tape

README

tape

High-performance telemetry codec library and CLI for Echo VR session data.

Module: github.com/echotools/tape

Installation

go get github.com/echotools/tape

tapedeck CLI

tapedeck is the command-line tool for working with tape files.

go install github.com/echotools/tape/cmd/tapedeck@latest

Commands

convert — Batch-convert .echoreplay files to .tape format. Supports parallel workers, recursive directory scanning, glob patterns, dry-run mode, and progress bars.

tapedeck convert *.echoreplay          # convert files in place
tapedeck convert -r -o out/ ./replays  # recursive, output to out/
tapedeck convert --workers 8 *.echoreplay

show — Display tape file contents (header, frames, footer). Output formats: text, json, summary. Optional event filtering.

tapedeck show capture.tape
tapedeck show --format json capture.tape
tapedeck show --events capture.tape

replay — Serve a tape file over HTTP, emulating Echo VR API endpoints (/session, /player_bones) at the original capture rate.

tapedeck replay capture.tape
tapedeck replay --addr :6721 --rate 2.0 capture.tape

Package Structure

pkg/
├── codec/       # File format readers/writers (.tape, .echoreplay)
├── conversion/  # Format conversion utilities
├── events/      # Event detection algorithms
└── processing/  # Frame processing pipeline

Tape Formats

Property	v2 (current)	v1 (legacy)
Envelope	telemetry.v2.Envelope oneof	Raw protobuf messages
Footer	Frame count, duration, keyframe/event indexes	None
Spatial	spatial.v1 float32 (~73.5% smaller)	repeated double (64-bit)
Extension	.tape	.tape / .nevrcap

EchoReplay (.echoreplay) — ZIP-compressed JSON, legacy format from the game engine.

Building

go build ./...                        # build all
go test -race ./...                   # tests with race detector
go test -bench=. -benchmem ./...      # benchmarks
go vet ./...                          # static analysis

Related

• nevr-proto — Protobuf definitions (BSR: buf.build/echotools/nevr-api)
• nevr-agent — Recording and streaming CLI

License

See LICENSE file for details.