Installation de Festival TTS sur Debian

Posted on April 4, 2015 by Marco Barnig

Last update : April 9, 2015

Suite à l’installation du système Festival TTS sur mon MacBook Air il y a trois mois, je viens de l’installer sur mon laptop avec système d’exploitation Debian 7 Linux. Les différentes archives du système Festival ont été téléchargées et décomprimées avec ARC.

Décompression d’une archive Festival

J’ai suivi ensuite la même procédure que sur Mac OSX, à savoir

création d’un répertoire Festival-TTS sur le desktop avec les sous-répertoires festival, speech_tools et festvox
compilation des programmes dans l’ordre speech_tools, festival, festvox
installation des voix et dictionnaires dans les sous-répertoires lib/voices et lib/dicts du répertoire festival

Configuration du programme speech_tools

La compilation du programme speech_tools s’est arrêtée avec les messages d’erreur

/usr/bin/ld: cannot find -lcurses
/usr/bin/ld: cannot find -lncurses

L’installation de la bibliothèque libncurses5-dev a réglé ce problème. La suite de la compilation s’est passée sans autres erreurs, abstraction faite de plusieurs avertissements concernant des variables spécifiées, mais non utilisées .

Il a été possible de démarrer le programme Festival avec la commande

/Desktop/Festival-TTS/festival/bin/festival

mais la synthèse d’une phrase de test

festival> (SayText "Hello, how are you")

a produit l’erreur

Linux: can't open /dev/dsp

Parmi les remèdes trouvés sur le net, j’ai opté pour la solution

apt-get install oss-compat
modprobe snd-pcm-oss

qui a été couronnée de succès.

Il ne restait plus que la configuration des différents chemins d’accès pour mettre le système Festival tout à fait opérationnel. Les commandes suivantes ont été ajoutées au script ~/.bashrc :

FESTIVALDIR="/home/mbarnig/Desktop/Festival-TTS/festival"
FESTVOXDIR="/home/mbarnig/Desktop/Festival-TTS/festvox"
ESTDIR="/home/mbarnig/Desktop/Festival-TTS/speech_tools"
PATH="$FESTIVALDIR/bin:$PATH"
PATH="$ESTDIR/bin:$PATH"
export PATH
export FESTIVALDIR
export FESTVOXDIR
export ESTDIR

Variables d’environnement et PATH du système Festival

Ca marche!

Lancement du programme Festival TTS sur Debian Linux Wheezy

Le chargement respectivement la compilation d’une nouvelle voix, comme le luxembourgeois, ne réussit que si la voix anglaise kal_diphon est présente, si non une erreur “unbound variable rfs_info” se produit.

Character encoding for Festival TTS files

Posted on March 13, 2015 by Marco Barnig

Today, the dominant character encoding for the World Wide Web and for text files is UTF-8 (Universal Character Set + Transformation Format 8 bits). UTF-8 uses one to 4 bytes to encode one symbol (1,112,064 valid code points in the Unicode code space). The first 128 characters of Unicode, which correspond one-to-one with ASCII, are encoded using a single byte with the same binary value as ASCII, making valid ASCII text valid UTF-8-encoded Unicode as well.

The Festival TTS package doesn’t support UTF-8. The development of Festival started about 20 years ago when UTF-8 was only known by a few people of the Open Group for Unix Systems. Festival only supports one byte character encoding. All files created with the Festvox tools to develop new languages or voices for Festival are in US-ASCII format.

Problems appear if we need to use non-ASCII characters in Festival, for example the characters é è ë à ä ö ü for the luxembourgish language. In UTF-8 these characters are encoded with two bytes (16 bits), which yields errors in Festival. There exist however a series of 8-bit character encoding standards defined by ECMA, IEC and ISO. These standards are known as ISO-8859-x, where x is one of 15 parts. The listed luxembourgish specific characters are included in the ISO-8859 parts 1, 2, 3, 4, 9, 10, 14, 15 and 16. The preferred ISO-8859 standard for the luxembourgish language is part 15, which includes the euro sign and provides the coverage of all the french and german letters. ISO 8859-15 encodes what it refers to as Latin alphabet no. 9.

Most text editors and other tools used today to write scripts and program code use UTF-8 as default format. On Windows I use Notepad++ to edit my files. Changing the encoding is easy. On my Mac OSX 10.10.2 (Yosemite) I use TextEdit, Terminal and Xcode to edit my files for Festival TTS. I changed the following preferences to encode my scripts and programs in ISO-8859-15.

TextEdit

I first checked the list of the encoding formats to show in the selection menu of the preference window.

List of character encoding formats in TextEdit

The Occidental (ISO Latin 9) format corresponds to the ISO-8859-15 standard.

Preferences selected in TextEdit

Terminal (bash)

Same procedure for the OSX terminal. I checked the list of the encoding formats to show in the selection menu of the preference window.

List of character encoding formats in the OSX Terminal

In the OSX terminal preference window I also selected the Occidental (ISO Latin 9) format corresponding to the ISO-8859-15 standard.

Preferences selected for the OSX Terminal

XCode 6.2

An ISO-8859-15 encoded text file (for example created witt TextEdit) is not recognized as such by Xcode 6.2. Characters as “é à è ö ä ü” are displayed as “È ‡ Ë ˆ ‰ ¸ “. The indicated Xcode decoding is Western (Mac OS Roman), even if the default text encoding set in Preferences > Text Editing is set to Western (ISO Latin 9). The characters are displayed as expected if the text is reinterpreted with the File Inspector to ISO Latin 9. Files created with Xcode are encoded always in UTF-8, the default text encoding setting seems to take no effect.

The Xcode window to select potential encoding formats uses a different presentation, but displays the same formats as those in TextEdit or OSX Terminal.

List of encoding formats in Xcode

Again I defined the default text encoding as Occidental (ISO Latin 9) alias ISO-8859-15.

Preferences selected for Xcode

File conversion

To check the text encoding of a file we can use the command file

mbarnig$ file -I name.ext

Some examples are shown hereafter :

Show file encoding with the command $ file -I

To convert an UTF-8 file in the ISO-8859-15 format we can use the command iconv

mbarnig$ iconv -f utf8 -t ISO-8859-1 utf8.txt > iso.txt

An example is shown hereafter :

File format conversion with the command $ iconv

The encoding formats available in iconv are listed with the option -l or –list :

Encoding formats available in iconv

Environment Variables

To show the environment variables we can use the command locale :

mbarnig$ locale

Environment variables in OSX locale

LANG= ; native language + local customization if no LC_ variables
LC_COLLATE=”C” ; character collation
LC_CTYPE=”C” ; character handling functions
LC_MESSAGES=”C” ; affirmative and negative responses
LC_MONETARY=”C” ; monetary related numeric formatting
LC_NUMERIC=”C” ; numeric formatting
LC_TIME=”C” ; date and timing formatting
LC_ALL= ; value to overwrite all LC_ variables

“C” stands for simplest locale (character set ASCII, single byte character encoding, language US-english, …)

To show all the available locales we use the option -a

mbarnig$ locale -a

List of locales defined in OSX 10.10.2

To change the locales we use the export function :

mbarnig$ export LANG=fr_CH
mbarnig$ export LC_ALL=fr_CH.ISO8859-15

Modification of locales in OSX 10.10.2 with the export command

The export functions can be included in the /Users/mbarnig/.bash_profile file.

Speech Utterance

Posted on February 24, 2015 by Marco Barnig

Last update : April 2, 2015

Utterance Definition

In linguistics an utterance is a unit of speech, without having a precise definition. It’s a bit of spoken language. It could be anything from “Baf!” to a full sentence or a long speech. The corresponding unit in written language is text.

Phonetically an utterance is a unit of speech bounded (preceded and followed) by silence. Phonemes, phones, morphemes, words etc are all considered items of an utterance.

In orthography, an utterance begins with a capital letter and ends in a period, question mark, or exclamation point.

In Speech Synthesis (TTS) the text that you wish to be spoken is contained within an utterance object (example : SpeechSynthesisUtterance). The Festival TTS system uses the utterance as the basic object for synthesis. Speech synthesis is the process that applies a set of programs to an utterance.

The main stages to convert textual input to speech output are :

Conversion of the input text to tokens
Conversion of tokens to words
Conversion of words to strings of phonemes
Addition of prosodic information
Generation of a waveform

In Festival each stage is executed in several steps. The number of steps and what actually happens may vary and is dependent on the particular language and voice selected. Each of the steps is achieved by a Festival module which will typically add new information to the utterance structure. Swapping of modules is possible.

Festival provides six synthesizer modules :

2 diphone engines : MBROLA and diphone
2 unit selection engines : clunits and multisyn
2 HMM engines : clustergen and HTS

Festival Utterance Architecture

A very simple utterance architecture is the string model where the high level items are replaced sequentially by lower level items, from tokens to phones. The disadvantage of this architecture is the loss of information about higher levels.

Another architecture is the multi-level table model with one hierarchy. The problem is that there are no explicit connections between levels.

Festival uses a Heterogeneous Relation Graph (HRG). This model is defined as follows :

Utterances consist of a set of items, representing things like tokens, words, phones,
Each item is related by one or more relations to other items.
Each item contains a set of features, having each a name and a value.
Relations define lists, trees or lattices of items.

The stages and steps to build an utterance in Festival, described in the following chapters, are related to the us-english language and to the clustergen voice cmu_us_slt_cg.

To explore the architecture (structure) of an utterance in Festival, I will analyse the relation-trees created by the synthesis of the text string “253”.

festival> (voice_cmu_us_slt_cg)
cmu_us_slt_cg
festival> (set! utter (SayText "253"))
#<Utterance 0x104c20720>
festival> (utt.relationnames utter)
(Token
 Word
 Phrase
 Syllable
 Segment
 SylStructure
 IntEvent
 Intonation
 Target
 HMMstate
 segstate
 mcep
 mcep_link
 Wave)
festival> (utt.relation_tree utter 'Token)
((("253"
   ((id "_1")
    (name "253")
    (whitespace "")
    (prepunctuation "")
    (token_pos "cardinal")))
  (("two"
    ((id "_2")
     (name "two")
     (pos_index 1)
     (pos_index_score 0)
     (pos "cd")
     (phr_pos "cd")
     (phrase_score -0.69302821)
     (pbreak_index 1)
     (pbreak_index_score 0)
     (pbreak "NB"))))
  (("hundred"
    ((id "_3")
     (name "hundred")
     (pos_index 1)
     (pos_index_score 0)
     (pos "cd")
     (phr_pos "cd")
     (phrase_score -0.692711)
     (pbreak_index 1)
     (pbreak_index_score 0)
     (pbreak "NB"))))
  (("fifty"
    ((id "_4")
     (name "fifty")
     (pos_index 8)
     (pos_index_score 0)
     (pos "nn")
     (phr_pos "n")
     (phrase_score -0.69282991)
     (pbreak_index 1)
     (pbreak_index_score 0)
     (pbreak "NB"))))
  (("three"
    ((id "_5")
     (name "three")
     (pos_index 1)
     (pos_index_score 0)
     (pos "cd")
     (phr_pos "cd")
     (pbreak_index 0)
     (pbreak_index_score 0)
     (pbreak "B")
     (blevel 3))))))
festival> (utt.relation_tree utter 'Word)
((("two"
   ((id "_2")
    (name "two")
    (pos_index 1)
    (pos_index_score 0)
    (pos "cd")
    (phr_pos "cd")
    (phrase_score -0.69302821)
    (pbreak_index 1)
    (pbreak_index_score 0)
    (pbreak "NB"))))
 (("hundred"
   ...
   ...
    (blevel 3)))))
festival> (utt.relation_tree utter 'Phrase)
((("B" ((id "_6") (name "B")))
  (("two"
    ((id "_2")
     (name "two")
     (pos_index 1)
     (pos_index_score 0)
     (pos "cd")
     (phr_pos "cd")
     (phrase_score -0.69302821)
     (pbreak_index 1)
     (pbreak_index_score 0)
     (pbreak "NB"))))
  (("hundred"
    ...
    ...
     (blevel 3))))))
festival> (utt.relation_tree utter 'Syllable)
((("syl" ((id "_7") (name "syl") (stress 1))))
 (("syl" ((id "_10") (name "syl") (stress 1))))
 (("syl" ((id "_14") (name "syl") (stress 0))))
 (("syl" ((id "_19") (name "syl") (stress 1))))
 (("syl" ((id "_23") (name "syl") (stress 0))))
 (("syl" ((id "_26") (name "syl") (stress 1)))))
festival> (utt.relation_tree utter 'Segment)
((("pau" ((id "_30") (name "pau") (end 0.15000001))))
 (("t" ((id "_8") (name "t") (end 0.25016451))))
 (("uw" ((id "_9") (name "uw") (end 0.32980475))))
 (("hh" ((id "_11") (name "hh") (end 0.39506164))))
 (("ah" ((id "_12") (name "ah") (end 0.48999402))))
 (("n" ((id "_13") (name "n") (end 0.56175226))))
 (("d" ((id "_15") (name "d") (end 0.59711802))))
 (("r" ((id "_16") (name "r") (end 0.65382934))))
 (("ax" ((id "_17") (name "ax") (end 0.67743915))))
 (("d" ((id "_18") (name "d") (end 0.75765681))))
 (("f" ((id "_20") (name "f") (end 0.86216313))))
 (("ih" ((id "_21") (name "ih") (end 0.93317086))))
 (("f" ((id "_22") (name "f") (end 1.0023116))))
 (("t" ((id "_24") (name "t") (end 1.0642071))))
 (("iy" ((id "_25") (name "iy") (end 1.1534019))))
 (("th" ((id "_27") (name "th") (end 1.2816957))))
 (("r" ((id "_28") (name "r") (end 1.3449684))))
 (("iy" ((id "_29") (name "iy") (end 1.5254952))))
 (("pau" ((id "_31") (name "pau") (end 1.6754951)))))
festival> (utt.relation_tree utter 'SylStructure)
((("two"
   ((id "_2")
    (name "two")
    (pos_index 1)
    (pos_index_score 0)
    (pos "cd")
    (phr_pos "cd")
    (phrase_score -0.69302821)
    (pbreak_index 1)
    (pbreak_index_score 0)
    (pbreak "NB")))
  (("syl" ((id "_7") (name "syl") (stress 1)))
   (("t" ((id "_8") (name "t") (end 0.25016451))))
   (("uw" ((id "_9") (name "uw") (end 0.32980475))))))
 (("hundred"
   ((id "_3")
    (name "hundred")
    (pos_index 1)
    (pos_index_score 0)
    (pos "cd")
    (phr_pos "cd")
    (phrase_score -0.692711)
    (pbreak_index 1)
    (pbreak_index_score 0)
    (pbreak "NB")))
  (("syl" ((id "_10") (name "syl") (stress 1)))
   (("hh" ((id "_11") (name "hh") (end 0.39506164))))
   (("ah" ((id "_12") (name "ah") (end 0.48999402))))
   (("n" ((id "_13") (name "n") (end 0.56175226)))))
  (("syl" ((id "_14") (name "syl") (stress 0)))
   (("d" ((id "_15") (name "d") (end 0.59711802))))
   (("r" ((id "_16") (name "r") (end 0.65382934))))
   (("ax" ((id "_17") (name "ax") (end 0.67743915))))
   (("d" ((id "_18") (name "d") (end 0.75765681))))))
 (("fifty"
   ((id "_4")
    (name "fifty")
    (pos_index 8)
    (pos_index_score 0)
    (pos "nn")
    (phr_pos "n")
    (phrase_score -0.69282991)
    (pbreak_index 1)
    (pbreak_index_score 0)
    (pbreak "NB")))
  (("syl" ((id "_19") (name "syl") (stress 1)))
   (("f" ((id "_20") (name "f") (end 0.86216313))))
   (("ih" ((id "_21") (name "ih") (end 0.93317086))))
   (("f" ((id "_22") (name "f") (end 1.0023116)))))
  (("syl" ((id "_23") (name "syl") (stress 0)))
   (("t" ((id "_24") (name "t") (end 1.0642071))))
   (("iy" ((id "_25") (name "iy") (end 1.1534019))))))
 (("three"
   ((id "_5")
    (name "three")
    (pos_index 1)
    (pos_index_score 0)
    (pos "cd")
    (phr_pos "cd")
    (pbreak_index 0)
    (pbreak_index_score 0)
    (pbreak "B")
    (blevel 3)))
  (("syl" ((id "_26") (name "syl") (stress 1)))
   (("th" ((id "_27") (name "th") (end 1.2816957))))
   (("r" ((id "_28") (name "r") (end 1.3449684))))
   (("iy" ((id "_29") (name "iy") (end 1.5254952)))))))
festival> (utt.relation_tree utter 'IntEvent)
((("L-L%" ((id "_32") (name "L-L%"))))
 (("H*" ((id "_33") (name "H*"))))
 (("H*" ((id "_34") (name "H*"))))
 (("H*" ((id "_35") (name "H*")))))
festival> (utt.relation_tree utter 'Intonation)
((("syl" ((id "_26") (name "syl") (stress 1)))
  (("L-L%" ((id "_32") (name "L-L%")))))
 (("syl" ((id "_7") (name "syl") (stress 1)))
  (("H*" ((id "_33") (name "H*")))))
 (("syl" ((id "_10") (name "syl") (stress 1)))
  (("H*" ((id "_34") (name "H*")))))
 (("syl" ((id "_19") (name "syl") (stress 1)))
  (("H*" ((id "_35") (name "H*"))))))
festival> (utt.relation_tree utter 'Target)
((("t" ((id "_8") (name "t") (end 0.25016451)))
  (("0" ((id "_36") (f0 101.42016) (pos 0.1)))))
 (("uw" ((id "_9") (name "uw") (end 0.32980475)))
  (("0" ((id "_37") (f0 121.11904) (pos 0.25)))))
 (("hh" ((id "_11") (name "hh") (end 0.39506164)))
  (("0" ((id "_38") (f0 119.19957) (pos 0.30000001)))))
 (("ah" ((id "_12") (name "ah") (end 0.48999402)))
  (("0" ((id "_39") (f0 123.81679) (pos 0.44999999)))))
 (("d" ((id "_15") (name "d") (end 0.59711802)))
  (("0" ((id "_40") (f0 117.02986) (pos 0.60000002)))))
 (("ax" ((id "_17") (name "ax") (end 0.67743915)))
  (("0" ((id "_41") (f0 110.17942) (pos 0.85000008)))))
 (("f" ((id "_20") (name "f") (end 0.86216313)))
  (("0" ((id "_42") (f0 108.59299) (pos 1.0000001)))))
 (("ih" ((id "_21") (name "ih") (end 0.93317086)))
  (("0" ((id "_43") (f0 115.24371) (pos 1.1500001)))))
 (("t" ((id "_24") (name "t") (end 1.0642071)))
  (("0" ((id "_44") (f0 108.76601) (pos 1.3000002)))))
 (("iy" ((id "_25") (name "iy") (end 1.1534019)))
  (("0" ((id "_45") (f0 102.23844) (pos 1.4500003)))))
 (("th" ((id "_27") (name "th") (end 1.2816957)))
  (("0" ((id "_46") (f0 99.160072) (pos 1.5000002)))))
 (("iy" ((id "_29") (name "iy") (end 1.5254952)))
  (("0" ((id "_47") (f0 90.843689) (pos 1.7500002))))
  (("0" ((id "_48") (f0 88.125809) (pos 1.8000003))))))
festival> (utt.relation_tree utter 'HMMstate)
((("pau_1" ((id "_49") (name "pau_1") (statepos 1) (end 0.050000001)*
 (("pau_2" ((id "_50") (name "pau_2") (statepos 2) (end 0.1))))
 (("pau_3" ((id "_51") (name "pau_3") (statepos 3) (end 0.15000001)*
 (("t_1" ((id "_52") (name "t_1") (statepos 1) (end 0.16712391))))
 (("t_2" ((id "_53") (name "t_2") (statepos 2) (end 0.23217295))))
 (("t_3" ((id "_54") (name "t_3") (statepos 3) (end 0.25016451))))
 (("uw_1" ((id "_55") (name "uw_1") (statepos 1) (end 0.2764155))))
 (("uw_2" ((id "_56") (name "uw_2") (statepos 2) (end 0.3001706))))
 (("uw_3" ((id "_57") (name "uw_3") (statepos 3) (end 0.32980475))))
 (("hh_1" ((id "_58") (name "hh_1") (statepos 1) (end 0.3502973))))
 ...
 ...
 (("iy_1" ((id "_100") (name "iy_1") (statepos 1) (end 1.3995106))))
 (("iy_2" ((id "_101") (name "iy_2") (statepos 2) (end 1.4488922))))
 (("iy_3" ((id "_102") (name "iy_3") (statepos 3) (end 1.5254952))))
 (("pau_1" ((id "_103") (name "pau_1") (statepos 1) (end 1.5754951)*
 (("pau_2" ((id "_104") (name "pau_2") (statepos 2) (end 1.6254952)*
 (("pau_3" ((id "_105") (name "pau_3") (statepos 3) (end 1.6754951)*
festival> (utt.relation_tree utter 'segstate)
((("pau" ((id "_30") (name "pau") (end 0.15000001)))
  (("pau_1" ((id "_49") (name "pau_1") (statepos 1) (end 0.050000001)
  (("pau_2" ((id "_50") (name "pau_2") (statepos 2) (end 0.1))))
  (("pau_3" ((id "_51") (name "pau_3") (statepos 3) (end 0.15000001)*
 (("t" ((id "_8") (name "t") (end 0.25016451)))
  (("t_1" ((id "_52") (name "t_1") (statepos 1) (end 0.16712391))))
  (("t_2" ((id "_53") (name "t_2") (statepos 2) (end 0.23217295))))
  (("t_3" ((id "_54") (name "t_3") (statepos 3) (end 0.25016451)))))
 (("uw" ((id "_9") (name "uw") (end 0.32980475)))
  (("uw_1" ((id "_55") (name "uw_1") (statepos 1) (end 0.2764155))))
  (("uw_2" ((id "_56") (name "uw_2") (statepos 2) (end 0.3001706))))
  (("uw_3" ((id "_57") (name "uw_3") (statepos 3) (end 0.32980475))))
 ...
 ...
 (("iy" ((id "_29") (name "iy") (end 1.5254952)))
  (("iy_1" ((id "_100") (name "iy_1") (statepos 1) (end 1.3995106))))
  (("iy_2" ((id "_101") (name "iy_2") (statepos 2) (end 1.4488922))))
  (("iy_3" ((id "_102") (name "iy_3") (statepos 3) (end 1.5254952))*
 (("pau" ((id "_31") (name "pau") (end 1.6754951)))
  (("pau_1" ((id "_103") (name "pau_1") (statepos 1) (end 1.5754951)*
  (("pau_2" ((id "_104") (name "pau_2") (statepos 2) (end 1.6254952)*
  (("pau_3" ((id "_105") (name "pau_3") (statepos 3) (end 1.6754951)*
festival> (utt.relation_tree utter 'mcep)
((("pau_1"
   ((id "_106")
    (frame_number 0)
    (name "pau_1")
    (clustergen_param_frame 19315))))
 (("pau_1"
   ((id "_107")
    (frame_number 1)
    (name "pau_1")
    (clustergen_param_frame 19315))))
 (("pau_1"
   ((id "_108")
    (frame_number 2)
    (name "pau_1")
    (clustergen_param_frame 19315))))
 (("pau_1"
   ((id "_109")
    (frame_number 3)
    (name "pau_1")
    (clustergen_param_frame 19315))))
 ...
 ...
 (("t_1"
   ((id "_137")
    (frame_number 31)
    (name "t_1")
    (clustergen_param_frame 26089))))
 (("t_1"
   ((id "_138")
    (frame_number 32)
    (name "t_1")
    (clustergen_param_frame 26085))))
 (("t_1"
   ((id "_139")
    (frame_number 33)
    (name "t_1")
    (clustergen_param_frame 26085))))
 (("t_2"
   ((id "_140")
    (frame_number 34)
    (name "t_2")
    (clustergen_param_frame 26642))))
...
...
 (("uw_1"
   ((id "_157")
    (frame_number 51)
    (name "uw_1")
    (clustergen_param_frame 27595))))
 ...
 (("pau_3"
   ((id "_438")
    (frame_number 332)
    (name "pau_3")
    (clustergen_param_frame 22148))))
 (("pau_3"
   ((id "_439")
    (frame_number 333)
    (name "pau_3")
    (clustergen_param_frame 22148))))
 (("pau_3"
   ((id "_440")
    (frame_number 334)
    (name "pau_3")
    (clustergen_param_frame 22148))))
 (("pau_3"
   ((id "_441")
    (frame_number 335)
    (name "pau_3")
    (clustergen_param_frame 22365)))))
festival> (utt.relation_tree utter 'mcep_link)
((("pau_1" ((id "_49") (name "pau_1") (statepos 1) (end 0.050000001).
  (("pau_1"
    ((id "_106")
     (frame_number 0)
     (name "pau_1")
     (clustergen_param_frame 19315))))
  (("pau_1"
    ((id "_107")
     (frame_number 1)
     (name "pau_1")
     (clustergen_param_frame 19315))))
  (("pau_1"
    ((id "_108")
     (frame_number 2)
     (name "pau_1")
     (clustergen_param_frame 19315))))
  ...
  ...
  (("pau_3"
    ((id "_439")
     (frame_number 333)
     (name "pau_3")
     (clustergen_param_frame 22148))))
  (("pau_3"
    ((id "_440")
     (frame_number 334)
     (name "pau_3")
     (clustergen_param_frame 22148))))
  (("pau_3"
    ((id "_441")
     (frame_number 335)
     (name "pau_3")
     (clustergen_param_frame 22365))))))
festival> (utt.relation_tree utter 'Wave)
((("0" ((id "_442") (wave "[Val wave]")))))
festival>

Notes :
* some parentheses have been deleted in the display for formating reasons
… some content has been deleted to reduce the size of the analyzed code

Results of the code analysis

The number of items created for the string “253” are shown in the following table :

number	item	id’s
1	token	1
4	word	2-5
1	phrase	6
6	syllable	7, 10, 14, 19, 23, 26
19	segment	8-9, 11-13, 15-18, 20-22, 24-25, 27-31
4	intevent	32-35
13	target	36-48
57	hmmstate	49-105
336	mcep	106-441
1	wave	442

The features associated to the different items are presented in the next table :

item	features
token	name, whitespace, prepunctuation, token_pos
word	name, pos_index, pos_index_score, pos, phr_pos, phrase_score, pbreak_index, pbreak_index_score, pbreak, blevel
phrase	name
syllable	name, stress
segment	name, end
intevent	name
target	f0, pos
hmmstate	name, statepos, end
mcep	name, frame_number, clustergen_param_frame
wave	Val

The last table shows the relations between the different items in the HRG :

item	daughter	leaf	relation
token	word	x	Token
word	syllable	–	SylStructure
phrase	word	x	Phrase
syllable	segment	x (except silence)	SylStructure
syllable	intevent	x	Intonation
segment	target	x	Target
segment	hmmstate	x	segstate
segment	mcep	x	mcep_link

Relations between utterance items

To better understand the relations between utterance items, I use a second example :

festival>
(set! utter (SayText "253 and 36"))
(utt.relation.print utter 'Token)

Festival SayText

There are 3 tokens. The Token relation is a list of trees where each root is the white space separated tokenized object from the input character string and where the daughters are the list of words associated with the tokens. Most often it is a one to one relationship, but in the case of digits a token is associated with several words. The following command shows the Token tree with the daughters :

(utt.relation_tree utter 'Token)

Festival Token_tree

We can check that the word list corresponds to the Token tree list :

(utt.relation.print utter 'Word)

Festival Word List

To access the second word of the first token we can use two methods :

(item.name (item.daughter2 (utt.relation.first utter 'Token)))

(item.name (item.next (utt.relation.first utter 'Word)))

Festival access methods to word item

TTS stages and steps

In the next chapters the different stages and steps executed to synthesize a text string are described with more details. In the first step a simple and a complex utterance of type Text are created :

(set! simple_utt (Utterance Text 
"The quick brown fox jumps over the lazy dog"))
(set! complex_utt (Utterance Text
"Mr. James Brown Jr. attended flight No AA4101 to Boston on
Friday 02/13/2014."))

The complex utterance named complex_utt is used in the following examples.

1. Text-to-Token Conversion

Text

Text is a string of characters in ASCII or ISO-8850 format. Written (raw) text usually contains also numbers, names, abbreviations, symbols, punctuation etc which must be translated into spoken text. This process is called Tokenization. Other terms used are (lexical) Pre-Processing, Text Normalization or Canonicalization. To access the items and features of the defined utterance named complex_utt in Festival we use the following modules :

festival> (Initialize complex_utt) ; Initialize utterance
festival> (utt.relationnames complex_utt) ; show created relations

Festival Utterance Initialization

The result nil indicates that there exist not yet a relation inside the text-utterance.

Tokens

The second step is the Tokenization which consists in the conversion of the input text to tokens. A token is a sequence of characters where whitespace and punctuation are eliminated. The following Festival command is used to convert raw text to tokens and to show them :

festival> (Text complex_utt) ; convert text to tokens
festival> (utt.relationnames complex_utt) ; check new relations
festival> (utt.relation.print complex_utt 'Token) ; display tokens

Festival Text Module to convert raw text to tokens

There are several methods to access individual tokens :

festival> (utt.relation.first complex_utt 'Token) ; returns 1st token
festival> (utt.relation.last complex_utt 'Token) ; returns last token
festival> (utt.relation_tree complex_utt 'Token) ; returns token tree

Festival Token Access

This utt.relation_tree method can also be applied to other relations than ‘Tokens.

2. Token-to-Word Conversion

Words

In linguistics, a word is the smallest element that may be uttered in isolation with semantic or pragmatic content. To convert the isolated tokens to words, we use the Festival commands :

festival> (Token complex_utt) ; token to word conversion
festival> (utt.relationnames complex_utt) ; check new relations
festival> (utt.relation.print complex_utt 'Word) ; display words

Festival Token Module to convert tokens to words

The rules to perform the token to word conversion are specified in the Festival script token.scm.

POS

Part-of-Speech (POS) Tagging is related to the Token-to-Word conversion. POS is also called grammatical tagging or word-category disambiguation. It’s the process of marking up a word in a text as corresponding to a particular part of speech, based on both its definition, as well as its context (identification of words as nouns, verbs, adjectives, adverbs, etc.)

To do the POS tagging, we use the commands

festival> (POS complex_utt) ; Part of Speech tagging
festival> (utt.relationnames complex_utt) ; check new relations
festival> (utt.relation.print complex_utt 'Word) ; display words

The relation check shows that no new relation was created with the POS method. There are however new features which have been added to the ‘Word relation.

Festival POS Module to tag the words

The new features are :

pos_index n
pos_index_score m
pos xx

Phrase

The last step of the Token-to-Word conversion is the phrasing. This process determines the places where phrase boundaries should be inserted. Prosodic phrasing in TTS makes the whole speech more understandable. The phrasing is launched with the following commands :

festival> (Phrasify complex_utt) ;
festival> (utt.relationnames complex_utt) ; check new relations
festival> (utt.relation.print complex_utt 'Phrase) ; display breaks

Festival Phrasify Module to insert boundaries

The result can be seen in new attributes in the Word relation:

festival> (utt.relation.print complex_utt 'Word)

phr_pos xx
phrase_score nn
pbreak_index n
pbreak_index_score m
pbreak yy (B for small breaks, BB is for big breaks, NB for no break)
blevel p

Festival Word list after phrasing (click to enlarge)

3. Word-to-Phoneme Conversion

The command

festival> (Word complex_utt)

generates 3 new relations : syllables, segments and SylStructure.

Festival relations generated by the Word method

Segment

Segments and phones are synonyms.

festival> (utt.relation.print complex_utt 'Segment)

Festival segments = phones

Syllable

Consonants and vowels combine to make syllables. They are often considered the phonological building blocks of words, but there is no universally accepted definition for a syllable. An approximate definition is : a syllable is a vowel sound together with some of the surrounding consonants closely associated with it. The general structure of a syllable consists of three segments :

Onset : a consonant or consonant cluster
Nucleus : a sequence of vowels or syllabic consonant
Coda : a sequence of consonants

Nucleus and coda are grouped together as a Rime. Prominent syllables are called accented; they are louder, longer and have a different pitch.

The following Festival command shows the syllables of the defined utterance.

festival> (utt.relation.print complex_utt 'Syllable)

Festival syllables

SylStructure

Words, segments and syllables are related in the HRG trought the SylStructure. The command

festival> (utt.relation.print complex_utt 'SylStructure)

prints these related items.

Festival SylStructure (click to enlarge)

4. Prosodic Information Addition

Besides the phrasing with break indices, additional prosodic components can be added to speech synthesis to improve the voice quality. Some of these elements are :

pitch accents (stress)
final boundary tones
phrasal tones
F0 contour
tilt
duration

Festival supports ToBI, a framework for developing community-wide conventions for transcribing the intonation and prosodic structure of spoken utterances in a language variety.

The process

festival> (Intonation complex_utt)

generates two additional relations : IntEvent and Intonation

Festival prosodic relations

IntEvent

The command

festival> (utt.relation.print complex_utt 'IntEvent)

prints the IntEvent items.

Festival IntEvent items

The following types are listed :

L-L% : low boundary tone
H* : peak accent
!H* : downstep high
L+H* : bitonal accent, rising peak

Intonation

The command

festival> (utt.relation.print complex_utt 'Intonation)

prints the Intonation items.

Festival Intonation items

Only the syllables with stress are displayed.

Duration

The process

festival> (Duration complex_utt)

creates no new relations and I have not seen any new items or features in other relations.

utt14

Target

The last process in the prosodic stage

festival> (Int_Targets complex_utt)

generates the additional relation Target.

Festival relations after the Int_Targets process

The command

festival> (utt.relation.print complex_utt 'Target)

prints the target items.

Festival clustergen targets

The unique target features are the segment name and the segment end time.

5. Waveform Generation

Wave

The process

festival> (Wave_Synth complex_utt)
festival> (utt.relation.print complex_utt 'Wave)

generates five new relations :

HMMstate
segstate
mcep
mcep_links
Wave

Festival Wave relations for clustergen voice

In the next chapters we use the method

(utt.relation.print complex_utt 'Relation)

to display the relations and features specific to the diphone voice.

Relation ‘HMMstate

HMMstates for Festival clustergen voice

Relation ‘segstate

segstates for Festival clustergen voice

Relation ‘mcep

mcep features for Festival clustergen voice

Relation ‘mcep_links

mcep_links relation for Festival clustergen voice

Relation ‘Wave

Wave relation for Festival clustergen voice

Diphone Voice Utterance

If we use a diphone voice (e.g. the default kal_diphone voice) instead of the clustergen voice, the last step of the prosodic stage (No 4) and the complete wave-synthesis stage (No 5) provide different relations and features.

We use the Festival method “SayText”, a combination of the above presented processes

Initialize utt
Text utt
Token utt
POS utt
Phrasify utt
Word utt
Intonation utt
Duration utt
Int_Targets utt
Wave_Synt utt

to create the same complex utterance as in the first example :

festival>
(set! complex_utt (SayText "Mr. James Brown Jr. attended flight 
No AA4101 to Boston on Friday 02/13/2014."))
(utt.relationnames complex_utt)

Here are the results :

Utterance relations for a Festival diphone voice

In the next chapters we use the method

(utt.relation.print complex_utt 'Relation)

to display the relations and features specific to the diphone voice.

Relation ‘Target

Relation Target for diphone voice

Relation ‘Unit

Relation Unit for diphone voice (click to enlarge)

Relation ‘SourceCoef

Relation ‘SourceCoef for diphone voice

Relation ‘fo

Relation f0 for diphone voice

Relation ‘TargetCoef

Relation TargetCoef for diphone voice

Relation ‘US_map

Relation US_map for diphone voice

Relation ‘Wave

Relation Wave for diphone voice

Playing and saving the diphone voice utterance :

Playing and saving a synthesized Festival utterance

Diphone voice utterance shown in Audacity :

Display of a synthesized Festival utterance

Clunits Voice Utterance

What is true for the diphone voice is also ture for a clunits voice. The last step of the prosodic stage (No 4) and the complete wave-synthesis stage (No 5) generate different relations and features. As an example we use a swedish clunits voice :

Relations for Festival clunits voice

Relation ‘Target

Relation Target for Festival clunits voice (click to enlarge)

Relation ‘Unit

Relation unit for Festival clunits voice (click to enlarge)

Relation ‘SourceSegments

Relation SourceSegments for Festival clunits voice

That’s all.

Festival TTS Scheme

Posted on February 21, 2015 by Marco Barnig

Last update : April 23, 2015

Scheme

The Scheme programmimg language is a dialect of Lisp designed to be more consistent. Originally specified in 1958, Lisp is the second-oldest high-level programming language; Fortran is one year older. Lisp has a distinctive, fully parenthesized Polish Notation. The name LISP derives from LISt Processing. All program code in Lisp is written as s-expressions, or parenthesized lists. Lots of brackets comes to most people’s mind when they look at s-expressions. Lisp was invented by John McCarthy in 1958 while he was at the Massachusetts Institute of Technology (MIT). Lisp became quickly the favored programming language for artificial intelligence (AI) research. Another dialect of Lisp is Common Lisp (CL).

Scheme was invented by Guy Lewis Steele Jr. and Gerald Jay Sussman. The Scheme language is standardized in the official IEEE standard and in a de facto standard called the Revisedn Report on the Algorithmic Language Scheme (RnRS). The latest standard R7RS was finalized in 2013. An improper list of Scheme resources is available at the schemers.org website.

The Festival TTS system uses an enhanced version of Scheme, based on George Carrette’s SIOD (Scheme in one Defun).

In Scheme, an expression is an atom or a list. Atoms can be symbols, numbers, strings or special types like functions, arrays, hash tables. A list consist of a left parenthesis, a number of expressions and a right parenthesis. Comments are started by a semicolon and run until end of line. Scheme is case sensitive.

Each member of a list (except set!) is evaluated. The 1st item is treated as function and applied using the remainder of the lists as arguments to the function. Strings are bounded by the double-quote character.

"This is a string with embedded \"...\" quotes"

Double quotes in a string are escaped with a backslash ( \ ).

Scheme Core Functions

The core functions are :

(set! SYMBOL VALUE) ; attribute a value to a variable
(define (FUNCNAME ARG0 ARG1 …) . BODY) ; declare the boy of a function with arguments
(if TEST TRUECASE [FALSECASE] ) ; if the value of TEST is non-nil, return value of evaluated truecase-expression, otherwise, if present, return evaluated falsecase-expressionor nil
(cond (TEST0 . BODY) (TEST1 . BODY) …) ; multipe if statement
(begin . BODY) ; returns the value of the last s-expression in a list
(or . DISJ) ; return the value of the 1st non-nil disjunct
(and : CONJ) ; return the value of the 1st nil conjunct or the value of the last conjunct
(car EXPR) ; return the 1st item of a list or nil for an atom or empty list
(cdr EXPR) ; return the rest of a list or nil for an atom or empty list
(cons EXPR0 EXPR1) ; build a new list with car of EXPR0 and crd of EXPR1
(list . BODY) ; form a list from each of the arguments
(append . BODY) ; join each of the arguments into a single list
(nth N LIST) ; return Nth member of list (1st item is 0th member)
(nth_cdr N LIST) ; return Nth cdr list
(last LIST) ; return last crd of a list
(reverse list) ; return the list in inverse order
(member ITEM LIST) ; returns the cdr in LIST whose car is ITEM or nil if not found
(assoc ITEM ALIST) ; standardlist format for representing value pairs
(intern “abc”) ; convert a string to a symbol
(parse-number “3.14”) ; convert a string to a number
(mapcar fct list1 list2 …) ; returns a list which is the result of applying the function fcn to the elements of each of the lists specified
(number? x) ; returns true if x is a number
(symbol? x) ; returns true if x is a symbol
(quote x) ; special form that returns x without evaluating it. Commonly written in abbreviated format as ‘x (apostrophe x = short hand for quote). The (quote something) form returns that something as itself no matter what the something is (symbol, list …). Self evaluated data like numbers and strings need not to be quoted.

If the 1st statement of a function is a string, it is treated as a documentation string. The string will be printed when help is requested for that function symbol. To request help, press the keys <Esc> and <h> simultaneously after entering the name of the function.

Scheme Help Function

s-expressions

A Scheme s-expression is a construct that returns a value. Typical s-expressions are

3
( 1 2 3)
(a ( b c ) d)
(( a b ) ( d e ))

Some examples of simple arithmetic scheme s-expressions are presented hereafter :

(+ 2 3 4)   ; add the arguments
(set! a 3)  ; define the variable a to 3
(* a 5)     ; multiply the arguments
(/ 8 a)     ; divide the 1st argument by the 2nd argument
(- 12 a)    ; substract the 2nd argument from the 1st argument
(cons 1 2)  ; join 2 arguments as a pair

The following figure shows the results :

Scheme arithmetic expressions

Here are some more examples of scheme s-expressions :

; define a list with 3 fruits
(set! fruits '(apples pears bananas))
; use the 1st item of the list
(car fruits) 
; use the remaining items following the 1st item of the list
(cdr fruits)
; define a list with 2 vegetables
(set! vegetables '(carrots beans)) 
; combine the fruit and vegetable lists
(append fruits vegetables) 
; get the number of items in the list
(length fruits)
; get the number of items in the combined list
(length (append fruits vegetables))
; join 2 lists as a pair
(cons vegetables fruits)

The next figure shows the results :

Scheme list expressions

Regular expressions

A regular expression is a sequence of characters that forms a search pattern, mainly for use in string matching (filters). A regular expression is sometimes called a rational expression and abbreviated as regex or regexp. The concept was formalized in the 1950s by the American mathematician Stephen Kleene who created a regular language. Today regular expressions are so useful in computing that the various systems to specify regular expressions have evolved to provide both a basic and extended standard for the grammar and syntax.

Festival Scheme uses a regex implementation based on Henry Spencer‘s regex code. In general all characters match themselves, except for the following ones which have special interpretations (meta-characters), if they are not preceded by a backslash :

.  *  +  ?  [  ]  (  )  |  ^  $  \

. matches any character in the regex
* matches zero or more occurences of the preceding item in the regex
+ matches one or more occurences of the preceding item in the regex
? matches zero or one occurence of the preceding item in the regex
[ ] defines a range of characters
( ) defines a section (scope, block, capturing group)
| or operator ; separates alternatives
^ if specified first negates the class
$ matches the ending position of a string
\ backslash to escape meta-characters

Examples :

a.c > abc, acc, adc
a*c > c, aac, ac, aaaaaaaac
a+c > ac, aaac
ab?c > ac, abc
[a-z] any lower case letter
[a-zA-Z] any lower or upper case letter
gr(e|a)y > grey, gray
^abc > any characters other than a, b or c

Boolean Values

Scheme provides a special unique object called false, whose written representation is #f and who is the result of a condition expression (if or cond). This is the only value that counts as false, all others count as true. For this reason there is no need to provide a boolean object true, but for clarity, Scheme provides an object written #t which can be used as true value. In Festival’s Scheme (SIOD), #f and #t are unbound variables. In SIOD the variable t stands for true and nil stands for false.

Named and unnamed (anonymous = lambda) functions

Here is an example of a new (named) function :

(define (add a b) (+ a b))
(add 7 5)

Scheme functions

Scheme provides a lot of useful string functions, for example

(string-equal ATOM1 ATOM2)
(string-append STR1 STR2)
(string-before STR SUBSTR)
(string-after STR SUBSTR)
(string-length SYMBOL)
(string-matches STR REGEX)
(Symbolexplode SYMBOL)
(member_string STR LIST)

A function that returns either true (t) or false (nil) is called a predicate.

Instead of a named function, we can create unnamed (anonymous) functions using the special lambda form.

(lambda (arg1 arg2 ...) form1 form2 ...)

This function is simply defined where it’s used; for example, to square the items of a list we can apply the following construct

(set! mylist '(1 3 6 8))
(mapcar (lambda (x) (* x x)) mylist)

Scheme lambda example

Conditionals

Scheme provides a very powerful nested conditional expression with the syntax

( cond < clause 1 > <c lause 2 > < clause 3 > ... )

where < clause > is of the form

( < predicate > < form > ...)

The last clause may be an else clause which has the syntax

( < else > < form 1> < form 2 > ...)

Cond is a special form where each clause is processed until the predicate expression of the clause evaluates true. Then each subform in the predicate is evaluated with the value of the last one becoming the value of the cond form.

A simple example is :

(cond (( > a b ) 'greater)
      (( < a b ) 'less)
      (t 'equal))

Scheme cond example

A more complex example is show hereafter :

(cond
((string-matches name "[1-9][0-9]+")
  (mbarnig_lb::number token name))
((string-matches name "[A-Z]+")
  (mbarnig_lb::upper_case_abbr token name))
((string-matches  name "[a-z]+")
  (mbarnig_lb::lower_case_abbr token name))
(t (list name))) ; when no specific rules apply do the general ones

Another special conditional form is

(and subform1 subform2 subform3 ...)

This form causes the evaluation of its subforms in order, from left to right, continuing if and only if the subform returns a non-null value.

System commands

Here are some examples of scheme system commands :

(quit) or (exit) ; close the program
(pwd) ; show the pathname of the current directory
(cd DIRECTORY)
(getenv NAME)
(setenv NAME VALUE)
(set_backtrace t) ; display a backtrace when a scheme error occurs
(unwind-protect …) ; catch errors and continue normally

Hooks

A hook in Scheme terms is a position within the program code where a user may specify his own customization. There a number of places in Festival where hooks are used. A hook variable contains either a function or a list of functions that are to be applied at some point in the processing. A list of defined hooks in Festival is shown below :

after_analysis_hooks : functions applied after analysis, before synthesis
default_after_analysis_hooks : default functions applied after analysis
before_synth_hooks : functions applied on synthesized utterances
default_before_synth_hooks : default functions applied on synthesized utterances
after_synth_hooks : functions applied after synthesis to manipulate waveforms
default_after_synth_hooks : default functions applied after synthesis
diphone_module_hooks : functions applied at the start of the diphone module
tts_hooks : functions applied during text to speech
xxml_hooks : functions applied before tts_hooks
xxml_token_hooks : functions applied to each token

Festival hooks

Links

A list with links to websites providing additional informations about Scheme is provided hereafter :

Festival Text-to-Speech Package

Posted on January 7, 2015 by Marco Barnig

Last update : April 22, 2015

Festival

The Festival Speech Synthesis System is a general multi-lingual speech synthesis system originally developed by Alan W. Black at the Centre for Speech Technology Research (CSTR) at the University of Edinburgh. Alan W. Black is now professor in the Language Technology Institute at Carnegie Mellon University where substantial contributions have been provided to Festival. The program is written in C++.

To set-up a complete Festival Environment on OS X (Yosemite 10.10.2), four packages are required :

Festival-2.4 (file festival-2.4-release.tar)
Edinburgh Speech-Tools (file speech_tools-2.4-release.tar)
Festvox (file festvox-2.7.0-release.tar.gz)
Languages (example file : english festvox_kallpc16k.tar.gz)

To compile and install the packages, I got some guidance from a Linguistic Mystic (alias Will Styler). After unzipping, the files have been moved into a common folder Festival-TTS on the desktop with the following names :

festival
speech-tools
festvox

The language files are installed in the festival folder in the sub-folders lib/voices/english.

The packages have been compiled in the following sequence :

mbarnig$ cd Desktop/Festival-TTS/speech_tools
mbarnig$ ./configure
mbarnig$ make
mbarnig$ make test
mbarnig$ make install

mbarnig$ cd Desktop/Festival-TTS/festival
mbarnig$ ./configure
mbarnig$ make
mbarnig$ make install

mbarnig$ cd Desktop/Festival-TTS/festvox
mbarnig$ ./configure
mbarnig$ make

At the end the voice folder with the language files was moved to the festival/lib directory.

After updating Xcode to version 6.1.1 and installing the audiotools for Xcode 6.1, I checked that afplay is working :

afplay check

I checked also that the festival/lib/siteinit.scm file contains the following statements :

(Parameter.set ‘Audio_Required_Format ‘riff)
(Parameter.set ‘Audio_Method ‘Audio_Command)
(Parameter.set ‘Audio_Command “afplay $FILE”)

The following files have been downloaded from the festvox website, unzipped and moved to the festival/lib/dicts folder :

festlex_CMU.tar.gz
festlex_OALD.tar.gz
festlex_POSLEX.tar.gz

I added finally the following statements to the .bash_profile file located in the homefolder (/Users/mbarnig) :

export FESTIVALDIR=”/Users/mbarnig/Desktop/Festival-TTS/festival”
export PATH=”$FESTIVALDIR/bin:$PATH”
export ESTDIR=”/Users/mbarnig/Desktop/Festival-TTS/speech_tools”
export PATH=”$ESTDIR/bin:$PATH”
export FESTVOXDIR=”/Users/mbarnig/Desktop/Festival-TTS/festvox”

The festival tool can now be started in the terminal window with the command

mbarnig$ $FESTIVALDIR/bin/festival

Festival version 2.4

All seems to be working great!

Festival embeds a basic small Scheme (Lisp) interpreter (SIOD : Scheme In One Defun 3.0) written by George Carrett.

Festival works in two fundamental modes, command mode and text-to-speech (tts) mode. If Festival is started without arguments (or with the option –command), it enters the default command mode (prompt = festival>). Information included in paranthesis is treated as commands and is interpreted by the Scheme interpreter. The following commands are accepted:

festival> 
> (intro)   :  short spoken introduction
> (voice.list)   : list of available voices
> (set! utt1 (Utterance Text "Hello world"))   : 
           create an utterance and save it in a variable
> (utt.synth utt1)    : synthesize utterance to get a waveform
> (utt.play utt1) : send the synthesized waveform to the audio device
> (SayText "Good morning, welcome to Festival")   : 
           speak text (combination of the 3 preceding commands)
> (tts "myfile" nil)    : speak file instead of text
> (manual nil)  : show the content of the manual
> (manual "Accessing an utterance")  : show the section "utterance"
> (PhoneSet.list)   : show the currently defined phonesets
> (tts "doremi.xml" 'singing)  : an XML based mode for specifying 
           songs, both notes and duration
> (quit)   : exit

If Festival is started with the –tts option, it enters tts-mode. Information (in files or through standard input) is treated as text to be rendered as speech.

Other options available at the start of Festival are :

--language LANG   : set the default language to LANG.
--server   : enter server mode where Festival waits for clients on a 
    known port (default port : 1314); connected clients may send 
    commands (or text) to the server and expect waveforms back.
--script scriptfile  : run scriptfile as a Festival script file.
--heap NUMBER   : to increase the scheme heap.
--batch  : after processing file arguments do not become interactive.
--interactive  : after processing file arguments become interactive.

Script mode :

festival mbarnig$  examples/saytime
festival mbarnig$  text2wave myfile.txt -o myfile.wav

An updated Festival System Documentation with 34 chapters, edited in December 2014, is available at the festvox website.

The following Festival voices are available :

festvox_cmu_us_ahw_cg
festvox_cmu_us_aup_cg
festvox_cmu_us_awb_cg
festvox_cmu_us_axb_cg
festvox_cmu_us_bdl_cg
festvox_cmu_us_clb_cg
festvox_cmu_us_fem_cg
festvox_cmu_us_gka_cg
festvox_cmu_us_jmk_cg
festvox_cmu_us_ksp_cg
festvox_cmu_us_rms_cg
festvox_cmu_us_rxr_cg
festvox_cmu_us_slt_cg
festvox_kallpc16k
festvox_rablpc16k
Leopold : AustrianGerman
IMS German Festival
OGIgerman by CSLU
Swedish by SOL
Hindi

Hindi and German are examples of Festival languages/voices with different phone-features in the phone-set as in the standard us and english phone-sets.

Edinburgh Speech Tools

The Edinburgh Speech Tools Library is a collection of C++ class, functions and related programs for manipulating objects used in speech processing. It includes support for reading and writing waveforms, parameter files (LPC, Ceptra, F0) in various formats and converting between them. It also includes support for linguistic type objects and support for various label files and ngrams (with smoothing). In addition to the library a number of programs are included. An intonation library which includes a pitch tracker, smoother and labelling system (using the Tilt Labelling system), a classification and regression tree (CART) building program called wagon. Also there is growing support for various speech recognition classes such as decoders and HMMs.

An introduction to the Edinburgh Speech Tools is provided by Festvox.

Festvox

The Festvox project aims to make the building of new synthetic voices for Festival more systemic and better documented, by offering the following resources :

Documentation
Aids to building synthetic voices for limited domains
Specific scripts to build new voices
Example Speech Databases
Demos
Discussion list

Festival Variables

Festival provides a list of variables available for general use. This list is automatically generated from the documentation strings of the variables defined in the source code. A variable can be displayed with the print command at the festival prompt. Some examples are shown hereafter :

festival>
> (print festival_version) ; current version of the system
> (print *ostype*) ; operation system that Festival is running on
> (print lexdir) ; default directory of the lexicons
> (print SynthTypes) ; list of synthesis types and functions
> (print token.letter_pos) ; POS tag for individual letters
> (print token.punctuation) ; characters treated as punctuation
> (print voice-path) ; list of folders to look for voices
> (print voice_default) ; function to load the default voice

Festival Variables

Festival Functions

Festival provides a list of functions available for general use. This list is automatically generated from the documentation strings of the functions defined in the source code. A function is called at the Festival prompt. Some examples are shown hereafter :

festival>
> (pwd) ; return current directory
> (lex.list) ; list names of all currently defined lexicons
> (voice.list) ; list all potential voices in the system
> (lex.lookup WORD FEATURES) ; lookup word in current lexicon
> (lex.compile ENTRYFILE COMPILEFILE) ; compile lexical entries
> (PhoneSet.list) ; list all currently defined PhoneSets
> (quit) ; exit from Festival

Festival Functions

Utterance Access Methods

Festival provides a number of standard functions that allow to access parts of an utterance, to traverse through it and to extract features.

Three utterances access methods are of particular interest :

(utt.feat UTT FEATNAME)
returns the value of feature FEATNAME in UTT
(item.feat ITEM FEATNAME)
returns the value of feature FEATNAME in ITEM
(utt.features UTT RELATIONNAME FUNCLIST)
returns vectors of feature values for each item, listed in FUNCLIST and related
in RELATIONNAME in UTT

FEATNAME may be a

feature name ; example : (item.feat sylb ‘stress)
feature function name ; example : (item.feat sylb ‘pos_in_word)
pathname ; examples : (item.feat sylb ‘nn.stress)
(item.feat sylb ‘R:SylStructure.parent.word)

Notes :
sylb is a syllable item
R: is a relation operator

RELATIONNAME may be ‘Token, ‘Word, ‘Phrase, ‘Segment, ‘Syllable, etc

FUNCLIST is a list of items ; example : ‘(name pos)

Some examples are shown hereafter :

festival>
(set! utter (SayText "Hello Marco, how are you?"))
(set! tok (utt.relation.first utter 'Token))
(utt.feat utter 'type)
(item.feat tok 'nn.name)
(item.feat tok 'R:Token.daughter1.name)
(utt.features utter 'Word '(name pos p.pos n.pos))

Utterance access methods

More informations about feature functions as FEATNAME are provided in the next chapter.

Festival Feature Functions

Festival provides a list of basic feature functions available as FEATNAME in utterances. Most are only available for specific items. Some examples are shown hereafter, related to the corresponding items :

Token item

festival>
(set! utter (SayText "Hello Marco, how are you?"))
(set! tok (utt.relation.first utter 'Token))
(item.name tok) ; first token
(item.feat tok 'name) ; first token
(item.feat tok 'n.name) ; second token
(item.feat tok 'nn.name) ; third token
(item.feat tok 'whitespace)
(item.feat tok 'prepunctuation)

Utterance Token

Word item

festival>
(set! utter (SayText "Hello Marco, how are you?"))
(set! wrd (item.next (utt.relation.first utter 'Word)))
(item.name wrd) ; second word
(item.feat wrd 'p.name) ; first word
(item.feat wrd 'cap)
(item.feat wrd 'word_duration)

Utterance Word

Segment item

festival>
(set! utter (SayText "Hello Marco, how are you?"))
(set! seg (item.prev (item.prev (utt.relation.last utter 'Segment))))
(item.name seg) ; third last segment
(item.feat seg 'n.name) ; second last segment
(item.feat seg 'seg_pitch)
(item.feat seg 'segment_end)
(item.feat seg 'R:SylStructure.parent.parent.name)

Utterance Segment

Syllable item

festival>
(set! utter (SayText "Hello Marco, how are you?"))
(set! sylb (utt.relation.first utter 'Syllable))
(item.features sylb) ; first syllable
(item.feat sylb 'asyl_out)
(item.feat sylb 'syl_midpitch)
(utt.features utter 'Syllable '(stress))
(item.feat sylb 'nn.stress) ; stress of third syllable
(item.feat sylb 'R:SylStructure.parent.name)
(item.feat sylb 'R:SylStructure.daughter1.name)
(item.feat sylb 'R:SylStructure.daughter2.name)

Utterance Syllable

SylStructure item

festival>
(set! utter (SayText "Hello Marco, how are you?"))
(set! sylst (item.prev (utt.relation.last utter 'SylStructure)))
(item.features sylst)
(item.feat sylst 'pos_index)
(item.feat sylst 'phrase_score)

Utterance SylStructure

Intonation item

festival>
(set! utter (SayText "Hello Marco, how are you?"))
(set! inton (utt.relation.first utter 'Intonation))
(item.features inton)
(item.feat inton 'id)

Utterance Intonation

Dumping features

Extracting basic features from a set of utterances is useful for most of the training techniques for TTS voice building. Festival provides a script dumpfeats in the festival/examples folder which does this task. The results can be saved in a single feature file or in separate files for each utterance. An example is shown below, the dumpfeats script was copied in the festival folder of my test voice mbarnig_lb_voxcg :

mbarnig$ ./dumpfeats -feats "(name p.name n.name)"
-relation Segment -output myfeats.txt utts/*.utt

Festival dumpfeats

FreeTTS : a Java speech synthesizer

Posted on June 19, 2005 by Marco Barnig

FreeTTS is a speech synthesis system written entirely in Java. It is based upon Flite, a small run-time speech synthesis engine developed at Carnegie Mellon University. Flite is derived from the Festival Speech Synthesis System from the University of Edinburgh and the FestVox project from Carnegie Mellon University.
Free TTS was built by the Speech Integration Group of Sun Microsystems Laboratories.

Possible uses of FreeTTS are:

JSAPI (Java Speech API) speech synthesizer
Remote TTS Server, to act as a back-end text-to-speech engine that works with a speech/telephony system, or does the “heavy lifting” for a wireless PDA
Workstation/Desktop TTS engine
Downloadable Web Application (FreeTTS can not be used in an applet)

FreeTTS includes the following demos :

JSAPI/HelloWorld: uses the JSAPI 1.0 Synthesis interface to speak “Hello, World”
JSAPI/MixedVoices: demonstrates using multiple voices and speech synthesizers in a coordinated fashion using JSAPI 1.0
JSAPI/Player: Swing-based GUI (graphical user interface) that allows the user to monitor and manipulate a JSAPI 1.0 Speech Synthesizer
JSAPI/JTime: JSAPI program that uses a limited-domain, high quality voice to tell the time
JSAPI/Emacspeak: uses JSAPI 1.0 to provide a text-to-speech server for Emacspeak
JSAPI/WebStartClock: JSAPI talking clock that can be downloaded from the web using Java Web Start
freetts/HelloWorld: low-level (non-JSAPI) program that speaks a greeting to the world
freetts/ClientServer: low-level (non-JSAPI) socket-based TTS server with sample clients written in the C programming language and the Java programming language.

To write software with FreeTTS, it is recommended to use the Java Speech API (JSAPI) 1.0 to interface with FreeTTS. The JSAPI interface provides the best method of controlling and using FreeTTS.

Currently, the FreeTTS distribution comes with these 3 voices:

a low quality, unlimited domain, 8kHz diphone voice, called kevin
a medium quality, unlimited domain, 16kHz diphone voice, called kevin16
a high quality, limited domain, 16kHz cluster unit voice, called alan

FreeTTS interfaces with the MBROLA synthesizer and can use MBROLA voices. It’s also possible to import voice data from Festival and FestVox or CMU ARCTIC voices.

A full implementation of Sun’s Java Speech API for Windows platforms, allowing a large range of SAPI4 and SAPI5 compliant Text-To-Speech and Speech-Recognition engines (in many different languages) to be programmed using the standard Java Speech API has been developped by CloudGarden. Packages and additional classes augment the capabilities of the JSAPI by, for example integrating with Sun’s JMF, allowing, amongst other things, MPEG audio files to be created and read, and compressed audio data to be transmitted across a network