I want to convert many .iso files to .mp4 with HandBrake, so I am trying to use the command line interface. I would prefer to write my scripts for this in powershell instead of batch files. However, the standard error contains linebreaks at random location if I use powershell.
For troubleshooting, I created a simplified script both in powershell and in batch.
Powershell:
& "$Env:ProgramFiles\HandBrake\HandBrakeCLI.exe" @(
'--input', 'V:\',
'--title', '1', '--chapter', '1',
'--start-at', 'duration:110', '--stop-at', 'duration:15',
'--output', 'pmovie.mp4',
'--format', 'av_mp4'
) > ".\pstd.txt" 2> ".\perr.txt"
Batch file:
"%ProgramFiles%\HandBrake\HandBrakeCLI.exe" --input V:\ --title 1 --chapter 1 --start-at duration:110 --stop-at duration:15 --output ".\cmovie.mp4" --format av_mp4 > ".\cstd.txt" 2> ".\cerr.txt"
Both scripts create the same .mp4 file, the difference is only the standard error output they create:
Powershell:
HandBrakeCLI.exe : [10:41:44] hb_init: starting libhb thread
At C:\Test\phandbrake.ps1:1 char:2
+ & <<<< "$Env:ProgramFiles\HandBrake\HandBrakeCLI.exe" @(
+ CategoryInfo : NotSpecified: ([10:41:44] hb_i...ng libhb thread
:String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError
[10:41:44] thread 541fc20 started ("libhb")
HandBrake 1.1.2 (2018090500) - MinGW x86_64 - https://handbrake.fr
8 CPUs detected
O
pening V:\...
[10:41:44] CPU: Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz
[10:41:44] - Intel microarchitecture Sandy Bridge
[10:41:44] - logical processor count: 8
[10:41:44] Intel Quick Sync Video support: no
[10:41:44] hb_scan: path=V:\, title_index=1
src/libbluray/disc/disc.c:424: error opening file BDMV\index.bdmv
src/libbluray/disc/disc.c:424: error opening file BDMV\BACKUP\index.bdmv
[10:41:44] bd: not a bd - trying as a stream/file instead
libdvdnav: Using dvdnav version 6.0.0
l
ibdvdnav: Unable to open device file V:\.
libdvdnav: vm: dvd_read_name failed
libdvdnav: DVD disk re
ports i
tself wi
th Region mask 0x
0000000
0. Reg
ions:
1 2 3 4 5
6 7 8
Batch file:
[10:41:35] hb_init: starting libhb thread
[10:41:35] thread 5a2cc30 started ("libhb")
HandBrake 1.1.2 (2018090500) - MinGW x86_64 - https://handbrake.fr
8 CPUs detected
Opening V:\...
[10:41:35] CPU: Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz
[10:41:35] - Intel microarchitecture Sandy Bridge
[10:41:35] - logical processor count: 8
[10:41:35] Intel Quick Sync Video support: no
[10:41:35] hb_scan: path=V:\, title_index=1
src/libbluray/disc/disc.c:424: error opening file BDMV\index.bdmv
src/libbluray/disc/disc.c:424: error opening file BDMV\BACKUP\index.bdmv
[10:41:35] bd: not a bd - trying as a stream/file instead
libdvdnav: Using dvdnav version 6.0.0
libdvdnav: Unable to open device file V:\.
libdvdnav: vm: dvd_read_name failed
libdvdnav: DVD disk reports itself with Region mask 0x00000000. Regions: 1 2 3 4 5 6 7 8
libdvdread: Attempting to retrieve all CSS keys
libdvdread: This can take a _long_ time, please be patient
libdvdread: Get key for /VIDEO_TS/VIDEO_TS.VOB at 0x00000130
libdvdread: Elapsed time 0
This bothers me because I would like to check these text files to be sure that there was no error during the encoding.
I suppose this may be related to a lack of synchronization between threads that write to the same stream but I am not sure about it.
The question: What can I do to get the standard error output from PowerShell without these random line breaks?
You might try the Start-Process command, with -RedirectStandardError, -RedirectStandardInput, and -Wait options.
These -Redirect... options on Start-Process do OS level I/O redirection directly to the target file, as most shells do. As I understand it, that's not how PowerShell angle-bracket redirection works, instead they the angle brackets pipe the output through another PowerShell pipeline, using Write-File (or something), which inserts line-breaks between strings it receives.
I'm not sure of the exact details of this, but I'm glad to hear it seems to address the problem for you as it has for me.