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• Android ffmpeg - camera surface stutters withffmpeg pulling thumbnails and audio from the mpegts stream

  11 mai 2019, par badtrader

  Android 6 NDK 23. I have a camera device which pulls content from HDMI-in port (capture card).

  I am displaying this input on a SurfaceView. At the same time, I am using MediaRecorder to access this h264 data in a mpegts container. I stream the mpegts into a ffmpeg process via pipe. I need this ffmpeg process to continuously extract thumbnails and PCM audio from the most recently captured data.

  The problem is that after varying amount of time(depending on ffmpeg and mediarecorder settings) the surfaceview display begins to stutter very heavily. It will work for about 30 minutes without error before stuttering begins to become more and more noticeable.

  Memory and cpu usage seems constant, cpu temps are low. I am stumped to what is happening here. Have exhausted nearly all the different ffmpeg settings. Should I be trying mediacodec rather than ffmpeg ?

  Even weirder this code works fine depending on the input device to hdmi-in capture. Some devices input will begin to stutter after a while while others won’t.

• how to set nVidia video bitrate in a system service ?

  12 septembre 2021, par qycx

  I use an nvidia card for compression and decompression in a video conferencing software. The program uses ffmpeg. The program is a system service. Need to control the bit rate. But I found that I didn't control it. The setting code rate was 700k, and the actual value was 10M. What went wrong ?

  


  /* put sample parameters */
    pUnit->encV_var.c->bit_rate = bitrate;//400000;
    /* resolution must be a multiple of two */
    pUnit->encV_var.c->width = in_w;//352;
    pUnit->encV_var.c->height = in_h;//288;
    pUnit->encV_var.c->qmin=10;
    pUnit->encV_var.c->qmax=30;
    /* frames per second */
    AVRational t1={1,25};
    t1.den=fps;
    pUnit->encV_var.c->time_base = t1;//(AVRational){1, 25};
    AVRational t2={25,1};
    t2.num=fps;
    pUnit->encV_var.c->framerate = t2;//(AVRational){25, 1};

    /* emit one intra frame every ten frames
     * check frame pict_type before passing frame
     * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
     * then gop_size is ignored and the output of encoder
     * will always be I frame irrespective to gop_size
     */
    pUnit->encV_var.c->gop_size = 256;//10;
    pUnit->encV_var.c->max_b_frames = 0;//1;
    pUnit->encV_var.c->pix_fmt = AV_PIX_FMT_YUV420P;


  


• ffmpeg usb Web cam recording terminates randomly before set duration

  16 mars 2018, par pomptondrive

  The output of this script is just fine ; it’s pretty much what I want. But it seems to terminate randomly. My next step will be to try this on another computer to see if the issue persists.

  My configuration :
  Dell Precision laptop, m4400
  2x Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz
  Linux Mint 18.3 Sylvia
  Kernel : Linux 4.4.0-116-generic (x86_64)
  Card : NVIDIA G96GLM [Quadro FX 770M]
  ffmpeg version 2.8.11-0ubuntu0.16.04.1
  USB Camera-B4.09.24.1 Sony Playstation Eye

  And this is the script that I’m running - the last time it recorded for about three hours and forty-five minutes, before that it was about 55 minutes ; once it ran five and a half hours :

  #!/bin/bash  
  
  echo "This is a shell script to make a timelapse video."  
  
  ffmpeg \
  
  -f v4l2 -input_format yuyv422 -video_size 640x480 -framerate 5 -t 09:00:00 -i /dev/video0 \
  
  -vf "select=not(mod(n\,5)),setpts=N/(60*TB),fps=60, drawtext=fontfile=/usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf:text='%{localtime\:%T}':x=20:y=20:fontcolor=white" \
  
  -c:v libx264 -preset superfast -crf 23 -pix_fmt yuv422p -g 15 -keyint_min 15 \
  
  -f mpegts /media/dkm/OneTB/Video/Timelapse_$(date +%Y-%m-%d_%H.%M.%S).ts

  Any suggestions would be appreciated. Thanks !