batch: how to get duration & number of frames of a wav file with ffprobe?

[marcorocchini]

Hi please, in the 25fps case

of the attached c0029.wav file


I have try


for /f "tokens=1,2 delims=^=" %%g in ('FFProbe.exe -hide_banner -loglevel fatal -pretty -select_streams a:0 -show_streams "%~1"') DO ( if "%%~g"=="duration_ts" set "NumberOfFrame=%%~h")

but I don't know, seems that duration_ts and NumberOfFrame are empty

[marcorocchini]

file attachment

it should be 234 frames, please I need of a procedure that put "234" into a variable

[ndjamena]

I won't download it, but getting the number 234 from a 1.71MB wav file seems a bit far fetched. Maybe I'm just missing something, I'll see what the answer is in the morning.

[Cornucopia]

"samples / second" * #seconds = # samples (audio)
"frames / second" * # seconds = # frames (video)

25fps * 9.36 = 234 check!

BUT,
"frames" is a video concept (disregarding packet and/or FFT compressed audio frame groupings which have no bearing on this).

What I think you are wanting to ask is: if I have this much time, how many frames would it line up with if I were to match it up with 25fps video?
And you are wanting to automatically generate this from the internal properties of the audio, right?

Well, you can't - not completely. There is nothing in the file that prefers one video framerate over another, nor even a place to store that data in standard WAV files (except as a custom, user-generated metadata comment/tag). And of course the "duration_ts" and "Number_of_frames" fields are empty: they don't exist for audio streams! And you don't YET have a video stream to place those field values into.

Scott

[marcorocchini]

sorry, instead of the framecount I need to have in a variable this 00:00:09.36 exactly in this format: 00:00:09.36



I'm looking for the command that with ffprobe do this ^^

[marcorocchini]

mm great effort of cat but maybe I have found

       rem #### check duration of avi file ####
       for /f "tokens=1,2 delims=^=" %%g in ('v:\automazioneclip\virtualdub\FFProbe -hide_banner -loglevel fatal -pretty  -show_streams -show_entries stream^=codec_type^,duration^,r_frame_rate^,width^,height^,sample_aspect_ratio:stream_disposition^=:format_tags^=timecode^,company_name^,product_name^,product_version "%~1" 2^>^&1') DO (
       if "%%~g"=="duration" set "catDuration=%%~h")          	 

       echo duration is %catduration%
       pause

[marcorocchini]

but is a problem of notation:

I would like have in a variable: 9,36 or 9.36 and not 00:00:09.36
is there a way to have from ffproble, the 9.36 so I can use directly? thanks

[Cornucopia]

No, you will have to do some string processing yourself.

Understand that things which make use of frame-based timing will always use either Absolute Integer framecounts (film-based, usually), e.g. "234", or use SMPTE/EBU timecode numbering, which is designated to be "HH:MM:SS:FF" (AudioCDframes, FILM, PAL & non-drop NTSC) or "HH:MM:SS;FF" (dropframe NTSC) - note the colons & semi-colon positioning.
Things which are NOT frame-based (audio samples, some midi stuff, old-school event-based interactive media) are denoted along the lines of "HH:MM:SS.msec" (usually to the 3 full decimal places) - note the period/dot/fullstop/comma positioning.

So, ffmpeg is giving you the appropriate nomenclature/designators/notation, whether you want them that way or not.

Scott

[pcspeak]

This works for a single file, but is probably easily broken.

@echo off
for %%a in (*.wav) do ffprobe -report %%a
for %%a in (*.log) do find "Duration:" <"%%a" >temp.txt
for /f "tokens=1,2,3,4,* delims=:, " %%a in (temp.txt) do set length=%%d
set
pause
del *.log *.txt

[pcspeak]

This is better. Multiple input files. (handles spaces in the file names)
Will still probably break

::@echo off
for %%a in (*.wav) do set FFREPORT=file=%%~na.log && ffprobe -report "%%a"
for %%a in (*.log) do find "Duration:" <"%%a"> "%%~na.txt" && for /f "usebackq tokens=1,2,3,4,5,* delims=:," %%b in ("%%~na.txt") do set %%~na=%%e
set
pause
del *.log *.txt

Mind you, if you have a large number of files to process then you will run out of environment space.

[marcorocchini]

pcspeack sorry but only now maybe I understand that, for example, in file C0029.wav I have do extract duration (09 sec 36 millisec) and do 9.36 X 25= 234

my target is get this 234 in a batch

but notation of ffprobe/ffmpeg seems 00:00:09.36 (and not 9.36)

please is there a way to get 234 and put on a variable?

consider I'm already in a batch, and the C0029.wav become %~dp1%~n1.wav

thanks

[marcorocchini]

there are no solution?

[pcspeak]

No.
Floating point math, to my knowledge, cannot be done in a batch file.

[marcorocchini]

from another post, assuming duration= 0:00:31.040000

You have to convert to frames. Obviously you cannot trim video on fraction of a frame

1/25 = 0.04
31 * 25 = 775
775+1 = 776 frames

[marcorocchini]

I have integrate the ndjamena's frame count calculator to my batch, but seems to me not for all files it recognize framecount

But for example, in the case of mp4 gopro it work perfectly.

I try to modify my megabatch so that, if the this (ndjamena) don't recognize the framecount ----> another procedure get me the frame count and this procedure, I think, maybe is this of (example) do duration * 25 = 234 frames

rem #### Find TimeCode Info ####
	Set AUCount=0;
	Set VDCount=0;
	Set STCount=0;
	Set "V_Number_Of_Frames="
	for /f "tokens=1,2 delims=^=" %%g in ('v:\automazioneclip\virtualdub\FFProbe -hide_banner -loglevel fatal -pretty -show_format -show_streams "%~f1" 2^>^&1') DO (
		CALL :Process_Item "%%~g" "%%~h"
	) 
	if NOT "%V_Time_Base%"=="" (
		for /F "tokens=1,2 delims=/" %%g in ("%V_Time_Base%") do (
			set "V_Time_Base_Denom=%%~g"
			set /a "V_Time_Base_Num=%%~h*10000"
		)
	)
	if NOT "%V_Frame_Rate%"=="" (
		for /F "tokens=1,2 delims=/" %%g in ("%V_Frame_Rate%") do (
			set /a "V_Frame_Rate_Num=%%~g*10000"
			set "V_Frame_Rate_Denom=%%~h"
		)
	)
	if "%V_Number_Of_Frames%"=="" Set /a "V_Number_Of_Frames=V_Duration/((V_Time_Base_Num/V_Time_Base_Denom)/(V_Frame_Rate_Num/V_Frame_Rate_Denom))"
       
	set "FPSforVirtualdub=%V_Number_Of_Frames%"

	echo "%FPSforVirtualdub%"
	
goto :eof

:Process_Item <item_field> <item_data>

	if "%~2"=="N/A" goto :eof
	if "%~1"=="[/STREAM]" (
		set "CType="
		goto :eof
	)
	if "%~1"=="[/FORMAT]" (
		set "CType="
		goto :eof
	)
	if "%~1"=="[FORMAT]" (
		set "CType=FORMAT"
		goto :eof
	)
	if "%~1"=="index" Set "cur_index=%~2"
	if "%~1"=="codec_name" Set "cur_codec=%~2"
	if "%~1"=="codec_type" (
		if "%~2"=="audio" (
			set /a AUCount+=1
			set "CType=audio"
		)
		if "%~2"=="video" if NOT "%cur_codec%"=="mjpeg" (
			Set /a VDCount+=1
			set "CType=video"
		)
		if "%~2"=="subtitle" (
			Set /a STCount+=1
			set "CType=subtitle"
		)
		goto :eof
	)
	if "%CType%"=="FORMAT" (
		if "%~1"=="TAG:company_name" set "T_Company_Name=%~2"
		if "%~1"=="TAG:product_name" set "T_Product_Name=%~2"
		if "%~1"=="TAG:product_version" set "T_Product_Version=%~2"
		if "%~1"=="TAG:timecode" set "TIMECODE=%~2"
		goto :eof
	)
	if "%CType%"=="video" (
		if %VDCount% GTR 1 (
			echo Multiple Video Streams!!!!
			pause
		)
		if "%~1"=="time_base" set "V_Time_Base=%~2"
		if "%~1"=="r_frame_rate" set "V_Frame_Rate=%~2"
		if "%~1"=="duration_ts" set "V_Duration=%~2"
		if "%~1"=="width" set "V_Width=%~2"
		if "%~1"=="height" set "V_Height=%~2"
		if "%~1"=="sample_aspect_ratio" set "V_PAR=%~2"
		if "%~1"=="nb_frames" set "V_Number_Of_Frames=%~2"
		goto :eof
	)
		
goto :eof

[pcspeak]

This will give you the number you wanted in a variable.

@echo off
if exist "eval.vbs" goto script
@echo Set objArgs = WScript.Arguments>"eval.vbs"
@echo wscript.echo eval(objArgs(0))>>"eval.vbs"

:script
for %%a in (*.wav) do set FFREPORT=file=%%~na.log && ffprobe -report "%%a"
for %%a in (*.log) do find "Duration:" <"%%a"> "%%~na.txt" && for /f "usebackq tokens=1,2,3,4,5,* delims=:," %%b in ("%%~na.txt") do for /f %%i in ('eval //nologo %%e*25') do set %%~na_count=%%i

set
pause
del *.log *.txt *.vbs

[marcorocchini]

thanks pcspeack, for kindness only 2 things:

1) I'm already in a batch file and I would like integrate this framecount into the batch

so my source is %4 (e.g. c:\cats\goprofile.mp4 or wav ecc.)


I have do this and seems work

echo Set objArgs = WScript.Arguments>"eval.vbs"
echo wscript.echo eval(objArgs(0))>>"eval.vbs"


v:\automazioneclip\virtualdub\FFProbe -i %4 2>>c:\ffprobe.txt
for %%a in (c:\ffprobe.txt) do find "Duration:" <"%%a"> "%%~na.txt" && for /f "usebackq tokens=1,2,3,4,5,* delims=:," %%b in ("%%~na.txt") do for /f %%i in ('eval //nologo %%e*25') do set %%~na_count=%%i

2) possibly I have to return the target value in a variable, not in a video screen
so I wonder: can the output is outputted in a variable (e.g. "thisframecountis")

3) is there a way to round the value into the lower integer? for example if the output is 144,5 frames ----> rounded is 144 ?
thanks

[pcspeak]

echo Set objArgs = WScript.Arguments>"eval.vbs"
echo wscript.echo eval(objArgs(0))>>"eval.vbs"


v:\automazioneclip\virtualdub\FFProbe -i %4 2>>c:\ffprobe.txt
for %%a in (c:\ffprobe.txt) do find "Duration:" <"%%a"> "%%~na.txt" && for /f "usebackq tokens=1,2,3,4,5,* delims=:," %%b in ("%%~na.txt") do for /f %%i in ('eval //nologo %%e*25') do set %%~na_count=%%i

This is the variable created by my batch file.
I used WAVname_count. Please call it whatever you wish

Rounding down. I have to investigate.

[marcorocchini]

a little kindness, for what I should do I don't need that appear the "windows script host" window that report the calculated output

is enought that the output is putted on a variable, for example "fnum"

so that in the case C0029.wav ---> %fnum% = 234 (does not matter the rouding down)

then in the batch I use the %fnum% for other processes

can you do this? ^^ thanks

[pcspeak]

To create variable %fnum%

@echo off
if exist "eval.vbs" goto script
@echo Set objArgs = WScript.Arguments>"eval.vbs"
@echo wscript.echo eval(objArgs(0))>>"eval.vbs"
:script
for %%a in (*.wav) do set FFREPORT=file=%%~na.log && ffprobe -report "%%a"
for %%a in (*.log) do find "Duration:" <"%%a"> "%%~na.txt" && for /f "usebackq tokens=1,2,3,4,5,* delims=:," %%b in ("%%~na.txt") do for /f %%i in ('eval //nologo %%e*25') do set fnum=%%i

[pcspeak]

@echo off
if exist "eval.vbs" goto script
@echo Set objArgs = WScript.Arguments>"eval.vbs"
@echo wscript.echo eval(objArgs(0))>>"eval.vbs"
:script
for %%a in (*.wav) do set FFREPORT=file=%%~na.log && ffprobe -loglevel quiet -report "%%a" >nul
for %%a in (*.log) do find "Duration:" <"%%a"> "%%~na.txt" && for /f "usebackq tokens=1,2,3,4,5,* delims=:," %%b in ("%%~na.txt") do for /f %%i in ('eval //nologo %%e*25') do set fnum=%%i