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• ffplay got extra delay seconds than ffmpeg

  14 juillet 2017, par jiandingzhe

  I am working on low-latency video streaming. When I was making some tests, I noticed ffplay got much extra latency than ffmpeg, though they are the same software package.

  The video is encoded in H.264, size 320x240, 15fps. The stream is packed in FLV format, uploading and receiving are both done via RTMP. ffmpeg is called fairly simple :

  $ ffmpeg -i 'rtmp://my.path.to/my_rtmp_stream' -f sdl window_title

  And ffplay is also called in simple way :

  $ ffplay 'rtmp://my.path.to/my_rtmp_stream'

  The ffmpeg would starts to show the video instantly, and plays the video with minor latency (<0.5s) ; while ffplay would start the video in 5 seconds, and introduce a delay of 8 seconds.

  I further optimized the ffplay way, by minimizing probe size :

  $ ffplay -probesize 32 'rtmp://my.path.to/my_rtmp_stream'

  In this way, the startup goes quickly, but the delay is still 3 seconds.

  Why they behave so differently ?

• avformat/dashenc : Simplify getting format string

  6 septembre 2023, par Andreas Rheinhardt

  avformat/dashenc : Simplify getting format string
  A switch is simpler than a lookup over a table with
  
  three entries, only two of which can happen at all.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavformat/dashenc.c

• Adding and reading timestamp to an image using ffmpeg

  17 novembre 2013, par Andrew Simpson

  I am not sure if i should be posting this type of question here and I have not uploaded any code as I am talking about concepts.

  I have a C# winform desktop application.

  It produces a flow of jpegs that have derived from a motion detection algorithm.

  I use the Graphics.DrawText to add a time stamp directly onto the image when it was created.

  I then use ffmpeg to produce a ogg video file.

  When i play the video file back I obviously see the image with the time stamp.

  What I would like to be able to do is read in code the time stamp that is on every image. I had thought of using some sort of OCR to do this but it seems overkill to me. I also have considered creating a separate text file that acts as the 'index' of the video file. But then I have to manage the 'transaction' between 2 different files.

  Corruption to the text file could happen.

  I would like a way of encapsulating this information to be easily read by my C# code.

  Has anyone had any experience doing this ? Any recommendations pls ?

  Many Thanks