Configure DeckLink Input Format in FFmpeg

Configuring Blackmagic DeckLink capture cards in FFmpeg requires defining the correct input format, such as 1080i59.94, to match your incoming SDI or HDMI video signal. This guide explains how to identify your DeckLink device name, list its supported video formats, and construct the precise FFmpeg command required to capture video using specific format codes.

Step 1: Find Your DeckLink Device Name

Before configuring the format, you must identify the exact name of your connected Blackmagic design device as recognized by FFmpeg. Run the following command to list all detected DeckLink input devices:

ffmpeg -f decklink -list_devices 1 -i dummy

Look at the console output for a line similar to: [decklink @ 0x...] Blackmagic connections: ... Identify your target device name (e.g., "DeckLink Mini Recorder" or "UltraStudio HD Mini").

Step 2: List Supported Format Codes

DeckLink devices use specific four-character format codes to define resolution and frame rate. To see the list of format codes supported by your specific device, run:

ffmpeg -f decklink -list_formats 1 -i "Your Device Name"

Replace "Your Device Name" with the exact name found in Step 1. The output will display a table containing format codes, resolutions, and frame rates. For example, you will see a line like:

hi59 for 1080i59.94 (1920x1080 at 29.97 fps, interlaced)
hp59 for 720p59.94 (1280x720 at 59.94 fps, progressive)
Hp50 for 1080p50 (1920x1080 at 50 fps, progressive)

Step 3: Configure and Run the Capture Command

Once you have identified the device name and the format code, use the -format_code option to configure the input.

To capture a 1080i59.94 signal using the format code hi59, use the following command structure:

ffmpeg -f decklink -format_code hi59 -i "Your Device Name" output.mp4

Additional Configuration Options

You can append extra parameters to the input command to match your specific hardware setup:

Specify Video Input (HDMI/SDI): Force the card to read from a specific physical port using the -video_input option.
```
ffmpeg -f decklink -video_input hdmi -format_code hi59 -i "Your Device Name" output.mp4
```
Specify Audio Input: Force audio to come from embedded SDI/HDMI or analog connections using -audio_input.
```
ffmpeg -f decklink -audio_input embedded -format_code hi59 -i "Your Device Name" output.mp4
```