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• How to use AVPacket as local variable(or said temporary variable)

  27 août 2020, par pango

  my program receive a aac audio stream from net,and use ffmpeg to decode the stream,so I must pack the stream data to a AVPacket struct,I use a local variable to do this, the code like below :

  


  bool OnRecvAACStream(const char * audioDataPtr,int audioDataSize,int64_t tBeg,int64_t tDura)
{
    AVPacket pkt_tmp;   // local varible
    av_init_packet(&pkt_tmp);
    pkt_tmp.data = audioDataPtr;
    pkt_tmp.size = audioDataSize;
    pkt_tmp.pts = tBeg;
    pkt_tmp.duration = tDura;
    
    if (avcodec_send_packet(m_codec_ctx, &pkt_tmp) < 0)
    {
        assert(false);
        return false;
    }
    while (avcodec_receive_frame(m_codec_ctx, m_dec_frame) == 0)
    {
       // read out dec audio data
       ...
    }
    
    retur true;
}



  


  I just use av_init_packet() to init the local varible, av_packet_unref() and av_packet_free() are not called,so is it valid ? is there any memory leak problem ?

  


• How do i convert (pulled from device) individual frames to a video file on linux and push it back to the same directory

  31 mars 2012, par RiASh

  First of all i have frames on my SD Card and frames are there in separate folders for each video..

  what i want to do is that i just want to make REALLY simple Java application for user(just a button to make video files) on the linux OS whose ActionEvent Handler pulls in all the individual frames and converts it to a video..deletes all the frames from the SD Card and then pushes the video file back to the same directory of SD Card..

  i wanted to know how do i pack frames into a video file on Linux(Ubuntu)..i think there is something ffmpeg but i dont know much..
  Can someone provide a example..please .. the images are named as image0000 to image9999

  and is it possible to create video file from those frames AND EVEN having sound in them using ffmpeg..?

  Can adb pull and push files without SD Card being connected..

  And finally wanted to know how do i run shell commands like adb pull, push, ffmpeg from JAVA..

  THERE ARE i think 4 QUESTIONS here but all related so i thought better ask them together..Thanks in advance ! :)

• Ghosting in colour channels

  24 mai 2024, par Blikpils

  This seems like a very specific question so i hope there is someone who can help me out.
Within FFMPEG i am trying to add (channel pack) 3 different grayscale videos in RGB within a webm or mp4 video. I got it to work to a degree via Merge planes.
This is what i tried :

  


  ffmpeg -y -i video1.webm -i video2.webm -i video3.webm -filter_complex "[0:v]format=gray[r]; [1:v]format=gray[g]; [2:v]format=gray[b]; [g][b][r]mergeplanes=0x001020:format=gbrp" -pix_fmt yuv420p -t 00:00:03 output.webm


  


  This is the result :


  


  As you see the 9 is visible in the red and blue channel and so are each of the other channels

  


  I have tried just extracting a single channel in a video, change the compression change the format change the color space, make sure that its all linear but each seem to have the limitation of some smearing/artifacts between the other channels.

  


  Is it at all possible to add different grayscale streams in the color channels without any artifacts and if so in which direction should i look ?

  


  Any help would be greatly appreciated !