Recherche avancée

Sur d’autres sites (8556)

• How to horizontal flip video captured from flutter front camera

  5 mai 2024, par JoyJoy

  Basically, I'm trying to flip video horizontally after capturing it from flutter front camera. So I start recording, stop recording, flip the video and pass it to another page. I'm fairly new and would appreciate any assistance as my code isn't working

  


  I've tried doing so using the new ffmpeg_kit flutter

  


• Live video streaming with Node js ,HTML5, MPEG-DASH, FFMPEG and IP camera/Raspberry Pi

  12 mai 2016, par sparks

  I am a programmer but i am very new in live video streaming concepts.I need help

  What i want to accomplish

  I want to develop an online live video streaming system.The scenario is i would have a device or number of devices(raspberry pi & camera only OR ip camera only ...not sure yet) to capture the video and stream the video live in real time remotely to my web app.Multiple clients can connect to the web app and watch the video live.The key things to note here, is that these devices should be wireless(able to connect to internet and live stream the content) and also i want to eliminate the idea of manually configuring the ip adrress to local WIFI router.So simply i turn on the device and it start streaming right away to the web app.

  Infrastructure, Platforms,Browsers, Streaming methods and formats

  In the beginning i just want to stream though chrome web browser(that’s all i care about).But in the future i would build android and IOS mobile apps.So long term i would expect to be Chrome and mobile(Android & IOS platforms)
  So based on my research i learned that the client should be HTML5, streaming method MPEG-DASH(In the future add HLS), the web app will be in Node Js.I also came across Dash.js for Html5.

  My understanding of streaming based on my research

  I also came across things like FFMPEG,Dash encoder and wowza which i am not clear about.Now correct me if i am wrong, my understanding is that FFMPEG get hold of the device/camera and the content(i am not sure the format of the content at this point)and format it(i am not sure what this means in simple english) and then Dash encoder picks up and re-format the content to MPEG-DASH format, which produces MPD and then Dash.js client uses MPD to display the video to the browser.

  QUESTIONS

  1. First correct me if i am wrong based on my understanding above or
     clarify for me.Also I am not sure of where the wowza streaming
     engine come into play. Do i even need it ?

  2. I am not sure of the devices to use between Raspberry pi with camera
     module/ Or IP Wifi camera by itself.I know with raspberry pi
     connected to internet you can set up all the necessary programs and
     stream the video to web app directly(not sure about quality and
     performance) but I am not sure about Wifi camera.Is it possible to
     connect to the wifi camera remotely from the web app programatically
     without opening the wifi router portal manually or i should stick
     with Raspbery Pi ?

  3. For raspberry Pi would i be able to connect it with high quality
     picture IP camera/web cam ? (The point here to get the best picture
     through raspbery Pi)

     My expectations

     Better performance and quality would be great.But i know live streaming is not easy so i am willing to compromise performance to a point but not quality.

  Thank you in advance, Anything will be appreciated.I know this is a lot so take your time :)

• FFmpeg camera encode h264 mp4 muxing atom avcC is too small

  18 mai 2016, par alijandro

  I tried to encode Android camera preview frame to h264, and mux to mp4 container.

  I can created mp4 file successfully. But the mp4 format seems corrupted.

  Use the ffprobe, I got the following error.

  $ ffprobe o.mp4
  
  [h264 @ 0x209fe50] non-existing PPS 0 referenced
  
  [h264 @ 0x209fe50] decode_slice_header error
  
  [h264 @ 0x209fe50] no frame!
  
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x209ea60] decoding for stream 0 failed
  
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x209ea60] Could not find codec parameters for stream 0 (Video: h264 (avc1 / 0x31637661), none, 568x320, 505 kb/s): unspecified pixel format

  Then I use mp4info tool to see if the information is correct. I found this.

  $ mp4info o.mp4 
  
  mp4info version 2.0.0
  
  o.mp4:
  
  ReadProperties: atom 'avcC' is too small; overrun at property: configurationVersion (src/mp4atom.cpp,386)
  
  mp4info: can't open o.mp4

  By hexdump the content of file, I got this

  $ xxd o.mp4 |grep -A 5 -B 5 avcC
  
  0039170: 6331 0000 0000 0000 0001 0000 0000 0000  c1..............
  
  0039180: 0000 0000 0000 0000 0000 0238 0140 0048  ...........8.@.H
  
  0039190: 0000 0048 0000 0000 0000 0001 0000 0000  ...H............
  
  00391a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
  
  00391b0: 0000 0000 0000 0000 0000 0000 0018 ffff  ................
  
  00391c0: 0000 0008 6176 6343 0000 0020 7374 7473  ....avcC... stts
  
  00391d0: 0000 0000 0000 0002 0000 004f 0000 0ea6  ...........O....
  
  00391e0: 0000 0001 0000 0000 0000 0058 7374 7373  ...........Xstss
  
  00391f0: 0000 0000 0000 0012 0000 0001 0000 0005  ................
  
  0039200: 0000 000a 0000 000f 0000 0014 0000 0019  ................
  
  0039210: 0000 001e 0000 0023 0000 0028 0000 0029  .......#...(...)

  If I didn’t add global header to AVCodecContext,

  if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER) {
  
      // oc_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
  
  }

  ffprobe can detect the format without error, also ffplay can play it. But the avcC atom still not correct. Other player cannot play it.

  Why the muxer didn’t write the correct avcC atom ?

  How can I solve it ?