=============================================================================== flac - Command-line FLAC encoder/decoder version 1.4.3 Copyright (C) 2000-2009 Josh Coalson Copyright (C) 2011-2023 Xiph.Org Foundation This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. =============================================================================== Usage: Encoding: flac [] [INPUTFILE [...]] Decoding: flac -d [] [FLACFILE [...]] Testing: flac -t [] [FLACFILE [...]] Analyzing: flac -a [] [FLACFILE [...]] Be sure to read the list of known bugs at: %%%!!! THIS SHOULD BE DELETED? But what should go instead? http://xiph.org/flac/documentation_bugs.html For encoding: The input file(s) may be PCM in WAVE, Wave64, RF64 or AIFF/AIFC file, or %%% New text: if "PCM WAVE" was is enough for WAVE (which can contain MP3 ...) as in old text, then PCM in [...] should be enough for aif(c) too? raw samples. The output file(s) will be in native FLAC or Ogg FLAC format. For decoding, the reverse is true. In addition, both input and output can be a FLAC / Ogg FLAC file. The file %%% New text will then be decoded and encoded anew, and tags will be transferred. A single INPUTFILE may be - for stdin. No INPUTFILE implies stdin. Use of stdin implies -c (write to stdout). Normally you should use: flac [options] -o outfilename or flac -d [options] -o outfilename instead of: flac [options] > outfilename or flac -d [options] > outfilename since the former allows flac to seek backwards to write the STREAMINFO or WAVE/AIFF header contents when necessary. General options: %%% Capital leading letter in General options, Encoding options, Decoding options, Analysis options (now in that order). -v, --version Show the flac version number -h, --help Show basic usage a list of all options -H, --explain Show this screen -d, --decode Decode (the default behavior is to encode) -t, --test Same as -d except no decoded file is written -a, --analyze Same as -d except an analysis file is written -c, --stdout Write output to stdout -f, --force Force overwriting of output files -o, --output-name=FILENAME Force the output file name; usually flac just changes the extension. May only be used when encoding a single file. May not be used in conjunction with --output-prefix. --output-prefix=STRING Prefix each output file name with the given STRING. This can be useful for encoding or decoding files to a different directory. Make sure if your STRING is a path name that it ends with a '/' slash. --delete-input-file Automatically delete the input file after a successful encode or decode. If there was an error (including a verify error) the input file is left intact. --preserve-modtime Output files have their timestamps/permissions set to match those of their inputs (this is default). Use --no-preserve-modtime to make output files have the current time and default permissions. --keep-foreign-metadata If encoding, save WAVE or AIFF non-audio chunks %%% Reworded. in FLAC metadata. If decoding, restore any saved non-audio chunks from FLAC metadata into the decoded file, and choose the right output format by default. Foreign metadata cannot be transcoded, e.g. WAVE chunks saved in a FLAC file cannot be restored when forcing AIFF output format. Input and output must be regular files, not stdin/out. --keep-foreign-metadata-if-present As previous option, but do not %%% Reworded. throw an error (only give a warning) in case foreign metadata of the appropriate kind cannot be found (or is not parseable). --skip={#|mm:ss.ss} Skip the first # samples of each input file; can be used both for encoding and decoding. The alternative form mm:ss.ss can be used to specify minutes, seconds, and fractions of a second. --until={#|[+|-]mm:ss.ss} Stop at the given sample number for each input file. The given sample number is not included in the decoded output. The alternative form mm:ss.ss can be used to specify minutes, seconds, and fractions of a second. If a `+' sign is at the beginning, the --until point is relative to the --skip point. If a `-' sign is at the beginning, the --until point is relative to end of the audio. -s, --silent Do not write runtime encode/decode statistics %%% Moved these down here. -ss,--totally-silent Do not print anything of any kind, including %%% Inserted "-ss", is that official? warnings or errors. The exit code will be the only way to determine successful completion. --no-utf8-convert Do not convert tags from local charset to UTF-8. %%%!!! DOES THIS BELONG HERE?! This is useful for scripts, and setting tags in situations where the locale is wrong. This option must appear before any tag options! -w, --warnings-as-errors Treat all warnings as errors Encoding options: For encoding options, a latter usually overrides a former; -mM becomes -M. %%% New explanation. Some exceptions are stated below, e.g. -p overrides -q. From 1.4.0 the numerical encoding presets will work as if given first and any option before or after will override, e.g. -m0 and -0m are both the same as -2. Each numerical preset -0 to -8 is synonymous with a set of encoding options, currently as follows: %%% "currently" because it may change. It has. -0, --compression-level-0, --fast -l 0 -b 1152 -r 3 --no-mid-side %%% Moved to here. Reformatted. -1, --compression-level-1 -l 0 -b 1152 -r 3 -M -2, --compression-level-2 -l 0 -b 1152 -r 3 -m -3, --compression-level-3 -l 6 -b 4096 -r 4 --no-mid-side -4, --compression-level-4 -l 8 -b 4096 -r 4 -M -5, --compression-level-5 -l 8 -b 4096 -r 5 -m -6, --compression-level-6 -l 8 -b 4096 -r 6 -m -A subdivide_tukey(2) -7, --compression-level-7 -l 12 -b 4096 -r 6 -m -A subdivide_tukey(2) -8, --compression-level-8, --best -l 12 -b 4096 -r 6 -m -A subdivide_tukey(3) -5 is the default. The encoder accepts the following options: %%% Not sure if my wording is fortunate, but here goes the information that -5 is the default. -l, --max-lpc-order=# Max LPC predictor order; does not restrict FIXED %%% Moved. Added information that would otherwise require the knowledge that "LPC" in FLAC lingo means "LPC type" subframes and not linear prediction by fixed predictors. predictor order, so 0 => only fixed predictors. Must be <= 12 for SUBSET streams if sample rate %%% Capitalized SUBSET everywhere. Ref to --lax is <=48kHz. (See --lax for non-SUBSET.) -b, --blocksize=# Specify the blocksize in samples; minimum is 16. %%% Moved, check rewording Current default is 1152 for -l 0, else 4096. %%% "Current" default to specify that it isn't god-given. Although we strictly speaking don't need the "-b" in the -0 to -8 table, it doesn't hurt up there? For SUBSET streams, blocksize must be <= 16384 and for sample rate <= 48kHz also <= 4608. There is usually no need for blocksizes that are %%% Recommendation ... hm, should be discussed? < 512 or not a multiple of 64. -r, --rice-partition-order=[#,]# Set [min,]max residual partition order, %%% moved, check rewording. min defaults to 0, max to 5. Encoder may reduce the max to comply with format specification. For SUBSET streams, max must be <= 8. -m, --mid-side Try mid-side coding for each frame (stereo only, %%% moved, "on by default" and "ignored otherwise". ignored otherwise); on by default. -M, --adaptive-mid-side Adaptive mid-side coding for all frames (stereo %%% moved and "ignored otherwise" only, ignored otherwise) -A, --apodization="function" Window audio data with the given function(s) %%% moved and reworded (default: tukey(5e-1)). Currently implemented functions: bartlett, bartlett_hann, blackman, blackman_harris_4term_92db, connes, flattop, gauss(STDDEV), hamming, hann, kaiser_bessel, nuttall, rectangle, triangle, tukey(P), welch, partial_tukey(n), punchout_tukey(n) and subdivide_tukey(n). More than one may be specified (separated by semicolon), but encoding time will scale up by their number, as they are tried in turn. -e, --exhaustive-model-search Do exhaustive model search (expensive!) %%% moved -p, --qlp-coeff-precision-search Do exhaustive search of LP coefficient %%% moved quantization (expensive!); overrides -q; does nothing if using -l 0. -q, --qlp-coeff-precision=# Specify precision in bits of quantized LP coefficients; minimum is 5, or use 0 (default) %%% moved and reworded to let the encoder decide. --limit-min-bitrate Ensure a minimum bitrate of 1 bit/sample, e.g. %%% reworded 48kbit/s for 48kHz input. May be useful for internet streaming. --lax Allow encoder to generate non-SUBSET streams %%% reworded admitting up to -l 32, -b 65535, -r 15. Beware that some 3rd party decoders reject non-SUBSET. --ignore-chunk-sizes Ignore data chunk sizes in WAVE/AIFF/RF64 files; %%% RF64 too, right? (But not W64?) may be useful when piping data from programs which generate bogus data chunk sizes. -V, --verify Verify a correct encoding by decoding the output %%% Now this is farther down than it was. -V was highlighted as "you doubt it is lossless? Look here!" feature in old days, is that necessary? If so, up between presets and -l? in parallel and comparing to the original. -P, --padding=# Tell the encoder to write a PADDING metadata %%% --replay-gain mentions PADDING, so I moved -P here, before all other tags. Now tags are after the audio encoding options, but before seektable block of the given length (in bytes) after the STREAMINFO block. This is useful if you plan to tag the file later with an APPLICATION %%%!!! with an APPLICATION block? What about with a vorbis comment block? Is this correct? block; instead of having to rewrite the entire file later just to insert your block, you can write directly over the PADDING block. Note that the total length of the PADDING block will be 4 bytes longer than the length given because of the 4 metadata block header bytes. You can force no PADDING block at all to be written with --no-padding. The encoder writes a PADDING block of 8192 bytes by default, or 65536 bytes if the input audio is more than 20 minutes long. --replay-gain Calculate ReplayGain values and store them as %%% Now tags options start here. FLAC tags. Title gains/peaks will be computed for each file, and an album gain/peak will be computed for all files. All input files must have the same resolution, sample rate, and number of channels. Only mono and stereo files %%%!!! [are these restrictions still in force?] are allowed, and the sample rate must be 8, 11.025, 12, 16, 18.9, 22.05, 24, 28, 32, 36, 37.8, 44.1, 48, 56, 64, 72, 75.6, 88.2, 96, 112, 128, 144, 151.2, 176.4, 192, 224, 256, 288, 302.4, 352.8, 384, 448, 512, 576, or 604.8 kHz. NOTE: this option may also leave a few extra bytes in the PADDING block. --cuesheet=FILENAME Import the given cuesheet file and store it in a CUESHEET metadata block. This option may only be used when encoding a single file. A seekpoint will be added for each index point in the cuesheet to the SEEKTABLE unless --no-cued-seekpoints is specified. --picture=SPECIFICATION Import a file and store it in a PICTURE block. %%% Reworded (for the 80 char limit, tbh) More than one --picture command can be given. The SPECIFICATION can either be a simple filename, or a complete specification whose parts are separated by | characters; defaults will be applied to missing parts, so merely using a filename is shorthand for "||||FILE". The SPECIFICATION format is: [TYPE]|[MIME-TYPE]|[DESCRIPTION]|[WIDTHxHEIGHTxDEPTH[/COLORS]]|FILE TYPE is optional; it is a number from one of: 0: Other 1: 32x32 pixels 'file icon' (PNG only) 2: Other file icon 3: Cover (front) 4: Cover (back) 5: Leaflet page 6: Media (e.g. label side of CD) 7: Lead artist/lead performer/soloist 8: Artist/performer 9: Conductor 10: Band/Orchestra 11: Composer 12: Lyricist/text writer 13: Recording Location 14: During recording 15: During performance 16: Movie/video screen capture 17: A bright coloured fish 18: Illustration 19: Band/artist logotype 20: Publisher/Studio logotype The default is 3 (front cover). There may only be one picture each of type 1 and 2 in a file. MIME-TYPE is optional; if left blank, it will be detected from the file. For best compatibility with players, use pictures with MIME type image/jpeg or image/png. The MIME type can also be --> to mean that FILE is actually a URL to an image, though this use is discouraged. DESCRIPTION is optional; the default is an empty string The next part specifies the resolution and color information. If the MIME-TYPE is image/jpeg, image/png, or image/gif, you can usually leave this empty and they can be detected from the file. Otherwise, you must specify the width in pixels, height in pixels, and color depth in bits-per-pixel. If the image has indexed colors you should also specify the number of colors used. FILE is the path to the picture file to be imported, or the URL if MIME type is --> -T, --tag=FIELD=VALUE Add a FLAC tag. Make sure to quote the comment if necessary. This option may appear more than once to add several comments. NOTE: all tags will be added to all encoded files. --tag-from-file=FIELD=FILENAME Like --tag, except FILENAME is a file whose contents will be read verbatim to set the tag value. The contents will be converted to UTF-8 from the local charset. This can be used to store a cuesheet in a tag (e.g. --tag-from-file="CUESHEET=image.cue"). Do not try to store binary data in tag fields! Use APPLICATION blocks for that. -S, --seekpoint={#|X|#x|#s} Include a point or points in a SEEKTABLE # : a specific sample number for a seek point X : a placeholder point (always goes at the end of the SEEKTABLE) #x : # evenly spaced seekpoints, the first being at sample 0 #s : a seekpoint every # seconds; # does not have to be a whole number You may use many -S options; the resulting SEEKTABLE will be the unique- ified union of all such values. With no -S options, flac defaults to '-S 10s'. Use -S- for no SEEKTABLE. Note: -S #x and -S #s will not work if the encoder can't determine the input size before starting. Note: if you use -S # and # is >= samples in the input, there will be either no seek point entered (if the input size is determinable before encoding starts) or a placeholder point (if input size is not determinable) Decoding options: -F, --decode-through-errors By default flac stops decoding with an error and removes the partially decoded file if it encounters a bitstream error. With -F, errors are still printed but flac will continue decoding to completion. Note that errors may cause the decoded audio to be missing some samples or have silent sections. --cue=[#.#][-[#.#]] Set the beginning and ending cuepoints to decode. The optional first #.# is the track and index point at which decoding will start; the default is the beginning of the stream. The optional second #.# is the track and index point at which decoding will end; the default is the end of the stream. If the cuepoint does not exist, the closest one before it (for the start point) or after it (for the end point) will be used. The cuepoints are merely translated into sample numbers then used as --skip and --until. A CD track can always be cued by, for example, --cue=9.1-10.1 for track 9, even if the CD has no 10th track. Analysis options: %%% Moved to after Decoding --residual-text Include residual signal in text output. This will make the file very big, much larger than even the decoded file. --residual-gnuplot Generate gnuplot files of residual distribution of each subframe. Format options: raw format options (encoding and decoding) %%% Since raw format spec became mandatory, they should follow. Put them first. --force-raw-format Read input as raw samples, or write output as raw samples in a headerless file with extension defaulting to .raw. Raw input must be specified as follows: --endian={big|little} (mandatory) Set byte order for samples --channels=# (mandatory) Number of channels --bps=# (mandatory) Number of bits per sample --sample-rate=# (mandatory) Sample rate in Hz --sign={signed|unsigned} (mandatory) Sign of samples --input-size=# (optional unless you use options that need to know the size of the input beforehand, e.g. with --skip, --until or --cueshet) Size of the raw input in bytes. If the size given is greater than what is found in the input stream, the encoder will complain about an unexpected end-of-file. If the size given is less, samples will be truncated. ogg encoding options: %%% --ogg options are format options right? --ogg When encoding, generate Ogg FLAC output instead of native FLAC. Ogg FLAC streams are FLAC streams wrapped in an Ogg transport layer. The resulting file should have an '.oga' extension and will still be decodable by flac. When decoding, force the input to be treated as Ogg FLAC. This is useful when piping input from stdin or when the filename does not end in '.oga' or '.ogg'. --serial-number When encoding to Ogg FLAC, assign serial number %%% Did this come out right? to the FLAC stream. Encoder will assign at random if not specified; for multiple files it will increment the serial number for each file. When decoding and no number is given, flac uses the serial number of the first page. decoding output format options: --force-aiff-format --force-rf64-format --force-wave64-format Force the decoder to output AIFF/RF64/WAVE64 format respectively. This option is not needed if the output filename (as set by -o) ends with *.aif* or *.aiff*, *.rf64* and *.w64* respectively. Also, this option has no effect when encoding since input is auto-detected. When none of these options nor --keep-foreign-metadata are given and no output filename is set, the output format is WAV by default. --force-legacy-wave-format --force-extensible-wave-format Instruct the decoder to output a WAVE file with WAVE_FORMAT_PCM and WAVE_FORMAT_EXTENSIBLE respectively. If none of these options nor --keep-foreign-metadata are given, FLAC outputs WAVE_FORMAT_PCM for mono or stereo with a bit depth of 8 or 16 bits, and WAVE_FORMAT_EXTENSIBLE for all other audio formats. --force-aiff-c-none-format --force-aiff-c-sowt-format Instruct the decoder to output an AIFF-C file with format NONE and sowt respectively. Negative options: --no-adaptive-mid-side --no-cued-seekpoints --no-decode-through-errors --no-delete-input-file --no-preserve-modtime --no-keep-foreign-metadata --no-exhaustive-model-search --no-lax --no-mid-side --no-ogg --no-padding --no-qlp-coeff-prec-search --no-residual-gnuplot --no-residual-text --no-ignore-chunk-sizes --no-seektable --no-silent --no-force --no-verify --no-warnings-as-errors