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eflv

A command-line tool for inspecting and manipulating FLV and E-FLV (Enhanced FLV) files.

Build

go build -o bin/

Usage

bin/eflv [command] [flags]

Commands

info

Display structural information about an FLV / E-FLV file.

bin/eflv info <input.flv> [--json] [--verbose]

Flag	Description
--json	Output machine-readable JSON instead of text
--verbose	Include lower-level details (offsets, timestamps, tag counts)

merge

Merge two E-FLV inputs into a single output FLV.

bin/eflv merge <a.flv> <b.flv> -o <out.flv> [--multitrack]

Flag	Description
-o, --output	Output file path (required)
--multitrack	Preserve each input as a separate track group

Project Structure

├── main.go          # Entry point
├── cmd/
│   ├── root.go      # Root CLI command (Cobra)
│   ├── info.go      # info subcommand
│   └── merge.go     # merge subcommand
├── flv/
│   ├── parser.go        # FLV file parsing
│   ├── amf0.go          # AMF0 decoder
│   ├── codec_config.go  # Codec configuration record parsing
│   └── merge.go         # FLV merge logic

Status

Work in progress. The tool is under active development. Current state:

• FLV header and tag counting are functional
• onMetaData script tag parsing with AMF0 decoding is implemented
• FourCC codec identification for E-RTMP is supported
• Codec configuration record parsing for video (AVC, HEVC, AV1, VP9) and audio (AAC, Opus, FLAC)
• JSON output, verbose mode, and merge logic are not yet implemented

Dependencies

• cobra — CLI framework