;
char* file_type;
int field_count;
int record_count;
int header_size;
int record_size;
char sample_record[33]; // Hex string + null terminator
} ADTFile;
ADTFile* adtfile_new(const char* filepath) {
ADTFile* adt = (ADTFile*)malloc(sizeof(ADTFile));
adt->filepath = strdup(filepath);
adt->file_extension = ".adt";
adt->file_type = "Advantage Database Table";
adt->header_size = HEADER_SIZE;
adt->record_size = RECORD_SIZE;
adt->file_size = 0;
adt->field_count = 0;
adt->record_count = 0;
strcpy(adt->sample_record, "N/A");
return adt;
}
void adtfile_free(ADTFile* adt) {
free(adt->filepath);
free(adt);
}
int adtfile_read(ADTFile* adt) {
FILE* file = fopen(adt->filepath, "rb");
if (!file) {
printf("Error: File %s not found\n", adt->filepath);
return 1;
}
// Get file size
fseek(file, 0, SEEK_END);
adt->file_size = ftell(file);
rewind(file);
// Read header
unsigned char header[HEADER_SIZE];
if (fread(header, 1, HEADER_SIZE, file) < HEADER_SIZE) {
printf("Error: File too small to contain valid header\n");
fclose(file);
return 1;
}
// Decode header (assume 4-byte integers for field and record counts)
adt->field_count = *(int*)header;
adt->record_count = *(int*)(header + 4);
// Read sample record
fseek(file, HEADER_SIZE, SEEK_SET);
unsigned char record[RECORD_SIZE];
if (fread(record, 1, RECORD_SIZE, file) == RECORD_SIZE) {
char* hex = adt->sample_record;
for (int i = 0; i < 16 && i < RECORD_SIZE; i++) {
sprintf(hex + i * 2, "%02x", record[i]);
}
strcat(hex, "...");
}
fclose(file);
return 0;
}
int adtfile_write(ADTFile* adt, int field_count, int record_count) {
FILE* file = fopen(adt->filepath, "wb");
if (!file) {
printf("Error: Could not create file %s\n", adt->filepath);
return 1;
}
// Write header
unsigned char header[HEADER_SIZE] = {0};
*(int*)header = field_count;
*(int*)(header + 4) = record_count;
fwrite(header, 1, HEADER_SIZE, file);
// Write empty records
unsigned char record[RECORD_SIZE] = {0};
for (int i = 0; i < record_count; i++) {
fwrite(record, 1, RECORD_SIZE, file);
}
fclose(file);
adt->file_size = HEADER_SIZE + record_count * RECORD_SIZE;
printf("File %s written successfully\n", adt->filepath);
return 0;
}
void adtfile_print_properties(ADTFile* adt) {
printf("file_extension: %s\n", adt->file_extension);
printf("file_path: %s\n", adt->filepath);
printf("file_size: %ld\n", adt->file_size);
printf("file_type: %s\n", adt->file_type);
printf("field_count: %d\n", adt->field_count);
printf("record_count: %d\n", adt->record_count);
printf("header_size: %d\n", adt->header_size);
printf("record_size: %d\n", adt->record_size);
printf("sample_record: %s\n", adt->sample_record);
}
int main() {
ADTFile* adt = adtfile_new("sample.adt");
adtfile_write(adt, 10, 100); // Create a sample file
adtfile_read(adt);
adtfile_print_properties(adt);
adtfile_free(adt);
return 0;
}
Explanation:
- Assumptions: Same simplified structure.
- Read: Opens the file in binary mode, reads the header, and extracts field/record counts and a sample record.
- Write: Creates a new file with a header and zero-filled records.
- Print: Outputs properties to the console.
- Limitations: Simplified model; real .ADT files require ADS libraries for proper access.
Notes and Limitations
- Proprietary Format: The ADS .ADT format is proprietary, and without access to the Advantage Database Server or its documentation, the classes use a hypothetical structure. Real-world use would require ADS-specific libraries or APIs.
- Alternative Formats: If the task intended a different .ADT format (e.g., ACT! Template, WoW Map, ADTS Audio), please specify, and I can adapt the classes to focus on that format’s properties (though similar specification limitations apply).
- File System Properties: The listed properties are generic to database files due to the lack of detailed ADS .ADT specs. If you have access to ADS documentation or a specific .ADT file sample, I can refine the implementation.
- Error Handling: The classes include basic error handling for file access and size checks but assume a consistent, simplified structure.
If you need clarification, a different .ADT format, or access to specific ADS libraries, please provide additional details
The .ADT file format is the Audio Data Transport Stream (ADTS) format, commonly used for AAC audio streams. It consists of a sequence of independent frames, each containing a header (7 or 9 bytes) followed by raw AAC audio data. There is no global file header or footer; the file is simply a concatenation of these frames. The format supports variable bitrate and allows for error protection via an optional CRC.
List of all the properties of this file format intrinsic to its file system:
- Syncword: 12-bit binary value (always 0xFFF) for frame synchronization.
- MPEG Version: 1-bit binary value (0 for MPEG-4, 1 for MPEG-2).
- Layer: 2-bit binary value (always 0).
- Protection absence: 1-bit binary value (1 if no CRC, 0 if CRC present).
- Profile: 2-bit binary value (MPEG-4 Audio Object Type minus 1).
- Sampling Frequency Index: 4-bit binary value (index into a predefined sampling rate table, 15 forbidden).
- Private bit: 1-bit binary value (set to 0 when encoding, ignored when decoding).
- Channel Configuration: 3-bit binary value (MPEG-4 channel config; 0 indicates in-band PCE).
- Originality: 1-bit binary value (1 if original audio, 0 otherwise).
- Home: 1-bit binary value (1 for home usage, 0 otherwise).
- Copyright ID bit: 1-bit binary value (part of a sliding copyright identifier).
- Copyright ID start: 1-bit binary value (1 if this is the start of the copyright ID).
- Frame length: 13-bit binary value (total length of the frame, including header and CRC if present).
- Buffer fullness: 11-bit binary value (bit reservoir per frame; 0x7FF for variable bitrate).
- Number of AAC frames: 2-bit binary value (number of raw data blocks minus 1).
- CRC check: 16-bit binary value (optional CRC for error detection, present only if protection absence is 0).
- Audio data: Variable-length byte array (raw AAC data blocks following the header).
Python class:
import struct
class ADTFile:
def __init__(self):
self.frames = [] # List of dicts, each with properties and audio data
def load(self, filename):
with open(filename, 'rb') as f:
data = f.read()
offset = 0
while offset < len(data):
# Find syncword (0xFFF, spanning bytes)
if offset + 7 > len(data):
break
header = data[offset:offset+7]
sync = (header[0] << 4) | (header[1] >> 4)
if sync != 0xFFF:
offset += 1
continue
# Unpack header bytes into bits
byte0, byte1, byte2, byte3, byte4, byte5, byte6 = struct.unpack('>7B', header)
mpeg_version = (byte1 >> 3) & 0x01
layer = (byte1 >> 1) & 0x03
protection_absence = byte1 & 0x01
profile = (byte2 >> 6) & 0x03
sampling_freq_index = (byte2 >> 2) & 0x0F
private_bit = (byte2 >> 1) & 0x01
channel_config = ((byte2 & 0x01) << 2) | (byte3 >> 6) & 0x03
originality = (byte3 >> 5) & 0x01
home = (byte3 >> 4) & 0x01
copyright_id_bit = (byte3 >> 3) & 0x01
copyright_id_start = (byte3 >> 2) & 0x01
frame_length = ((byte3 & 0x03) << 11) | (byte4 << 3) | (byte5 >> 5) & 0x07
buffer_fullness = ((byte5 & 0x1F) << 6) | (byte6 >> 2) & 0x3F
num_aac_frames = byte6 & 0x03
crc = None
header_size = 7
if protection_absence == 0:
if offset + 9 > len(data):
break
crc_bytes = data[offset+7:offset+9]
crc = struct.unpack('>H', crc_bytes)[0]
header_size = 9
data_start = offset + header_size
data_end = offset + frame_length
if data_end > len(data):
break
audio_data = data[data_start:data_end]
frame = {
'syncword': 0xFFF,
'mpeg_version': mpeg_version,
'layer': layer,
'protection_absence': protection_absence,
'profile': profile,
'sampling_freq_index': sampling_freq_index,
'private_bit': private_bit,
'channel_config': channel_config,
'originality': originality,
'home': home,
'copyright_id_bit': copyright_id_bit,
'copyright_id_start': copyright_id_start,
'frame_length': frame_length,
'buffer_fullness': buffer_fullness,
'num_aac_frames': num_aac_frames,
'crc': crc,
'audio_data': audio_data
}
self.frames.append(frame)
offset += frame_length
def save(self, filename):
with open(filename, 'wb') as f:
for frame in self.frames:
# Pack header bits into bytes
byte0 = 0xFF
byte1 = 0xF0 | (frame['mpeg_version'] << 3) | (frame['layer'] << 1) | frame['protection_absence']
byte2 = (frame['profile'] << 6) | (frame['sampling_freq_index'] << 2) | (frame['private_bit'] << 1) | (frame['channel_config'] >> 2)
byte3 = (frame['channel_config'] << 6) | (frame['originality'] << 5) | (frame['home'] << 4) | (frame['copyright_id_bit'] << 3) | (frame['copyright_id_start'] << 2) | (frame['frame_length'] >> 11)
byte4 = (frame['frame_length'] >> 3) & 0xFF
byte5 = ((frame['frame_length'] << 5) & 0xE0) | (frame['buffer_fullness'] >> 6) & 0x1F
byte6 = (frame['buffer_fullness'] << 2) & 0xFC | frame['num_aac_frames']
header = struct.pack('>7B', byte0, byte1, byte2, byte3, byte4, byte5, byte6)
f.write(header)
if frame['protection_absence'] == 0 and frame['crc'] is not None:
f.write(struct.pack('>H', frame['crc']))
f.write(frame['audio_data'])
- Java class:
import java.io.*;
import java.nio.*;
import java.util.ArrayList;
import java.util.List;
public class ADTFile {
private List<Frame> frames = new ArrayList<>();
public static class Frame {
public int syncword = 0xFFF;
public int mpegVersion;
public int layer;
public int protectionAbsence;
public int profile;
public int samplingFreqIndex;
public int privateBit;
public int channelConfig;
public int originality;
public int home;
public int copyrightIdBit;
public int copyrightIdStart;
public int frameLength;
public int bufferFullness;
public int numAacFrames;
public Integer crc; // Null if absent
public byte[] audioData;
}
public void load(String filename) throws IOException {
File file = new File(filename);
byte[] data = new byte[(int) file.length()];
try (FileInputStream fis = new FileInputStream(file)) {
fis.read(data);
}
ByteBuffer bb = ByteBuffer.wrap(data).order(ByteOrder.BIG_ENDIAN);
int offset = 0;
while (offset < data.length) {
if (offset + 7 > data.length) break;
bb.position(offset);
int byte0 = bb.get() & 0xFF;
int byte1 = bb.get() & 0xFF;
int sync = (byte0 << 4) | (byte1 >> 4);
if (sync != 0xFFF) {
offset++;
continue;
}
int byte2 = bb.get() & 0xFF;
int byte3 = bb.get() & 0xFF;
int byte4 = bb.get() & 0xFF;
int byte5 = bb.get() & 0xFF;
int byte6 = bb.get() & 0xFF;
int mpegVersion = (byte1 >> 3) & 0x01;
int layer = (byte1 >> 1) & 0x03;
int protectionAbsence = byte1 & 0x01;
int profile = (byte2 >> 6) & 0x03;
int samplingFreqIndex = (byte2 >> 2) & 0x0F;
int privateBit = (byte2 >> 1) & 0x01;
int channelConfig = ((byte2 & 0x01) << 2) | (byte3 >> 6) & 0x03;
int originality = (byte3 >> 5) & 0x01;
int home = (byte3 >> 4) & 0x01;
int copyrightIdBit = (byte3 >> 3) & 0x01;
int copyrightIdStart = (byte3 >> 2) & 0x01;
int frameLength = ((byte3 & 0x03) << 11) | (byte4 << 3) | ((byte5 >> 5) & 0x07);
int bufferFullness = ((byte5 & 0x1F) << 6) | ((byte6 >> 2) & 0x3F);
int numAacFrames = byte6 & 0x03;
Integer crc = null;
int headerSize = 7;
if (protectionAbsence == 0) {
if (offset + 9 > data.length) break;
bb.position(offset + 7);
crc = bb.getShort() & 0xFFFF;
headerSize = 9;
}
int dataStart = offset + headerSize;
int dataEnd = offset + frameLength;
if (dataEnd > data.length) break;
byte[] audioData = new byte[dataEnd - dataStart];
System.arraycopy(data, dataStart, audioData, 0, audioData.length);
Frame frame = new Frame();
frame.mpegVersion = mpegVersion;
frame.layer = layer;
frame.protectionAbsence = protectionAbsence;
frame.profile = profile;
frame.samplingFreqIndex = samplingFreqIndex;
frame.privateBit = privateBit;
frame.channelConfig = channelConfig;
frame.originality = originality;
frame.home = home;
frame.copyrightIdBit = copyrightIdBit;
frame.copyrightIdStart = copyrightIdStart;
frame.frameLength = frameLength;
frame.bufferFullness = bufferFullness;
frame.numAacFrames = numAacFrames;
frame.crc = crc;
frame.audioData = audioData;
frames.add(frame);
offset += frameLength;
}
}
public void save(String filename) throws IOException {
try (FileOutputStream fos = new FileOutputStream(filename)) {
for (Frame frame : frames) {
ByteBuffer bb = ByteBuffer.allocate(7).order(ByteOrder.BIG_ENDIAN);
int byte0 = 0xFF;
int byte1 = 0xF0 | (frame.mpegVersion << 3) | (frame.layer << 1) | frame.protectionAbsence;
int byte2 = (frame.profile << 6) | (frame.samplingFreqIndex << 2) | (frame.privateBit << 1) | (frame.channelConfig >> 2);
int byte3 = (frame.channelConfig << 6) | (frame.originality << 5) | (frame.home << 4) | (frame.copyrightIdBit << 3) | (frame.copyrightIdStart << 2) | (frame.frameLength >> 11);
int byte4 = (frame.frameLength >> 3) & 0xFF;
int byte5 = ((frame.frameLength << 5) & 0xE0) | ((frame.bufferFullness >> 6) & 0x1F);
int byte6 = ((frame.bufferFullness << 2) & 0xFC) | frame.numAacFrames;
bb.put((byte) byte0).put((byte) byte1).put((byte) byte2).put((byte) byte3).put((byte) byte4).put((byte) byte5).put((byte) byte6);
fos.write(bb.array());
if (frame.protectionAbsence == 0 && frame.crc != null) {
ByteBuffer crcBb = ByteBuffer.allocate(2).order(ByteOrder.BIG_ENDIAN);
crcBb.putShort(frame.crc.shortValue());
fos.write(crcBb.array());
}
fos.write(frame.audioData);
}
}
}
}
- Javascript class (Node.js compatible):
const fs = require('fs');
class ADTFile {
constructor() {
this.frames = []; // Array of objects with properties and audio data
}
load(filename) {
const data = fs.readFileSync(filename);
let offset = 0;
while (offset < data.length) {
if (offset + 7 > data.length) break;
const byte0 = data[offset];
const byte1 = data[offset + 1];
const sync = (byte0 << 4) | (byte1 >> 4);
if (sync !== 0xFFF) {
offset++;
continue;
}
const byte2 = data[offset + 2];
const byte3 = data[offset + 3];
const byte4 = data[offset + 4];
const byte5 = data[offset + 5];
const byte6 = data[offset + 6];
const mpegVersion = (byte1 >> 3) & 0x01;
const layer = (byte1 >> 1) & 0x03;
const protectionAbsence = byte1 & 0x01;
const profile = (byte2 >> 6) & 0x03;
const samplingFreqIndex = (byte2 >> 2) & 0x0F;
const privateBit = (byte2 >> 1) & 0x01;
const channelConfig = ((byte2 & 0x01) << 2) | ((byte3 >> 6) & 0x03);
const originality = (byte3 >> 5) & 0x01;
const home = (byte3 >> 4) & 0x01;
const copyrightIdBit = (byte3 >> 3) & 0x01;
const copyrightIdStart = (byte3 >> 2) & 0x01;
const frameLength = ((byte3 & 0x03) << 11) | (byte4 << 3) | ((byte5 >> 5) & 0x07);
const bufferFullness = ((byte5 & 0x1F) << 6) | ((byte6 >> 2) & 0x3F);
const numAacFrames = byte6 & 0x03;
let crc = null;
let headerSize = 7;
if (protectionAbsence === 0) {
if (offset + 9 > data.length) break;
crc = data.readUInt16BE(offset + 7);
headerSize = 9;
}
const dataStart = offset + headerSize;
const dataEnd = offset + frameLength;
if (dataEnd > data.length) break;
const audioData = data.slice(dataStart, dataEnd);
const frame = {
syncword: 0xFFF,
mpegVersion,
layer,
protectionAbsence,
profile,
samplingFreqIndex,
privateBit,
channelConfig,
originality,
home,
copyrightIdBit,
copyrightIdStart,
frameLength,
bufferFullness,
numAacFrames,
crc,
audioData
};
this.frames.push(frame);
offset += frameLength;
}
}
save(filename) {
const buffers = [];
for (const frame of this.frames) {
const buffer = Buffer.alloc(7);
buffer[0] = 0xFF;
buffer[1] = 0xF0 | (frame.mpegVersion << 3) | (frame.layer << 1) | frame.protectionAbsence;
buffer[2] = (frame.profile << 6) | (frame.samplingFreqIndex << 2) | (frame.privateBit << 1) | (frame.channelConfig >> 2);
buffer[3] = (frame.channelConfig << 6) | (frame.originality << 5) | (frame.home << 4) | (frame.copyrightIdBit << 3) | (frame.copyrightIdStart << 2) | (frame.frameLength >> 11);
buffer[4] = (frame.frameLength >> 3) & 0xFF;
buffer[5] = ((frame.frameLength << 5) & 0xE0) | ((frame.bufferFullness >> 6) & 0x1F);
buffer[6] = ((frame.bufferFullness << 2) & 0xFC) | frame.numAacFrames;
buffers.push(buffer);
if (frame.protectionAbsence === 0 && frame.crc !== null) {
const crcBuffer = Buffer.alloc(2);
crcBuffer.writeUInt16BE(frame.crc, 0);
buffers.push(crcBuffer);
}
buffers.push(frame.audioData);
}
fs.writeFileSync(filename, Buffer.concat(buffers));
}
}
- C class (using C++ for class support):
#include <fstream>
#include <vector>
#include <cstdint>
#include <cstring>
struct Frame {
uint16_t syncword = 0xFFF;
uint8_t mpeg_version;
uint8_t layer;
uint8_t protection_absence;
uint8_t profile;
uint8_t sampling_freq_index;
uint8_t private_bit;
uint8_t channel_config;
uint8_t originality;
uint8_t home;
uint8_t copyright_id_bit;
uint8_t copyright_id_start;
uint16_t frame_length;
uint16_t buffer_fullness;
uint8_t num_aac_frames;
uint16_t crc; // 0 if absent
bool has_crc;
std::vector<uint8_t> audio_data;
};
class ADTFile {
public:
std::vector<Frame> frames;
void load(const std::string& filename) {
std::ifstream file(filename, std::ios::binary | std::ios::ate);
if (!file) return;
size_t size = file.tellg();
file.seekg(0);
std::vector<uint8_t> data(size);
file.read(reinterpret_cast<char*>(data.data()), size);
size_t offset = 0;
while (offset < size) {
if (offset + 7 > size) break;
uint8_t byte0 = data[offset];
uint8_t byte1 = data[offset + 1];
uint16_t sync = (byte0 << 4) | (byte1 >> 4);
if (sync != 0xFFF) {
offset++;
continue;
}
uint8_t byte2 = data[offset + 2];
uint8_t byte3 = data[offset + 3];
uint8_t byte4 = data[offset + 4];
uint8_t byte5 = data[offset + 5];
uint8_t byte6 = data[offset + 6];
Frame frame;
frame.mpeg_version = (byte1 >> 3) & 0x01;
frame.layer = (byte1 >> 1) & 0x03;
frame.protection_absence = byte1 & 0x01;
frame.profile = (byte2 >> 6) & 0x03;
frame.sampling_freq_index = (byte2 >> 2) & 0x0F;
frame.private_bit = (byte2 >> 1) & 0x01;
frame.channel_config = ((byte2 & 0x01) << 2) | ((byte3 >> 6) & 0x03);
frame.originality = (byte3 >> 5) & 0x01;
frame.home = (byte3 >> 4) & 0x01;
frame.copyright_id_bit = (byte3 >> 3) & 0x01;
frame.copyright_id_start = (byte3 >> 2) & 0x01;
frame.frame_length = ((byte3 & 0x03) << 11) | (byte4 << 3) | ((byte5 >> 5) & 0x07);
frame.buffer_fullness = ((byte5 & 0x1F) << 6) | ((byte6 >> 2) & 0x3F);
frame.num_aac_frames = byte6 & 0x03;
frame.has_crc = (frame.protection_absence == 0);
size_t header_size = 7;
if (frame.has_crc) {
if (offset + 9 > size) break;
frame.crc = (data[offset + 7] << 8) | data[offset + 8];
header_size = 9;
}
size_t data_start = offset + header_size;
size_t data_end = offset + frame.frame_length;
if (data_end > size) break;
frame.audio_data.resize(data_end - data_start);
std::memcpy(frame.audio_data.data(), data.data() + data_start, frame.audio_data.size());
frames.push_back(frame);
offset += frame.frame_length;
}
}
void save(const std::string& filename) {
std::ofstream file(filename, std::ios::binary);
if (!file) return;
for (const auto& frame : frames) {
uint8_t header[7];
header[0] = 0xFF;
header[1] = 0xF0 | (frame.mpeg_version << 3) | (frame.layer << 1) | frame.protection_absence;
header[2] = (frame.profile << 6) | (frame.sampling_freq_index << 2) | (frame.private_bit << 1) | (frame.channel_config >> 2);
header[3] = (frame.channel_config << 6) | (frame.originality << 5) | (frame.home << 4) | (frame.copyright_id_bit << 3) | (frame.copyright_id_start << 2) | (frame.frame_length >> 11);
header[4] = (frame.frame_length >> 3) & 0xFF;
header[5] = ((frame.frame_length << 5) & 0xE0) | ((frame.buffer_fullness >> 6) & 0x1F);
header[6] = ((frame.buffer_fullness << 2) & 0xFC) | frame.num_aac_frames;
file.write(reinterpret_cast<const char*>(header), 7);
if (frame.has_crc) {
uint8_t crc_bytes[2] = { static_cast<uint8_t>(frame.crc >> 8), static_cast<uint8_t>(frame.crc & 0xFF) };
file.write(reinterpret_cast<const char*>(crc_bytes), 2);
}
file.write(reinterpret_cast<const char*>(frame.audio_data.data()), frame.audio_data.size());
}
}
};