TWOLAME(1) ========== Nicholas J Humfrey NAME ---- twolame - an optimised MPEG Audio Layer 2 (MP2) encoder SYNOPSIS -------- 'twolame' [options] [outfile] DESCRIPTION ----------- TwoLAME is an optimised MPEG Audio Layer 2 (MP2) encoder based on tooLAME by Mike Cheng, which in turn is based upon the ISO dist10 code and portions of LAME. Encoding is performed by the libtwolame library backend. OPTIONS ------- Input File ~~~~~~~~~~ twolame uses libsndfile for reading the input sound file, so the input file can be in any format supported by libsndfile. To read raw PCM audio from STDIN, then use - as the input filename. Output File ~~~~~~~~~~~ If no output filename is specified, then suffix of the input filename is automatically changed to .mp2. To write the encoded audio to STDOUT then use - as the output filename. Input Options ~~~~~~~~~~~~~ -r, --raw-input:: Specifies that input is raw signed PCM audio. If audio is stereo, than audio samples are interleaved between the two channels. -x, --byte-swap:: Force byte-swapping of the input. Endian detection is performed automatically by libsndfile, so this option shouldn't normally be needed. -s, --samplerate :: If inputting raw PCM sound, you must specify the sample rate of the audio in Hz. Valid sample rates: 16000, 22050, 24000, 32000, 44100, 48000Hz. Default sample rate is 44100Hz. --samplesize :: Specifies the sample size (in bits) of the raw PCM audio. Valid sample sizes: 8, 16, 24, 32. Default sample size is 16-bit. -N, --channels :: If inputting raw PCM sound, you must specify the number of channels in the input audio. Default number of channels is 2. -g, --swap-channels:: Swap the Left and Right channels of a stereo input file. --scale :: Scale the input audio prior to encoding. All of the input audio is multiplied by specified value. Value between 0 and 1 will reduce the audio gain, and a value above 1 will increase the gain of the audio. --scale-l :: Same as --scale, but only affects the left channel. --scale-r :: Same as --scale, but only affects the right channel. Output Options ~~~~~~~~~~~~~~ -m, --mode :: Choose the mode of the resulting audio. Default is auto. - "a" auto - choose mode automatically based on the input - "s" stereo - "d" dual channel - "j" joint stereo - "m" mono -a, --downmix:: If the input file is stereo then, downmix the left and right input channels into a single mono channel. -b, --bitrate :: Sets the total bitrate (in kbps) for the output file. The default bitrate depends on the number of input channels and samplerate. ------------------------------ Sample Rate Mono Stereo ------------------------------ 48000 96 192 44100 96 192 32000 80 160 24000 48 96 22050 48 96 16000 32 64 ------------------------------ -P, --psyc-mode :: Choose the psycho-acoustic model to use (-1 to 4). Model number -1 is turns off psycho-acoustic modelling and uses fixed default values instead. Please see the file 'psycho' for a full description of each of the models available. Default model is 3. -v, --vbr:: Enable VBR mode. See 'vbr' documentation file for details. Default VBR level is 5.0. -V, --vbr-level :: Enable VBR mode and set quality level. The higher the number the better the quality. Maximum range is -50 to 50 but useful range is -10 to 10. See 'vbr' documentation file for details. -l, --ath :: Set the ATH level. Default level is 0.0. -q, --quick :: Enable quick mode. Only re-calculate psycho-acoustic model every specified number of frames. -S, --single-frame:: Enables single frame mode: only a single frame of MPEG audio is output and then the program terminates. Miscellaneous Options ~~~~~~~~~~~~~~~~~~~~~ -c, --copyright:: Turn on Copyright flag in output bitstream. -o, --non-original:: Turn off Original flag in output bitstream. --original:: Turn on Original flag in output bitstream. -p, --protect:: Enable CRC error protection in output bitstream. An extra 16-bit checksum is added to frames. -d, --padding:: Turn on padding in output bitstream. -R, --reserve :: Reserve specified number of bits in the each from of the output bitstream. -e, --deemphasis :: Set the de-emphasis type (n/c/5). Default is none. -E, --energy:: Turn on energy level extensions. Verbosity Options ~~~~~~~~~~~~~~~~~ -t, --talkativity :: Set the amount of information to be displayed on stderr (0 to 10). Default is 2. --quiet:: Don't send any messages to stderr, unless there is an error. (Same as --talkativity=0) --brief:: Only display a minimal number of messages while encoding. This setting is quieter than the default talkativity setting. (Same as --talkativity=1) --verbose:: Display an increased number of messages on stderr. This setting is useful to diagnose problems. (Same as --talkativity=4) Return Codes ------------ If encoding completes successfully, then twolame will return 0. However if encoding is not successful, then it will return one of the following codes. - 1 (No encoding performed) - 2 (Error opening input file) - 4 (Error opening output file) - 6 (Error allocating memory) - 8 (Error in chosen encoding parameters) - 10 (Error reading input audio) - 12 (Error occured while encoding) - 14 (Error writing output audio) EXAMPLES -------- This will encode sound.wav to sound.mp2 using the default constant bitrate of 192 kbps and using the default psycho-acoustic model (model 3): twolame sound.wav Constant bitrate of 160kbps and joint stereo encoding, saved to file sound_160.mp2: twolame -b 160 -m j sound.aiff sound_160.mp2 Encode sound.wav to newfile.mp2 using psycho-acoustic model 2 and encoding with variable bitrate: twolame -P 2 -v sound.wav newfile.mp2 Same as example above, except that the negative value of the "-V" argument means that the lower bitrates will be favoured over the higher ones: twolame -P 2 -V -5 sound.wav newfile.mp2 Resample audio file using sox and pipe straight through twolame: sox sound_11025.aiff -t raw -r 16000 | twolame -r -s 16000 - - > out.mp2 AUTHORS ------- The twolame frontend was (re)written by Nicholas J Humfrey. The libtwolame library is based on toolame by Mike Cheng. For a full list of authors, please see the AUTHORS file. RESOURCES --------- TwoLAME web site: http://www.twolame.org/ SEE ALSO -------- lame(1), mpg123(1), madplay(1), sox(1) COPYING ------- Copyright (C) 2004-2006 The TwoLAME Project. Free use of this software is granted under the terms of the GNU Lesser General Public License (LGPL).