Strange problem with FFMPEG's stdout

[criobot]

I'm not sure if the problem is with PB's Process library or within FFMPEG itself. I am using the latest FFMPEG build. And it behaves very strange even with these simple parameters from the code below. It returns only exit code 1 and no output, but if I change the parameters to "-h", it behaves normally and outputs all the help with exit code 0. ReadProgramString does not read any program output, nor does ReadProgramData. My goal is to keep track on the conversion process through the console output, but no success so far...

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asdf = RunProgram("ffmpeg.exe", "-i test.mp4", "", #PB_Program_Open|#PB_Program_Read|#PB_Program_Hide|#PB_Program_Error)
If IsProgram(asdf)
  While ProgramRunning(asdf)
    If AvailableProgramOutput(asdf)
      Debug ReadProgramString(asdf)
    EndIf
  Wend
  Debug ProgramExitCode(asdf)
  CloseProgram(asdf)
EndIf

[ricardo]

This coide (that i found somewhere) works with FFMPEG

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ProcedureDLL.s GetProgramResult(Command.s) 
  
  proc.PROCESS_INFORMATION ;Process info filled by CreateProcessA 
  ret.l ;long variable For get the Return value of the 
  start.MySTARTUPINFO ;StartUp Info passed To the CreateProceeeA 
  sa.SECURITY_ATTRIBUTES ;Security Attributes passeed To the 
  hReadPipe.l ;Read Pipe handle created by CreatePipe 
  hWritePipe.l ;Write Pite handle created by CreatePipe 
  lngBytesread.l ;Amount of byte Read from the Read Pipe handle 
  strBuff.s=Space(256) ;String buffer reading the Pipe 
  
  ;Consts For functions 
  #NORMAL_PRIORITY_CLASS = $20 
  #STARTF_USESTDHANDLES = $100 
  #STARTF_USESHOWWINDOW = $1 
  
  ;Create the Pipe 
  sa\nLength =SizeOf(SECURITY_ATTRIBUTES) ;Len(sa) 
  sa\bInheritHandle = 1 
  sa\lpSecurityDescriptor = 0 
  ret = CreatePipe_(@hReadPipe, @hWritePipe, @sa, 0) 
  If ret = 0 
    ;If an error occur during the Pipe creation exit 
    MessageRequester("info", "CreatePipe failed. Error: ",0) 
    End 
  EndIf 
  
  
  start\cb = SizeOf(MySTARTUPINFO) 
  start\dwFlags = #STARTF_USESHOWWINDOW | #STARTF_USESTDHANDLES 
  
  ;set the StdOutput And the StdError output To the same Write Pipe handle 
  start\hStdOutput = hWritePipe 
  start\hStdError = hWritePipe 
  
  ;Execute the command 
  ret = CreateProcess_(0, Command, sa, sa, 1, #NORMAL_PRIORITY_CLASS, 0, 0, @start, @proc) 
  
  If ret <> 1 
    retour.s="" 
  Else 
    
    ;Now We can ... must close the hWritePipe 
    ret = CloseHandle_(hWritePipe) 
    
    mOutputs.s = "" 
    
    ;Read the ReadPipe handle 
    While ret<>0 
      ret = ReadFile_(hReadPipe, strBuff, 255, @lngBytesread, 0) 
      If lngBytesread>0 
        mLine$ = Left(strBuff, lngBytesread)
        ;Debug mLine$
        ParseaData(mLine$)
        mOutputs = mOutputs + mLine$ 
      EndIf 
    Wend 
    
    ;Close the opened handles 
    ret = CloseHandle_(proc\hProcess) 
    ret = CloseHandle_(proc\hThread) 
    ret = CloseHandle_(hReadPipe) 
    ;ret=CloseHandle_(hWritePipe) 
    
    retour.s=mOutputs 
    
  EndIf 
  
  ProcedureReturn mOutputs ;ConformationAsciiEtenduVersAscii(mOutputs) 
EndProcedure 

bCommandLine$ = "FFmpeg -y -i abc.mp3 abc.flac"
  Datos$ = GetProgramResult(bCommandLine$)

[DarkPlayer]

I think your problem is that FFMPEG can't find your input file.
Depeding on your compiler settings, the working directory might be C:\Program Files\Purebasic, if you start your program within the IDE. Just try an absolut path for the input file.
The reason why you can't see an error in the program output is that critical errors are written to STDERR and you are just collecting the output from STDOUT. You also have to use ReadProgramError() to collect all output messages from FFMPEG.

[NY152]

i have a little question:

ParseaData is not function ! Where is this function ?

[Bitblazer]

read this

[NY152]

Thank you but this code does not work with the little test I made

I tested with a simple command

With the program and parameter : C:\Windows\System32\where.exe notepad

The program must return the notepad path, this is not the case, the output is empty.

[Bitblazer]

Just read what i linked to. ffmpeg is using STDOUT and STDERR in a non-standard way due to the way how ffmpeg is often used as a piping tool in *nix environments (for example 'cat inputfile.bin | ffmpeg -parameters >newvideo.mpg'). So they decided to use STDOUT for the output video stream and use STDERR for regular "STDOUT" output to achieve this kind of common usage in the *nix world work. That's why using other Programs to test your PB use with FFMPEG is a bit pointless. The code from ricardo assigns STDIN and STDERR into one pipe to work, i personally wouldn't do that as it makes it impossible to distinguish between STDIN and STDERR.

[NY152]

Whether in STDOUT or STDERR, I do not have the result, it's empty ...

[ricardo]

For the records, add this to your FFMPEG command: -progress pipe:2

and you will be able to read as stdout.

[jacdelad]

Six years later...

...why not. I just had the same problem and simply gave up (my program waits until ffmpeg is done). Thanks ricardo, I'll try.

[ricardo]

In fact in FFMPEG tou can use also this at the end of the command to redirect both outputs (st and err) to the same output


-f null NUL 2>&1

Like in:

FFMPEG -i input.mp3 -f null NUL 2>&1

[Piero]

No logged infos on stdout (warnings/errors still on stderr):

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ffmpeg -v 24 -i in.mp4 out.mp3

Log only progress every 1.5 seconds, also overwriting output file without "interactive" asking:

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ffmpeg -v 24 -stats_period 1.5 -progress pipe:1 -i in.mp4 -y out.mp3

Set to non-interactive mode (-nostdin) and use stdout only for warnings/errors:

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ffmpeg -nostdin -v 24 -i in.mp4 out.mp3 2>&1

Log file info (just ignore the "no output file" error):

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ffmpeg -hide_banner -i file.mp4 2>&1

[Piero]

To get duration without error messages:

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ffmpeg -nostdin -hide_banner -nostats -i file.mp4 -f null -c copy - 2>&1

Edit/Note: ffmpeg 7 "Duration: " seems to be reliable enough for a simple completion % check using the "-progress" output

[Piero]

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; ffmpeg monitor "early prototype"

EnableExplicit
Define dur$,pro$,md,mp 

Enumeration
   #Duration
   #Out_time
   #Speed
   #ProgressBarFF = 0
   ;#ProgressBarFiles
EndEnumeration

Macro regexp(a,b)
   CreateRegularExpression(a,b,
      #PB_RegularExpression_MultiLine|#PB_RegularExpression_AnyNewLine)
EndMacro

regexp(#Duration, "^\s*Duration: \K[^.]+")
regexp(#Out_time, "^out_time=\K[^.]+")
regexp(#Speed, "^speed=\s*\K[^x]+") ; has space after "="!?

Procedure.s reg(r,s.s)
   Dim Result$(0)
   ExtractRegularExpression(r,s,Result$())
   ProcedureReturn Result$(0)
EndProcedure

; ProgressBarGadget(#ProgressBarFF, x, y, Width, Height, 0, 1); initialize

; Simulated file info log (stdout) from:
; ffmpeg -nostdin -hide_banner -nostats -i in.mp4 -f null -c copy - 2>&1
dur$=~"...\n  Duration: 01:00:00.96, start: 0.000000, bitrate: 415 kb\n..."

md=ParseDate("%hh:%ii:%ss",reg(#Duration,dur$)) ; media time duration
; SetGadgetAttribute(#ProgressBarFF, #PB_ProgressBar_Maximum, md); set max

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; PROGRESS PROCESSING:

; Simulated progress log (stdout) from (-y = overwrite):
; ffmpeg -v 24 -nostdin -stats_period 1.0 -progress pipe:1 -i in.mp4 -y out.mp3
pro$=~"...\nout_time=00:20:00.912086\n...\nspeed= 10x\nprogress=Continue"

mp=ParseDate("%hh:%ii:%ss",reg(#Out_time,pro$)) ; media time processed

; Remaining time:
Debug "ETA: " + FormatDate("%hh:%ii:%ss",((md-mp)/Val(reg(#Speed,pro$)))); 0?
; Percent completed:
Debug "" + Int(Round(1/(md/mp)*100,#PB_Round_Down)) + "%"
; Update ProgressBar:
; SetGadgetState (#ProgressBarFF,mp)

[tj1010]

I ran in to the stderr problem a while back. I do a lot of transcoding and upscaling work with libx264 and mkv and acc(no hwaccel for best quality). I never thought to just read it back through named pipes..

FYI

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-vf scale=3840x2560:flags=lanczos

is the absolute best 16:9 4k upscale; better than Topaz AI filters even

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-c:a aac -b:a 128k -ac 2

for auto stereo channel transcode; aac supported by most blueray players. It will auto-separate 7.1 and 5.1 to stereo using dolby and dts metadata

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-map 0:a?

all audio from source

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-map 0:s?

all subs from source

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-vf nlmeans="1.0:7:5:3:3"

most optimal denoise

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-protocol_whitelist https,tls,tcp,file

m3u8/HLS/every-video-stream-on-the-internet as source to single out-file

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-listen 1 -i <> -c:v libx264 -crf 21 -preset veryfast -c:a aac -b:a 128k -ac 2 -f hls -hls_time 4 -hls_playlist_type event stream.m3u8

FFMPEG also has a built in HLS server via RTMP. HLS is basically what every in-browser video and audio stream on the net is using; including YouTube, Netflix, Hulu, and Amazon. It also supports RTSP and about thirty other protocols. HTML5>Video tag supports m3u8

If you care about quality never use a hwaccel even with the slowest encode and CBR, and .mkv you can embed all sub in the video file and it works on any player that supports .mkv, which is most.. I don't think ffmpeg has audio normalization(removing loudness difference between audio tracks).

If you do want to use -hwaccel auto

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-c:v h264_amf -usage quality -cq 18

AMD(works through directX API on Windows)

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-c:v x264_nvenc -preset p7 -cq 18

Nvidia

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-c:v x264_qsv -preset veryslow -global_quality 18 

Intel