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• FFMPEG converting media type aswell as relocating MOOV atom [migrated]

  11 juin 2013, par Samuel Richards

  I have found this line online

  ffmpeg -i input.mp4 -c:a copy -c:v copy -movflags faststart output.mp4

  Which takes an input, and copies the audio, video and sets the MOOV atom to the beginning in an element called output.mp4. Basically creating the same video with the MOOV atoms in a new place.

  I need to convert the type of this media though - so I have the line

  ffmpeg -i input.wmv -vcodec h264 -f mp4 output.mp4

  My problem is, is this possible in one line ? I know I can run one after another but that creates a couple of videos when I only need the resulting video, which could result in a lot of memory wasted.

  I am sure the line

  ffmpeg -i input.wmv -movflags faststart -vcodec h264 -f mp4 output.mp4 

  Is legitimate, but without the straight copies, this takes a long long time to compute.

  Any input on MOOV atoms and ffmpeg computation is welcome.

• Exporting MPEG Transport Stream (.ts) keyframes to images in C/C++ ? Libavcodec / FFMPEG ?

  11 mai 2021, par CyberBully2003

  I have some buffers made up of 188 byte TS packets. When I write them to a file, I can successfully view these .ts files in a video player. MPEG-2/H.264 is the format of the Transport Streams.

  


  Now, I would like to export the keyframes from these Transport Streams buffers (or .ts files) as .jpeg or some other common image format in my C/C++ project.

  


  This is a trivial task from the command line using ffmpeg, where I just feed it the .ts file and some parameters.

  


  However, for the purpose of this project, I would like to accomplish this conversion/exporting of keyframes as images code-side in my current C/C++ directory because the raw bytes from these generated images will be put into another format.

  


  People online seem to recommend using libavcodec. There is an mpegets file in the ffmpeg source that seems like it might have some of the backend to do what I want.

  


  However, the steps needed to achieve this task using the library is not apparent.

  


  I know I could call ffmpeg from C++ and use stdin, but this isn't a preferred solution for this project.

  


  If someone could give me some guidance (and even better some example code) to accomplish this task, it would be greatly appreciated !

  


• How would I create a radially offset mosaic of rtsp streams that transitions to a logo

  18 juillet 2018, par Jack

  I’m new to stack overflow, but I’ve been researching how to do this for a couple weeks to no avail. I’m hoping perhaps one of you has some knowledge I haven’t seen online yet.

  Here is a crude illustration of what I hope to accomplish. I have a video wall of eight monitors - four each of two different sizes. The way it’s set up now, all eight monitors are treated together as one big monitor displaying an oddly shaped cutout of a desktop.

  Eventually I need each individual monitor to display a separate RTSP stream for about thirty seconds, then have the entire display - all eight monitors in conjunction - to fade out into a large logo.

  My problem right now is that I don’t know of a way to mask an rtsp stream so it looks like this rather than this, let alone how to arrange them into a weirdly spaced, oddly angled, multiple aspect-ratio mosaic like in the original illustration.

  Thank you all for your time. I’m just an intern here without insane technical knowhow, but I’ll try to clarify as much as I can.

  -J