JPEG 2000 Video

JPEG 2000 Video

JPEG 2000 (J2K) for high-quality, low-latency video streaming.

Overview

JPEG 2000 is an intra-frame codec providing:

  • Consistent frame-to-frame latency
  • High quality with flexible compression
  • No temporal dependencies
  • Broadcast and cinema industry standard

Characteristics

Aspect JPEG 2000 H.264/H.265
Compression Type Intra-frame Inter-frame
Latency Very low Higher
Error Resilience Excellent Frame dependencies
Edit Friendliness Frame-accurate GOP-based
Compression Ratio Moderate High

GStreamer Backend

MediaX uses GStreamer for JPEG 2000 encoding and decoding:

  • OpenJPEG software codec
  • Hardware acceleration where available

Transmitting JPEG 2000 Video

#include "jpeg2000/gst/rtp_jpeg2000_payloader.h"

mediax::rtp::jpeg2000::gst::RtpJpeg2000GstPayloader payloader;

mediax::rtp::StreamInformation stream_info;
stream_info.session_name = "j2k-stream";
stream_info.hostname = "239.192.1.1";
stream_info.port = 5004;
stream_info.width = 1920;
stream_info.height = 1080;
stream_info.framerate = 30;
stream_info.encoding = mediax::rtp::ColourspaceType::kColourspaceJpeg2000;

payloader.SetStreamInfo(stream_info);
payloader.Open();

// Send RGB24 frames
std::vector<uint8_t> rgb_buffer(1920 * 1080 * 3);
// Fill buffer with video frame...
payloader.Transmit(rgb_buffer.data(), true);

payloader.Close();

Receiving JPEG 2000 Video

#include "jpeg2000/gst/rtp_jpeg2000_depayloader.h"

mediax::rtp::jpeg2000::gst::RtpJpeg2000GstDepayloader depayloader;

mediax::rtp::StreamInformation stream_info;
stream_info.hostname = "239.192.1.1";
stream_info.port = 5004;
stream_info.width = 1920;
stream_info.height = 1080;
stream_info.encoding = mediax::rtp::ColourspaceType::kColourspaceJpeg2000;

depayloader.SetStreamInfo(stream_info);
depayloader.Open();
depayloader.Start();

// Receive decoded RGB frames
std::vector<uint8_t> rgb_buffer(1920 * 1080 * 3);
depayloader.Receive(rgb_buffer.data(), 1000);

depayloader.Stop();
depayloader.Close();

Bandwidth Requirements

JPEG 2000 offers configurable quality vs bandwidth:

Resolution Quality Ratio Approximate Bitrate
1920x1080 10:1 ~50 Mbps
1920x1080 20:1 ~25 Mbps
1920x1080 40:1 ~12 Mbps
3840x2160 10:1 ~200 Mbps
3840x2160 20:1 ~100 Mbps

RTP Payload Format

MediaX implements RFC 5371 for JPEG 2000 RTP payload:

  • Codestream fragmentation
  • Tile-based packetization
  • Progressive decoding support

Software Setup

OpenJPEG

# Ubuntu/Debian
sudo apt install gstreamer1.0-plugins-bad libopenjp2-7-dev

# Verify encoder
gst-inspect-1.0 openjpegenc

# Verify decoder
gst-inspect-1.0 openjpegdec

Use Cases

JPEG 2000 is ideal for:

  • Broadcast contribution: Low latency, high quality
  • Medical imaging: Lossless option available
  • Digital cinema: DCI specification
  • Defense applications: Consistent latency

Latency Comparison

JPEG 2000 provides predictable latency due to intra-frame coding:

Codec Typical Encoding Latency
Uncompressed 0 ms
JPEG 2000 5-10 ms
H.264 30-100 ms
H.265 50-150 ms

Quality Modes

Lossy Compression

Default mode with configurable quality:

  • Higher compression ratios
  • Visual quality preserved at moderate ratios
  • Best for real-time streaming

Visually Lossless

High quality setting for critical applications:

  • Minimal visible artifacts
  • Higher bandwidth requirement
  • Suitable for color grading workflows

Mathematically Lossless

No data loss (where supported):

  • Exact pixel reconstruction
  • Highest bandwidth
  • Medical and scientific applications

Support

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