Project for the Programmazione di Sistema course at Politecnico di Torino
- Francesco Lonardo S291039
- Marco Barca S281702
ScreenRecorder is a project based on two main components:
- the ScreenRecorder library, a multiplatform C++ library, which allows to record the video from the screen and (optionally) the audio from the microphone.
- the CommandLineInterface library, a multiplatform C++ cli frontend, used to interact with the ScreenRecorder library.
Composed by ScreenRecorder.ccp and ScreenRecorder.h, it uses the ffmpeg libraries to capture the frames (video/audio), to elaborate them, and to save the result in a .mp4 file. These libraries are avcodec, avdevice, avfilter, avformat, avutil, libswscale and libswresample.
It uses two threads for the video and two threads for the audio (optional) recording.
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capture packets video: it gets the raw (encoded) video packets from the os virtual device (x11grab on Linux, gdigrab on Windows and avfoundation on Mac OS) and inserts them in a queue.
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elaborate packets video: it takes the raw packets, one at a time, from the video queue, and subsequently first performs an elaboration (decode and encode) and then writes them in the output file.
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capture packets audio: it gets the raw (encoded) audio packets from the os virtual device (pulse on Linux, dshow on Windows and avfoundation on Mac OS) and inserts them in a queue.
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elaborate packets audio: it takes the raw packets, one at a time, from the audio queue, and subsequently first performs an elaboration (decode and encode) and then writes them in the output file.
It uses one thread for the management/changing of the recording status.
- change recording status: it waits for the user's key pressing [p] to pause, [r] to record, [s] to stop
These are the features offered by the library:
- record screen video w/o microphone audio
- pause and resume recording without creating separated files
- allows the user to specify the size and the offsets of the screen area to be recorded
- allows the user to specify the output filename (the extension must be .mp4)
- in case of internal errors throws an exception with a description of the error and stop the recording, creating the output video file with what has been recorded till that moment
Composed by CommandLineInterface.ccp and CommandLineInterface.h, it uses the ncurses library to show in the command line an interface for pausing, stopping and resuming the recording.
