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• ffmpeg : sws_scale not able to convert image from YUV to RGB

  1er octobre 2020, par Abhinav Singh

  I m trying to convert my image from YUV420P to RGB24 below is my code for extracting the frame and decoding it,

  


  frame extracting

  


  while(av_read_frame(avc,avpacket) == 0){
        if(avpacket->stream_index == videoStream){
            int res = avcodec_send_packet(avctx,avpacket);
            if(res == AVERROR(EAGAIN)){
                continue;
            }
            else if(res<0){
                std::cout<<"error reading packet\n";
                break;
            }
            else{
                AVFrame* avframeRGB = av_frame_alloc();
                res = avcodec_receive_frame(avctx,avframeRGB);
                if(res == AVERROR(EAGAIN)){
                    continue;
                }
                else if(res<0){
                    std::cout<<"Error reading frame";
                    break;
                }
                else{
                    ++i;
                    convertImage(&avframeRGB,avctx->pix_fmt,AV_PIX_FMT_RGB24);
                    displayImage(avframeRGB);
                }
            }
        }
    }


  


  Function convertImage

  


  void convertImage(AVFrame** frame, AVPixelFormat srcFmt, AVPixelFormat destFmt){
    AVFrame* tframe = *frame;
    struct SwsContext* swscaler = sws_getContext(tframe->width,tframe->height,srcFmt,tframe->width,tframe->height,destFmt, SWS_BILINEAR,NULL,NULL,NULL);
    AVFrame* tmp = av_frame_alloc();
    tmp->width = tframe->width;
    tmp->height = tframe->height;
    tmp->format = destFmt;
    if(av_frame_get_buffer(tmp,32) !=0)
        return;
    int res = sws_scale(swscaler,(uint8_t const * const*)tframe->data,tframe->linesize,0,tframe->height,tmp->data,tmp->linesize);
    *frame = tmp;
}


  


  Before calling convertImage
avframeRGB

  


  data : {0x555555988ec0 &#x27;\020&#x27; <repeats 200="200" times="times">..., 0x555555a6f940 &#x27;\200&#x27; <repeats 200="200" times="times">..., 0x555555aa9440 &#x27;\200&#x27; <repeats 200="200" times="times">..., 0x0, 0x0, 0x0, 0x0, 0x0}&#xA;height : 720&#xA;width : 1280&#xA;</repeats></repeats></repeats>

  


  after calling convertImage

  


  data : {0x7fffdde19040 "", 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
height : 0
width : 0


  


  I m not able to understand why my data is NULL and my height and width is 0 ?

  


  ffmpeg version - 4.3.2

  


• FFMpeg overlay and fade images and text in and out at over video background

  28 décembre 2019, par grootester

  Prior to applying the drawbox and drawtext text option I was able to fade in and out images easily. However, attempting to incorporate the drawtext produces unwanted errors. Any ideas how this could be rememdied ? Love to show multi-line text (different fonts) centered over box at specific times with fade in fade out times that works alongside images fading in out at specific times.

  ffmpeg -i vids/testVid.mp4 -loop 1 -i slideshow/pic1.png -loop 1 -i slideshow/pic2.png -loop 1 -i slideshow/pic3.png -i slideshow/pic4.png -filter_complex "[0:v]drawbox=x=40:y=40:w=250:h=75:color=white,drawtext=fontfile=arialb.ttf:fontsize=24:font color=black:text=Micky Mouse,drawtext=fontfile=arial.ttf:fontsize=24 : font color=black:text=January 1st 1938 — December 19th 2019fade=st=0:d=1:alpha=1,fade=out:st=5:d=1:alpha=1,trim=0:6,setpts=PTS+4/TB[ovr1] ; [2]fade=st=0:d=1:alpha=1,fade=out:st=5:d=1:alpha=1,trim=0:6,setpts=PTS+10/TB[ovr2] ; [3]fade=st=0:d=1:alpha=1,fade=out:st=5:d=1:alpha=1,trim=0:6,setpts=PTS+16/TB[ovr3] ; [4]fade=st=0:d=1:alpha=1,fade=out:st=5:d=1:alpha=1,trim=0:6,setpts=PTS+22/TB[ovr4] ; [0:v][ovr1]overlay=(main_w-overlay_w)/2 :(main_h-overlay_h)/2:enable=’between(t,4,10)’[base1] ; [base1][ovr2]overlay=(main_w-overlay_w)/2 :(main_h-overlay_h)/2:enable=’between(t,10,16)’[base2] ; [base2][ovr3]overlay=(main_w-overlay_w)/2 :(main_h-overlay_h)/2:enable=’between(t,16,22)’[base3] ; [base3][ovr4]overlay=(main_w-overlay_w)/2 :(main_h-overlay_h)/2:enable=’between(t,22,28)’[out]" -map "[out]" -c:v libx264 -c:a copy -flags +global_header -crf 27 -preset veryfast -s 1920x1080 -y slideshow/outTest.mp4

• How to create a video from images on a .tif format with FFmpeg ?

  18 décembre 2018, par ecjb

  I just discovered FFmpeg : awesome software. After reading this this stackoverflow question I could efficiently create a movie with pictures in a .png format with the following line :

  ffmpeg -r 1/5 -i img%03d.png -c:v libx264 -vf "fps=25,format=yuv420p" out.mp4

  In an experiment, however, I took high quality pictures on a .tif format and would like to create a movie out of them. I just copied the line above and replaced the name of the files as well as the format .png by .tif but I got a message error saying "This format is not supported". Here is the report :

  [tiff @ 0x7fce5c02a600] This format is not supported (bpp=12, bppcount=1)
  
  Last message repeated 1 times
  
  Error while decoding stream #0:0: Invalid data found when processing input
  
  [tiff @ 0x7fce5c01bc00] This format is not supported (bpp=12, bppcount=1)
  
  Last message repeated 7 times
  
  Cannot determine format of input stream 0:0 after EOF
  
  Error marking filters as finished
  
  Conversion failed!

  Should I just forget it or is there a workaround with ffmpeg ?