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Stereo master soundtrack
17 octobre 2011, par
Mis à jour : Octobre 2011
Langue : English
Type : Audio
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ED-ME-5 1-DVD
11 octobre 2011, par
Mis à jour : Octobre 2011
Langue : English
Type : Audio
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1,000,000
27 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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Demon Seed
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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The Four of Us are Dying
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
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Corona Radiata
26 septembre 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
Autres articles (55)
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Sur d’autres sites (10233)
-
Trying to find a way to limit the number of List that can run at one time
14 mars 2024, par JakeMy application has a List of Tasks. Each Task launches a FFMPEG process that requires a lot of resources on my machine. At times, this list can contain 200+ processes to FFMPEG. While processing, my memory is at 99% and everything freezes up.


I need to limit the amount of processes that can run at one time. I have read a little about SemaphoreSlim ; however, I cannot wrap my mind around it's implementation.


Is this a solution for this particular problem and if so, any ideas on how to implement it in my code ?


Below is my code :


public async System.Threading.Tasks.Task GetVideoFiles()
{ 
 OpenFileDialog openFileDialog = new OpenFileDialog();
 openFileDialog.Multiselect = true;
 
 if (openFileDialog.ShowDialog() == true)
 {
 AllSplices.Clear();
 AllSplices = new ObservableCollection<splicemodel>();
 IsBusy = true;
 IsBusyMessage = "Extracting Metadata";
 IsBusyBackgroundVisible = "Visible";
 NotifyPropertyChanged(nameof(IsBusy));
 NotifyPropertyChanged(nameof(IsBusyMessage));
 NotifyPropertyChanged(nameof(IsBusyBackgroundVisible));
 metaTasks = new List>(); 
 extractFramesTask = new List();
 
 foreach (string file in openFileDialog.FileNames)
 {
 FileInfo fileInfo = new FileInfo(file);
 bool canAdd = true;
 var tempFileName = fileInfo.Name;
 
 foreach (var video in AllVideos)
 {
 if (file == video.VideoPath)
 {
 canAdd = false;
 break;
 }

 if (video.VideoName.Contains(tempFileName))
 {
 video.VideoName = "_" + video.VideoName; 
 } 
 }
 if (canAdd)
 { 
 metaTasks.Add(System.Threading.Tasks.Task.Run(() => ProcessMetaData(file))); 
 } 
 }
 var metaDataResults = await System.Threading.Tasks.Task.WhenAll(metaTasks); 
 
 foreach (var vid in metaDataResults)
 { 
 if(vid == null)
 {
 continue;
 }
 
 vid.IsNewVideo = true; 
 AllVideos.Add(vid);
 
 // This list of task launches up to 200 video processing processes to FFMPEG
 extractFramesTask.Add(System.Threading.Tasks.Task.Run(() => ExtractFrames(vid)));
 
 vid.IsProgressVisible = "Visible";
 TotalDuration += vid.VideoDuration;
 vid.NumberOfFrames = Convert.ToInt32(vid.VideoDuration.TotalSeconds * 30);
 _ = ReportProgress(vid);
 }
 
 IsBusyMessage = "Importing Frames";
 NotifyPropertyChanged(nameof(IsBusyMessage)); 
 await System.Threading.Tasks.Task.WhenAll(extractFramesTask); 
 }
</splicemodel>


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avutil/mem : limit alignment to maximum simd align
3 décembre 2023, par Timo Rothenpieleravutil/mem : limit alignment to maximum simd align
FFmpeg has instances of DECLARE_ALIGNED(32, ...) in a lot of structs,
which then end up heap-allocated.
By declaring any variable in a struct, or tree of structs, to be 32 byte
aligned, it allows the compiler to safely assume the entire struct
itself is also 32 byte aligned.This might make the compiler emit code which straight up crashes or
misbehaves in other ways, and at least in one instances is now
documented to actually do (see ticket 10549 on trac).
The issue there is that an unrelated variable in SingleChannelElement is
declared to have an alignment of 32 bytes. So if the compiler does a copy
in decode_cpe() with avx instructions, but ffmpeg is built with
— disable-avx, this results in a crash, since the memory is only 16 byte
aligned.Mind you, even if the compiler does not emit avx instructions, the code
is still invalid and could misbehave. It just happens not to. Declaring
any variable in a struct with a 32 byte alignment promises 32 byte
alignment of the whole struct to the compiler.This patch limits the maximum alignment to the maximum possible simd
alignment according to configure.
While not perfect, it at the very least gets rid of a lot of UB, by
matching up the maximum DECLARE_ALIGNED value with the alignment of heap
allocations done by lavu. -
avutil/mem : limit alignment to maximum simd align
3 décembre 2023, par Timo Rothenpieleravutil/mem : limit alignment to maximum simd align
FFmpeg has instances of DECLARE_ALIGNED(32, ...) in a lot of structs,
which then end up heap-allocated.
By declaring any variable in a struct, or tree of structs, to be 32 byte
aligned, it allows the compiler to safely assume the entire struct
itself is also 32 byte aligned.This might make the compiler emit code which straight up crashes or
misbehaves in other ways, and at least in one instances is now
documented to actually do (see ticket 10549 on trac).
The issue there is that an unrelated variable in SingleChannelElement is
declared to have an alignment of 32 bytes. So if the compiler does a copy
in decode_cpe() with avx instructions, but ffmpeg is built with
— disable-avx, this results in a crash, since the memory is only 16 byte
aligned.Mind you, even if the compiler does not emit avx instructions, the code
is still invalid and could misbehave. It just happens not to. Declaring
any variable in a struct with a 32 byte alignment promises 32 byte
alignment of the whole struct to the compiler.This patch limits the maximum alignment to the maximum possible simd
alignment according to configure.
While not perfect, it at the very least gets rid of a lot of UB, by
matching up the maximum DECLARE_ALIGNED value with the alignment of heap
allocations done by lavu.