Recherche avancée

Sur d’autres sites (10263)

• Webpage with several IP-cameras' streams

  28 mars 2013, par JustLogin

  I have some live RTSP streams from IP-cameras with H.264 video and g-729 sound codecs. I need to display them on a webpage, which could be opened in any popular browser in Windows, Linux and Mac. Also, there must be an option to record and to save to user's PC a video from any stream to flv file , using Start/Stop recording button.
  The problem is, I don't know what technologies to choose : all solutions which I came up with, have several problems.

  The first variant is to transcode stream to RTMP with FFmpeg, changing audio codec to MP3.That way it can be played with a small Flash app. It works, but I don't know, how to save video because the .flv-writing library requires Bitmaps and ByteArray sound data chunks as input. It's not a problem to get images from Video class, but I have no idea about sound : SoundMixer class couldn't recieve any data from Video (or NetStream) with it's computeSpectrum method. So , impossibility of writing sound to .flv is the only problem of this solution.

  Another variant is to use java applet, based on Xuggler library. It work's fine, but the library is VERY huge, and "applet's" size is near 40mb !

  I also tryed Silverlight (it's problem is, it isn't popular, so everyone have to download it for 1 app only) and HTML5 (which does not allow capturing sound from incoming live stream, like Flash), but they give no solutions too. So I don't know, how to realize this project, can you give me any idea please ?

• Ffmpeg won't cut excerpt of video correctly

  6 mai 2022, par user17661390

  I am using a DOS batch to automate and cut excerpts of various high definition videos (mkv's with more than 1GB each).
The script is very convenient and runs fast and fine, but Ffmpeg is not doing its job correctly (it seems Murphy's law is inexorably enthralled into technology, things never come easy, which is why I love and hate it).

  


  Anyway, to cut a long story short, each time the batch job runs, a code like below is executed. Note the path to ffmpeg is specified, since it's not in the PATH environment variable, so the below form works always.

  


  "C:\ffmpeg\bin\ffmpeg.exe" -y -i "D:\S01\SATC - S01E03 - Bay of Married Pigs.mkv" -ss 00:18:05 -to 00:19:15 -codec copy "002-SATC - S01E03 - Bay of Married Pigs-00_18_05-00_19_15.mp4"


  


  The problem is that the first 6 seconds or so of the resulting video has no video, only audio with a frozen image that only starts to move after about 6 seconds, which is a huge defect, not to mention very annoying (a big let down, after all my meticulous scripting work :(). And this happens for most of the files, except a few ones.

  


  Even though this is copying and changing the format from mkv to mp4, per another thread on this site (https://askubuntu.com/questions/396883/how-to-simply-convert-video-files-i-e-mkv-to-mp4), this is not re-encoding, so this is not the issue. Actually, the same problem occurs even if I don't change the format from mkv to mp4.

  


  Even though I foresee a "there's no way to fix this", let me ask : is there a way to fix this ? Hopefully there is a way.

  


• Merge multiple videos without using command line-FFMPEG [on hold]

  19 avril 2018, par Valgrind1691

  I am developing an android application which has video processing features involved.
  For video processing I have been working with FFMPEG library. As for now ffmpeg is directly being consumed by android and the processing is being done by
  framing commands and executing it using ffmpeg executable running in the background.
  This approach has two drawbacks :

  1) Video Processing time is huge even after trying ultrafast and other options to reduce processing

  2) APK size is large

  For solving two major problems we seek c/c++ native implementation for video processing by using the ffmpeg code.
  The C/C++ code will be cross compiled for android and iOS platforms and provided to mobile platform as a library (.so file in case of Android)
  The .so file will have

  1. jni for communication between Android(java) and c/c+

  2. c++ code for functionality implementation of video processing. All
     the video processing i.e scaling, transcoding, merging,
     cropping etc will be done by C/C++ code.

  I have a query around the C/C++ side , how can we use ffmpeg not to process using command line rather we can define algorithms for the process. Transcoding, muxing etc I have achieved looking into the examples of ffmpeg but I am still unable to figure out algorithm for merging of multiple(upto 6) videos in a single video file.
  I have looked into every question posted in this context and none helped.
  Can someone help me merge videos using source code of ffmpeg without using command line ? Any help is appreciated.