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• Storing high quality video stream (from IP Action Camera) continuously to a Storage Device and issues around Write-Speed bottlenecks

  21 mai 2017, par Aldo

  I am looking to get an Action Camera (Eken H8R, or a GoPro) for a project. Let me explain the scenario I have :

  I will obtain a live stream from the camera on to a Raspberry Pi (over WiFi) as shown here. Next, I want to continuously segment this live stream into 10-15 minute video clips and store them in an external Hard Drive (which is connected to the RPi). I am considering this thread, and the avconvcommand mentioned in the answer by Alexander.

  Now, my concern is write-speed limitations. The video stream would probably have a high bitrate, and might be 4k30fps, in which case file sizes would be huge. Would write speed to disk be a bottleneck ? If so, how will the Pi maintain a buffer to achieve this ? Could I run out of space as the memory stick on the Pi would only be around 8 gigs ? If so, what’s a better alternative ? Please correct me if I’m wrong on these as I’m only a beginner.

• Storing high quality video stream (from IP Action Camera) continuously to a Storage Device and issues around Write-Speed bottlenecks

  21 mai 2017, par Aldo

  I am looking to get an Action Camera (Eken H8R, or a GoPro) for a project. Let me explain the scenario I have :

  I will obtain a live stream from the camera on to a Raspberry Pi (over WiFi) as shown here. Next, I want to continuously segment this live stream into 10-15 minute video clips and store them in an external Hard Drive (which is connected to the RPi). I am considering this thread, and the avconvcommand mentioned in the answer by Alexander.

  Now, my concern is write-speed limitations. The video stream would probably have a high bitrate, and might be 4k30fps, in which case file sizes would be huge. Would write speed to disk be a bottleneck ? If so, how will the Pi maintain a buffer to achieve this ? Could I run out of space as the memory stick on the Pi would only be around 8 gigs ? If so, what’s a better alternative ? Please correct me if I’m wrong on these as I’m only a beginner.

• Is there a set of working P/Invoke declarations for FFMpeg, libavutil, libavformat and libavcodec in .NET ?

  11 février 2014, par casperOne

  I'm currently looking to access libavutil, libavformat and libavcodec (all part of FFMpeg) from .NET.

  Currently, I'm getting the libraries from the automated builds of the shared FFMpeg package performed every night for Windows 32-bit.

  I am also using the code from the ffmpeg-sharp project. In that project, I have removed a number of classes that were not compiling (they are wrapper classes not the P/Invoke declarations).

  The code compiles fine, but I am running into a few issues.

  First, it appears that the build of av*.dll uses the cdecl calling convention, as I was receiving a number of PInvokeStackImbalanceException when trying to call av_open_input_file. This was easy enough to change to get it to work right. The AVFormatContext structure is populated.

  After that, I want to call av_find_stream_info to get information about the streams in the file. However, when calling that with the AVFormatContext retrieved from the call to av_open_input_file, an AccessViolationException is thrown indicating that I am trying to read or write from protected memory.

  Has anyone used P/Invoke to access the libavutil, libavformat and libavcodec dll libraries through P/Invoke and have gotten it to work ?

  I should mention that working with the command-line version of FFMpeg, while a solution, is not a viable solution in this case, access needs to occur through the libraries. The reason for this is that I'd have to thrash the disk way too much to do what I need to do (I have to do a frame-by-frame analysis of some very high definition video) and I want to avoid the disk as much as possible.