This is an informal changelog, a summary of changes in each release. (See also known bugs.) Particulary important for developers is the precise description of changes to the library interfaces. See also the porting guide for specific instructions on porting to newer versions of FLAC.

FLAC 1.1.4

• General:
  • Improved compression with no change to format or decrease in speed.
  • Encoding and decoding speedups for all modes. Encoding at -8 is twice as fast.
• FLAC format:
  • (none)
• Ogg FLAC format:
  • (none)
• flac:
  • Improved compression with no change to format or decrease in speed.
  • Encoding and decoding speedups for all modes. Encoding at -8 is twice as fast.
  • Added a new option -w,--warnings-as-errors for treating all warnings as errors.
  • Allow --picture option to take only a filename, and have all other attributes extracted from the file itself.
  • Fixed a bug that caused suboptimal default compression settings in some locales (SF #1608883).
  • Fixed a bug where FLAC-to-FLAC transcoding of a corrupted FLAC file would truncate the transcoded file at the first error (SF #1615019).
  • Fixed a bug where using -F with FLAC-to-FLAC transcoding of a corrupted FLAC would have no effect (SF #1615391).
  • Fixed a bug where new PICTURE metadata blocks specified with --picture would not be transferred during FLAC-to-FLAC transcoding (SF #1627993).
• metaflac:
  • Allow --import-picture-from option to take only a filename, and have all other attributes extracted from the file itself.
• plugins:
  • Fixed a bug in the XMMS plugin where Ctrl-3 (file info) would cause a crash if the file did not exist (SF #1634941).
• build system:
  • Fixed a makefile linkage bug with libogg (SF #1611414).
  • Added pkg-config files for libFLAC and libFLAC++ (SF #1647881).
  • Added --disable-ogg option for building without Ogg support even if libogg is installed (SF #1196996).
• libraries:
  • Completely rewritten bitbuffer which uses native machine word size instead of bytes for dramatic speed improvements. The speedup should be most dramatic on CPUs with slower byte manipulation capability and big-endian machines.
  • Much faster Rice partition size estimation which greatly speeds encoding in higher modes.
  • Increased compression for all modes.
  • Reduced memory requirements for encoder and decoder.
  • Fixed a bug with default apodization settings that were erroneous in some locales (SF #1608883).
• Interface changes:
  • libFLAC:
    • (behavior only) FLAC__stream_encoder_set_metadata() now makes a copy of the "metadata" array of pointers (but still not copies of the objects themselves) so the client does not need to maintain its copy of the array after the call.
  • libFLAC++:
    • (none)

FLAC 1.1.3

• General:
  • Improved compression with no impact on format or decoding speed.
  • Much better recovery for corrupted files
  • Better multichannel support
  • Large file (>2GB) support everywhere
  • flac now supports FLAC and Ogg FLAC as input to the encoder (e.g. can re-encode FLAC to FLAC) and preserve all the metadata like tags, etc.
  • New PICTURE metadata block for storing things like cover art, new --picture option to flac and --import-picture-from option to metaflac for importing pictures, new --export-picture-to option to metaflac for exporting pictures, and metadata API additions for searching for suitable pictures based on type, size and color constraints.
  • Support for new REPLAYGAIN_REFERENCE_LOUDNESS tag.
  • Fixed a bug in Ogg FLAC encoding where metadata was not being updated properly. Existing Ogg FLAC files should be recoded to fix up the metadata, e.g. flac -Vf -S 10s --ogg file.ogg
  • In the developer libraries, the interface has been simplfied by merging the three decoding layers into a single class; ditto for the encoders. Also, libOggFLAC has been merged into libFLAC and libOggFLAC++ has been merged into libFLAC++ so there is a single API supporting both native FLAC and Ogg FLAC.
• FLAC format:
  • New PICTURE metadata block for storing things like cover art.
  • Speaker assignments and channel orders for 3-6 channels (see frame header).
  • Further restrictions on the FLAC subset when the sample rate is <=48kHz; in this case the maximum LPC order is now 12 and maximum blocksize is 4608. This is to further limit the processing and memory requirements for hardware implementations while not measurably affecting compression.
• Ogg FLAC format:
  • (none)
• flac:
  • Improved the -F option to allow decoding of FLAC files whose metadata is corrupted, and other kinds of severe corruption.
  • Encoder can now take FLAC and Ogg FLAC as input. The output FLAC file will have all the same metadata as the original unless overridden with options on the command line.
  • Encoder can now take WAVEFORMATEXTENSIBLE WAVE files as input; decoder will output WAVEFORMATEXTENSIBLE WAVE files when necessary to conform to the latest Microsoft specifications.
  • Now properly supports AIFF and WAVEFORMATEXTENSIBLE multichannel input, performing necessary channel reordering both for encoding and decoding. WAVEFORMATEXTENSIBLE channel mask is also saved to a tag on encoding and restored on decoding for situations when there is no natural mapping to FLAC channel assignments.
  • Expanded support for "odd" sample resolutions to WAVE and AIFF input; all resolutions from 4 to 24 bits-per-sample now supported for all input types.
  • Added a new option --tag-from-file for setting a tag from file (e.g. for importing a cuesheet as a tag).
  • Added a new option --picture for adding pictures.
  • Added a new option --apodization for specifying the window function(s) to be used in LPC analysis.
  • Added support for encoding from non-compressed AIFF-C (SF #1090933).
  • Importing of non-CDDA-compliant cuesheets now only issues a warning, not an error (see here).
  • MD5 comparison failures on decoding are now an error instead of a warning and will also return a non-zero exit code (SF #1493725).
  • The default padding size is now 8K, or 64K if the input audio stream is more than 20 minutes long.
  • Fixed a bug in cuesheet parsing where it would return an error if the last line of the cuesheet did not end with a newline.
  • Fixed a bug that caused a crash when -a and -t were used together (SF #1229481).
  • Fixed a bug with --sector-align where appended samples were not always totally silent (SF #1237707).
  • Fixed bugs with --sector-align and raw input files.
  • Fixed a bug printing out unknown AIFF subchunk names (SF #1267476).
  • Fixed a bug where WAVE files with "data" subchunks of size 0 where accepted (SF #1293830).
  • Fixed a bug where sync error at end-of-stream of truncated files was not being caught (SF #1244071).
  • Fixed a problem with filename parsing if file does not have extension but also has a . in the path (SF #1161916).
  • Fixed a problem with fractional-second parsing for --skip/--until in some locales (SF #1031043).
  • Increase progress report rate when -p and -e are used together (SF #1580122).
• metaflac:
  • Added support for read-only operations on Ogg FLAC files.
  • Added a new option --set-tag-from-file for setting a tag from file (e.g. for importing a cuesheet as a tag).
  • Added a new option --import-picture-from for importing pictures.
  • Added a new option --export-picture-to for exporting pictures.
  • Added shorthand operation --remove-replay-gain for removing ReplayGain tags.
  • --export-cuesheet-to now properly specifies the FLAC file name (SF #1272825).
  • Importing of non-CDDA-compliant cuesheets now issues a warning.
  • Removed the following deprecated tag editing options; you should use the new option names shown instead:
    • Removed --show-vc-vendor; use --show-vendor-tag
    • Removed --show-vc-field; use --show-tag
    • Removed --remove-vc-all; use --remove-all-tags
    • Removed --remove-vc-field; use --remove-tag
    • Removed --remove-vc-firstfield; use --remove-first-tag
    • Removed --set-vc-field; use --set-tag
    • Removed --import-vc-from; use --import-tags-from
    • Removed --export-vc-to; use --export-tags-to
  • Disallow multiple input FLAC files when --import-tags-from=- is used (SF #1082577).
• plugins:
  • When ReplayGain is on, if tags for the preferred kind of gain (album/track) are not in a stream, the other kind will be used.
  • Added ReplayGain info to file info box in XMMS plugin
  • Fixed UTF-8 decoder to disallow non-shortest-form and surrogate sequences (see here).
• build system:
  • Added support for building on OS/2 with EMX (SF #1229495)
  • Added support for building with Borland C++ (SF #1599018)
  • Added a --disable-xmms-plugin option to configure to prevent building the XMMS plugin (SF #930494).
  • Added a --disable-doxygen-docs option to configure for disabling Doxygen-based API doc generation (SF #1365935).
  • Added a --disable-thorough-tests option to configure to do the basic library, stream, and tool tests in a reasonable time (SF #1077948).
  • Added large file support with AC_SYS_LARGEFILE; use --disable-largefile with configure to disable.
• libraries:
  • Merged libOggFLAC into libFLAC; both formats are now supporte through the same API.
  • Merged libOggFLAC++ into libFLAC++; both formats are now supporte through the same API.
  • libFLAC and libFLAC++: Simplified encoder setup with new FLAC__stream_encoder_set_compression_level() function.
  • libFLAC: Improved compression with no impact on FLAC format or decoding time by adding a windowing stage before LPC analysis.
  • libFLAC: Fixed a bug where missing STREAMINFO fields (min/max framesize, total samples, MD5 sum) and seek point offsets were not getting rewritten back to Ogg FLAC file (SF #1338969).
  • libFLAC: Fixed a bug in cuesheet parsing where it would return an error if the last line of the cuesheet did not end with a newline.
  • libFLAC: Fixed UTF-8 decoder to disallow non-shortest-form and surrogate sequences (see here).
  • libFLAC: Fixed a bug in the return value for FLAC__stream_decoder_set_metadata_respond_application() and FLAC__stream_decoder_set_metadata_ignore_application() when there was a memory allocation error (SF #1235005).
• Interface changes (see also the porting guide for specific instructions on porting to FLAC 1.1.3):
  • all libraries;
    • Merged libOggFLAC into libFLAC; both formats are now supporte through the same API.
    • Merged libOggFLAC++ into libFLAC++; both formats are now supporte through the same API.
    • Merged seekable stream decoder and file decoder into the stream decoder.
    • Merged seekable stream encoder and file encoder into the stream encoder.
    • Added #defines for the API version number to make porting easier; see include/lib*FLAC*/export.h.
  • libFLAC:
    • Added FLAC__stream_encoder_set_apodization()
    • Added FLAC__stream_encoder_set_compression_level()
    • Added FLAC__metadata_object_cuesheet_calculate_cddb_id()
    • Added FLAC__metadata_get_cuesheet()
    • Added FLAC__metadata_get_picture()
    • Added FLAC__metadata_chain_read_ogg() and FLAC__metadata_chain_read_ogg_with_callbacks()
    • Changed FLAC__stream_encoder_finish() now returns a FLAC__bool to signal a verify failure, or error processing last frame or updating metadata.
    • Changed FLAC__StreamDecoderState: removed state FLAC__STREAM_DECODER_UNPARSEABLE_STREAM
    • Changed FLAC__StreamDecoderErrorStatus: new error code FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM
    • The above two changes mean that when the decoder encounters what it thinks are unparseable frames from a future decoder, instead of returning a fatal error with the FLAC__STREAM_DECODER_UNPARSEABLE_STREAM state, it just calls the error callback with FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM and leaves the behavior up to the application.
  • libFLAC++:
    • Added FLAC::Metadata::Picture
    • Added FLAC::Encoder::Stream::set_apodization()
    • Added FLAC::Encoder::Stream::set_compression_level()
    • Added FLAC::Metadata::CueSheet::calculate_cddb_id()
    • Added FLAC::Metadata::get_cuesheet()
    • Added FLAC::Metadata::get_picture()
    • Changed FLAC::Metadata::Chain::read() to accept a flag denoting Ogg FLAC input
    • Changed FLAC::Decoder::Stream::finish() now returns a bool to signal an MD5 failure like FLAC__stream_decoder_finish() does.
    • Changed FLAC::Encoder::Stream::finish() now returns a bool to signal a verify failure, or error processing last frame or updating metadata.
  • libOggFLAC:
    • Merged into libFLAC.
  • libOggFLAC++:
    • Merged into libFLAC++.

FLAC 1.1.2

• General:
  • Sped up decoding by a few percent overall.
  • Sped up encoding when not using LPC (i.e. when using flac options -0, -1, -2, or -l 0).
  • Fixed a decoding bug that could cause sync errors with some ID3v1-tagged FLAC files.
  • Added HTML documentation for metaflac.
• FLAC format:
  • (none)
• Ogg FLAC format:
  • (none)
• flac:
  • New option --input-size to manually specify the input size when encoding raw samples from stdin.
• metaflac:
  • (none)
• plugins:
  • Added support for HTTP streaming in XMMS plugin. NOTE: there is a bug in the XMMS mpg123 plugin that hijacks FLAC streams; to fix it you will need to add the '.flac' extension to the list of exceptions in Input/mpg123/mpg123.c:is_our_file() in the XMMS sources and recompile.
• build system:
  • (none)
• libraries:
  • libFLAC: Sped up Rice block decoding in the bitbuffer, resulting in decoding speed gains of a few percent.
  • libFLAC: Sped up encoding when not using LPC (i.e. max_lpc_order == 0).
  • libFLAC: Trailing NUL characters maintained on Vorbis comment entries so they can be treated like C strings.
  • libFLAC: More FLAC tag (i.e. Vorbis comment) validation.
  • libFLAC: Fixed a bug in the logic that determines the frame or sample number in a frame header; the bug could cause sync errors with some ID3v1-tagged FLAC files.
  • libFLAC, libOggFLAC: Can now be compiled to use only integer instructions, including encoding. The decoder is almost completely integer anyway but there were a couple places that needed a fixed-point replacement. There is no fixed-point version of LPC analysis yet, so if libFLAC is compiled integer-only, the encoder will behave as if the max LPC order is 0 (i.e. used fixed predictors only). LPC decoding is supported in all cases as it always was integer-only.
• Interface changes:
  • libFLAC:
    • Changed: Metadata object interface now maintains a trailing NUL on Vorbis comment entries for convenience.
    • Changed: Metadata object interface now validates all Vorbis comment entries on input and returns false if an entry does not conform to the Vorbis comment spec.
    • Added FLAC__format_vorbiscomment_entry_name_is_legal()
    • Added FLAC__format_vorbiscomment_entry_value_is_legal()
    • Added FLAC__format_vorbiscomment_entry_is_legal()
    • Added FLAC__metadata_object_vorbiscomment_entry_from_name_value_pair()
    • Added FLAC__metadata_object_vorbiscomment_entry_to_name_value_pair()
    • Changed the signature of FLAC__metadata_object_vorbiscomment_entry_matches(): the first argument is now FLAC__StreamMetadata_VorbisComment_Entry entry (was const FLAC__StreamMetadata_VorbisComment_Entry *entry), i.e. entry is now pass-by-value.
  • libFLAC++:
    • Changed: Metadata object interface now maintains a trailing NUL on Vorbis comment values for convenience.
    • Changed: Metadata object interface now validates all Vorbis comment entries on input and returns false if an entry does not conform to the Vorbis comment spec.
    • Changed: All Metadata objects' operator=() methods now return a reference to themselves.
    • Added methods to FLAC::Metadata::VorbisComment::Entry for setting comment values from null-terminated strings:
      • Entry(const char *field)
      • Entry(const char *field_name, const char *field_value)
      • bool set_field(const char *field)
      • bool set_field_value(const char *field_value)
    • Changed the signature of FLAC::Metadata::VorbisComment::get_vendor_string() and FLAC::Metadata::VorbisComment::set_vendor_string() to use a UTF-8, NUL-terminated string const FLAC__byte * for the vendor string instead of FLAC::Metadata::VorbisComment::Entry.
    • Added FLAC::Metadata::*::assign() to all Metadata objects.
    • Added bool FLAC::Metadata::get_tags(const char *filename, VorbisComment &tags)
  • libOggFLAC:
    • (none)
  • libOggFLAC++:
    • (none)

FLAC 1.1.1

• General:
  • Ogg FLAC seeking now works
  • New optimizations almost double the decoding speed on PowerPC (e.g. Mac G4/G5)
  • A native OS X release thanks to updated Project Builder and autotools files
• FLAC format:
  • Made invalid the metadata block type 127 so that audio frames can always be distinguished from metadata by seeing 0xff as the first byte. (This was also required for the Ogg FLAC mapping.)
• Ogg FLAC format:
  • First official FLAC->Ogg bitstream mapping standardized (see new FLAC-to-Ogg mapping specification). See the documentation for the --ogg switch about having to re-encode older Ogg FLAC files.
• flac:
  • Print an error when output file already exists instead of automatically overwriting.
  • New option -f (--force) to force overwriting if the output file already exists.
  • New option --cue to select a specific section to decode using cuesheet track/index points.
  • New option --totally-silent to suppress all output.
  • New (but undocumented) option --apply-replaygain-which-is-not-lossless which applies ReplayGain to the decoded output. See this thread for usage and caveats.
  • When encoding to Ogg FLAC, use a random serial number (instead of 0 as was done before) when a serial number is not specified.
  • When encoding multiple Ogg FLAC streams, --serial-number or random serial number sets the first number, which is then incremented for subsequent streams (before, the same serial number was used for all streams).
  • Decoder no longer exits with an error when writing to stdout and the pipe is broken.
  • Better explanation of common error messages.
  • Default extension when writing AIFF files is .aif (before, it was .aiff).
  • Write more common representation of SANE numbers in AIFF files.
  • Bug fix: calculating ReplayGain on 48kHz streams.
  • Bug fix: check for supported block alignments in WAVE files.
  • Bug fix: "offset" field in AIFF SSND chunk properly handled.
  • Bug fix: #679166: flac doesn't respect RIFF subchunk padding byte.
  • Bug fix: #828391: --add-replay-gain segfaults.
  • Bug fix: #851155: Can't seek to position in flac file.
  • Bug fix: #851756: flac --skip --until reads entire file.
  • Bug fix: #877122: problem parsing cuesheet with CATALOG entry.
  • Bug fix: #896057: parsing ISRC number from cuesheet.
• metaflac:
  • Renamed the tag editing options as follows (the ...-vc-... options still work but are deprecated):
    • --show-vc-vendor becomes --show-vendor-tag
    • --show-vc-field becomes --show-tag
    • --remove-vc-all becomes --remove-all-tags
    • --remove-vc-field becomes --remove-tag
    • --remove-vc-firstfield becomes --remove-first-tag
    • --set-vc-field becomes --set-tag
    • --import-vc-from becomes --import-tags-from
    • --export-vc-to becomes --export-tags-to
  • Better explanation of common error messages.
  • Bug fix: calculating ReplayGain on 48kHz streams.
  • Bug fix: incorrect numbers when printing seek points.
• plugins:
  • Speed optimization in ReplayGain synthesis.
  • Speed optimization in XMMS playback.
  • Support for big-endian architectures in XMMS plugin.
  • Removed support for ID3 tags.
  • Bug fix: make hard limiter default to off in XMMS plugin.
  • Bug fix: stream length calculation bug in XMMS plugin, debian bug #200435; see also.
  • Bug fix: small memory leak in XMMS plugin.
• build system:
  • ordinals.h is now static, not a build-generated file anymore.
• libraries:
  • libFLAC: PPC+Altivec optimizations of some decoder routines.
  • libFLAC: Make stream encoder encode the blocksize and sample rate in the frame header if at all possible (not in STREAMINFO), even if subset encoding was not requested.
  • libFLAC: Bug fix: fixed seek routine where infinite loop could happen when seeking past end of stream.
  • libFLAC, libFLAC++: added methods to skip single frames, useful for quickly finding frame boundaries (see interface changes below).
  • libOggFLAC, libOggFLAC++: New seekable-stream and file encoder and decoder APIs to match native FLAC APIs (see interface changes below).
• Interface changes:
  • libFLAC:
    • Added FLAC__metadata_get_tags()
    • Added callback-based versions of metadata editing functions:
      • FLAC__metadata_chain_read_with_callbacks()
      • FLAC__metadata_chain_write_with_callbacks()
      • FLAC__metadata_chain_write_with_callbacks_and_tempfile()
      • FLAC__metadata_chain_check_if_tempfile_needed()
    • Added decoder functions for skipping single frames, also useful for quickly finding frame boundaries:
      • FLAC__stream_decoder_skip_single_frame()
      • FLAC__seekable_stream_decoder_skip_single_frame()
      • FLAC__file_decoder_skip_single_frame()
    • Added new required tell callback on seekable stream encoder:
      • FLAC__SeekableStreamEncoderTellStatus and FLAC__SeekableStreamEncoderTellStatusString[]
      • FLAC__SeekableStreamEncoderTellCallback
      • FLAC__seekable_stream_encoder_set_tell_callback()
    • Changed FLAC__SeekableStreamEncoderState by adding FLAC__SEEKABLE_STREAM_ENCODER_TELL_ERROR
    • Changed Tell callback is now required to initialize seekable stream encoder
    • Deleted erroneous and unimplemented FLAC__file_decoder_process_remaining_frames()
  • libFLAC++:
    • Added FLAC::Metadata::get_tags()
    • Added decoder functions for skipping single frames, also useful for quickly finding frame boundaries:
      • FLAC::Decoder::Stream::skip_single_frame()
      • FLAC::Decoder::SeekableStream::skip_single_frame()
      • FLAC::Decoder::File::skip_single_frame()
    • Added encoder functions for setting metadata:
      • FLAC::Encoder::Stream::set_metadata(FLAC::Metadata::Prototype **metadata, unsigned num_blocks)
      • FLAC::Encoder::SeekableStream::set_metadata(FLAC::Metadata::Prototype **metadata, unsigned num_blocks)
      • FLAC::Encoder::File::set_metadata(FLAC::Metadata::Prototype **metadata, unsigned num_blocks)
    • Added new required tell callback on seekable stream encoder:
      • pure virtual FLAC::Encoder::SeekableStream::tell_callback()
    • Changed Tell callback is now required to initialize seekable stream encoder
    • Deleted the following methods:
      • FLAC::Decoder::Stream::State::resolved_as_cstring()
      • FLAC::Encoder::Stream::State::resolved_as_cstring()
  • libOggFLAC:
    • Added OggFLAC__SeekableStreamDecoder interface
    • Added OggFLAC__FileDecoder interface
    • Added OggFLAC__SeekableStreamEncoder interface
    • Added OggFLAC__FileEncoder interface
    • Added OggFLAC__stream_decoder_get_resolved_state_string()
    • Added OggFLAC__stream_encoder_get_resolved_state_string()
    • Added OggFLAC__stream_encoder_set_metadata_callback()
    • Changed OggFLAC__StreamDecoderState by adding OggFLAC__STREAM_DECODER_END_OF_STREAM
  • libOggFLAC++:
    • Added OggFLAC::Decoder::SeekableStream interface
    • Added OggFLAC::Decoder::File interface
    • Added OggFLAC::Encoder::SeekableStream interface
    • Added OggFLAC::Encoder::File interface
    • Added OggFLAC::Decoder::Stream::get_resolved_state_string()
    • Added OggFLAC::Encoder::Stream::get_resolved_state_string()
    • Added pure virtual OggFLAC::Encoder::Stream::metadata_callback()