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• Streaming raw h264 video from Raspberry PI to server for capture and viewing [closed]

  24 juin 2024, par tbullers

  This is really an optimization question - I have been able to stream h264 from a raspberry pi 5 to a linux system and capture the streams and save them to .mp4 files.

  


  But I intend to run the video capture and sending on a battery powered Pi Zero 2 W and want to use the least amount of power to maximize battery life and still providing good video quality.

  


  I've explored many different configuration settings but am getting lost in all the options.

  


  This is what I run on the pi :

  


  rpicam-vid -t 30s --framerate 30 --hdr --inline --listen -o tcp://0.0.0.0:5000


  


  I retrieve this video from the more powerful Ubuntu server with :

  


  ffmpeg -r 30 -i tcp://ralph:5000 -vcodec copy video_out103.mp4


  


  It generally works but I receive lots of errors on the server side like this :

  


  [mp4 @ 0x5f9aab5d0800] pts has no valuee= 975.4kbits/s speed=1.19x
Last message repeated 15 times
[mp4 @ 0x5f9aab5d0800] pts has no valuee=1035.3kbits/s speed=1.19x
Last message repeated 15 times
[mp4 @ 0x5f9aab5d0800] pts has no valuee=1014.8kbits/s speed=1.18x
Last message repeated 9 times
[mp4 @ 0x5f9aab5d0800] pts has no valuee=1001.1kbits/s speed=1.17x
Last message repeated 7 times
[mp4 @ 0x5f9aab5d0800] pts has no value
Last message repeated 1 times
[out#0/mp4 @ 0x5f9aab5ad5c0] video:3546kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead : 0.120360%
size= 3550kB time=00:00:27.50 bitrate=1057.5kbits/s speed=1.18x

  


  Any suggestions on how to correct these errors ?

  


  Also any suggestions on how to make the video capture side more efficient ? Should I use a different codec ? (yuv instead of h264 ?) Would using UDP decrease overhead ? Can I improve video quality with the mode or hdr options ? What does denoise do ?

  


  With all the options available with these tools I think it's unlikely that I have a well thought out approach to capture and streaming. I'm hoping that people who are more familiar with this space might be able to provide some suggestions.

  


  Thank you !

  


  -tom

  


• dts to m4a (aac) ffmpeg to qaac output issue

  10 avril 2014, par user8979

  Looking to encode 2 dts 5.1 audio sources (Sonic Landscape and The Digital Experience) to m4a (aac) 5.1 with qaac 2.35. Input piped to qaac using :

  ffmpeg -report -loglevel verbose -i "input.file" -vn -f wav -codec:a pcm_f32le - | qaac --cvbr 160 --quality 2 --rate=keep --ignorelength --no-delay - -o "output.m4a"

  • Sonic Landscape duration : 18.848s, qaac output duration : 18.859s

    • output .m4a duration mismatch
    • mediainfo reports output is 2ch while mediatab and ffmpeg report output is 5.1ch (lfe)
      
      

  • The Digital Experience duration : 32.875s, qaac output duration : 32.875s

    • mediainfo reports output is 2ch while mediatab and ffmpeg report output is 5.1ch (lfe)
      
      

  1. what caused the duration mismatch in the first one ? how can it be fixed ?
  2. is the output 2ch or 5.1ch ?
     
     • if it is 2ch, what qaac option(s) leave the channels in output same as input ?
     • if the output is 5.1ch, does qaac then always preserve channels unless explicitly told otherwise ?

• Capturing two video sources into a single MKV with Java

  7 avril 2014, par Luke

  Problem

  I need my application to let the user record its screen, web cam and audio simultaneously. I have been able to accomplish this using a mix of Sarxos, Robot and Xuggler. But the various output files have different timing and are out of sync when played back synchronously.

  This is not hard to imagine given that the capturing is started asynchronously.

  ---

  Possible solution

  I'm thinking that capturing the various sources into an MKV file with multiple video tracks might be a better solution. Some timer could poll the sources in parallel at regular intervals. Or at the very least blank audio/video-data could be inserted before any late capture start, to keep the video's and audio in sync.

  JMF would allow for very easy capturing, but doesn't seem to support MKV and is supposedly very outdated. I question whether it will work properly on current PCs and Macs. The FMJ Project might be an alternative, but MKV-support seems to be restricted to FFMPEG. This would defeat the purpose, as any kind of muxing or re-encoding afterwards would still leave the videos and audio out of sync. I could use Xuggler, as I do now, but it's impossible to find any relevant documentation or hints.

  Still, recording into a single file seems to make sense in order to get the timing straight.

  ---

  My question

  Is anyone aware of a Java solution that would allow for encoding two video sources and an audio source into a single MKV container ?