# Probe and Debug
## Hardware probe
```bash
direct_play_nice --probe-hw
direct_play_nice --probe-hw --probe-json
```
## Codec inventory
```bash
direct_play_nice --probe-codecs --only-video
direct_play_nice --probe-codecs --only-video --only-hw --probe-json
```
## Input stream probe
```bash
direct_play_nice --probe-streams input.mkv
direct_play_nice --probe-streams --output json input.mkv
```
## Concurrency controls
- `DIRECT_PLAY_NICE_MAX_JOBS`
- `DIRECT_PLAY_NICE_JOBS_PER_GPU`
Use these to tune parallel conversion throughput per machine.
For GPU architecture guidance and official vendor/runtime references (ONNX,
CUDA, DirectML, Video Codec SDK, oneVPL, AMF, VideoToolbox), see
[Hardware Acceleration](./hardware-acceleration.md).
## OCR runtime diagnostics (Linux)
- verify ONNX Runtime linkage if OCR provider loading fails
- set `ORT_DYLIB_PATH` when `libonnxruntime.so` is in a non-standard location
- set `DPN_OCR_REQUIRE_GPU=1` for fail-fast behavior when GPU OCR is mandatory