#!/usr/bin/ruby -w
=begin
* gtf.rb Copyright (c) 2008, Paul Lutus
* Released under the GPL
* This Ruby program is largely based on:
* -------------------------------------------------------------
* gtf.c Generate mode timings using the GTF Timing Standard
*
* Copyright (c) 2001, Andy Ritger aritger@nvidia.com
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* o Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* o Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* o Neither the name of NVIDIA nor the names of its contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
=end
class Mode
attr_accessor :hr, :hss, :hse, :hbl, :hfl, :vr, :vbase, :vss, :vse, :vfl, :pclk, :h_freq, :v_freq, :interlace, :interlaced
end
class Options
attr_accessor :x, :y,:v_freq,:xf86mode,:interlaced,:margins
def initialize()
@xf86mode = true
@margins = false
@interlaced = false
end
end
class Gtf
# constants from GTF specification
MARGIN_PERCENT = 1.8 # % of active vertical image
CELL_GRAN = 8.0 # assumed character cell granularity
MIN_PORCH = 1 # minimum front porch
V_SYNC_RQD = 3 # width of vsync in lines
H_SYNC_PERCENT = 8.0 # width of hsync as % of total line
MIN_VSYNC_PLUS_BP = 550.0 # min time of vsync + back porch (microsec)
M = 600.0 # blanking formula gradient
C = 40.0 # blanking formula offset
K = 128.0 # blanking formula scaling factor
J = 20.0 # blanking formula scaling factor
def initialize()
@verbose = false
compute()
end
# imitate the effect of "rint()" from the math.c library
def rint(v)
return ((v+0.5).to_i).to_f
end
def print_verbose(n, name, val)
if (@verbose)
printf("%2d: %-27s: %15f\n", n, name, val);
end
end
def print_xf86_mode (m)
s_int1 = (m.interlaced)?"i":""
s_int2 = (m.interlaced)?" interlace":""
printf("\n # %dx%d @ %.2f Hz (GTF) hsync: %.2f kHz; pclk: %.2f MHz\n",
m.hr, m.vbase, m.v_freq, m.h_freq, m.pclk)
printf(" Modeline \"%dx%d_%.2f%s\" %.2f" +
" %d %d %d %d" +
" %d %d %d %d" +
" -HSync +Vsync%s\n\n",
m.hr, m.vbase, m.v_freq, s_int1, m.pclk,
m.hr, m.hss, m.hse, m.hfl,
m.vr, m.vss, m.vse, m.vfl,s_int2)
end
def print_fb_mode (m)
printf("\nmode \"%dx%d %.2fHz 32bit (GTF)\"\n",
m.hr, m.vbase, m.v_freq)
printf(" # PCLK: %.2f MHz, H: %.2f kHz, V: %.2f Hz\n",
m.pclk, m.h_freq, m.v_freq)
printf(" geometry %d %d %d %d 32\n",
m.hr, m.vbase, m.hr, m.vr)
printf(" timings %d %d %d %d %d %d %d\n",
rint(1000000.0/m.pclk), # pixclock in picoseconds
m.hfl - m.hse, # left margin (in pixels)
m.hss - m.hr, # right margin (in pixels)
m.vfl - m.vse, # upper margin (in pixel lines)
m.vss - m.vr, # lower margin (in pixel lines)
m.hse - m.hss, # horizontal sync length (in pixels)
m.vse - m.vss); # vert sync length (in pixel lines)
printf(" hsync low\n")
printf(" vsync high\n")
printf(" laced true\n") if m.interlaced
printf("endmode\n\n")
end
def comp_stage_1(options)
=begin
/* 1. In order to give correct results, the number of horizontal
* pixels requested is first processed to ensure that it is divisible
* by the character size, by rounding it to the nearest character
* cell boundary:
*
* [H PIXELS RND] = ((ROUND([H PIXELS]/[CELL GRAN RND],0))*[CELLGRAN RND])
*/
=end
h_pixels_rnd = rint(options.x.to_f / CELL_GRAN) * CELL_GRAN
print_verbose(1, "[H PIXELS RND]", h_pixels_rnd)
=begin
/* 2. If interlace is requested, the number of vertical lines assumed
* by the calculation must be halved, as the computation calculates
* the number of vertical lines per field. In either case, the
* number of lines is rounded to the nearest integer.
*
* [V LINES RND] = IF([INT RQD?]="y", ROUND([V LINES]/2,0),
* ROUND([V LINES],0))
*/
=end
v_lines_rnd = (options.interlaced)?
rint(options.y.to_f)/ 2.0 :
rint(options.y.to_f);
print_verbose(2, "[V LINES RND]", v_lines_rnd);
=begin
/* 3. Find the frame rate required:
*
* [V FIELD RATE RQD] = IF([INT RQD?]="y", [I/P FREQ RQD]*2,
* [I/P FREQ RQD])
*/
=end
v_field_rate_rqd = (options.interlaced)? (options.v_freq * 2.0) : (options.v_freq);
print_verbose(3, "[V FIELD RATE RQD]", v_field_rate_rqd);
=begin
/* 4. Find number of lines in Top margin:
*
* [TOP MARGIN (LINES)] = IF([MARGINS RQD?]="Y",
* ROUND(([MARGIN%]/100*[V LINES RND]),0),
* 0)
*/
=end
top_margin = (options.margins)? rint(MARGIN_PERCENT / 100.0 * v_lines_rnd) : (0.0);
print_verbose(4, "[TOP MARGIN (LINES)]", top_margin);
=begin
/* 5. Find number of lines in Bottom margin:
*
* [BOT MARGIN (LINES)] = IF([MARGINS RQD?]="Y",
* ROUND(([MARGIN%]/100*[V LINES RND]),0),
* 0)
*/
=end
bottom_margin = (options.margins)? rint(MARGIN_PERCENT/100.0 * v_lines_rnd) : (0.0)
print_verbose(5, "[BOT MARGIN (LINES)]", bottom_margin);
=begin
/* 6. If interlace is required, then set variable [INTERLACE]=0.5:
*
* [INTERLACE]=(IF([INT RQD?]="y",0.5,0))
*/
=end
interlace = (options.interlaced)? 0.5 : 0.0;
print_verbose(6, "[INTERLACE]", interlace);
=begin
/* 7. Estimate the Horizontal period
*
* [H PERIOD EST] = ((1/[V FIELD RATE RQD]) - [MIN VSYNC+BP]/1000000) /
* ([V LINES RND] + (2*[TOP MARGIN (LINES)]) +
* [MIN PORCH RND]+[INTERLACE]) * 1000000
*/
=end
h_period_est = (((1.0/v_field_rate_rqd) - (MIN_VSYNC_PLUS_BP/1000000.0)) /
(v_lines_rnd + (2*top_margin) + MIN_PORCH + interlace) * 1000000.0)
print_verbose(7, "[H PERIOD EST]", h_period_est);
=begin
/* 8. Find the number of lines in V sync + back porch:
*
* [V SYNC+BP] = ROUND(([MIN VSYNC+BP]/[H PERIOD EST]),0)
*/
=end
vsync_plus_bp = rint(MIN_VSYNC_PLUS_BP/h_period_est);
print_verbose(8, "[V SYNC+BP]", vsync_plus_bp);
=begin
/* 9. Find the number of lines in V back porch alone:
*
* [V BACK PORCH] = [V SYNC+BP] - [V SYNC RND]
*
* XXX is "[V SYNC RND]" a typo? should be [V SYNC RQD]?
*/
=end
v_back_porch = vsync_plus_bp - V_SYNC_RQD;
print_verbose(9, "[V BACK PORCH]", v_back_porch);
=begin
/* 10. Find the total number of lines in Vertical field period:
*
* [TOTAL V LINES] = [V LINES RND] + [TOP MARGIN (LINES)] +
* [BOT MARGIN (LINES)] + [V SYNC+BP] + [INTERLACE] +
* [MIN PORCH RND]
*/
=end
total_v_lines = v_lines_rnd + top_margin + bottom_margin + vsync_plus_bp +
interlace + MIN_PORCH;
print_verbose(10, "[TOTAL V LINES]", total_v_lines);
=begin
/* 11. Estimate the Vertical field frequency:
*
* [V FIELD RATE EST] = 1 / [H PERIOD EST] / [TOTAL V LINES] * 1000000
*/
=end
v_field_rate_est = 1.0 / h_period_est / total_v_lines * 1000000.0;
print_verbose(11, "[V FIELD RATE EST]", v_field_rate_est);
=begin
/* 12. Find the actual horizontal period:
*
* [H PERIOD] = [H PERIOD EST] / ([V FIELD RATE RQD] / [V FIELD RATE EST])
*/
=end
h_period = h_period_est / (v_field_rate_rqd / v_field_rate_est);
print_verbose(12, "[H PERIOD]", h_period);
=begin
/* 13. Find the actual Vertical field frequency:
*
* [V FIELD RATE] = 1 / [H PERIOD] / [TOTAL V LINES] * 1000000
*/
=end
v_field_rate = 1.0 / h_period / total_v_lines * 1000000.0;
print_verbose(13, "[V FIELD RATE]", v_field_rate);
=begin
/* 14. Find the Vertical frame frequency:
*
* [V FRAME RATE] = (IF([INT RQD?]="y", [V FIELD RATE]/2, [V FIELD RATE]))
*/
=end
v_frame_rate = (options.interlaced)? v_field_rate / 2.0 : v_field_rate;
print_verbose(14, "[V FRAME RATE]", v_frame_rate);
=begin
/* 15. Find number of pixels in left margin:
*
* [LEFT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",
* (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /
* [CELL GRAN RND]),0)) * [CELL GRAN RND],
* 0))
*/
=end
left_margin = (options.margins)?
rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN :
0.0;
print_verbose(15, "[LEFT MARGIN (PIXELS)]", left_margin);
=begin
/* 16. Find number of pixels in right margin:
*
* [RIGHT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",
* (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /
* [CELL GRAN RND]),0)) * [CELL GRAN RND],
* 0))
*/
=end
right_margin = (options.margins)?
rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN :
0.0
print_verbose(16, "[RIGHT MARGIN (PIXELS)]", right_margin);
=begin
/* 17. Find total number of active pixels in image and left and right
* margins:
*
* [TOTAL ACTIVE PIXELS] = [H PIXELS RND] + [LEFT MARGIN (PIXELS)] +
* [RIGHT MARGIN (PIXELS)]
*/
=end
total_active_pixels = h_pixels_rnd + left_margin + right_margin;
print_verbose(17, "[TOTAL ACTIVE PIXELS]", total_active_pixels);
=begin
/* 18. Find the ideal blanking duty cycle from the blanking duty cycle
* equation:
*
* [IDEAL DUTY CYCLE] = [C'] - ([M']*[H PERIOD]/1000)
*/
=end
ideal_duty_cycle = (((C - J) * K/256.0) + J) - ((K/256.0 * M) * h_period / 1000.0);
print_verbose(18, "[IDEAL DUTY CYCLE]", ideal_duty_cycle);
=begin
/* 19. Find the number of pixels in the blanking time to the nearest
* double character cell:
*
* [H BLANK (PIXELS)] = (ROUND(([TOTAL ACTIVE PIXELS] *
* [IDEAL DUTY CYCLE] /
* (100-[IDEAL DUTY CYCLE]) /
* (2*[CELL GRAN RND])), 0))
* * (2*[CELL GRAN RND])
*/
=end
h_blank = rint(total_active_pixels *
ideal_duty_cycle /
(100.0 - ideal_duty_cycle) /
(2.0 * CELL_GRAN)) * (2.0 * CELL_GRAN);
print_verbose(19, "[H BLANK (PIXELS)]", h_blank);
=begin
/* 20. Find total number of pixels:
*
* [TOTAL PIXELS] = [TOTAL ACTIVE PIXELS] + [H BLANK (PIXELS)]
*/
=end
total_pixels = total_active_pixels + h_blank;
print_verbose(20, "[TOTAL PIXELS]", total_pixels);
=begin
/* 21. Find pixel clock frequency:
*
* [PIXEL FREQ] = [TOTAL PIXELS] / [H PERIOD]
*/
=end
pixel_freq = total_pixels / h_period;
print_verbose(21, "[PIXEL FREQ]", pixel_freq);
=begin
/* 22. Find horizontal frequency:
*
* [H FREQ] = 1000 / [H PERIOD]
*/
=end
h_freq = 1000.0 / h_period;
print_verbose(22, "[H FREQ]", h_freq);
m = Mode.new
m.hr = (h_pixels_rnd).to_i
m.hbl = h_blank.to_i
m.hfl = (total_pixels).to_i
m.vbase = options.y # non-interlaced vertical line count
m.vr = (v_lines_rnd).to_i
m.vfl = (total_v_lines).to_i
m.pclk = pixel_freq
m.h_freq = h_freq
m.v_freq = options.v_freq
m.interlace = interlace # the value
m.interlaced = options.interlaced # the flag
return(m)
end # comp_stage_1()
def comp_stage_2(m)
=begin
/* 17. Find the number of pixels in the horizontal sync period:
*
* [H SYNC (PIXELS)] =(ROUND(([H SYNC%] / 100 * [TOTAL PIXELS] /
* [CELL GRAN RND]),0))*[CELL GRAN RND]
*/
=end
h_sync = rint(H_SYNC_PERCENT/100.0 * m.hfl / CELL_GRAN) * CELL_GRAN;
print_verbose(17, "[H SYNC (PIXELS)]", h_sync);
=begin
/* 18. Find the number of pixels in the horizontal front porch period:
*
* [H FRONT PORCH (PIXELS)] = ([H BLANK (PIXELS)]/2)-[H SYNC (PIXELS)]
*/
=end
h_front_porch = (m.hbl / 2.0) - h_sync;
print_verbose(18, "[H FRONT PORCH (PIXELS)]", h_front_porch);
=begin
/* 36. Find the number of lines in the odd front porch period:
*
* [V ODD FRONT PORCH(LINES)]=([MIN PORCH RND]+[INTERLACE])
*/
=end
v_odd_front_porch_lines = MIN_PORCH + m.interlace;
print_verbose(36, "[V ODD FRONT PORCH(LINES)]", v_odd_front_porch_lines)
m.hss = (m.hr + h_front_porch).to_i
m.hse = (m.hr + h_front_porch + h_sync).to_i
m.vss = (m.vr + v_odd_front_porch_lines).to_i
m.vse = (m.vr + v_odd_front_porch_lines + V_SYNC_RQD).to_i
if(m.interlaced)
m.vr *= 2;
m.vss *= 2;
m.vse *= 2;
m.vfl *= 2;
end
return(m)
end # comp_stage_2()
def usage()
printf("\nusage: %s x y refresh [options]\n\n", __FILE__)
puts("Required arguments:\n")
puts(" x : the desired horizontal resolution, pixels (example 640)\n")
puts(" y : the desired vertical resolution, pixels (example 480)\n")
puts(" refresh : the desired refresh rate, Hz (example 60)\n")
puts("Options:\n")
puts(" -m|--margins : include standard image margins (#{MARGIN_PERCENT}%)\n")
puts(" -i|--interlaced : interlaced video mode\n")
puts(" -v|--verbose : print all intermediate values\n")
puts(" -x|--xf86mode : output an XFree86-style mode description (default)\n")
puts(" -f|--fbmode : output an fbset(8)-style mode description\n\n")
end
def parse_command_line()
if ARGV.size < 3 # not enough args
usage()
return false
else # ARGV count valid
options = Options.new
options.x = ARGV.shift.to_i
options.y = ARGV.shift.to_i
options.v_freq = ARGV.shift.to_f
if(options.x == 0 || options.y == 0 || options.v_freq == 0)
usage()
return false
end
ARGV.each do |arg|
case arg
when "-v","--verbose"
@verbose = true;
when "-f","--fbmode"
options.xf86mode = false;
when "-x","--xf86mode"
options.xf86mode = true;
when "-i","--interlaced"
options.interlaced = true;
when "-m","--margins"
options.margins = true;
else # option error
usage()
return false
end # case
end # ARGV.each do
end # ARGV count valid
return options
end # parse_command_line()
def compute()
if(options = parse_command_line())
m = comp_stage_1(options)
m = comp_stage_2(m)
if (options.xf86mode)
print_xf86_mode(m)
else
print_fb_mode(m)
end
end # if options valid
end # main()
end # class Gtf
gtf = Gtf.new
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