Answers.Body: <p>This is a very broad questions so let me try to answer it in a general sense.</p>
  
  <p>Yes, it is more likely for corrupted files to appear when encoding more files. It is only more likely by a very thin margin though, so using a batch-render-queue is not something to "not do" - in fact, many big budget productions use render-queues to render many many sequences one after another, and I personally wouldn't demotivate you from doing it. However, encoding to mp4 (I assume h.264) always comes with compression, meaning that the file will be lossy and not as good as the original. The CPU being at 100% shouldn't cause any problems though if you didn't overclock your cpu or tinkered with the flags from within ffmpeg (which I assume you didn't do).</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-07-05T18:56:06.933Z
Answers.Text: So the only drawback of launching multiple ffmpeg encodes is that each one will take longer? Creating a queue would be too much complex for me. Easier to just launch many and wait
Answers.UserDisplayName: Freedo
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Answers.CreationDate: 2019-07-07T11:36:58.760Z
Answers.Text: If you are running so many processes at once that your computer runs out of memory, then the speed will be MANY times slower than it would normally be, because the computer will start swapping memory out to hard disk, which is thousands of times slower than RAM. It will also shorten the life of your HDD. It's worth your time learning a little bit of scripting to avoid this. A description of how to do it is on my blog here (scroll down to part II): https://blob.pureandapplied.com.au/proxynator/
Answers.UserDisplayName: stib
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-07-23T08:06:18.993Z
Answers.Text: @stib I'm on linux sadly :/ but memory is not a issue
Answers.UserDisplayName: Freedo
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-07-23T12:45:18.170Z
Answers.Text: You can certainly use that technique on posix systems, It's been a while so I'm not the person to ask about bash or zsh, but it's not hard to find. This kinda thing is why shell scripting exists, on all platforms
Answers.UserDisplayName: stib
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Answers.CreationDate: 2019-07-05T07:48:48.817Z
Answers.LastActivityDate: 2019-07-05T07:48:48.817Z
Answers.UserDisplayName: Florian Claaßen
Body: <p>Converting ~30 files at once with ffmpeg to mp4, and it took around ~19 hours to finish. My CPU was at 100% the whole time.</p>
  
  <p>Is there any drawback in doing this many encodes at once, if time is not a big concern? </p>
  
  <p>Like can ffmpeg lose frames or something because the CPU is busy and thus corrupt a file, make lower quality files or something. </p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-07-05T21:29:26.607Z
Comments.Text: No concern. This is what computers are designed for. Obviously, industrial computers are designed for years of work without turning off, but even a home computer should perform normally with proper cooling. Modern computers throttle themselves down if cooling is not adequate, so you should not experience a meltdown. If you notice that your computer behaves less stable under load, freezes or reboots, then it is a sign to replace the computer (or at least RAM modules and/or HDD).
Comments.UserDisplayName: Rusty Core
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-07-05T21:32:27.660Z
Comments.Text: @RustyCore I was thinking more if doing this could impact the quality of my encoded files because I'm overloading the CPU. It's a server in a datacenter
Comments.UserDisplayName: Freedo
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-07-05T21:33:25.687Z
Comments.Text: No, it will not impact the quality — it is all digital and is driven by algorithm.
Comments.UserDisplayName: Rusty Core
Tags: <ffmpeg>
Title: Can too many ffmpeg encodes at once cause loss of quality?
UserDisplayName: Freedo
ThreadText: # Can too many ffmpeg encodes at once cause loss of quality?
  
  (Asked by: username_0 on 2019-07-04)
  
  Converting ~30 files at once with ffmpeg to mp4, and it took around ~19 hours to finish. My CPU was at 100% the whole time.
  
  Is there any drawback in doing this many encodes at once, if time is not a big concern?
  
  Like can ffmpeg lose frames or something because the CPU is busy and thus corrupt a file, make lower quality files or something.
  
  **Tags:** ffmpeg
  
  > **Comments:**
  > **username_1**: No concern. This is what computers are designed for. Obviously, industrial computers are designed for years of work without turning off, but even a home computer should perform normally with proper cooling. Modern computers throttle themselves down if cooling is not adequate, so you should not experience a meltdown. If you notice that your computer behaves less stable under load, freezes or reboots, then it is a sign to replace the computer (or at least RAM modules and/or HDD).  
  > **username_0**: @username_1 I was thinking more if doing this could impact the quality of my encoded files because I'm overloading the CPU. It's a server in a datacenter  
  > **username_1**: No, it will not impact the quality — it is all digital and is driven by algorithm.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2019-07-05. Score: 1
  
  This is a very broad questions so let me try to answer it in a general sense.
  
  Yes, it is more likely for corrupted files to appear when encoding more files. It is only more likely by a very thin margin though, so using a batch-render-queue is not something to "not do" - in fact, many big budget productions use render-queues to render many many sequences one after another, and I personally wouldn't demotivate you from doing it. However, encoding to mp4 (I assume h.264) always comes with compression, meaning that the file will be lossy and not as good as the original. The CPU being at 100% shouldn't cause any problems though if you didn't overclock your cpu or tinkered with the flags from within ffmpeg (which I assume you didn't do).
  
  > **Comments:**
  > **username_0**: So the only drawback of launching multiple ffmpeg encodes is that each one will take longer? Creating a queue would be too much complex for me. Easier to just launch many and wait  
  > **username_3**: If you are running so many processes at once that your computer runs out of memory, then the speed will be MANY times slower than it would normally be, because the computer will start swapping memory out to hard disk, which is thousands of times slower than RAM. It will also shorten the life of your HDD. It's worth your time learning a little bit of scripting to avoid this. A description of how to do it is on my blog here (scroll down to part II): https://blob.pureandapplied.com.au/proxynator/  
  > **username_0**: @username_3 I'm on linux sadly :/ but memory is not a issue  
  > **username_3**: You can certainly use that technique on posix systems, It's been a while so I'm not the person to ask about bash or zsh, but it's not hard to find. This kinda thing is why shell scripting exists, on all platforms  
  
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