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• Splitting audio tracks with incorrect length - FFMPEG

  26 mars 2018, par channae

  Version : com.writingminds:FFmpegAndroid:0.3.2

  I have an audio file with length 43 seconds. And I wrote an algorithm to split at each 10 seconds mark where a word ends (For this I used IBM Watson to get ending timestamp). So cropping duration is always around 10 seconds to 11 seconds. Of course except the 5th one. I have printed my commands so that you will understand my use-case better.

  System.out: Split Command: -y -i /storage/emulated/0/AudioClipsForSpeakerRecognition/merge.wav -ss 00:00:00.000 -codec copy -t 00:00:10.010 /storage/emulated/0/AudioClipsForSpeakerRecognition/segment_1.wav
  
  
  
  System.out: Split Command: -y -i /storage/emulated/0/AudioClipsForSpeakerRecognition/merge.wav -ss 00:00:10.010 -codec copy -t 00:00:21.090 /storage/emulated/0/AudioClipsForSpeakerRecognition/segment_2.wav
  
  
  
  System.out: Split Command: -y -i /storage/emulated/0/AudioClipsForSpeakerRecognition/merge.wav -ss 00:00:21.090 -codec copy -t 00:00:30.480 /storage/emulated/0/AudioClipsForSpeakerRecognition/segment_3.wav
  
  
  
  System.out: Split Command: -y -i /storage/emulated/0/AudioClipsForSpeakerRecognition/merge.wav -ss 00:00:30.480 -codec copy -t 00:00:40.120 /storage/emulated/0/AudioClipsForSpeakerRecognition/segment_4.wav
  
  
  
  System.out: Split Command: -y -i /storage/emulated/0/AudioClipsForSpeakerRecognition/merge.wav -ss 00:00:40.120 -codec copy -t 00:00:43.000 /storage/emulated/0/AudioClipsForSpeakerRecognition/segment_5.wav

  However when playing all cropped audio files I noticed segment_1 is about 10 seconds and segment_2 is about 20 seconds etc. Therefore some of the audio parts belong to segment_1 also available in segment 2 etc etc. Why is this happening ?

  Appreciate your response.

• 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".

  


• Cut video in chunks at nearest keyframe to the nearest scene change (ffmpeg)

  11 janvier 2024, par Toxiro

  I want to cut a video in let’s say approximately 30 minute chunks. I first want to find the nearest scene change each 30 minutes and then cut at the nearest keyframe to that scene changes (without reencoding).

  


  I guess I can’t do that in a single ffmpeg command, but I maybe here are some pros with very helpful tips. Is it possible for example to just output the nearest scene change (or maybe just the next scene change) at a timecode, so that ffmpeg does not need to analyze the whole video ?

  


  I hope someone can help. If I have a solution, probably a bash script, I will post it here.