exhale - ecodis extended high-efficiency and low-complexity encoder

Software Release Notes, Version History, Known Issues, Upcoming Feature Roadmap


   The version of this distribution of the «exhale» software release is 1.0.2 (official pub­lic minor release) from March 2020. Please check www.ecodis.de regularly for new versions of this software. A summary of each version up to this release, a list of known issues with this release, and a roadmap of additional functionality are provided below.


Chronological Version History

   Version 1.0.2  Mar. 2020, this release

  • added basic low/mid-rate joint-stereo coding functionality, bugfixes, and speedups

  • exhaleApp: support for input sampling rates of up to 48000 Hz with CVBR mode 2

  • exhaleLib: frame adaptive joint-stereo preprocessing and coding (CVBR mode <5)

  • exhaleLib: accelerated R/D opt. coding, stability and quality fixes (issues 2 and 3)

   Version 1.0.1  Feb. 2020

  • improved low-bitrate coding efficiency and support for MPEG-D loudness metadata

  • exhaleApp: increased MP4 file versatility (issue 1) and calculation of loudness info

  • exhaleLib: backward compatible API extension to support writing of loudness info

  • exhaleLib: extended R/D optimized coding, improved short-transform quantization

   Version 1.0.0  Jan. 2020

  • compilation fixes and executable printout changes for Linux and MacOS™ platform

  • exhaleApp: fixed reading of WAVE files including metadata after the «data» chunk

  • exhaleLib: some tuning of transform and noise level detection for transient signals

  • exhaleLib: support for export as DLL on Microsoft Windows™ (not tested, though)

   Version 1.0RC Dec. 2019

  • initial release for testing with only basic channel-independent coding functionality

  • only support for Microsoft Windows™ (32-bit and 64-bit) platform provided so far.


Known Issues with This Release

   If you notice an issue with this release not mentioned below, please contact ecodis or a contributor with the details (configuration, input file) needed to reproduce the issue.

  • exhaleLib: Coding of stereo or multichannel input occasionally leads to suboptimal audio quality because the joint-channel coding functionality provided by ISO/IEC 23003-3 has not been fully implemented. See the functionality roadmap below.

  • exhaleApp: Only basic WAVE input file reading functionality has been implemen­ted. Specifically, 8-bit WAVE input is assumed to contain an even number of audio samples, and the Broadcast and Extensible WAVE file formats are not supported.


Roadmap of Upcoming Features

   If you are in need of an additional library or application feature not mentioned below, please contact ecodis or a contributor with a request, and we will see what we can do.

  • support for coding with a core coder frame length of 768 samples, no version plan

  • exhaleLib: finalized integration of higher-rate joint-channel coding, version 1.0.3

  • exhaleLib: quality tuning and bug fixing for low-rate stereo coding, version 1.0.3

  • exhaleLib: finalization of support for 3.0 – 5.1 multichannel coding, version 1.0.4

  • exhaleLib: speed-ups and further quality tuning for critical signals, version 1.0.5.


Written by C. R. Helmrich for exhale 1.0.2, Mar. 2020. Available at www.ecodis.de/exhale/release.htm.