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• How do I create a 360 [stereo] panorama video of a virtual scene using OpenGL or DirectX ?

  14 novembre 2015, par Prashant Raina

  Like many of you, I have seen the magical 360 degree videos doing the rounds on Facebook right now. I would really like to know how to programmatically create such a video using OpenGL or DirectX, but I found surprisingly little information about it.
  There are several issues I am not clear on :

  1. How do I set up my vertex and fragment shaders to render a frame of 360 video ?
  2. Do I have to generate one image per frame, or a cubemap, or something else ?
  3. Once I have the frames, how do I combine them into a single video file for upload ? My Googling suggests that I should use ffmpeg, but I couldn’t figure out which parameters to use, or what sort of input it expects for 360 video.
  4. What additional steps are needed to make a stereo 360 video ?

  I am not asking how to render an existing video onto the screen, or how to use physical cameras for 360 video.

  Thanks in advance !

• FFmpeg Streaming Video SpringBoot endpoint not show video duration in video players

  7 avril 2024, par lxluxo23

  it turns out that I've been working on a personal project just out of curiosity.
the main function is to stream video by first encoding it through ffmpeg
then playback said video from any other device
call it "plex" very very primitive

  


  although I achieve my goal which is to encode and send the video to the devices that make the request
this video is sent so to speak as a live broadcast.
I can only pause it, no forward or rewind, anyone have any idea what I am doing wrong or if I should take some other approach either in my service or controller ?

  


  I leave fragments of my code

  


  THE CONTROLLER

  


  @RestController&#xA;@RequestMapping("/api")&#xA;@Log4j2&#xA;public class StreamController {&#xA;&#xA;    @Autowired&#xA;    VideoStreamingService videoStreamingService;&#xA;&#xA;    @Autowired&#xA;    VideoService videoService;&#xA;&#xA;&#xA;    @GetMapping("/stream/{videoId}")&#xA;    public ResponseEntity<streamingresponsebody> livestream(@PathVariable Long videoId,@RequestParam(required = false)  String codec) {&#xA;        Video video = videoService.findVideoById(videoId);&#xA;        if (video != null) {&#xA;            Codec codecEnum = Codec.fromString(codec);&#xA;            return ResponseEntity.ok()&#xA;                    .contentType(MediaType.valueOf("video/mp4"))&#xA;                    .body(outputStream -> videoStreamingService.streamVideo(video.getPath(), outputStream,codecEnum));&#xA;        }&#xA;        return ResponseEntity.notFound().build();&#xA;    }&#xA;}&#xA;</streamingresponsebody>

  


  THE SERVICE

  


  @Service
public class VideoStreamingService {

    public void streamVideo(String videoPath, OutputStream outputStream, Codec codec) {

        FFmpeg ffmpeg = FFmpeg.atPath()
                .addArguments("-i", videoPath)
                .addArguments("-b:v", "5000k")
                .addArguments("-maxrate", "5000k")
                .addArguments("-bufsize", "10000k")
                .addArguments("-c:a", "aac")
                .addArguments("-b:a", "320k")
                .addArguments("-movflags", "frag_keyframe+empty_moov+faststart")
                .addOutput(PipeOutput.pumpTo(outputStream)
                        .setFormat("mp4"))
                .addArgument("-nostdin");
        if (codec == Codec.AMD) {
            ffmpeg.addArguments("-profile:v", "high");
        }
        ffmpeg.addArguments("-c:v", codec.getFfmpegArgument());
        ffmpeg.execute();
    }
}


  


  I have some enums to vary the encoding and use hardware acceleration or not.

  


  and here is an example from my player
the endpoint is the following

  


  http://localhost:8080/api/stream/2?codec=AMD
screenshot

  


  I'm not sure if there's someone with more knowledge in either FFmpeg or Spring who could help me with this minor issue, I would greatly appreciate it. I've included the URL of the repository in case anyone would like to review it when answering my question

  


  repo

  


  I tried changing the encoding format.
I tried copying the metadata from the original video.
I tried sending a custom header.
None of this has worked.

  


  I would like to achieve what is mentioned in many sites, which is when you load a video from the network, the player shows how much of that video you have in the local "buffer".

  


• ffmpeg overlays the video on the background video and deletes the black background of the original video

  4 avril 2023, par codecapture

  I use this command to remove black background

  


  ffmpeg -i bg.mp4 -i video.mp4 -filter_complex [1:v]colorkey=0x000000:0.1:0.1[ckout];[0:v][ckout]overlay[out] -map [out] -t 5 -c:a copy -c:v libx264 -y result.mp4


  


  enter image description here
The black color on the person in the original video will also be removed, how to solve it ?