RAW file format

Definition

RAW files store the output of the event camera without any decoding or processing. RAW sensor data can be stored using various encoding formats.

RAW files are written in binary little-endian

RAW File Header

RAW file header contains ASCII information and metadata associated to the RAW file. It is a sequence of “keyword, value” pairs written line by line. More precisely, the file header is composed of text lines starting with “%” (0x25) followed by a space (0x20), a keyword, a space (0x20), a value and New Line NL / Line Feed (0x0A).

Here is an example of RAW file header:

% date 2020-09-14 14:18:29
% integrator_name Prophesee
% plugin_name hal_plugin_gen4_fx3
% serial_number 00001034
% evt 3.0
% firmware_version 3.2.3
% system_ID 26
% subsystem_ID 537921537

Below, a table with common keyword, value pairs:

Keyword

Value

Mandatory

date

Recording date, format: YYY-MM-DDHH:MM:SS

integrator_name

Company Name of the Camera maker

YES

plugin_name

HAL plugin used to generate the RAW file

YES

serial_number

Camera serial number

YES

evt

Event Encoding Format

firmware_version

Camera firmware version. Camera Maker specific.

system_ID

System ID: Camera maker specific

subsystem_ID

Subsystem ID: Camera maker specific

width

Horizontal size of image sensor array.

height

Vertical size of image sensor array.

RAW File Event Data

Even if not available in the header metadata, the data encoding format of a RAW file can be figured out using metavision_raw_info tool.

Prophesee Evaluation Kits use either EVT 2.0 or EVT 3.0 encoding formats. Reference decoder code is available in the samples above:

  • For decoding data from EVT 2.0 RAW file, see EVT2 RAW File decoder sample. The sample decodes an EVT2 format RAW file and writes the decoded events in a CSV file. The sample is installed in <install-prefix>/share/metavision/samples/metavision_evt2_raw_file_decoder.cpp.

  • For decoding data from EVT 3.0 RAW file, see EVT3 RAW File decoder sample. The sample decodes an EVT3 format RAW file and writes the decoded events in a CSV file. The sample is installed in <install-prefix>/share/metavision/samples/metavision_evt3_raw_file_decoder.cpp.