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• Getting "moov atom not found" error on linux but not windows/mac ?

  22 juin 2020, par flynnstone9

  Hey I have a tool I built that makes a video for me and it works locally on a mac / windows machine. I setup a digital ocean ubuntu server to host my app and the final video is giving a "moov atom not found" when running ffprobe output.mp4.

  


  The way the video is being created is thru this cmd :

  


  


  ffmpeg -i 1.mp4 -i 3.mp4 -filter_complex "[0:v][0:a][1:v][1:a]concat=n=2:v=1:a=1" output.mp4

  


  


  I'm using slightly different versions of ffmpeg on linux v Mac. I was running 4.3-2ubuntu0 18.04.sav0 on linux and ffmpeg version 4.2.2 on Mac.

  


  Is this a linux specific issue or is it something with the video container I'm missing ?

  


• Different results using qt-faststart and "ffmpeg -movflags +faststart"

  31 mars 2020, par Juan Ignacio Sánchez

  I have a set of videos generated by security cameras, which have the MOOV atom at the end of the file, like this :

  ftyp (32 bytes)
  
  free (8 bytes)
  
  mdat (29647845 bytes)
  
  moov (42054 bytes)

  I want to serve these files using progressive downloads (pseudo streaming) and it’s the only acceptable way to do it.

  Knowing that I tried to use tools like qt-faststart or directly ffmpeg with the corresponding flags (-movflags +faststart). Other detail is that I’m running this on a low profile machine, and FFmpeg takes like 6 8 seconds to finish (even using -c copy) and the other tool results to be much more efficient since it only moves some bytes, taking less than a second to finish. The thing here is that qt-faststart produces a video that can’t be pseudo streamed but ffmpeg does it. Here are some comparisons :

  ffmpeg :

  ftyp (32 bytes)
  
  moov (42422 bytes)
  
  free (8 bytes)
  
  mdat (29647845 bytes)

  qt-faststart :

  ftyp (32 bytes)
  
  moov (42054 bytes)
  
  free (8 bytes)
  
  mdat (29647845 bytes)

  As you can see, FFmpeg adds some extra bytes on the MOOV atom, can anyone point me in some research direction ? Thank you all.

• ffmpeg - how to "set" continuity counters when generating .ts segments for HLS live streaming ?

  17 mars 2021, par Rob

  Say I have a batch of 40 JPEGs that represent 2 FPS video, and I want to generate a m3u8 playlist + h264 ts segments for an HLS live stream - so I do something like this :

  



  ffmpeg -y -framerate 2 -start_number 0 -i /frames/frame_%d.jpg -frames:v 40 \
       -c:v libx264 -crf 21 -preset veryfast -g 2 \
       -f hls -hls_time 4 -hls_list_size 5 -hls_flags omit_endlist \
       -start_number 0 -segment_start_number 0 -segment_list_flags +live video/stream.m3u8


  



  and it gives me a playlist like this :

  



  #EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:4
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:4.000000,
stream0.ts
#EXTINF:4.000000,
stream1.ts
#EXTINF:4.000000,
stream2.ts
#EXTINF:4.000000,
stream3.ts
#EXTINF:4.000000,
stream4.ts


  



  Great. Now say I get another batch of 40 JPEGS that follows the first, and I want to drop stream0.ts (the first 4 seconds / 8 frames of the original 40 JPEGS), and add a new stream5.ts (the first 4 seconds / 8 frames of the next 40 JPEGS) :

  



  ffmpeg -y -framerate 2 -start_number 8 -i /frames/frame_%d.jpg -frames:v 40 \
       -c:v libx264 -crf 21 -preset veryfast -g 2 \
       -f hls -hls_time 4 -hls_list_size 5 -hls_flags omit_endlist \
       -start_number 1 -segment_start_number 1 -segment_list_flags live video/stream.m3u8


  



  Then I get this :

  



  #EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:4
#EXT-X-MEDIA-SEQUENCE:1
#EXTINF:4.000000,
stream1.ts
#EXTINF:4.000000,
stream2.ts
#EXTINF:4.000000,
stream3.ts
#EXTINF:4.000000,
stream4.ts
#EXTINF:4.000000,
stream5.ts


  



  Great. But when I try to play the HLS stream with something like HLS.js or video.js, my video stream stalls out. And when I inspect the stream with TSLemurs HLS Checker tool, it warns me about "CC" errors, which I assume means continuity counter errors :

  



  

  



  How can I fix these continuity counter errors ? Is there anyway to do this at all with ffmpeg ?