Advanced search

On other websites (3217)

• How do I play back video on Android with custom playback speed?

  13 November 2015, by guidow

  I want to play back a video in Android, rendering it to a SurfaceTexture or something else that is usable as an OpenGL ES texture, but I need very precise control over the playback speed of the video to synchronize it to a stream of external events. These events will happen at a roughly predictable speed, but the exact speed will depend on many small mechanical details, influenced by many small factors, including the weather (and possibly even the phase of the moon...).

  The android.media.MediaPlayer class provided by android allows rendering to a SurfaceTexture (and the 360Videos app from the Oculus Mobile SDK successfully uses that feature), but unfortunately does not seem to allow altering the playback speed, at least not as far as I could tell from the documentation here.

  I have tried pausing and resuming the playback using pause() and start() respectively, to influence the playback speed, but that leads to extremely choppy and slow playback. My idea here was to make the video have a higher framerate than would ever be needed, and to then manually retard every frame until it actually needs to be shown. From the messages in the log, it looks to me like the MediaPlayer class will release various needed resources on pause and rerequest them on resume, which obviously kills performance if you do that once per frame.

  Another option I am looking at is ffmpeg. This one seems like it will do what i want, it doesn’t do any timings itself, it just decodes frames whenever I tell it to to a buffer, leaving me to use it however I want, whenever I want. The obvious drawback is that ffmpeg, at least on android, doesn’t do hardware decoding and probably won’t be able to decode 4K media in realtime.

  Yet another thing I was looking at was OpenMAX AL. Unfortunately, OpenMax AL is pretty hard to get into. I haven’t found any good beginner’s documentation yet, only some old, maybe outdated, READMEs as well as the interface specification from Khronos. The latter is a very long and cumbersome read, though, and I couldn’t yet even figure out if OpenMAX AL will even allow me to do my own timings...

• avformat/rtmpproto: send proper status for response to play command

  14 April 2022, by Marton Balint

  avformat/rtmpproto: send proper status for response to play command
  This fixes referencing the uninitialized filename variable.
  Fixes ticket #9711.
  Signed-off-by: Marton Balint <cus@passwd.hu>
  

  • [DH] libavformat/rtmpproto.c

• unable to play AES-CBC encrypted mpeg-ts stream on ffplay/ffmpeg

  22 May 2022, by AquilaCoder

  how to play a encrypted camera/live stream using ffplay/ffmpeg.

  


  the original stream was encrypted with tsduck scrambler plugin with aes-cbc option, we have tried with many players nothing works.

  


  

  • iv: 627CBD824E93CDC9DA754BAC72DB2205

  


  • cw: 6CC47461F65084AB5C5F90EDA1C2F9F0

  


  


  stream info

  


  

  


  sample stream