Media Transcoder

FFmpeg video transcoding with profile management, job queue, progress tracking, and optional NVIDIA NVENC acceleration.

MuxCore sidecar module (media-transcoder) exposing muxcore.transcoder.v1.TranscodeService over gRPC.

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How It Works

Enqueue(input, output, profile) ──→ FFmpeg job ──→ output file
         │                              │
         ├── SQLite profiles + jobs     ├── progress / fps (stderr parse)
         └── DetectHardware (nvenc/vaapi advertised)

Key Features

• Profile CRUD — video/audio codec, preset, CRF, max width/height, GPU flag, container
• Job queue — enqueue, cancel, list (paged), get by ID; concurrent slots via TRANSCODER_MAX_CONCURRENT
• Default profiles — h264_fast (H.264 Fast), hevc_gpu (HEVC GPU, max height 1080)
• Hardware detection — reports NVENC / VAAPI encoders when FFmpeg lists them
• GPU encode path — when use_gpu and NVENC are available: h264_nvenc / hevc_nvenc / av1_nvenc; otherwise libx264 / libx265 / libaom-av1
• Workflow — capability transcoder for seeded media-transcode DAG (with media-ffprobe)

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Configuration

Variable	Default	Description
TRANSCODER_DB_PATH	/var/lib/media-transcoder/transcoder.db	SQLite database path
TRANSCODER_GRPC_ADDR	:9525	gRPC listen address (also reported as HTTPAddr)
TRANSCODER_MAX_CONCURRENT	2	Max simultaneous FFmpeg jobs
MUXCORE_GRPC_ADDR	—	Core mesh address (optional)
MUXCORE_INSECURE_DISABLE_TLS	false	Disable TLS for local/dev mesh

Module info: ID media-transcoder, version 0.1.1, capabilities media.transcoder / executor.transcode / transcoder, role transcoder, min core 0.4.0.

Optional MVP host: MVP_ENABLE_MEDIA_TRANSCODER=1 (compose profile transcoder).

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Quick Start

go build -o media-transcoder ./cmd/module

export MUXCORE_INSECURE_DISABLE_TLS=true
./media-transcoder --muxcore-mesh-addr localhost:9090

# List profiles
grpcurl :9525 muxcore.transcoder.v1.TranscodeService/ListProfiles

# Enqueue a job
grpcurl -d '{"input_path":"/path/in.mkv","output_path":"/path/out.mkv","profile_id":"h264_fast"}' \
  :9525 muxcore.transcoder.v1.TranscodeService/Enqueue

# Detect hardware
grpcurl :9525 muxcore.transcoder.v1.TranscodeService/DetectHardware

Requires ffmpeg on PATH (Health fails closed without it).

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gRPC API

Proto: proto/transcodev1/transcoder.proto

RPC	Purpose
ListProfiles / CreateProfile / UpdateProfile / DeleteProfile	Transcode profiles
Enqueue / CancelJob / ListJobs / GetJob	Job lifecycle
DetectHardware	Available hardware encoders

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Development

go test -race -count=1 ./...