flv4j

Our in-house library for FLV, RTMP and AMF.

Goals

• Fully parse FLV, RTMP and AMF
• Have sane data structures
• Be fault tolerant to future extensions to the protocol (e.g Veovera's enhanced format)

Non-goals

• Decode or encode video or audio codecs/formats.
• Provide high-level APIs for creating services.
• Provide APIs for playing or capturing video or audio.

What works

✅: Fully Supported
❌: Not Supported
➖: Partially Supported
❓: Not Sure

AMF

• ✅ Version 0
• ❌ Version 3

FLV

• ✅ (De)muxing
• ✅ File Header
• ➖ Audio Tag
  • ✅ Header
    • ✅ Codec/Format
    • ✅ Sample Rate
    • ✅ Sample Size
    • ✅ Audio Channels
  • ✅ Enhanced Header
    • ✅ Type
    • ✅ Modifiers
    • ✅ Multitrack
  • ➖ Codec/Format Structures
    • ➖ Standard AAC
    • ❌ Enhanced Codec/Format Structures
• ✅ Script Tag (AMF)
• ➖ Video Tag
  • ✅ Header
    • ✅ Frame Type
    • ✅ Codec
      • ✅ Non-Standard REALH263 (codec 8)
      • ✅ Non-Standard MPEG4 (codec 9)
      • ✅ Non-Standard HEVC (codec 12)
  • ✅ Enhanced Header
    • ✅ Type
    • ✅ Modifiers
    • ✅ Multitrack
  • ➖ Codec/Format Structures
    • ➖ Standard H264
    • ➖ Non-Standard HEVC (codec 12)
    • ➖ Enhanced
      • ➖ H264
      • ➖ HEVC

RTMP

• ✅ Handshake
• ✅ Chunk Streams
• ✅ Enhanced

Relevant specs

• SWF
• FLV
• AMF0
• RTMP
• Veovera's Enhanced RTMP