Task 783: .VOB File Format
Task 783: .VOB File Format
File Format Specifications for the .VOB File Format
The .VOB (Video Object) file format is a container used in DVD-Video media, defined by the DVD Forum as part of the DVD-Video specification. It is a strict subset of the MPEG-2 Program Stream format (ISO/IEC 13818-1), with additional constraints and private streams for DVD-specific data such as navigation, menus, and subtitles. The format multiplexes video, audio, and subtitle streams, often with copy protection via the Content Scramble System (CSS). VOB files typically contain H.262/MPEG-2 Part 2 or MPEG-1 Part 2 video, audio in formats like LPCM, AC-3 (Dolby Digital), DTS, or MPEG-1/2 Audio Layer II, and bitmap-based subpictures for subtitles. The internal structure consists of packs starting with a pack header (0x000001BA), followed by optional system headers and Packetized Elementary Stream (PES) packets for the various streams.
- List of All Properties of This File Format Intrinsic to Its File System
Based on the specifications, the properties intrinsic to the .VOB file format in the context of its organization within the DVD file system (typically a UDF/ISO 9660 bridge format) include the following:
- Directory location: Stored exclusively within the VIDEO_TS directory at the root of the DVD.
- File extension: .vob (case-insensitive, but typically lowercase).
- Maximum file size: Limited to 1 GB (1,073,741,824 bytes) per file to ensure compatibility across operating systems.
- Naming convention: Files are named in patterns such as VIDEO_TS.VOB (for video manager menus), VTS_xx_0.VOB (for title set menus), and VTS_xx_y.VOB (for title set content, where xx is the title set number from 01 to 99, and y is the segment number starting from 1).
- File segmentation: Content for a single title set is contiguous but segmented into multiple .VOB files if exceeding 1 GB.
- Physical layout requirements: All files must be allocated contiguously on the disc; related files (e.g., VOB, IFO, BUP for the same title set) should be placed adjacent to each other, with numbered files in ascending order.
- Companion files: Each .VOB set is associated with corresponding .IFO (information) files for navigation data (e.g., chapter starts, stream locations) and .BUP (backup) files as redundant copies of .IFO files, placed in separate physical sectors for redundancy against disc damage.
- Copy protection integration: Often encrypted with CSS, requiring authentication and decryption keys stored in the disc's lead-in area (inaccessible to standard file reads); this affects file accessibility outside authorized players.
- File system compatibility: Designed for hybrid UDF (Universal Disk Format) and ISO 9660 file systems, ensuring readability on both computers and DVD players.
- Contiguity and ordering: Files within a title set must maintain logical and physical contiguity for seamless playback; BUP files are physically separated from IFO files for error recovery.
These properties ensure the format's integration with the DVD file system for reliable playback and navigation.
- Two Direct Download Links for Files of Format .VOB
- https://filesamples.com/samples/video/vob/sample_1280x720_surfing_with_audio.vob
- https://filesamples.com/samples/video/vob/sample_960x400_ocean_with_audio.vob
These links provide sample .VOB files for testing purposes.
- Ghost Blog Embedded HTML JavaScript for Drag-and-Drop .VOB File Analysis
The following is an embeddable HTML snippet with JavaScript suitable for integration into a Ghost blog post (via the HTML card in the editor). It allows users to drag and drop a .VOB file, parses the file to extract the listed properties (using basic MPEG-2 PS header scanning for intrinsic details like stream counts and video/audio metadata), and displays them on the screen. Note that full parsing requires handling binary data; this implementation focuses on key headers for demonstration and assumes the file is unencrypted.
Drag and drop a .VOB file here
- Python Class for .VOB File Handling
The following Python class opens a .VOB file, decodes key headers to read the properties, prints them to the console, and includes a write method to save a modified version (e.g., with a dummy header change for demonstration). It uses pure Python for binary parsing.
import struct
import os
class VOBHandler:
def __init__(self, filepath):
self.filepath = filepath
self.properties = {}
self.data = None
def decode_and_read(self):
with open(self.filepath, 'rb') as f:
self.data = f.read()
self.properties = self._parse_properties()
self.print_properties()
def _parse_properties(self):
properties = {
'directoryLocation': 'VIDEO_TS (inferred from format)',
'fileExtension': '.vob',
'maxFileSize': '1 GB (specification limit)',
'namingConvention': 'VTS_xx_y.VOB (inferred from filename: ' + os.path.basename(self.filepath) + ')',
'fileSegmentation': 'Segmented (exceeds 1 GB)' if len(self.data) > 1073741824 else 'Single segment',
'physicalLayout': 'Contiguous allocation required',
'companionFiles': '.IFO and .BUP (associated)',
'copyProtection': 'Potential CSS (not parsed)',
'fileSystemCompatibility': 'UDF/ISO 9660',
'contiguityAndOrdering': 'Ascending order required',
}
# Parse MPEG PS for additional intrinsic properties
offset = 0
has_nav_pack = False
video_streams = set()
audio_streams = set()
subtitle_streams = set()
while offset + 14 < len(self.data):
pack_start = struct.unpack_from('>I', self.data, offset)[0]
if pack_start == 0x000001BA:
offset += 14
while offset + 6 < len(self.data):
pes_start = struct.unpack_from('>I', self.data, offset)[0]
if pes_start == 0x000001E0: # Video
video_streams.add('MPEG-2 Video')
elif pes_start == 0x000001BD: # Private 1
sub_id = self.data[offset + 9]
if 0x20 <= sub_id <= 0x3F:
subtitle_streams.add('Subtitle')
elif sub_id == 0x80:
audio_streams.add('AC-3')
# Add more sub-ID checks as needed
elif pes_start == 0x000001BF:
has_nav_pack = True
pes_length = struct.unpack_from('>H', self.data, offset + 4)[0]
offset += pes_length + 6
offset += 1
properties['hasNavigationPacks'] = 'Yes' if has_nav_pack else 'No'
properties['numberOfVideoStreams'] = len(video_streams)
properties['numberOfAudioStreams'] = len(audio_streams)
properties['numberOfSubtitleStreams'] = len(subtitle_streams)
return properties
def print_properties(self):
for key, value in self.properties.items():
print(f"{key}: {value}")
def write(self, output_path):
# For demonstration, write the data with a minor modification (e.g., add a dummy pack)
if self.data:
dummy_header = b'\x00\x00\x01\xBA' + b'\x00' * 10 # Simplified dummy pack
modified_data = dummy_header + self.data
with open(output_path, 'wb') as f:
f.write(modified_data)
print(f"File written to {output_path}")
# Example usage:
# handler = VOBHandler('example.vob')
# handler.decode_and_read()
# handler.write('modified.vob')
- Java Class for .VOB File Handling
The following Java class performs similar operations: opens a .VOB file, decodes headers, reads and prints properties, and writes a modified version.
import java.io.*;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.*;
public class VOBHandler {
private String filepath;
private Map<String, String> properties = new HashMap<>();
private byte[] data;
public VOBHandler(String filepath) {
this.filepath = filepath;
}
public void decodeAndRead() throws IOException {
data = Files.readAllBytes(Paths.get(filepath));
properties = parseProperties();
printProperties();
}
private Map<String, String> parseProperties() {
Map<String, String> props = new HashMap<>();
props.put("directoryLocation", "VIDEO_TS (inferred from format)");
props.put("fileExtension", ".vob");
props.put("maxFileSize", "1 GB (specification limit)");
props.put("namingConvention", "VTS_xx_y.VOB (inferred from filename: " + new File(filepath).getName() + ")");
props.put("fileSegmentation", data.length > 1073741824 ? "Segmented (exceeds 1 GB)" : "Single segment");
props.put("physicalLayout", "Contiguous allocation required");
props.put("companionFiles", ".IFO and .BUP (associated)");
props.put("copyProtection", "Potential CSS (not parsed)");
props.put("fileSystemCompatibility", "UDF/ISO 9660");
props.put("contiguityAndOrdering", "Ascending order required");
// Parse MPEG PS
ByteBuffer buffer = ByteBuffer.wrap(data).order(ByteOrder.BIG_ENDIAN);
int offset = 0;
boolean hasNavPack = false;
Set<String> videoStreams = new HashSet<>();
Set<String> audioStreams = new HashSet<>();
Set<String> subtitleStreams = new HashSet<>();
while (offset + 14 < data.length) {
if (buffer.getInt(offset) == 0x000001BA) {
offset += 14;
while (offset + 6 < data.length) {
int pesStart = buffer.getInt(offset);
if (pesStart == 0x000001E0) {
videoStreams.add("MPEG-2 Video");
} else if (pesStart == 0x000001BD) {
int subId = Byte.toUnsignedInt(data[offset + 9]);
if (subId >= 0x20 && subId <= 0x3F) {
subtitleStreams.add("Subtitle");
} else if (subId == 0x80) {
audioStreams.add("AC-3");
}
} else if (pesStart == 0x000001BF) {
hasNavPack = true;
}
int pesLength = buffer.getShort(offset + 4);
offset += pesLength + 6;
}
}
offset++;
}
props.put("hasNavigationPacks", hasNavPack ? "Yes" : "No");
props.put("numberOfVideoStreams", String.valueOf(videoStreams.size()));
props.put("numberOfAudioStreams", String.valueOf(audioStreams.size()));
props.put("numberOfSubtitleStreams", String.valueOf(subtitleStreams.size()));
return props;
}
public void printProperties() {
properties.forEach((key, value) -> System.out.println(key + ": " + value));
}
public void write(String outputPath) throws IOException {
if (data != null) {
byte[] dummyHeader = new byte[]{0x00, 0x00, 0x01, (byte)0xBA, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
byte[] modifiedData = new byte[dummyHeader.length + data.length];
System.arraycopy(dummyHeader, 0, modifiedData, 0, dummyHeader.length);
System.arraycopy(data, 0, modifiedData, dummyHeader.length, data.length);
Files.write(Paths.get(outputPath), modifiedData);
System.out.println("File written to " + outputPath);
}
}
// Example usage:
// public static void main(String[] args) throws IOException {
// VOBHandler handler = new VOBHandler("example.vob");
// handler.decodeAndRead();
// handler.write("modified.vob");
// }
}
- JavaScript Class for .VOB File Handling
The following JavaScript class (Node.js compatible) opens a .VOB file, decodes headers, reads and prints properties to the console, and writes a modified version. Requires Node.js with 'fs' module.
const fs = require('fs');
class VOBHandler {
constructor(filepath) {
this.filepath = filepath;
this.properties = {};
this.data = null;
}
decodeAndRead() {
this.data = fs.readFileSync(this.filepath);
this.properties = this.parseProperties();
this.printProperties();
}
parseProperties() {
const properties = {
directoryLocation: 'VIDEO_TS (inferred from format)',
fileExtension: '.vob',
maxFileSize: '1 GB (specification limit)',
namingConvention: `VTS_xx_y.VOB (inferred from filename: ${this.filepath.split('/').pop()})`,
fileSegmentation: this.data.length > 1073741824 ? 'Segmented (exceeds 1 GB)' : 'Single segment',
physicalLayout: 'Contiguous allocation required',
companionFiles: '.IFO and .BUP (associated)',
copyProtection: 'Potential CSS (not parsed)',
fileSystemCompatibility: 'UDF/ISO 9660',
contiguityAndOrdering: 'Ascending order required',
};
// Parse MPEG PS using Buffer
const view = new DataView(this.data.buffer);
let offset = 0;
let hasNavPack = false;
const videoStreams = new Set();
const audioStreams = new Set();
const subtitleStreams = new Set();
while (offset + 14 < this.data.length) {
if (view.getUint32(offset) === 0x000001BA) {
offset += 14;
while (offset + 6 < this.data.length) {
const pesStart = view.getUint32(offset);
if (pesStart === 0x000001E0) {
videoStreams.add('MPEG-2 Video');
} else if (pesStart === 0x000001BD) {
const subId = view.getUint8(offset + 9);
if (subId >= 0x20 && subId <= 0x3F) {
subtitleStreams.add('Subtitle');
} else if (subId === 0x80) {
audioStreams.add('AC-3');
}
} else if (pesStart === 0x000001BF) {
hasNavPack = true;
}
const pesLength = view.getUint16(offset + 4);
offset += pesLength + 6;
}
}
offset++;
}
properties.hasNavigationPacks = hasNavPack ? 'Yes' : 'No';
properties.numberOfVideoStreams = videoStreams.size;
properties.numberOfAudioStreams = audioStreams.size;
properties.numberOfSubtitleStreams = subtitleStreams.size;
return properties;
}
printProperties() {
for (const [key, value] of Object.entries(this.properties)) {
console.log(`${key}: ${value}`);
}
}
write(outputPath) {
if (this.data) {
const dummyHeader = Buffer.from([0x00, 0x00, 0x01, 0xBA, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
const modifiedData = Buffer.concat([dummyHeader, this.data]);
fs.writeFileSync(outputPath, modifiedData);
console.log(`File written to ${outputPath}`);
}
}
}
// Example usage:
// const handler = new VOBHandler('example.vob');
// handler.decodeAndRead();
// handler.write('modified.vob');
- C++ Class for .VOB File Handling
The following C++ class opens a .VOB file, decodes headers, reads and prints properties to the console, and writes a modified version.
#include <iostream>
#include <fstream>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <cstdint>
class VOBHandler {
private:
std::string filepath;
std::map<std::string, std::string> properties;
std::vector<uint8_t> data;
public:
VOBHandler(const std::string& fp) : filepath(fp) {}
void decodeAndRead() {
std::ifstream file(filepath, std::ios::binary | std::ios::ate);
if (!file) {
std::cerr << "Failed to open file." << std::endl;
return;
}
std::streamsize size = file.tellg();
file.seekg(0, std::ios::beg);
data.resize(size);
file.read(reinterpret_cast<char*>(data.data()), size);
properties = parseProperties();
printProperties();
}
std::map<std::string, std::string> parseProperties() {
std::map<std::string, std::string> props;
props["directoryLocation"] = "VIDEO_TS (inferred from format)";
props["fileExtension"] = ".vob";
props["maxFileSize"] = "1 GB (specification limit)";
size_t pos = filepath.find_last_of("/\\");
std::string filename = (pos == std::string::npos) ? filepath : filepath.substr(pos + 1);
props["namingConvention"] = "VTS_xx_y.VOB (inferred from filename: " + filename + ")";
props["fileSegmentation"] = (data.size() > 1073741824) ? "Segmented (exceeds 1 GB)" : "Single segment";
props["physicalLayout"] = "Contiguous allocation required";
props["companionFiles"] = ".IFO and .BUP (associated)";
props["copyProtection"] = "Potential CSS (not parsed)";
props["fileSystemCompatibility"] = "UDF/ISO 9660";
props["contiguityAndOrdering"] = "Ascending order required";
// Parse MPEG PS
size_t offset = 0;
bool hasNavPack = false;
std::set<std::string> videoStreams;
std::set<std::string> audioStreams;
std::set<std::string> subtitleStreams;
while (offset + 14 < data.size()) {
uint32_t packStart = (data[offset] << 24) | (data[offset + 1] << 16) | (data[offset + 2] << 8) | data[offset + 3];
if (packStart == 0x000001BA) {
offset += 14;
while (offset + 6 < data.size()) {
uint32_t pesStart = (data[offset] << 24) | (data[offset + 1] << 16) | (data[offset + 2] << 8) | data[offset + 3];
if (pesStart == 0x000001E0) {
videoStreams.insert("MPEG-2 Video");
} else if (pesStart == 0x000001BD) {
uint8_t subId = data[offset + 9];
if (subId >= 0x20 && subId <= 0x3F) {
subtitleStreams.insert("Subtitle");
} else if (subId == 0x80) {
audioStreams.insert("AC-3");
}
} else if (pesStart == 0x000001BF) {
hasNavPack = true;
}
uint16_t pesLength = (data[offset + 4] << 8) | data[offset + 5];
offset += pesLength + 6;
}
}
offset++;
}
props["hasNavigationPacks"] = hasNavPack ? "Yes" : "No";
props["numberOfVideoStreams"] = std::to_string(videoStreams.size());
props["numberOfAudioStreams"] = std::to_string(audioStreams.size());
props["numberOfSubtitleStreams"] = std::to_string(subtitleStreams.size());
return props;
}
void printProperties() {
for (const auto& pair : properties) {
std::cout << pair.first << ": " << pair.second << std::endl;
}
}
void write(const std::string& outputPath) {
if (!data.empty()) {
std::vector<uint8_t> dummyHeader = {0x00, 0x00, 0x01, 0xBA, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
std::vector<uint8_t> modifiedData;
modifiedData.reserve(dummyHeader.size() + data.size());
modifiedData.insert(modifiedData.end(), dummyHeader.begin(), dummyHeader.end());
modifiedData.insert(modifiedData.end(), data.begin(), data.end());
std::ofstream outFile(outputPath, std::ios::binary);
outFile.write(reinterpret_cast<const char*>(modifiedData.data()), modifiedData.size());
std::cout << "File written to " << outputPath << std::endl;
}
}
};
// Example usage:
// int main() {
// VOBHandler handler("example.vob");
// handler.decodeAndRead();
// handler.write("modified.vob");
// return 0;
// }