Recherche avancée

Sur d’autres sites (2245)

• Elastic Transcoder output duration doesnt match with the sum of my Input duration

  28 mars 2019, par auricless

  I have multiple media file to concatenate into a single video file. Composed of different media types including video, audio and image. I use FFMPEG to convert audio and images to a video then finally, will use Elastic Transcoder to stitch/concatenate the video files in a single one. On creating transcoder job, whenever I placed the input video which is originally an image, converted by FFMPEG, to be the last input in order, it shrinks the duration of its exposure in the final output by 5 seconds whenever its original duration is > 5. This happens only with that condition.

  Example :
  (1) video1 - 10s
  (2) image1 - 10s
  (3) video2 - 15s
  (4) image2 - 20s
  output : video - 40s
  (image2’s duration or exposure in the output shrinks to approx. 5s)

  Clearly, the sum of Input duration and the Output duration does not match. It is even explicitly stated on the Job result of elastic transcoder.

  ---

  Thought I had a wrong conversion settings in FFMPEG so I changed some options. After some changes and comparing the image converted to video (V1) with an authentic video to stitch with (V2), their settings are almost the same. In this I use ffmpeg -i myVideo.mp4 to check its details. They differ only on SAR, DAR, tbr and tbn and I dont really know what are their use.

  Already checked the duration of the converted images after ffmpeg conversion and it is accurate, it only messed up after feeding it to the elastic transcoder and placed as the last input.

  Here is my conversion command with FFMPEG(image to video) :
  ffmpeg -r 29.97 -i [input.jpg] -f lavfi -i anullsrc=r=48000:cl:stereo -t [duration] -acodec aac -vcodec libx264 -profile:v baseline -pix_fmt yuv420p -t [duration] -vf scale=854:480 -strict -2 [output.mp4]

  The expected result should be that the output file is consistent with the actual duration it has.

  [EDIT]

  Here’s real videos I feed on Elastic Transcoder using ffprobe filename :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'clip2.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.71.100
  
    Duration: 00:00:10.05, start: 0.042667, bitrate: 476 kb/s
  
      Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
      Stream #0:1(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 854x480 [SAR 2136:2135 DAR 89:50], 341 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'image2.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf56.12.100
  
    Duration: 00:02:10.03, start: 0.033333, bitrate: 130 kb/s
  
      Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 854x480 [SAR 1943:1004 DAR 829661:240960], 2636 kb/s, SAR 283440:146461 DAR 1181:343, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, mono, fltp, 128 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler

• FFmpeg output doesn't match source

  10 octobre 2019, par Patrick O'Brien

  I can’t seem to match the ffmpeg output with the source exr. Linking to the source exr and movie here : https://www.dropbox.com/sh/mc19q5m9bf17goi/AAAfs4o_vxnAePIZVrOBrEZRa?dl=0. I’ve tried a lot of flags, the closest seems to be this :

  C :\PyAniTools\apps\pyShoot\ffmpeg\bin\ffmpeg.exe -apply_trc iec61966_2_1 -i C :\Users\Patrick\Downloads\050_020_render_layer\char_back\char_back.1062.exr -vcodec libx264 -pix_fmt yuv420p -preset slow -crf 18 -r 25 C :\Users\Patrick\Downloads\050_020_render_layer\char_back\char_back.1062.mp4

  It’s still different though. Source exr :
  

  It’s hard to tell probably but parts of the image get darker :
  

  Any help would be greatly appreciated, I’ve been trying things for days. Thanks,
  Patrick

• FFmpeg and QuickTime Player dimensions of video do not match [duplicate]

  31 mai 2020, par GRS

  I have a video.mp4, which I scaled using FFmpeg to get out.mp4. The new video has the following probe :

  



  {'streams': [{'index': 0,
   'codec_name': 'h264',
   'codec_long_name': 'H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10',
   'profile': 'High',
   'codec_type': 'video',
   'codec_time_base': '1/50',
   'codec_tag_string': 'avc1',
   'codec_tag': '0x31637661',
   'width': 886,
   'height': 1920,
   'coded_width': 896,
   'coded_height': 1920,
   'has_b_frames': 2,
   'sample_aspect_ratio': '5120:1329',
   'display_aspect_ratio': '16:9',
   'pix_fmt': 'yuv420p',
   'level': 40,
   'chroma_location': 'left',
   'refs': 1,
   'is_avc': 'true',
   'nal_length_size': '4',
   'r_frame_rate': '25/1',
   'avg_frame_rate': '25/1',
   'time_base': '1/12800',
   'start_pts': 0,
   'start_time': '0.000000',
   'duration_ts': 384512,
   'duration': '30.040000',
   'bit_rate': '490832',
   'bits_per_raw_sample': '8',
   'nb_frames': '751',
   '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'}}],
 'format': {'filename': 'out.mp4',
  'nb_streams': 1,
  'nb_programs': 0,
  'format_name': 'mov,mp4,m4a,3gp,3g2,mj2',
  'format_long_name': 'QuickTime / MOV',
  'start_time': '0.000000',
  'duration': '30.040000',
  'size': '1852948',
  'bit_rate': '493461',
  'probe_score': 100,
  'tags': {'major_brand': 'isom',
   'minor_version': '512',
   'compatible_brands': 'isomiso2avc1mp41',
   'encoder': 'Lavf58.20.100'}}}


  



  I am expecting my video player to say the video is 886 x 1920, however, it is 3413:1920.


  



  What could be the error ? I am using pix_frmt=yuva420p and codec=libx264 to create the video.

  



  The error is that my ascpect ratio remains 16:9, which is the original input video, when it should automatically change to 9:19. E.g. 3413 = 1920 * 16 / 9. So why isn't the ascpect ratio changed when the video is scaled ?