DVB Inspector Tips & Tricks for Faster Troubleshooting

How to Use DVB Inspector to Analyze Digital TV Streams

What DVB Inspector Is

DVB Inspector is a free, Java-based tool for inspecting, analyzing, and troubleshooting MPEG-TS (DVB) streams. It decodes tables (PAT/PMT/NIT/SDT), shows PID usage, logs errors, and provides payload-level views useful for broadcasters, engineers, and hobbyists.

Getting Started

1. Download & install Java: Ensure Java 8+ is installed.
2. Get DVB Inspector: Download the latest JAR from the project site and place it in a folder.
3. Launch: Run java -jar dvbinspector.jar (double-click works on some systems).

Loading a Stream

• From file: Use File → Open and select an MPEG-TS (.ts/.mpeg) capture.
• From network: Use File → Open network stream and enter an HTTP/UDP/RTP URL (e.g., udp://@239.0.0.1:1234).
• Live capture: Capture to a file with a separate tool (ffmpeg, dvbstream) and open that file in DVB Inspector.

Main Interface Overview

• Packet list: Shows TS packets (PID, continuity counter, errors).
• Tables view: Decoded PSI/SI tables: PAT, PMT, NIT, SDT, EIT.
• Elementary Streams: Lists audio/video/subtitles and codecs.
• PID usage chart: Visual PID allocation and bitrates.
• Errors/log: CRC, continuity, parsing errors.

Step-by-Step Analysis Workflow

1. Basic sanity check: Scan for packet errors and CRC/continuity issues in the packet list. High error rates indicate capture/network problems.
2. Verify PAT/PMT: Open PAT to confirm program numbers and PMT PIDs. Inspect PMT to identify all component PIDs (video, audio, teletext, subtitles).
3. Check PID bitrate and allocation: Use the PID usage chart to spot unexpected high bitrates or unused PIDs. Sudden bitrate changes can indicate encoder glitches.
4. Inspect elementary streams: Select a video or audio PID to view codec, resolution, and timestamps (PCR/PTS/DTS). Verify PCR stability and that PTS/DTS make sense (no large jumps).
5. Examine SI data: Check NIT/SDT/EIT for correct service labeling and network info—useful for receiver compatibility.
6. Look for service disruptions: Search the log for PMT changes, service additions/removals, or frequent PID reassignments indicating multiplexing issues.
7. Payload inspection: For deeper debugging, view PES payloads and PES headers to confirm stream framing and codec-level markers (SPS/PPS for H.264, for example).
8. Record findings: Use the export feature to save decoded tables and logs for reporting or further offline analysis.

Common Issues and How to Diagnose

• Continuity counter errors: Usually packet loss; check capture device, network multicast configuration, or tuner signal strength.
• PCR jitter / drift: Causes audio/video sync problems; look for irregular PCR intervals or encoder clock issues.
• Incorrect PMT mapping: Receiver won’t find components; verify PMT entries contain correct stream_type and PID.
• Null or unexpected PIDs: Null packets can fill bitrate gaps — high null percentage may indicate overprovisioning or muxing issues.

Tips & Best Practices

• Use consistent capture tools (ffmpeg/tsduck) to avoid introducing artifacts.
• When analyzing live multicast, mirror the stream to a local file for repeatable testing.
• Filter views by PID to reduce noise when investigating a single service.
• Compare a known-good capture with the problematic one to spot differences quickly.

Useful Commands & Shortcuts

• Open file: File → Open
• Open network: File → Open network stream
• Export PSI/SI: Right-click table → Export
• Filter PID: Enter PID in the filter box (hex/decimal)

Conclusion

DVB Inspector is a powerful, lightweight utility for inspecting MPEG-TS streams. Follow the workflow above—sanity check, validate tables, inspect P