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• Using ffprobe in Android

  13 décembre 2017, par Sirojiddin Komolov

  I'm using Ffmpeg via this link and works fine, but it failures when I try to use "ffprobe" commands to get video info. For example, currently I'm using these lines of codes :

  ffmpeg.execute("ffprobe -v quiet -print_format json -show_format -show_streams some.mp4",
   new ExecuteBinaryResponseHandler() { ... });
  

  Above code lines don't work and ExecuteBinaryResponseHandler's onFailure method get called. But reason message of onFailure is empty. I don't know what I'm doing wrong. Any idea?

• why changed volume after merge ? in ffmpeg. How to turn off change volume [duplicate]

  13 décembre 2017, par Нодирбек Раззоков

  This question already has an answer here:

  • FFMPEG amix filter volume issue with inputs of different duration 4 answers

  why changed volume after the merge? in FFmpeg.

  How to turn off change volume. I need an original volume of music after the merge.

  please check my command

  ffmpeg -i song.mp3 -i mix.mp3 -filter_complex \"[1]adelay=10000|10000[b];[0][b]amix=2,volume='1-max(0.25*(t-13),0)'\" -ac 2 -i cover.jpg -c copy -id3v2_version 3 -codec:a libmp3lame -q:a 4 -b:a 128k -y output.mp3
  

• Unable to receive RTP payload type 96 without an SDP file describing it

  13 décembre 2017, par BanaSong

  How can I use SDP files in iOS FFmpeg? I've tried this:

  char *url = "rtp://127.0.0.1:1234"; 
  AVFormatContext *oc = NULL; 
  avformat_open_input(&oc, url, NULL , NULL); 
  

  But I get the following error:

  [rtp @ 028568e0] Unable to receive RTP payload type 96 without an SDP file describing it.

• FFMPEG : Creating a video, which has the maximum value per pixel of n-input videos

  13 décembre 2017, par LighthouseZGZ

  Imagine a collection of short videos, each one showing a shooting star.

  I would like to get a composite video of all shooting stars. Not in sequence, at the same time. The (x,y) pixel of the nth frame in the output video should have the maximum value for that (x,y) pixel of the same frame in all the videos.

  I know how to do that using images and imagemagick:

  magick *.bmp -evaluate-sequence max output.bmp

  I need something similar for video. Frame by frame.

  Any help would be appreciated. Thanks.

• No data written to stdin or stderr from ffmpeg

  13 décembre 2017, par Mikkel Bachmann

  I have a dummy client that is suppose to simulate a video recorder, on this client i want to simulate a video stream; I have gotten so far that i can create a video from bitmap images that i create in code.

  The dummy client is a nodejs application running on an Raspberry Pi 3 with the latest version of raspian lite.

  In order to use the video I have created, I need to get ffmpeg to dump the video to pipe:1. The problem is that I need the -f rawvideo as a input parameter, else ffmpeg can't understand my video, but when i have that parameter set ffmpeg refuses to write anything to stdio

  ffmpeg is running with these parameters

  ffmpeg -r 15 -f rawvideo -s 3840x2160 -pixel_format rgba -i pipe:0 -r 15 -vcodec h264 pipe:1

  Can anybody help with a solution to my problem?

  --Edit

  Maybe i sould explain a bit more. The system i am creating is to be set up in a way, where instead of my stream server ask the video recorder for a video stream, it will be the recorder that tells the server that there is a stream.