WriteFile (clip, string filename, string expression1, ... , string expression16, bool "append", bool "flush")WriteFileIf (clip, string filename, string expression1, ... , string expression16, bool "append", bool "flush")WriteFileStart (clip, string filename, string expression1, ... , string expression16, bool "append")WriteFileEnd (clip, string filename, string expression1, ... , string expression16, bool "append")
WriteFile evaluates expressionN, converts the result to a string and puts the result into a file.
The "run-time" variable current_frame is set so that you can use it in an "expression"
(this works similar as with ScriptClip, look there in the docu for more infos).
current_frame is set to -1 when the script is loaded and to -2 when the script is closed.
WriteFile evaluates the ''expression''s and generates output for each frame rendered by the filter. WriteFileIfis similar, but generates output only if the first expression is true. In both cases, there is no output at script opening or closure. Note that since output is produced only for ''rendered'' frames, there will be no output at all if the result of the filter is not used in deriving the final result of the script.
WriteFileStart and WriteFileEndgenerate output only on script opening and closure respectively, there is no action on each frame. In both cases, the ''expression''s are evaluated exactly once, at the location of the filter in the script.
When append = true, the result will be appended on any existing file.
When flush = true, the file is closed and reopened after each operation so you can see the result immidiately (this may be slower).
For WriteFileStartand WriteFileEndflush is always true.
The default for append is always true, except for WriteFileStart(here it is false).
filename = "c:\myprojects\output.txt" # create a test video to get frames Version() # the expression here is only a variable, which is evaluated and put in the file # you will get a file with the framenumber in each line WriteFile(filename, "current_frame") # this line is written when the script is opened WriteFileStart(filename, """ "This is the header" """) # and this when the script is closed WriteFileEnd(filename, """ "Now the script was closed" """)
Look how you can use triple-quotes to type a string in a string!
If the expression cannot be evaluated, the error message is written instead.
In case this happens with the If-expression in WriteFileIfthe result is assumed to be true.
# will result in "I don't know what "this" means" WriteFile(filename, "this is nonsense")
... with this example you can see how to use the "runtime functions" together with FrameEvaluate:
# create a test video to get different frames
Version.FadeIn(50).ConvertToYV12
# this will print the frame number, a ":" and the average luma for that frame
colon = ": "
WriteFile("F:\text.log", "current_frame", "colon", "AverageLuma")Or maybe you want the actual time printed too:
# create a test video to get different frames
Version.FadeIn(50).ConvertToYV12
# this will print the frame number, the current time and the average luma for that frame
# the triple quotes are necessary to put quotes inside a string
WriteFile(last, filename, "current_frame", """ time(" %H:%M:%S") """, "AverageLuma") In WriteFileIfthe FIRST expression is expected to be boolean (true or false).
Only if it is TRUE the other expressions are evaluated and the line is printed.
(Remember: && is AND, || is OR, == is EQUAL, != is NOT EQUAL)
That way you can ommit lines completely from your file.
# create a test video to get different frames Version.FadeIn(50).ConvertToYV12 # this will print the frame number, but only of frames where AverageLuma is between 30 and 60 WriteFileIf(last, filename, "(AverageLuma>30) && (AverageLuma<60)", "current_frame", """ ":" """, "AverageLuma")
$Date: 2008/12/21 09:23:02 $