; -----------------------------------------------------------------------------
;
;   srt2subtitle 0.15
;   =================
;   Script to create subtitles from "SubRip" files (*.srt).
;
;   Copyright (c) 2006 Martin Zuther (http://www.mzuther.de/)
;
;   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., 675 Mass Ave, Cambridge, MA 02139, USA.
;
; -----------------------------------------------------------------------------

(script-fu-register
	"script-fu-srt2subtitle-batch"
	"<Toolbox>/Xtns/Script-Fu/mzuther/srt2subtitle (batch mode)"
	"Creates subtitles for PAL and NTSC by reading a \"SubRip\" file (*.srt). This file has to use Unix newline characters."
	"Martin Zuther"
	"2006, Martin Zuther"
	"26.12.2006"
	""
	SF-FILENAME		_"SubRip file"				"/home/mzuther/subtitles/subtitles.srt"
	SF-TEXT			_"Output path"				"/home/mzuther/subtitles/output"
	SF-TEXT			_"Filename prefix"		"subtitle_"
	SF-OPTION		_"Format"					'("PAL (720 x 576)" "NTSC (720 x 486)")
	SF-COLOR			_"Text color"				'(255 255 0)
	SF-COLOR			_"Shadow color"			'(0 0 0)
	SF-ADJUSTMENT	_"Shadow size (pixels)"	'(2 0 5 1 10 0 0)
	SF-ADJUSTMENT	_"Safe area (percent)"	'(10 0 25 1 10 0 0)
	SF-FONT			_"Font"						"Sans"
	SF-ADJUSTMENT	_"Font size (pixels)"	'(20 8 40 1 10 0 0)
	SF-TOGGLE		_"Antialias"				TRUE
)

(define (script-fu-srt2subtitle-batch strInputFilename strOutputPath strOutputFilenamePrefix nFormat colText colShadow nShadowSize nSafeArea fontName nFontSize bAntiAlias)
	; who really needs so many different line endings?
	(set! strNewlineCharacterUnix "\n")
	(set! strNewlineCharacterDOS "\r\n")
	(set! strNewlineCharacterMac "\r")

	; open subrip file (*.srt)
	(set! file (fopen strInputFilename "r") )
	(set! strSubtitles "")

	(while (set! strInput (fread 1 file) )
		(set! strSubtitles (string-append strSubtitles strInput) )
	)

	(fclose file)

	; make sure the last subtitle doesn't get too long
	(set! strSubtitles (string-append strSubtitles strNewlineCharacterUnix strNewlineCharacterUnix) )

	; double newlines signal next subtitle
	(set! listSubtitles (strbreakup strSubtitles (string-append strNewlineCharacterUnix strNewlineCharacterUnix) ) )

	; initialize loop variable
	(set! script-fu-srt2subtitle-batch-looper 0)

	; loop through list with text lines
	(while (< script-fu-srt2subtitle-batch-looper (length listSubtitles) )
		; get indexed subtitle information
		(set! strSubtitleInformation (lref-default listSubtitles script-fu-srt2subtitle-batch-looper "") )

		(set! pDisplay (car (cadr (script-fu-srt2subtitle-create-image strOutputPath strOutputFilenamePrefix nFormat colText colShadow nShadowSize nSafeArea fontName nFontSize bAntiAlias strSubtitleInformation) ) ) )

		; close image
		(if (> pDisplay -1)
			(gimp-display-delete pDisplay)
		)

		; update loop variable
		(set! script-fu-srt2subtitle-batch-looper (+ script-fu-srt2subtitle-batch-looper 1) )
	)
)

(script-fu-register
	"script-fu-srt2subtitle-create-image"
	"<Toolbox>/Xtns/Script-Fu/mzuther/srt2subtitle (single subtitle)"
	"Creates a single subtitle for PAL and NTSC from the section of a \"SubRip\" file (*.srt).\n\nMostly called from batch mode or used for debugging..."
	"Martin Zuther"
	"2006, Martin Zuther"
	"26.12.2006"
	""
	SF-TEXT			_"Output path"				"/home/mzuther/subtitles"
	SF-TEXT			_"Filename prefix"		"subtitle_"
	SF-OPTION		_"Format"					'("PAL (720 x 576)" "NTSC (720 x 486)")
	SF-COLOR			_"Text color"				'(255 255 0)
	SF-COLOR			_"Shadow color"			'(0 0 0)
	SF-ADJUSTMENT	_"Shadow size (pixels)"	'(2 0 5 1 10 0 0)
	SF-ADJUSTMENT	_"Safe area (percent)"	'(10 0 25 1 10 0 0)
	SF-FONT			_"Font"						"Sans"
	SF-ADJUSTMENT	_"Font size (pixels)"	'(20 8 40 1 10 0 0)
	SF-TOGGLE		_"Antialias"				TRUE
	SF-TEXT			_"Text"						"1\n00:01:00,000 --> 00:05:00,000\nShort line\n\"A long line with quotes and stuff...\"\nAnother line!"
)

(define (script-fu-srt2subtitle-create-image strOutputPath strOutputFilenamePrefix nFormat colText colShadow nShadowSize nSafeArea fontName nFontSize bAntiAlias strSubtitleInformation)
	; who really needs so many different line endings?
	(set! strNewlineCharacterUnix "\n")
	(set! strNewlineCharacterDOS "\r\n")
	(set! strNewlineCharacterMac "\r")

	; create custom palette
	(set! pPalette (car (gimp-palette-new "srt2subtitle-temp") ) )
	(gimp-palette-add-entry pPalette "Text color" colText)

	; mix between text and shadow color
	(set! colRedPart (/ (+ (car colText) (car colShadow) ) 2) )
	(set! colGreenPart (/ (+ (cadr colText) (cadr colShadow) ) 2) )
	(set! colBluePart (/ (+ (caddr colText) (caddr colShadow) ) 2) )
	(gimp-palette-add-entry pPalette "AntiAlias color" (list colRedPart colGreenPart colBluePart) )

	(gimp-palette-add-entry pPalette "Shadow color" colShadow)

	; "decode" subtitle information
	(set! listSubtitleInformation (strbreakup strSubtitleInformation strNewlineCharacterUnix) )

	; check that at least two newlines were detected
	(if (> (length listSubtitleInformation) 2)
		(begin
			(set! strSubtitleNumber (car listSubtitleInformation) )
			(set! strSubtitleStartTime (car (strbreakup (cadr listSubtitleInformation) " --> ") ) )
			(set! listText (cddr listSubtitleInformation) )
		
			; initialize image format (PAL or NTSC)
			(cond
				(
					(= nFormat 0)
					(set! nImageWidth 720)
					(set! nImageHeight 576)
				)
				(
					(= nFormat 1)
					(set! nImageWidth 720)
					(set! nImageHeight 486)
				)
			)
		
			; create image and background layer
			(set! pImage (car (gimp-image-new nImageWidth nImageHeight RGB) ) )
			(set! pLayerBackground (car (gimp-layer-new pImage nImageWidth nImageHeight RGB-IMAGE "Background" 100 NORMAL-MODE) ) )
		
			; add background with alpha channel to image
			(gimp-layer-add-alpha pLayerBackground)
			(gimp-image-add-layer pImage pLayerBackground -1)
		
			; empty background layer
			(gimp-selection-all pImage)
			(gimp-edit-clear pLayerBackground)
			(gimp-selection-none pImage)
		
			; initialize vertical start position
			(set! nVerticalPosition (- nImageHeight (* (length listText) nFontSize 1.25) ) )
			(set! nVerticalPosition (- nVerticalPosition (* nImageHeight (/ nSafeArea 100) ) ) )
		
			; initialize loop variable
			(set! script-fu-srt2subtitle-create-image-looper 0)
		
			; loop through list with text lines
			(while (< script-fu-srt2subtitle-create-image-looper (length listText) )
				; get indexed text line
				(set! strOutput (lref-default listText script-fu-srt2subtitle-create-image-looper "") )
		
				; output text line (if not empty)
				(if (not (= 0 (strcmp strOutput "") ) )
					(begin
						(set! nVerticalPosition (+ nVerticalPosition (* nFontSize 1.25) ) )
		
						(script-fu-srt2subtitle-create-layer pImage nVerticalPosition nShadowSize colText colShadow fontName nFontSize bAntiAlias strOutput)
					)
				)
		
				; update loop variable
				(set! script-fu-srt2subtitle-create-image-looper (+ script-fu-srt2subtitle-create-image-looper 1) )
			)
		
			; merge all layers with background
			(gimp-image-merge-visible-layers pImage CLIP-TO-IMAGE)
		
			; convert to maximum number of allowed colors (minus one for alpha channel)
			(gimp-image-convert-indexed pImage FS-DITHER CUSTOM-PALETTE 3 0 1 "srt2subtitle-temp")
		
			; display new image
			(set! pDisplay (gimp-display-new pImage) )
		
			; hand the filename over to GIMP ...
			(set! strSubtitleStartTime (string-append (substring strSubtitleStartTime 0 2) (substring strSubtitleStartTime 3 5) (substring strSubtitleStartTime 6 8) "_" (substring strSubtitleStartTime 9 12) ) )
			(set! strOutputFilename (string-append strOutputPath "/" strOutputFilenamePrefix strSubtitleStartTime ".png") )
			(gimp-image-set-filename pImage strOutputFilename)
		
			; ... and save the image
			(set! pDrawable (car (gimp-image-active-drawable pImage) ) )
			(file-png-save2 1 pImage pDrawable strOutputFilename strOutputFilename 1 9 0 0 0 1 1 0 0)
		
			; clear dirty flag
			(gimp-image-clean-all pImage)
		)
		(begin
			(set! pImage -1)
			(set! pDisplay (list -1) )
		)
	)

	; delete custom palette
	(gimp-palette-delete pPalette)

	; return image (or invalid pointers)
	(list pImage pDisplay)
)

(define (script-fu-srt2subtitle-create-layer pImage nVerticalPosition nShadowSize colText colShadow fontName nFontSize bAntiAlias strText)
	; initialize colors
	(gimp-palette-set-foreground colText)
	(gimp-palette-set-background colShadow)

	; initialize image and text sizes
	(set! nImageWidth (car (gimp-image-width pImage) ) )
	(set! nImageHeight (car (gimp-image-height pImage) ) )

	; create and center text layer
	(set! pLayerText (car (gimp-text-fontname pImage -1 0 nVerticalPosition strText -1 bAntiAlias nFontSize PIXELS fontName) ) )
	(set! nTextWidth (car (gimp-drawable-width pLayerText) ) )
	(set! nHorizontalPosition (/ (- nImageWidth nTextWidth) 2) )
	(gimp-layer-set-offsets pLayerText nHorizontalPosition nVerticalPosition)

	; create shadow #1
	(if (> nShadowSize 0)
		(begin
			; initialize colors
			(gimp-palette-set-foreground colText)
			(gimp-palette-set-background colShadow)

			; create new layer for shadow
			(set! pLayerShadow (car (gimp-layer-new pImage nImageWidth nImageHeight RGB-IMAGE "Shadow" 100 NORMAL-MODE) ) )
			(gimp-image-add-layer pImage pLayerShadow -1)
			(gimp-image-lower-layer pImage pLayerShadow)
		
			; empty shadow layer
			(gimp-selection-all pImage)
			(gimp-edit-clear pLayerShadow)
			(gimp-selection-none pImage)
		
			; add alpha channel to shadow layer
			(gimp-layer-add-alpha pLayerShadow)
		
			; create shadow
			(gimp-selection-layer-alpha pLayerText)
			(gimp-selection-grow pImage nShadowSize)
			(gimp-selection-invert pImage)
			(gimp-edit-clear pLayerShadow)
			(gimp-selection-none pImage)
	
			; merge both layers
			(set! pLayerText (car (gimp-image-merge-down pImage pLayerText CLIP-TO-IMAGE) ) )
			(gimp-drawable-set-name pLayerText strText)
		)
	)

	; return both image and layer
	(list pImage pLayerText)
)