OK, here's some instructions on how to generate new ATC voices for FlightGear. Hopefully this will make some sense to somebody, ask if it's unclear.
If you want to record the phrases in a local accent or even a different language go right ahead, I'll add code support for it. You'll need to supply a translation if its in a different language though! Have fun! Cheers - Dave ----------------------------------------------- Instructions for Generating FlightGear ATC and AI Voices, Feb/2004, DCL. First off, I'm most definately NOT any sort of audio expert - its just not one of my things. This is simply the scheme I devised to get the ATIS voices in. There's undoubtably a lot of scope for improvement, and if anyone has any ideas for improvement then shout and we'll see if we can accomodate them. Currently, FlightGear audio support is limited to 8kHz, 8bit mono, but at this setting voice recordings are noticably degraded, so I recommend keeping both the master recordings and the final edited version at a better quality (22kHz, 16bit, say) and export to 8,8 at the very end, in order that the better quality master is available in the future when hopefully FG audio support improves. Keep hold of the originals for the future - you'll need to add to them if the phraseology is extended. A final proviso is that FlightGear's ATC phraseology is not fully (or even close to!) mature yet - there will undoubtably be more phrases, or changes to phrases, required in the future. If you want your recordings to be used in the future you may need to record some additional phrases at some point. With all that in mind, it would still be great to have as many voices as possible now to get the ball rolling, so here goes. Two files are required for each voice - a wave file containing the actual sounds, and an index file that basically describes where in the wave file buffer to find each word or phrase. The current voices for the ATIS can be found in $FG_ROOT/data/ATC and are called default.wav and default.vce for the wave and index file respectively. Note that one important change will be made in default.vce - currently it is indexed by byte position into the sound buffer, but I've decided it would be better to index by time into the buffer, since that is more robust to changing the recording quality, and in the future possiby using encoding such as Ogg Vorbis. Also, the first line currently contains the number of subsequent lines, but I think that can be ditched! The basic idea is to record all the phraseology needed, which will also contain much that isn't needed, then cut and paste the required words or phrases into a new track, which is saved to something like tower1.wav. Then index the position of everything needed, and save it to something corresponding like tower1.vce. Then send it to me ([EMAIL PROTECTED]) so it can be put into FG. Phrases can be entered and indexed either as phrases, with the words joined by underscores, or as individual words. Is is quite permissible to index one part of the buffer more than once, eg. Cleared_for_takeoff t1 t4 Cleared t1 t2 for t2 t3 takeoff t3 t4 Cleared_for t1 t3 where t1 - t4 are times into the buffer. In general, I suspect that the longer the phrases run to, the more likely the dialogue is to sound natural, but the larger the wav file size will become. I guess this is something that will only become clear with experimentation and experience. A lot of the phraseology needed takes the form of lists - the phonetic alphabet, numbers, airport names etc. However, I find that they tend to come out more naturally if they are recorded as part of a proper phrase eg "Cessna six nine foxtrot cleared for takeoff runway one five winds two three zero at one five", and repeat a lot of different phrases until you have everything you want. The final recording for FlightGear will be much smaller since the words wanted should be crammed together as much as possible - listen to default.wav (the ATIS) to see what I mean. I'm sure that real-life pilots are likely to have some beef with the suggested phraseology - it's all open to change, and a lot of it isn't currently used. At the moment the voices most needed are the tower control and AI GA planes, particularly AI planes since on a given frequency there will be several of them per one controller so a variety of voices would sound better. The tower phraseology is posted below - I'll try and post the AI VFR phraseology as soon as possible. Note that the tower phraseology below is very VFR operation orientated - it will expand for IFR ops at some point in the future. Finally, as set up at the moment, you can't simply test your new voice in FlightGear. I'll hack at the code a bit and post some instructions on how to make it be heard. It would be nice to have a voice testing mode in FlightGear, to run with the sim paused and play a selection of phrases from files under development. The trouble is, I envisage folk working at higher quality while editing the files, and exporting an 8kHz, 8bit version at the end, which is all FG will currently play. It might be possible to knock up a simple utility to play phrases from files under development. Good Luck! Here is the tower phaseology required: ===================================== All the phonetic alphabet. Numbers zero to nine, including both nine and niner. hundred, thousand (officially pronounced tousand?) left, right numbers ten to twelve Optionally numbers thirteen to thirty-six as well for lazy runway designation (I've heard 'fifteen' used instead of 'one five' on a recording before). O'Clock The directions of the compass, at least four, probably eight to get them natural sounding. A selection of callsigns - including but not limited to: Cessna, Piper, Seneca, Cherokee, Heavy, Speedbird, Trainer A selection of airport names relevant to the intended country or region, plus the Bay Area (default). knot knots mile miles feet meters good bad surface_conditions water ice snow hail windshear turbulence wake_turbulence caution_wake_turbulence the_preceeding_aircraft_is_a obstruction obstructions on_the_runway the_runway_is_clear_of This_is You_are_now_clear_of_my_airspace cleared_for_taxi_to_the_GA_parking fly_suggested_heading turn_left, turn_right Good_day Report Traffic about less_than_a_mile climbing, descending follow_the follow_him orbit_three_sixty short_final mile_final long_final miles_out downwind straight_in left_downwind right_downwind number go_around I_repeat_go_around traffic_on_runway runway airport the_airport of_the_airport hold hold_position hold_your_position hold_for hold_short hold_short_for hold_SHORT hold_SHORT_for please_ensure_you_read_back_all_hold_short_instructions ident please_ident ident_please wind winds surface_wind at cleared cleared_for cleared_for_takeoff cleared_for_immediate_takeoff cleared_for_departure cleared_for_landing cleared_for_the_option example phrases: "Piper six eight sierra Oakland Tower Report 2 miles out for left downwind runway two six right." "Traffic, 10 O'clock, less than a mile, descending inbound." "Cessna Golf Foxtrot Sierra Cleared for immediate takeoff traffic is a cherokee on base wind three three zero at one five" "Cessna five nine Victor Go around, I repeat go around, traffic on runway." "Cross runway one niner left, hold short runway one niner right." _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
