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• How to stream (udp) a series of tiff images using ffmpeg

  20 avril 2020, par Michael Carey

  I have written a program that receives images from a camera and then packages the images into a basic tiff format. Then I broadcast the tiff image out on UDP on localhost port 8999.

  



  I then run ffmpeg (on Windows 10) from a command line as follows :

  



  ffmpeg -i udp://127.0.0.1:8999 -preset ultrafast -vcodec libx264 -tune zerolatency -f mpegts udp://127.0.0.1:9000


  



  The idea with the above command is to receive the tiff images from my program, convert them into mpeg, and to then rebroadcast it out on a different port. (once I prove this, I may clip and compress the image as well)

  



  Finally, I open another command window and run ffPlay as follows so that I may see my output :

  



  ffplay udp://127.0.0.1:9000


  



  My output from the ffmpeg command is here :

  



  ffmpeg -i udp://127.0.0.1:8999 -preset ultrafast -vcodec libx264 -tune zerolatency -f mpegts udp://127.0.0.1:9000
ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 9.2.1 (GCC) 20200122
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
[tiff_pipe @ 0000021ebbe2d280] Could not find codec parameters for stream 0 (Video: tiff, none): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, tiff_pipe, from 'udp://127.0.0.1:8999':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: tiff, none, 25 tbr, 25 tbn, 25 tbc
Output #0, mpegts, to 'udp://127.0.0.1:9000':
Output file #0 does not contain any stream


  


• Feeding a series of images to ffmpeg as each image is created [closed]

  5 février 2013, par Mark Schneider

  I'm trying to use ffmpeg to build a 1280x720 slide-show from a sequence of pictures and videos, but I have concerns about potential disk I/O bottleneck.

  I expect a typical slide-show to have about 50 pictures and 2-3 videos (10-15 seconds each at 30 fps). I would like to show each picture for 3-4 seconds (possibly with a
  Ken Burns effect) with a smooth 2 second crossfade between each set of pictures (or for pictures adjacent to videos - between the picture and the first/last frame of the video).

  Given about 50 pictures, the crossfades alone would amount to about 3,000 images (50 transitions x 2 secs/transition x 30 fps). And I suppose if I implement a Ken Burns effect during each picture's 3-4 second showing, I'd have to provide ffmpeg with individual images for each of those frames. (I'm writing a script in Ruby that will pull a list of images from a database and in turn call ImageMagick to create the individual images for each frame. As I understand it, the RMagick library interfaces with ImageMagick such that the output images come back as in-memory objects without needing to write to disk. FWIW, I'm developing in Windows 8 and will deploy to Heroku.)

  All of the slideshow examples I've found online feed ffmpeg a set of images which have already been created. However, in an effort to avoid waiting on considerable disk I/O, I'd like to feed each image to ffmpeg as the image is created rather than create them all in advance.

  Is there a way to send each image file to ffmpeg on the fly as the file is created in memory ?

• FFmpeg returns negative PTS and DTS for first non key frame

  18 février 2020, par Olga Pshenichnikova

  We have some envelope of FFmpeg, that processes the video.
  The tree first frames of video are : B -> B -> I as shown below :

  

  PTS and DTS returns negative for first frame :

  

  We have some code, that skips the frames that are below some timepoint (0 for first frame).
  Is it possible to ask FFmpeg to start from first frame and not from first I frame ?