adm_to_user_metadata

README.md

Contents

1. ADM to IAMF Conversion Tool
2. Building the library
   • Prerequisites
   • Build the binary
   • Run the binary
3. License

ADM to IAMF Conversion Tool

This is a C++ implementation of the tool to convert an ADM-BWF file (conformant to Recommendation ITU-R BS.2076-2) to Immersive Audio Model and Formats (IAMF) textproto file and the associated set of wav file(s) to be used as inputs for an IAMF encoder. The tool does not handle the ADM-BWF files with <metadata/features> not supported by the IAMF specification v1.0.0-errata.

Folder Structure

The description of each directory is as follows:

• adm - Components related to parsing an ADM-BWF file.
  • tests - Tests for files under adm.
• app - An example application which uses the conversion tool.
  • tests - Tests for files under app.
• iamf - Components related to transforming ADM into user metadata suitable for the iamf-tools encoder.
  • tests - Tests for files under iamf.

Building the library

Prerequisites

1. Git.
2. Bazel.

Build the binary

bazel build -c opt app:adm_to_user_metadata_main

Run the binary

Running bazel build creates the binary file adm_to_user_metadata_main. The input format required to run the binary is as below:

 ./adm_to_user_metadata_main <options>

options:
  --adm_filename (required) - ADM wav file to process.
  --importance_threshold (optional) - Used to reject objects whose importance is below the given threshold of range 0 to 10 (default 0).
  --frame_duration_ms (optional) - Target frame duration in ms. The actual output may be slightly lower due to rounding. (default 10).
  --write_binary_proto (optional) - Whether to write the output as a binary proto or a textproto (default true)
  --output_file_path (optional) - Path to write output files to. (default current directory)


  Example:
    - ./adm_to_user_metadata_main --adm_filename input.wav
    - ./adm_to_user_metadata_main --write_binary_proto=false --adm_filename input.wav
    - ./adm_to_user_metadata_main --frame_duration_ms=20 --adm_filename input.wav
    - ./adm_to_user_metadata_main --importance_threshold=4 --adm_filename input.wav

Conversion details

• IA Sequence Header OBU: a base profile sequence header is always generated.
• Codec Config OBU: an LPCM codec config is created with sample rate and bit-depth determined based on the input file. number_of_samples_per_frame is determined based on the --frame_duration_ms flag.
• Audio Element OBUs: audio elements are created based on ADM audioObjects. Low importance objects are filtered out based on the --importance_threshold flag.
• Mix Presentation OBUs: mix presentations are generated based on ADM audioProgrammes.

License

Released under the BSD 3-Clause Clear License. See LICENSE for details.