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• Create video file by mixing video and audio byte arrays FFmpeg & C++

  20 January 2021, by Sergey Zinovev

  I capture audio and video.

  


  Video is captured by using Desktop Duplication API and, as a result, I get Textures 2D.
These Textures 2D are char arrays.

  


  m_immediateContext->CopyResource(currTexture, m_acquiredDesktopImage.Get());&#xA;&#xA;D3D11_MAPPED_SUBRESOURCE* resource = new D3D11_MAPPED_SUBRESOURCE;&#xA;UINT subresource = D3D11CalcSubresource(0, 0, 0);&#xA;&#xA;m_immediateContext->Map(currTexture, subresource, D3D11_MAP_READ_WRITE, 0, resource);&#xA;&#xA;uchar * buffer = new uchar[(m_desc.Height * m_desc.Width * 4)];&#xA;const uchar * mappedData = static_cast<uchar>(resource->pData);&#xA;memcpy(buffer, mappedData, m_desc.Height * m_desc.Width * 4);&#xA;</uchar>

  


  Then the Textures 2D convert in cv::Mat and write Video using OpenCV.

  


  Audio captured by using WASAPI and, as a result, I get samples.

  


  BYTE * buffer = new BYTE[(numFramesAvailable * pwfx->nBlockAlign)];
memcpy(buffer, pData, numFramesAvailable * pwfx->nBlockAlign);


  


  These samples are byte arrays then write in WAV file.

  


  As a result, I get two files - video and audio, which merged by using FFmpeg.

  


  I want to skip the creation of video and audio files and promptly create one file compose of two strims (video and audio) from raw data.

  


  In order to make it I need help with FFmpeg code.
Specifically, in a way of creating and setting the correct output context and output streams, and how to encode raw data.

  


  I've already learned doc/examples FFmpeg, but still can't make the working code. So, I really need your help guys.

  


• video previews on video just like xvideos

  28 June 2020, by zjose

  Video previews are usually images that rotate every so often in a small video. But since that format is old and boring, I would like to be able to create them with ffmpeg just like xvideos does.

  


  example (you don't have to worry) -> https://img-l3.xvideos-cdn.com/videos/videopreview/dc/8b/0f/dc8b0facd2879bad18f93dff44d1de2c_169.mp4

  


  They are in size: 362x204.
They last: 5 seconds.

  


  and they are several fragments in video, and not in images.

  


  How could I do it using ffmpeg?

  


• Use ffmpeg to add video watermark. But the second video added does not move, only static images can be seen

  19 February 2021, by cantoe

  Use ffmpeg to add video watermark.
But the second video added does not move, only static images can be seen.
Does anyone know what's going on?
Can you help me?

  


  ffmpeg -i sucai/s3o.ts  -i sucai/s2o.ts -i sucai/s4o.ts  -filter_complex "overlay=x=main_w/2-overlay_w/2:y=main_h/2-overlay_h/2:enable='between(t,1,3)',overlay=x=main_w/2-overlay_w/2:y=main_h/2-overlay_h/2:enable='between(t,8,10)'" -vcodec libx265 sucai/s34.mp4 -y