Creating image only select I (intra) frame from source with FFmpegSource

[siella]

I used ffmpegsource (http://ffmpegsource.googlecode.com/svn/trunk/doc/ffms2-avisynth.html) filter
I try to get i-frame type screen shot from video clip. But i coundt do

i use this scritp
import("C:\Program Files (x86)\AviSynth 2.5\plugins\avs\FFMS2.avsi")
FFmpegSource2("F:\1.avi")
Killaudio()
ConvertToRGB()
vid= last
fps=25
dk=3
i= Round(fps*60*dk)

vid2= imagewriter("E:\thumbs\",type="png")
#selectevery(i,0)

FFInfo(framenum = false, cfrtime=false, vfrtime=false)
ConditionalFilter(vid,vid2,"chr(FFPICT_TYPE)","equals","I")
#writefileif("framelog.txt","""chr(FFPICT_TYPE)=="I" ""","current_frame")
i get " i don't know what "FFPICT_TYPE" means
but when use it with writeif like this
writefileif("framelog.txt","""chr(FFPICT_TYPE)=="I" ""","current_frame")
its work but i dont know how can read framelog.txt with avisynth and selecting frame.

[raffriff42]

Does this help? This test script inserts a subtitle over I-frames, for testing. EDIT - and writes images.
import("C:\Program Files (x86)\AviSynth 2.5\plugins\avs\FFMS2.avsi")
FFmpegSource2("F:\1.avi")
ConvertToRGB32()

global my_string = ""
FrameEvaluate("""my_string = Chr(Eval("FFPICT_TYPE")) """, after_frame=true)

vid = Last
#vid2 = Last.Subtitle("[I]", align=9, size=56) ## TEST
vid2 = ImageWriter("E:\thumbs\",type="png")

return ConditionalFilter(Last,
\ vid, vid2,
\ """my_string=="I" """, "==", "false")

[Gavino]

The real problem is that ConditionalFilter (unlike WriteFileIf) evaluates the condition before reading the frame, so FFPICT_TYPE is not defined on the first frame.

raffriff42's solution masks this by initialising 'my_string' (btw the 'global' is unnecessary), but the frames selected are still out by one, since the FFPICT_TYPE tested will each time be that of the previous frame.

I think it should work if you replace the ConditionalFilter(...) in the original script by:
ScriptClip("""chr(FFPICT_TYPE)=="I" ? vid2 : vid""", after_frame=true)

[raffriff42]

Thank you, Gavino -- confirmed I was off by one (aaargh) import("C:\Program Files (x86)\AviSynth 2.5\plugins\avs\FFMS2.avsi")
FFmpegSource2("F:\1.avi")
ConvertToRGB32()

## EDIT deleted per Gavino (see post #7)
#global my_string = ""
#FrameEvaluate("""my_string = Chr(Eval("FFPICT_TYPE")) """, after_frame=true)

vid = Last
#vid2 = Last.Subtitle("[I]", align=9, size=56) ## TEST
vid2 = ImageWriter("E:\thumbs\",type="png")

return ScriptClip("""chr(FFPICT_TYPE)=="I" ? vid2 : vid""", after_frame=true)

[siella]

Does this help? This test script inserts a subtitle over I-frames, for testing. EDIT - and writes images.
import("C:\Program Files (x86)\AviSynth 2.5\plugins\avs\FFMS2.avsi")
FFmpegSource2("F:\1.avi")
ConvertToRGB32()

global my_string = ""
FrameEvaluate("""my_string = Chr(Eval("FFPICT_TYPE")) """, after_frame=true)

vid = Last
#vid2 = Last.Subtitle("[I]", align=9, size=56) ## TEST
vid2 = ImageWriter("E:\thumbs\",type="png")

return ConditionalFilter(Last,
\ vid, vid2,
\ """my_string=="I" """, "==", "false")


Thanks your helping but it is not correctly working.
it gives wrong i frame, next frame is correct
example 12230 appear i-frame but correct i-frame is 12231

Thank you, Gavino -- confirmed I was off by one (aaargh) import("C:\Program Files (x86)\AviSynth 2.5\plugins\avs\FFMS2.avsi")
FFmpegSource2("F:\1.avi")
ConvertToRGB32()

## EDIT deleted per Gavino (see post #7)
#global my_string = ""
#FrameEvaluate("""my_string = Chr(Eval("FFPICT_TYPE")) """, after_frame=true)

vid = Last
#vid2 = Last.Subtitle("[I]", align=9, size=56) ## TEST
vid2 = ImageWriter("E:\thumbs\",type="png")

return ScriptClip("""chr(FFPICT_TYPE)=="I" ? vid2 : vid""", after_frame=true)
That's works perfect

[siella]

### Movie Screenshot, thumbnails creator###
### Thanks to Gavino and raffriff42 for helping ##
###-----Selection Start----###
video ="F:\1.avi" #source path
path = "E:\thumbs\" #save image path
thumb = "no" # yes or no
wr = "no" # yes or no
type = "I" # I , P or B
img = "png" # png, jpg, bmp, etc.
###----Selection end-------###
import("C:\Program Files (x86)\AviSynth 2.5\plugins\avs\FFMS2.avsi")
FFVideoSource(video)
ConvertToRGB32()
AssumeFrameBased()
ar = Float(width())/Float(height())
y = Round(300/ar)
type == "I" ? SelectRangeEvery(750,30): SelectEvery(3000, 0,100)
thumb == "yes" ? BicubicResize(300,y) : nop()
vid = Last
vid2 = (wr == "yes") ? Last.Subtitle("Frame Type:I", align=7, size=20).ImageWriter(path,type=img) : Last.ImageWriter(path,type=img)
return ScriptClip("""chr(FFPICT_TYPE) == type ? vid2 : vid""", after_frame=true)

I use this script creating random screeen shoot.
Maybe some one need that.
I added thumb function. If you change thumb = "yes" it will creat thumbnails.
If you input yes to wr variable will wite framet type on image files
You can change frame type I P or B but P and B frame will be much more so i added getting every about 5 minites.
I used Avsmeter (http://forum.doom9.org/showthread.php?t=165528) to run script
Also can use avs2avi (http://forum.doom9.org/showthread.php?t=71493) or avs2avi64 (http://forum.doom9.org/showthread.php?t=152800)I tried too. but must use with -c null o -n parameters.

[Gavino]

Thanks for posting your script, siella.

You can remove the lines 'global my_string ...' and 'FrameEvaluate(...)', which were part of raffriff42's solution and are unnecessary. (When I referred to the 'original' script in my earlier post, I meant your script from post #1.)

[siella]

That's right its not necessity. I've edited. Thanks Gavino

[raffriff42]

Thanks Gavino. For future Googlers, could this thread title be changed from "select 1 frame" to "select I (Intra) frame" ?

[Guest]

Done.

Actually the original title was incoherent and I tried to fix it, so blame me for the "1", not the original poster.

[jmac698]

Thanks, that was useful to me. I had an idea that you can take two recordings of the same material from digital TV and combine them for greater quality; and it's true. Especially for 24p material on a 60p stream, a P frame after an I frame which happens to be a film frame looks better. A TV stream is encoded continuously which means that two showings can have different "phases", or start at a different spot within a GOP. This is a rough explanation.

[raffriff42]

Here is a version that includes the frame number in the file name.
import("C:\Program Files (x86)\AviSynth 2.5\plugins\avs\FFMS2.avsi")
FFmpegSource2("F:\1.avi")
ConvertToRGB32()

return ScriptClip("""chr(FFPICT_TYPE)=="I"
\ ? Last.ImageWriter("E:\thumbs\filename_prefix-",
\ start=current_frame, end=current_frame, type="png")
\ : Last""",
\ after_frame=true) Output = "filename_prefix-<frame number>.png" -- of course, filename_prefix can be anything.

[Gavino]

Here is a version that includes the frame number in the file name.
Doesn't the previous version do that anyway?

@siella
I see you have edited your post#5, deleting the previous edit that said the solution actually worked. Was there a problem?

[raffriff42]

>Doesn't the previous version do that anyway?
Yes it does - sorry about that.

[siella]

Doesn't the previous version do that anyway?

@siella
I see you have edited your post#5, deleting the previous edit that said the solution actually worked. Was there a problem?

There is no problem. That answer for post 2 so it maybe confused.

[siella]

###-----Selection Start----###
video ="D:\1.mkv" #source path
global path = "D:\thumbs\" #save image path
thumb = "no" # yes or no
wr = "yes" # yes or no
type = "I" # I , P or B
img = "png" # png, jpg, bmp, etc.
###----Selection end-------###
import("C:\Program Files\AviSynth 2.5\plugins\FFMS2.avsi")
FFVideoSource(video)
ConvertToRGB32()
AssumeFrameBased()
FrameEvaluate("""asd= string(current_frame)""",after_frame=true)

wr == "yes" ? ScriptClip("""Subtitle("Frame Number:"+asd, align=7, size=20)""",after_frame=true) :nop()
ar = Float(width())/Float(height())
y = Round(300/ar)
type == "I" ? SelectRangeEvery(1000,20): SelectEvery(7500, 0)
thumb == "yes" ? BicubicResize(300,y) : nop()
vid = Last
vid2 = ScriptClip( """(wr == "yes") ? Last.Subtitle("Frame Type:I", align=9, size=20)
\.ImageWriter(path+asd+"-",type=img) : ImageWriter(path+ asd +"-",type=img)""",after_frame=true)

return ScriptClip("""chr(FFPICT_TYPE) == type ? vid2 : vid""", after_frame=true)


imagewrite give frame name as file name but it is not correct frame number because of frame number changed due to using SelectRangeEvery.
I add currently frames of source video to filename, thas's first is real frame name . Also if you choose wr = "yes" frame number will appear.

[Guest]

video ="D:\GALACTICA\Battlestar.Galactica.(1978).S01E04.The.Lost.Planet.of.the.Gods.part1.DVDRip.X264.AC3.PRoDJi.mkv" #source path
Closed for rule 6 violation.