2.1 (Aug 18, 2026)

	[ Nils Schimmelmann ]
	* Honor ABI backward compatibility for faac_params
	* SBR: align payload timing with core audio frames
	* Add optional hard per-frame peak-bitrate limiter (`--cap-rate`)
	* HUFF2: size both books of a codebook pair in one pass

2.0 (Jul 20, 2026)

	[ Fabian Greffrath ]
	* Remove obsolete pkg-config template
	* Restrict LTO to the shared library only

	[ Orbis Security AI ]
	* filtbank: Fix an out-of-bounds `memcpy` in `FilterBank()` that used
	  `FRAME_LEN` instead of `BLOCK_LEN_LONG` for the overlap buffer copies

	[ Nils Schimmelmann ]
	* Harden input parsing and guard against allocation failures.
	* Replace the classic `faacEnc*` C API with a new `faac_*` API in
	  `faac.h`: parameters supplied once to `faac_encoder_open()`, uniform
	  `faac_status` error reporting, resolved-property queries, and
	  library-owned AudioSpecificConfig. The legacy `faacEnc*` surface and
	  `faaccfg.h` are removed; the encoder core they exposed is now internal.
	  SONAME bumped to 1 (libfaac.so.1). `faac.h` now defines
	  `FAAC_VERSION_MAJOR`/`MINOR`/`PATCH`, tracking the SONAME, so callers
	  can detect the new API at compile time (`FAAC_VERSION_MAJOR >= 1`).
	* frontend: Port `faac` and the Win32 GUI to the new API; this fixes the
	  AudioSpecificConfig memory leak on the MP4 output path.
	* Add HE-AAC v1 (AAC-LC core + Spectral Band Replication) encoding via
	  `FAAC_OBJ_HE_AAC_V1`, or `FAAC_OBJ_AUTO`, which picks LC or HE-AAC from
	  the bitrate. The SBR core runs dual-rate (half-rate core, 2048-sample
	  frame); `faac_encoder_get_info()` reports the full output rate and frame
	  size so callers need no SBR-specific handling. CLI:
	  `--object-type lc|he-aac-v1|auto`.
	* stereo: Add Mixed Mode joint stereo (`--joint 3`) as the new default:
	  per scale-factor band, picks IS above 5.5 kHz, M/S where channels are
	  correlated, or L/R otherwise. Fix a midside band-silencing bug that
	  produced L=R=0 on decode, guard against negative rounding before
	  sqrt, and keep IS available at low sample rates.
	* quantize: Restore short-window masking penalty, floor masking
	  targets in quiet bands, drop stale tonal scaling in bmask, and keep
	  `global_gain` a valid regular scalefactor -- fixing energy drops,
	  quiet-band artifacts, and a decoder out-of-range error.
	* tns: Cap TNS filter order to 12 to fix AAC-LC decoder rejections and
	  audio dropouts in FFmpeg/FAAD.
	* Retire the never-implemented MAIN/SSR/LTP object types across
	  filtbank, frame, and the frontend, and collapse the single-model
	  psychoacoustic vtable into direct calls.
	* Fix a lookahead regression that had truncated the encoder's
	  lookahead to an effective 1-frame delay, causing pre-echo artifacts
	  and broken stereo coherence; then simplify the lookahead into a
	  unified per-channel FIFO and energy timeline, replacing the ad hoc
	  sampleBuff/next*SampleBuff/overlapBuff/prevSamples buffers.
	* Relicense: rewrite stereo, quantize, channels, bitstream, filtbank,
	  tns, huffdata, huff2, and the MP4 output code as original work under
	  LGPL-2.1-or-later, and drop the matching MPEG reference-code preamble
	  from README.md, --license, and docs/. Every source file is now free
	  software. Update the license header itself from GNU Library GPL to
	  Lesser GPL wording.
	* fft: Replace the radix-2 FFT with radix-4 decimation-in-frequency as
	  the sole implementation and precompute MDCT twiddles, for ~18%
	  faster encode versus the radix-2 baseline.
	* Standardize libfaac on single-precision floating point: drop the
	  `floating-point` Meson build option and `faac_real.h`, and use
	  `float`/`sinf`/`cosf`/`sqrtf` directly throughout the per-sample hot
	  path. One-time init-time table generators (FFT/MDCT/SBR twiddles,
	  window shapes, quantizer limits) keep `double` precision, where it's
	  free. Benchmarked MOS-neutral versus the prior double-precision path.
	* blockswitch: Move short-window detection to the time domain.
	* Performance passes: reuse a shared work buffer for filtbank's MDCT
	  scratch, and optimize TNS and stereo IS-gate hot paths.
	* frame: Buffer encoder input so any input chunk size works.
	* bitstream: Stop embedding the libfaac version string.
	* build: Fix compiler warnings and transition to C11.
	* frontend: Add a `--creation-time` flag for configurable MP4
	  timestamps, vendor mingw-w64 wingetopt as a minimal-diff getopt
	  fallback for MSVC builds, and keep TNS off by default in the GUI to
	  match the CLI.

1.50 (Apr 16, 2026)

	[ Fabian Greffrath ]
	* Build quantize_sse library with hidden symbols
	* Don't call `exit()` from the library
	* Define some more `default_options` in Meson build
	* Fix some warnings in `frontend/maingui.c`
	* Default to `buildtype=release` in Meson build
	* Initialize `data` variable in `huffcode()`
	* Remove the faulty `HAVE_STRCASECMP` check and other pointless header checks
	* CI: Let Meson build set `CFLAGS`

	[ Nils Schimmelmann ]
	* Disallow PNS in MPEG-2 mode to match spec
	* frontend: Change default to MPEG-4 as MPEG-2 is obsolete
	* Add `max-channels` option to change `MAX_CHANNELS` from 64
	* Fix PNS to stay on in `JOINT_MS` for low-bitrate accuracy
	* Replace redundant `cpe`, `sce`, and `lfe` boolean flags in `ChannelInfo` with an `enum`
	* Reduce `MAX_CHANNELS` to 8 for ADTS compliance
	* tns: Prevent division-by-zero or instability on highly correlated signals
	* Implement MOS-optimized bandwidth calculation
	* Fine-tune rate controller to restore bitrate accuracy
	* Fix channel-specific group metadata in joint-stereo
	* Enable link-time optimization (LTO) in Meson build
	* stereo: Fix undefined behaviour in intensity stereo for degenerate bands
	* Fix scalefactor delta overflows to comply with AAC spec (ISO 14496-3)
	* quantize: Pre-clamp scalefactor deltas to fix encoder/decoder mismatch

1.40 (Mar 17, 2026)

	[ tatsuz ]
	* Fix compilation with Visual Studio

	[ enWILLYado ]
	* Fix SIMD calls

	[ David Fort ]
	* Add meson as build system

	[ KokonoeTooru ]
	* Meson: Install faac executable

	[ Fabian Greffrath ]
	* CI: fix artifact path
	* Remove autoconf/automake build system
	* Remove plugins stuff, unmaintained for decades
	* Remove MSVC projects, deprecated in favour of meson
	* Do not check for unused headers
	* Generalize OS check in CI rule
	* Remove redundant defines
	* Make `faacgui` usable again
	* Report library version on version mismatch
	* Maintain library SONAME version 0.0.0
	* Build both static and shared library by default
	* Properly declare symbol visibility as hidden

	[ Nils Schimmelmann ]
	* Add options to disable DRM and opt for single floating-point precision
	* CI: add native MSVC build and fix Windows compatibility
	* Remove dead code
	* Optimize FFT reordering by combining real and imaginary passes
	* Optimize FFT performance
	* CI: update GitHub Actions and add Dependabot configuration
	* Refactor quantizer for portable C and extensible SIMD dispatch
	* Optimize memory allocation and unify MDCT implementation
	* Optimize MDCT by removing conditional branches and hoisting logic
	* Rrefactor the hot path for writing bits to the output stream
	* Remove Digital Radio Mondiale (DRM) support

1.31.1 (Mar 03, 2025)

	[ Fabian Greffrath ]
	* Reduce autoconf requirement back down to 2.69
	* Reformat configure.ac for the ac2ver.exe hack to work
	* Upload Windows artifacts

1.31 (Feb 28, 2025)

	[ Tatsuya Suzuki ]
	* updated Visual Studio projects to VS 2019
	* main.c : progress report keeps alignment when encoding a large file
	* project/msvc : cleanup, fixes and changes

	[ Christopher Degawa ]
	* frontend: fix out-of-root build

	[ Fabian Greffrath ]
	* add a pkg-config file
	* avoid division by zero
	* Remove #pragma pack from faacEncStruct (thanks Locutus of Borg)
	* Reduce memory (thanks xnvi)
	  + Remove `BwpInfo bwpInfo` from `struct CoderInfo`
	  + Remove `nextSampleBuff[]` and `next2SampleBuff[]` from `struct faacEncStruct`
	* tns: Initialize `rArray[]` variable
	* update autoconf.ac and friends
	* do not pass add-stdcall-alias option to clang
	* always build both the regular and the DRM library
	* fix cppcheck warnings
	* add some basic CI
	* fix compilation with clang on Windows
	* Append INSTALL to README

	[ Steve Fosdick ]
	* Add album artist and various sort order MP4 tags

	[ Aaron Boxer ]
	* set libfaac library name to "faac" rather than "libfaac"

	[ Frank ]
	* Error C2065 (add #define _USE_MATH_DEFINES)

	[ pine3ree ]
	* Allow genre-id up to 255

1.30 (Oct 16, 2019)

	[ Robert Kausch ]
	* Fix Joint Stereo coding

	[ Krzysztof Nikiel ]
	* Code cleanup and compilation fixes
	* Fix endianness conversion functions

	[ Takashi Yoshi ]
	* Fix compilation with GCC < 4.6
	* Fix compilation on big endian systems

	[ Fabian Greffrath ]
	* Fix division by zero errors
	* Fix compilation with GCC <= 4.7.3
	* Change pointer type for proper arithmetics
	* Fix logic error in compiler detection
	* Revert back to some more generic SSE2 code
	* Fix a memory leak
	* Fix some cppcheck warnings in the Cfaac code
	* Check index ranges before dereferencing book arrays (CVE-2018-19886)
	* Clean up stdint.h header inclusions
	* Consistently use stdint.h types

	[ Michael Fink ]
	* Update Visual Studio 2017 projects
	* Add stdint.h header inclusions
	* Port over ac2ver tool from faad2 to generate PACKAGE_VERSION
	  when compiling with Visual Studio

	[ Eugène Filin ]
	* Memory allocations redefined

1.29.9.2 (Nov 14, 2017)

	* fixed max MP4 bitrate calculation

1.29.9 (Nov 2, 2017)

	* initial version of PNS coding
	* Intensity Stereo coding
	* more speed improvements
	* finer bandwidth/cutoff setting (doesn't work with PNS)
	* fixed more bugs
	* rewritten mid/side coding
	* fixed bug in blockswitch

1.29.8 (Oct 15, 2017)

	* changed default mode to ABR 64kbps/channel
	* implemented short windows grouping
	* new huffman coder
	* SSE quantizer
	* modified functioning of ABR mode (-b option)
	* improved autotools support
	* allowed even higher bitrates, including ADTS
	* framebuffer size bug fixed
	* removed broken object types: Main and LTP
	* some mp4 atoms fixed for better compalibility
	* stdin seek bug fixed

1.29.7 (Aug 22, 2017)

	* quantizer tweaked to better support high bitrates
	* allow higher quality for mp4 files (-q 5000 max)
	* removed mid frequency boost (it turned out useless)
	* cutoff frequency adjusted to fully utilize upper band
	* --help-long option removed, it was just an alias for -H
	* -b option bug fixed

1.29.6 (Aug 18, 2017)

	- quality related bug fixed

1.29.5 (Aug 17, 2017)

	- updated manpage
	- check if output file exists; --overwrite option added
	- help/usage options reorganized
	- block switching is now tuned to match quality/bitrate
	- give more quality to lower frequancies (less to highs)
	- quantizer updated again

1.29.4 (Aug 14, 2017)

	- rewritten quantizer: faster, diffrerent quality, different bitrates
	- ftyp atom: set brands like itunes does, shoud be more compatible
	  with picky tools
	- new option(--tag) to add named tags (iTunes '----')
	- faster and better short/long window type switch
	- Don't build DRM(Digital Radio Mondiale) by default.
	  Use ./configure --enable-drm to build DRM version.
	- fixed bugs
	  * rounding in QuantizeReflectionCoeffs (tns.c)
	  * use +60 value for scalefactor.
	  * use clipped diff instead of original value (huffman.c)

1.29.3 (Jul 21, 2017)

	- MP4 tag options improved
	- fixed MP4 'meta' atom bug
	- new option to set verbosity (-v0 to silence output)

1.29.2 (Jul 17, 2017)

	- new mp4 output code

1.29 (Jul 4, 2017)

	- various patches applied and bugs fixed

1.28 (Feb 5, 2009)

	* Prevent out of range scalefactors
	* Updated to latest mpeg4ip mp4 file format library
	* Added -s option to make the encoder output optimized mp4 layout
	* Improved JPEG detection for album art
	* Lot's of compilation issues solved
