Newest 'ffmpeg' Questions - Stack Overflow

Les articles publiés sur le site

• FFmpeg prebuilt binaries for Android [on hold]

  7 mai 2018, par user1049280

  I'm using this project to build FFmpeg: https://github.com/WritingMinds/ffmpeg-android. All other building guides didn't work for me.

  When I try to concat videos - some videos are being concated well and some are not. However when I use the same ffmpeg-command on my PC - all videos are being concated without any troubles. So I guess the problem is with my ffmpeg binary. Where can I download pre-built fresh ffmpeg binary (ffmpeg.so) to test if it's the real problem?

  Api level 16+, cpu arm/x86

• Video Filters like Instagram and save in SDCARD

  7 mai 2018, par Harsh Bhavsar

  Color Channel Mixer (Info.) https://ffmpeg.org/ffmpeg-filters.html#colorchannelmixer

  I am trying to creating video filters using FFMpeg and OpenCV just like Instagram Video filters. So if I want to create Sepia Effect Then I have to use color channel mixer for that with RGBA values ex. colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131 (This code for Sepia Effect) Now I want to create more effects like Instagram. So need different color channel mixers for that How to create them?

  Ref. -- https://github.com/krazykira/VidEffects/wiki/Permanent-video-effects

  I got only 2 filters

  Sepia colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131

  Grayscale colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3

  I need more filters.

  private void initVideoRecorder(String path) { 
  try { 
  filter = new F FmpegFrameFilter("colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131", VIDEO_GRABBER.getImageWidth(), VIDEO_GRABBER.getImageHeight()); 
  videoRecorder = FFmpegFrameRecorder.createDefault(path, VIDEO_GRABBER.getImageWidth(), VIDEO_GRABBER.getImageHeight()); videoRecorder.start(); 
  } 
  catch (FrameRecorder.Exception e) { 
  e.printStackTrace(); 
  }
   }
  

• avformat_open_input() fails to open url

  7 mai 2018, par subha

  I tried to open URL using avformat_open_input API function. Initially, I got a warning like,

  Using network protocols without global network initialization. Please use avformat_network_init(), this will become mandatory later.

  After initializing avformat_network_init(), I am getting a negative return value for avformat_open_input() function call.

  INPUT URL: https://mnmedias.api.telequebec.tv/m3u8/29880.m3u8

  Can anyone please help me to find the issue?

• ffmpeg : Turning images/audio into video with ffmpeg

  7 mai 2018, par melanie93

  I am using ffmpeg to turn a sequence of images (img001.png, img002.png, and so on) into a video (output.mp4) using the following command:

  ffmpeg -r 1/5 -i img%03d.png  -r 25 -qscale:v 2 -shortest -codec:a copy output.mp4
  

  The result is a video that displays every input image for five (5) seconds.

  1. Is it possible to have ffmpeg parse the filename paths and timings from a file? I tried the slideshow tutorial on the official ffmpeg website but the output displayed only the last image, briefly, at the end of the video.
  2. Is it possible to bundle audio files with those settings?

  For example:

  file 'image001.png'
  file 'sound001.wav'
  duration 5
  file 'image002.png'
  file 'sound002.wav'
  duration 2
  file 'image003.png'
  file 'sound003.wav'
  duration 3
  

  Image001 is displayed for five(5) seconds while sound001 is being played back and so on.

• FFMPEG spends 6 seconds to create first video frame after i feed first image to it ?

  7 mai 2018, par Chen Yang

  I use ffmpeg to convert a sequence of images to a video, i find that after i feed first image to it and almost 6 seconds later ffmpeg output first video frame to me.

  I use command as follow:

  ffmpeg -f image2pipe -r 100 -i pipe:0 -f flv -r 100 -tune zerolatency -preset ultrafast -bufsize 2M -codec:v libx264 -codec:a libmp3lame -bf 0 -muxdelay 0.001 -s 478x850 -b:v 2M pipe:1
  

  Is my options is right?

  Or others led to this result?

  How can i get first video frame quickly once i feed the first frame?