OpenDCP Workflow: From ProRes to DCP in 5 Steps### Introduction
Creating a Digital Cinema Package (DCP) is a critical step when delivering films to theaters and festivals. OpenDCP is a free, open-source toolset widely used by independent filmmakers to convert common post-production formats (like Apple ProRes) into industry-standard DCPs. This guide walks through a complete, practical workflow — from preparing your ProRes files to generating and verifying a final DCP — in five clear steps. It includes best practices, common pitfalls, and tips for audio, subtitles, color, and file naming so your DCP plays reliably on cinema servers.
Step 1 — Prepare and QC Your Source Files
Before conversion, ensure your ProRes master is technically and creatively ready.
Key checks:
- Frame rate: Confirm whether your project is 23.976, 24.000, 25, 29.97, or 30 fps. Feature films typically use 24.000 fps.
- Resolution and aspect ratio: Know whether you’re delivering to 2K (2048×1080 or 1998×1080) or 4K (4096×2160) and whether your image is Flat (1.85:1), Scope (2.39:1), or Full Frame (1.90:1).
- Color space: Work in a color-managed pipeline. Your ProRes should be grade-locked in Rec.709 (common for DCP) or with a known LUT if working in log formats.
- Audio format: Stereo or 5.1? OpenDCP typically expects uncompressed WAV files. Ensure channels are correctly ordered and balanced.
- Timecode and black/lead: Add 3 minutes of 0-frame leader and proper SMPTE timecode if required by the festival.
Quality control:
- Run a visual watch-through, spot-checking for dropped frames, artifacts, or codec issues.
- Use tools like MediaInfo to confirm codecs, bitrates, and frame rates.
- Normalize and peak-limit audio to avoid clipping; target -6 dBFS to the loudest peaks for cinema.
Step 2 — Install and Configure OpenDCP
OpenDCP runs on Windows, macOS, and Linux. Installation is straightforward, but configure project settings before use.
Installation:
- Download the latest OpenDCP release for your OS from the official repository or releases page.
- Install dependencies if required (FFmpeg, Java runtime on some builds).
Configuration:
- Launch OpenDCP and set working directories for source files, temporary files, and output DCPs.
- Check and set the default frame rate and resolution presets matching your project.
- For color, if you have an XYZ LUT or color transform, note the steps needed to apply or bake the LUT before using OpenDCP (OpenDCP expects image files in a linear light space for XYZ conversion).
Tip: Keep your ProRes files and audio WAVs in a single folder named with the project and final frame rate (e.g., ProjectName_24fps).
Step 3 — Extract and Prepare Audio
OpenDCP separates video and audio during the DCP build. Prepare audio tracks cleanly.
Audio extraction and prep:
- Export audio from your NLE/DAW as interleaved or multi-channel WAVs at 48 kHz (preferred) or 48 kHz with 24-bit depth. For 5.1, export as a single 6-channel WAV or split into mono files labeled L, R, C, LFE, LS, RS.
- Ensure channel mapping follows cinema conventions: L, R, C, LFE, LS, RS.
- Normalize dialog and apply final compression/limiting as needed. Avoid excessive loudness — aim for a theatrical mix; many festivals request a reference level around -20 dBFS LKFS integrated loudness, but check festival specs.
- Name files clearly: ProjectName_5.1.wav or ProjectName_L.wav etc.
Verification:
- Open the WAV in a waveform editor to check for clipping, silence, or DC offset.
- Confirm sample rate/bit depth with MediaInfo or similar.
Step 4 — Create the XYZ Images and Generate the DCP
This is where OpenDCP converts video frames into XYZ JPEG2000 frames and assembles the DCP.
Video prepping:
- If your ProRes is not already in XYZ-compatible color space, render/export a TIFF/DPX sequence from your finishing application in a known color space (Rec.709 or ACES-to-XYZ pass) or use FFmpeg to extract frames.
- For most indie deliveries, exporting a high-quality TIFF sequence in Rec.709 then using OpenColorIO/FFmpeg to convert to XYZ works reliably.
Using OpenDCP:
- Use the “Image to JPEG2000” tool to convert your TIFF/DPX sequence to JPEG2000 (JPEG2000 quality settings control file size vs. fidelity).
- Use the “Audio to WAV” or appropriate audio tool to ensure WAVs are correctly formatted.
- Use the “MXF DCP” or “Create DCP” tool to combine the JPEG2000 track and WAV audio into a DCP. Enter metadata: title, reel names, aspect ratio, frame rate, and audio channel configuration.
Settings notes:
- For 2K DCPs, choose 2048×1080 (Flat or Scope crops as needed).
- Set interop vs SMPTE: SMPTE DCPs are more modern and compatible with most servers; choose SMPTE unless a venue requires Interop.
- Compression: choose visually lossless JPEG2000 settings; mid-to-high Q factors usually suffice for ProRes masters.
Step 5 — Validate, Test, and Deliver
Final checks ensure the DCP will play on projection servers.
Validation:
- Use OpenDCP’s validator (or third-party validators like DCP-o-matic’s checker) to verify asset integrity, UUIDs, and MXF container correctness.
- Check CPL (Composition Play List) metadata for correct frame rate, duration, and reel order.
Testing:
- Play the DCP locally using a DCP player (e.g., NeoDCP, EasyDCP Player, or DCP-o-matic’s player) to verify sync, aspect ratio, subtitles, and audio mapping.
- If possible, run a projector check at the venue or with a technician to ensure color and sound conform to expectations.
Delivery:
- Deliver via a physically encrypted hard drive (CineCert/HSM) or a secure upload, following festival/server requirements.
- Include a text file with playback notes, frame rate, runtime, audio configuration, and any special instructions.
Common Pitfalls and Troubleshooting
- Frame rate mismatch: converting 23.976 to 24 without proper handling can cause drift. Use frame-rate conversion tools if necessary.
- Wrong color space: image appears desaturated or oversaturated if not converted to XYZ correctly. Bake LUTs before conversion.
- Channel mapping errors: surround channels swapped or silent channels occur when WAV channels are misordered; verify channel order carefully.
- Large file sizes: JPEG2000 can produce very large DCPs; balance compression to stay within delivery size limits without visible artifacts.
Quick Checklist (Summary)
- Confirm frame rate, resolution, and aspect ratio (24.000 fps, 2K/4K).
- Export high-quality ProRes or TIFF/DPX sequences in Rec.709 or a known color space.
- Export audio as 48 kHz WAVs with correct channel order (L, R, C, LFE, LS, RS).
- Use OpenDCP tools to convert images to JPEG2000 and assemble the DCP (choose SMPTE unless otherwise specified).
- Validate the DCP, test playback, and deliver with clear notes.
If you want, I can produce a step-by-step OpenDCP command list for FFmpeg/OpenDCP or a checklist tailored to a specific project (frame rate, audio format, and resolution).
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