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• Difference between 'display_aspect_ratio' and 'sample_aspect_ratio' in ffprobe [duplicate]

  18 juin 2018, par John Allard

  This question already has an answer here :

  • ffmpeg scaling not working for video
    
    1 answer
    

  I have an issue where a video is played in the correct 16:9 aspect ratio when played through VLC or quicktime player, but when I attempt to extract individual frames with ffmpeg the frames come out as 4:3 aspect ratio.

  The ffprobe output on the video in question is as follows

  $ ffprobe -v error -select_streams v:0 -show_entries stream -of default=noprint_wrappers=1 -print_format json movie.mp4
  
  
  
  {
  
  "programs": [
  
  
  
  ],
  
  "streams": [
  
      {
  
          "index": 0,
  
          "codec_name": "h264",
  
          "codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
  
          "profile": "Main",
  
          "codec_type": "video",
  
          "codec_time_base": "126669/6400000",
  
          "codec_tag_string": "avc1",
  
          "codec_tag": "0x31637661",
  
          "width": 2592,
  
          "height": 1944,
  
          "coded_width": 2592,
  
          "coded_height": 1944,
  
          "has_b_frames": 0,
  
          "sample_aspect_ratio": "4:3",
  
          "display_aspect_ratio": "16:9",
  
          "pix_fmt": "yuvj420p",
  
          "level": 50,
  
          "color_range": "pc",
  
          "color_space": "bt709",
  
          "color_transfer": "bt709",
  
          "color_primaries": "bt709",
  
          "chroma_location": "left",
  
          "refs": 1,
  
          "is_avc": "true",
  
          "nal_length_size": "4",
  
          "r_frame_rate": "25/1",
  
          "avg_frame_rate": "3200000/126669",
  
          "time_base": "1/12800",
  
          "start_pts": 0,
  
          "start_time": "0.000000",
  
          "duration_ts": 126682,
  
          "duration": "9.897031",
  
          "bit_rate": "4638928",
  
          "bits_per_raw_sample": "8",
  
          "nb_frames": "250",
  
          "disposition": {
  
              "default": 1,
  
              "dub": 0,
  
              "original": 0,
  
              "comment": 0,
  
              "lyrics": 0,
  
              "karaoke": 0,
  
              "forced": 0,
  
              "hearing_impaired": 0,
  
              "visual_impaired": 0,
  
              "clean_effects": 0,
  
              "attached_pic": 0,
  
              "timed_thumbnails": 0
  
          },
  
          "tags": {
  
              "language": "und",
  
              "handler_name": "VideoHandler"
  
          }
  
      }
  
  ]
  
  }

  So it says

      "width": 2592,
  
      "height": 1944,
  
      "coded_width": 2592,
  
      "coded_height": 1944,
  
      "has_b_frames": 0,
  
      "sample_aspect_ratio": "4:3",
  
      "display_aspect_ratio": "16:9",

  which seems odd to me. The width/height are in 4:3, the sample aspect ratio is 4:3, the display is 16:9 ?

  Now, when I play this through VLC/Quicktime the video looks fine (screenshot below)

  

  but now, if I run an ffmpeg command to extract individual frames from this video, they come out in 4:3

  ffmpeg -y -hide_banner -nostats -loglevel error -i movie.mp4 -vf select='eq(n\,10)+eq(n\,20)+eq(n\,30)+eq(n\,40)',scale=-1:640 -vsync 0 /tmp/ffmpeg_image_%04d.jpg

  

  So I guess my questions are as follows :

  1. what is the relation between display aspect ratio, sample aspect ratio, and the width/height ratio ?
  2. how to I get ffmpeg to output in the correct aspect ratio ?

• ffmpeg - split video into multiple parts with different duration

  16 avril 2023, par Pierrou

  in order to split very old episodes from my VHS rips, I would like to split video files into multiple parts according to timestamps in csv file :

  


  file1;00:01:13.280;00:14:22.800;Part 1
file1;00:14:41.120;00:26:05.400;Part 2
file1;00:26:23.680;00:39:41.720;Part 3
file1;00:40:00.000;00:51:43.280;Part 4
file1;00:53:50.200;01:06:15.680;Part 5
file1;01:06:33.960;01:20:58.400;Part 6
file1;01:21:16.680;01:34:57.320;Part 7
file1;01:35:15.600;01:48:21.640;Part 8
file1;01:49:15.160;01:51:54.720;Part 9
file2;00:01:13.280;00:13:30.960;Part 1
file2;00:13:49.240;00:29:04.240;Part 2
file2;00:29:22.520;00:43:24.080;Part 3
file2;00:43:42.360;00:58:12.560;Part 4
file2;01:00:03.880;01:12:52.840;Part 5
file2;01:13:11.120;01:24:13.280;Part 6
file2;01:24:31.560;01:51:12.720;Part 7
file2;01:52:06.840;01:54:55.640;Part 8


  


  So how can I have multiple lines like those ?

  


  ffmpeg -i file1.avi -c copy -ss 00:01:13.280 -to 00:14:22.800 file1/part1.avi


  


  So I would like to keep each parts in individual files and remove everything else.

  


• FFMPEG : new m3u8 playlist in every hour from the same segmented stream

  23 mars 2018, par iPog

  I’m using the latest Windows build of FFMPEG (by Zeranoe).

  Currently I create 2 outputs from the same raw live video input. I use the tee pseudo-muxer to give the user the following outputs :

  • PRIMARY OUTPUT : transcoded live stream ; using the HLS or the segment muxer ; 14 pieces of 10-second-long segments on a ramdisk.
  • SECONDARY OUTPUT : from the same transcoding I store every segment on the hard drive ; to make the hard drive versions watchable, I create m3u8 playlists with an automated batch script in every hour ; all individual playlist files contain 1 hour of content.

  Is it possible to achieve the same result with FFMPEG only ? I.e. the secondary output should be able to finish the current m3u8 playlist, and start a new one with a new filename at every hour o’clock.

  (My batch-based solution works fine, so it isn’t that important, but it would be nice to know if it is possible at all. I could not find a similar approach in the documentation/wiki.)