#!/usr/bin/env python
#
# Ffmpeg video thumbnailer
#  generates a thumbnail from a video file
#
# requires ffmpeg, imagemagick and filmholes.png from totem
#
# Use:
#	ffmpeg-video-thumbnailer [-s geometry] input output
#
# geometry	= thumbnail geometry, eg. "128" or "128x96"
# input		= video file name
# output	= thumbnail file name
#
# Author: JM. Philippe - http://philipjm.free.fr/blog/
# Public domain

import sys, os, re, commands, urllib

# the ffmpeg command to be executed (extracts 1st video image)
FfmpegCmd = "ffmpeg -i '%s' -vcodec png -vframes 1 -s %s -f rawvideo -y '%s'"

# the imagemagick command (composes images)
MagickCmd = "composite -compose atop -geometry %s %s %s %s"

# film holes to be overlaid (from totem install)
FilmHoles = '/usr/share/totem/filmholes.png'
HoleHeight = 35		# film holes image dimensions
#HoleWidth = 9

# log file for debugging
LogFile = os.path.expanduser('~/ffmpeg-thumbnailer.log')
WriteLog = False	# True to write log file

##################
##################
def log(Text):
	"""
	writes a log file for debugging
	"""
	if WriteLog:
		FileId = open(LogFile, 'a')
		FileId.write(str(Text) + '\n')
		FileId.close()

##################
##################
def dims(FileName):
	"""
	gets video dimensions
	"""
	Result = commands.getoutput("ffmpeg -i '%s'" % FileName)
	#log(Result)
	Orient = re.findall(r'(\d+)x(\d+)', Result)
	#log(Orient)
	if len(Orient):
		return map(int, Orient[0])
	else:
		return 0, 0

##################
##################
def film_holes(FileName, Height):
	"""
	adds film holes on the left side
	"""
	Start = 0
	while Start < Height:		# repeat pattern vertically
		Position = '+%d+%d' % (0, Start)
		commands.getoutput(MagickCmd % (Position, FilmHoles, FileName, FileName))
		Start += HoleHeight

##################
# get parameters
if sys.argv[1] == "-s":
	ThumbSize, Input, Output = sys.argv[2:5]
else:
	ThumbSize = "128"
	Input, Output = sys.argv[1:3]
log('********')
log(str(sys.argv))

##################
# URL's to pathnames
Input = urllib.url2pathname(Input.replace('file://', ''))
Output = urllib.url2pathname(Output.replace('file://', ''))

##################
# thumbnail size
if 'x' not in ThumbSize:
	ImgWidth, ImgHeight = dims(Input)
	ThumbWidth = int(ThumbSize)
	if ImgWidth >= ImgHeight:
		ThumbHeight = ThumbWidth * ImgHeight / ImgWidth
	else:
		ThumbHeight = ThumbWidth
		ThumbWidth = ThumbHeight * ImgWidth / ImgHeight
	ThumbSize = '%dx%d' % (ThumbWidth, ThumbHeight)

##################
# make thumbnail
Result = commands.getoutput(FfmpegCmd % (Input, ThumbSize, Output))
film_holes(Output, ThumbHeight)
commands.getoutput("mogrify -flop " + Output)	# flip left to right
film_holes(Output, ThumbHeight)
commands.getoutput("mogrify -flop " + Output)

##################
# write log (continued)
log(Input)
log('%dx%d' % (ImgWidth, ImgHeight))
log(Output)
log(FfmpegCmd % (Input, ThumbSize, Output))
log(Result)
log('')