Recherche avancée

Sur d’autres sites (5958)

• Playing H.264 video in an application through ffmpeg using DXVA2 acceleration

  28 avril 2012, par cloudraven

  I am trying to output H.264 video in a Windows application. I am moderately familiar with FFMPEG and I have been successful at getting it to play H.264 in a SDL window without a problem. Still, I would really benefit from using Hardware Acceleration (probably through DXVA2)

  I am reading raw H264 video, no container, no audio ... just raw video (and no B-frames, just I and P). Also, I know that all the systems that will use this applications have Nvidia GPUs supporting at least VP3.
  Given that set of assumptions I was hoping to cut some corners, make it simple instead of general, just have it working for my particular scenario.

  So far I know that I need to set the hardware acceleration in the codec context by filling the hwaccel member through a call to ff_find_hwaccel. My plan is to look at Media Player Classic Home Cinema which does a pretty good job at supporting DXVA2 using FFMPEG when decoding H.264. However, the code is quite large and I am not exactly sure where to look. I can find the place where ff_find_hwaccel is called in h264.c, but I was wondering where else should I be looking at.

  More specifically, I would like to know what is the minimum set of steps that I have to code to get DXVA2 through FFMPEG working ?

  EDIT : I am open to look at VLC or anything else if someone knows where I can find the "important" piece of code that does the trick. I just mentioned MPC-HC because I think it is the easiest to get to compile in Windows.

• How does sunshine capture and stream the desktop

  24 juin 2024, par user16235056

  I am looking to understand the Sunshine project by Loki which works with moonlight to stream a desktop with very low latency based on Nvidia's GameStream.

  


  I looked at the source code on GitHub, but couldn't figure out how the screen is captured and the stream is converted to an RTSP packet.
I think they use ffmpeg to capture the screen.

  


  I did find the RTSP packet definition here

  


  Could someone explain how this works ?
I am trying to understand this on a low level, since I want to implement a similar program as part of a project later(probably in C++ itself).

  


  I don't have much experience here, but am looking to get my hands dirty ! :)

  


  Hope my question is clear and any help to understand this or other resources I could take a look at would be greatly appreciated.

  


• Fully utilising hardware acceleration for ffmpeg cropping

  22 avril 2020, par user2384705

  I'm trying to crop several sections of one video (a screen recording), and am hoping to fully utilise NVIDIA graphics acceleration for the process. My understanding is that the cuvid codecs have crop capabilities built in, but when I run the video through ffmpeg, the CPU gets pegged. I believe the decoding and re-encoding is happening on the GPU, but I believe I could get better performance if everything took place on the GPU. What am I missing ? Thanks !

  



  ffmpeg -hwaccel cuda -c:v hevc_cuvid -i "foo.mp4" -filter_complex "[0:v]crop=1080:350:0:0[out1];[0:v]crop=1080:350:0:350[out2];[0:v]crop=1080:350:0:700[out3];[0:v]crop=1080:380:0:1080[out4];[0:v]crop=1080:380:0:1460[out5];[0:v]crop=1080:380:0:1835[out6];[0:v]crop=1080:380:0:2210[out7];[0:v]crop=1080:380:0:2590[out8]" -c:v hevc_nvenc -map [out1] out1.mp4 -map [out2] out2.mp4 -map [out3] out3.mp4 -map [out4] out4.mp4 -map [out5] out5.mp4 -map [out6] out6.mp4 -map [out7] out7.mp4 -map [out8] out8.mp4