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• Interplay MVE : Implement frame format 0x10

  25 juin 2017, par Hein-Pieter van Braam

  Interplay MVE : Implement frame format 0x10
  This implements the 0x10 frame format for Interplay MVE movies. The
  
  format is a variation on the 0x06 format with some changes. In addition
  
  to the decoding map there's also a skip map. This skip map is used to
  
  determine what 8x8 blocks can change in a particular frame.
  This format expects to be able to copy an 8x8 block from before the last
  
  time it was changed. This can be an arbitrary time in the past. In order
  
  to implement this this decoder allocates two additional AVFrames where
  
  actual decoding happens. At the end of a frame decoding changed blocks
  
  are copied to a finished frame based on the skip map.
  The skip map's encoding is a little convulted, I'll refer to the code
  
  for details.
  Values in the decoding map are the same as in format 0x06.
  Signed-off-by : Hein-Pieter van Braam <hp@tmm.cx>
  

  • [DH] libavcodec/interplayvideo.c
  • [DH] libavformat/ipmovie.c

• How can I reencode a video to match another's codec exactly ?

  24 janvier 2020, par Stephen Schrauger

  When I’m on vacation, I usually use our camcorder to record videos. Since they’re all the same format, I can use ffmpeg to concat them into one large, smooth video without re-encoding.

  However, sometimes I will use a phone or other camera to record a video (if the camcorder ran out of space/battery or was left at a hotel).

  I’d like to determine the codec, framerate, etc used by my camcorder and use those parameters to convert the phone vidoes into the same format. That way, I will be able to concatonate all the videos without re-encoding the camcorder videos.

  Using ffprobe, I found my camcorder has this encoding :

    Input #0, mpegts, from 'camcorderfile.MTS':
  
    Duration: 00:00:09.54, start: 1.936367, bitrate: 24761 kb/s
  
    Program 1 
  
      Stream #0:0[0x1011]: Video: h264 (High) (HDPR / 0x52504448), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc
  
      Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 256 kb/s
  
      Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090), 1920x1080

  The phone (iPhone 5s) encoding is :

    Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'mov.MOV':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 0
  
      compatible_brands: qt  
  
      creation_time   : 2017-01-02T03:04:05.000000Z
  
      com.apple.quicktime.location.ISO6709: +12.3456-789.0123+456.789/
  
      com.apple.quicktime.make: Apple
  
      com.apple.quicktime.model: iPhone 5s
  
      com.apple.quicktime.software: 10.2.1
  
      com.apple.quicktime.creationdate: 2017-01-02T03:04:05-0700
  
    Duration: 00:00:14.38, start: 0.000000, bitrate: 11940 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 11865 kb/s, 29.98 fps, 29.97 tbr, 600 tbn, 1200 tbc (default)
  
      Metadata:
  
        creation_time   : 2017-01-02T03:04:05.000000Z
  
        handler_name    : Core Media Data Handler
  
        encoder         : H.264
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 63 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-01-02T03:04:05.000000Z
  
        handler_name    : Core Media Data Handler
  
      Stream #0:2(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-01-02T03:04:05.000000Z
  
        handler_name    : Core Media Data Handler
  
      Stream #0:3(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-01-02T03:04:05.000000Z
  
        handler_name    : Core Media Data Handler

  I’m presuming that ffmpeg will automatically take any acceptable video format, and that I only need to figure out the output settings. I think I need to use -s 1920x1080 and -pix_fmt yuv420p for the output, but what other flags do I need in order to make the phone video into the same encoding as the camcorder video ?

  Can I get some pointers as to how I can translate the ffprobe output into the flags I need to give to ffmpeg ?

  Edit : Added the entire Input #0 for both media files.

• AV_PIX_FMT_YUVJ422P to jpeg conversion

  4 mars 2019, par user3743908

  i am able to convert image from AV_PIX_FMT_YUVJ422P to jpeg format (below Code) but the resultant image having green shade on complete bottom half plz suggest where i am doing wrong.
  Following step i have taken

  1. Initially i have AV_PIX_FMT_UYVY422 image from camera, i have convert it in AV_PIX_FMT_YUVJ422P format and able to see this image on http://rawpixels.net/ the parameters shown by website is size 2448X2050, Bpp1= 8,Bpp2 = 8 and Bpp3 = 8,alignment 1, SubSampling H =2, and SubSampling V = 1, format : YUV422P
     so input image is Correct AV_PIX_FMT_YUVJ422P format. & also able to see on "YUV image viewer Software" using YUV422 format.

  2. Now i am trying to convert it in jpeg format using below Code and attached is the resultant Image having green shade on complete bottom half.

         AVFormatContext*    pFormatCtx;
     
         AVOutputFormat*     fmt;
     
         AVStream*           video_st;
     
         AVCodecContext*     pCodecCtx;
     
         AVCodec*            pCodec;
     
     
     
         uint8_t*            picture_buf;
     
         AVFrame*            picture;
     
         AVPacket            pkt;
     
         int                 y_size;
     
         int                 size;
     
         int                 got_picture=0;  
     
         int                 ret=0;
     
     
     
     int main( int argc, char* argv[] )
     
     {
     
     
     
         FILE *in_file                       =   NULL;   
     
         unsigned int        in_width        =   2448;    
     
         unsigned int        in_height       =   2050;   
     
         const char* out_file                =   "encoded_pic.jpg";    
     
     
     
     
     
             in_file =   fopen("c:\\test_Planar.yuv","rb");
     
             if(in_file == NULL) { printf("\n\tFile Opening error...!!"); exit(1); }
     
             else printf("\n\tYUV File Open Sucessfully...!!\n\n");
     
     
     
             av_register_all();  // Loads the whole database of available codecs and formats.
     
     
     
             pFormatCtx          =   avformat_alloc_context();           
     
             fmt             =   NULL;
     
             fmt             =   av_guess_format("mjpeg",NULL,NULL);
     
             pFormatCtx->oformat     =   fmt;
     
     
     
     //------Output URL-------------------------
     
     if (avio_open(&pFormatCtx->pb,out_file, AVIO_FLAG_READ_WRITE) < 0)
     
     {
     
         printf("Couldn't open output file.");
     
         return -1;
     
     }
     
     
     
     video_st = avformat_new_stream(pFormatCtx, 0);    
     
     if (video_st==NULL)        return -1;
     
     
     
     
     
     pCodecCtx               =   video_st->codec;
     
     pCodecCtx->codec_id     =   fmt->video_codec;
     
     pCodecCtx->codec_type   =   AVMEDIA_TYPE_VIDEO;
     
     pCodecCtx->pix_fmt      =   AV_PIX_FMT_YUVJ422P;
     
     
     
     //--------------------------MY SOURCE PIXEL FORMAT--------------
     
     
     
     pCodecCtx->width        =   in_width;
     
     pCodecCtx->height       =   in_height;
     
     
     
     pCodecCtx->time_base.num = 1;
     
     pCodecCtx->time_base.den = 1;//25;
     
     
     
     //Output some information
     
     av_dump_format(pFormatCtx, 0, out_file, 1);
     
     
     
     // Determine if desired video encoder is installed 
     
     pCodec = avcodec_find_encoder(pCodecCtx->codec_id);
     
     
     
     if (!pCodec)
     
     {
     
         printf("Codec not found.");
     
         return -1;
     
     }
     
     
     
     printf("\nCodec Identified done\n");
     
     
     
     if (avcodec_open2(pCodecCtx, pCodec,NULL) < 0){
     
         printf("Could not open codec.\n");
     
         return -1;
     
     }
     
     picture     =   av_frame_alloc();
     
     size            =   avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
     
     picture_buf     =   (uint8_t *)av_malloc(size);
     
     if (!picture_buf)    return -1;
     
     
     
     avpicture_fill((AVPicture *)picture, picture_buf, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
     
     
     
     printf("\t\nWrite Header..");
     
     avformat_write_header(pFormatCtx,NULL);
     
     y_size = pCodecCtx->width * pCodecCtx->height;
     
     av_new_packet(&pkt,y_size*3);
     
     
     
     
     
     //Read YUV
     
     if (fread(picture_buf, 1, y_size*3/2, in_file) <=0)
     
     {
     
         printf("Could not read input file.");
     
         return -1;
     
     }
     
      //--------------------------------------------input image format UYVY
     
     picture->data[0] = picture_buf;             // Y
     
     picture->data[1] = picture_buf+ y_size;         // U
     
     picture->data[2] = picture_buf+ y_size*5/4;     // V
     
     //-----------------------------------------------
     
     
     
     printf("\t\n Encode the image..\n");
     
     ret = avcodec_encode_video2(pCodecCtx, &pkt,picture, &got_picture);
     
     if(ret < 0)
     
     {
     
         printf("Encode Error.\n");
     
         return -1;
     
     }
     
     
     
     if (got_picture==1)
     
     {
     
         pkt.stream_index = video_st->index;
     
         ret = av_write_frame(pFormatCtx, &pkt);
     
     }
     
     
     
     av_free_packet(&pkt);
     
     //Write Trailer
     
     av_write_trailer(pFormatCtx);    
     
     printf("Encode Successful.\n");
     
     
     
     if (video_st)
     
     {
     
         avcodec_close(video_st->codec);
     
         av_free(picture);
     
         av_free(picture_buf);
     
     }
     
     
     
     avio_close(pFormatCtx->pb);
     
     avformat_free_context(pFormatCtx);    
     
     
     
         fclose(in_file);
     
         printf("\n\tYUV File Close Sucessfully...!!");    
     
     }

  Resultant output jpeg encoded image from yuvj422p image having green shade