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• Ffmpeg burnt in subtitles out of sync when converting to hls

  19 mai 2020, par user1503606

  I have a file that has subtitles burn into it and they are perfectly in sync.

  



  Here is the file. https://983yqbz442.s3.amazonaws.com/little-mermaid-captions.mp4

  



  I run this command to convert to hls and it creates the .ts files and the .vtt files.

  



  ffmpeg -i little-mermaid-captions.mp4 -profile:v baseline -level 3.0 -s 640x360 -start_number 0 -hls_time 10 -hls_list_size 0 -f hls index.m3u8


  



  I also then create a master.m3u8 file in the same folder with the following.

  



  #EXTM3U
#EXT-X-VERSION:3
#EXT-X-INDEPENDENT-SEGMENTS
#EXT-X-STREAM-INF:BANDWIDTH=800000,RESOLUTION=640x360,SUBTITLES="subtitles"
index.m3u8
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subtitles",NAME="English",DEFAULT=YES,AUTOSELECT=YES,FORCED=NO,LANGUAGE="ENG",URI="index_vtt.m3u8"


  



  Now if I play the master.m3u8 file the subtitles are now out of sync and are about 1 sec to quick. I understand this is probably a setting I am missing through FFmpeg but really stuck on this and would appreciate any insight.

  



  Thanks

  



  More info.

  



  Here is a link to the direct .m3u8 this can be opened in Safari.

  



  https://983yqbz442.s3.amazonaws.com/hlstests/master.m3u8

  



  The generated vtt file is here.

  



  https://983yqbz442.s3.amazonaws.com/hlstests/subs-0.vtt

  



  If you look at the start of the .vtt file you will see this.

  



  WEBVTT

00:06.840 --> 00:10.320
once long ago in the deep blue below


  



  It should start at 00:06.840 but when playing the .m3u8 file in Safari you should see it starts at around 5 seconds not 6 about a second too early.

  


• ffmpeg video unable to play properly in most video players

  7 septembre 2022, par Lars

  I'm trying to set up a node.js app that allows me to download files from a web interface.
I'm using yt-dl to get the video and audio stream and ffmpeg to pipe those streams into an mp4. This works and returns a mp4 file.

  


  Now the only issue I have is that when I play the file through most video players, the video player is unable to seek, or skip through the song. I found somewhere deep down on a forum that means that that means the mp4 headers are not working but that is all I could find.
Here is my code, almost unchanged from this response on another thread.

  


  Can anyone provide a solution for this issue.

  


  ytdl.getInfo(link, options).then(info => {
        audioStream = ytdl.downloadFromInfo(info, { ...options, quality: 'highestaudio' });
        videoStream = ytdl.downloadFromInfo(info, { ...options, quality: 'highestvideo' });
        // create the ffmpeg process for muxing
        ffmpegProcess = cp.spawn(ffmpegPath, [
            // supress non-crucial messages
            '-loglevel', '8', '-hide_banner',
            // input audio and video by pipe
            '-i', 'pipe:3', '-i', 'pipe:4',
            // map audio and video correspondingly
            '-map', '0:a', '-map', '1:v',
            // no need to change the codec
            '-c', 'copy',
            // output mp4 and pipe
            '-f', 'matroska', 'pipe:5'
        ], {
            // no popup window for Windows users
            windowsHide: true,
            stdio: [
                // silence stdin/out, forward stderr,
                'inherit', 'inherit', 'inherit',
                // and pipe audio, video, output
                'pipe', 'pipe', 'pipe'
            ]
        });
        audioStream.pipe(ffmpegProcess.stdio[3]);
        videoStream.pipe(ffmpegProcess.stdio[4]);
        ffmpegProcess.stdio[5].pipe(result);
    });


  


• Cutting and fading ts segment with ffmpeg ?

  6 juillet 2017, par Matt W

  I’m trying to cut a ts segment and apply a fade from white at the initial point of the cut segment. This is used in a situation where I need to "crop" some material from the beginning of a video and apply a fade for a smoother entry. In my test, I am cutting an 8 second segment at the 5.5s mark to yield a 2.5 second segment that will fade from white over the first second.

  The cut command by itself works fine :

  ffmpeg  -i test.ts  -ss 5.5 -c:v libx264 -profile:v baseline -c:a aac -map 0 -mpegts_copyts 1  -preset ultrafast -f ssegment -initial_offset 5.5 -segment_format mpegts   ~/Desktop/cut%d.ts

  I’ve successfully used this fade filter syntax before :

  -filter:v fade=t=in:st=0:d=1:color=0xffffff

  But I can’t seem to make the whole thing work :

  ffmpeg  -i test.ts  -filter:v fade=t=in:st=5.5:d=1:color=0xffffff  -ss 5.5 -c:v libx264 -profile:v baseline -c:a aac -map 0 -mpegts_copyts 1  -preset ultrafast -f ssegment -initial_offset 5.5 -segment_format mpegts   ~/Desktop/cut%d.ts

  I’m getting the following error :

  x264 [error] : baseline profile doesn’t support 4:4:4

  [libx264 @ 0x7fd9db002400] Error setting profile baseline.

  [libx264 @ 0x7fd9db002400] Possible profiles : baseline main high high10
  high422 high444

  Error initializing output stream 0:1 — Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height

  [aac @ 0x7fd9db001200] Qavg : nan

  Conversion failed !

  My knowledge of ffmpeg just isn’t deep enough to figure out why this is happening. Any thoughts ?

  Thanks,
  Matt