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• FFMPEG with -vf yadif on progressive file produces incorrect 'Original Frame Rate' metadata double

  28 septembre 2020, par hedgehog90

  I've got an ffmpeg command that I often use, I incorporate the yadif argument for content that may or may not be interlaced :

  


  ffmpeg -i input.mkv -c copy -c:v hevc_nvenc -c:a:0 aac -b:a 192k -vf yadif=mode=1:deint=1 output.mkv

  


  This means if input.mkv is an interlaced video, I get double the frame rate and the footage is deinterlaced, and if it's progressive it remains so and the frame rate doesn't change, exactly as I want it.

  


  However, I've just noticed in Mediainfo that progressive videos processed by this command, it adds this mysterious "Original Frame Rate" tag (I assume it's just metadata)

  


  

  


  It doesn't appear to affect playback in VLC or MPV, however it is recognized in MPV as 'framerate (Specified)'...

  


  How do I prevent ffmpeg from generating this tag when using the yadif filter ?

  


• Edited video produces smaller image that original, even with higher resolution

  10 juillet 2020, par ceperman

  I've a .ts format recording from my Humax, which completely fills the window horizontally when played with VLC. In full-screen it fills the screen horizontally in letterbox style, and the same on the TV when played through my PS/3. All good so far.

  


  This is the ffprobe output :

  


  Duration: 02:16:37.72, start: 74238.902878, bitrate: 2554 kb/s
Stream #0:0[0x931]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv), 704x576 [SAR 16:11 DAR 16:9], max. 15000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc


  


  I used ffmpeg to change the audio track :

  


  ffmpeg -i movie.ts -c:v libx264 -c:a ac3 -crf 20 -map 0:v:0 -map 0:a:1 movie.mp4


  


  and produced an .mp4 which also plays correctly.

  


  ffprobe :

  


  Duration: 02:16:37.68, start: 0.005333, bitrate: 1129 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 704x576 [SAR 16:11 DAR 16:9], 932 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)


  


  However, if I edit it using OpenShot, I cannot find any export format that produces an image that fills the window horizontally in the same way, regardless of what resolution or aspect ratio I use.

  


  Example : export format "DV/DVD Widescreen PAL (720x576)" produces this (sample) file :

  


  Duration: 00:00:39.12, start: 0.040000, bitrate: 563 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 720x576, 477 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)


  


  OpenShot appears not to set the AR, so it initially shows in VLC in 5:4 aspect, but even changing the VLC AR to the maximum of 2.39:1 does not stretch it fully from side-to-side.

  


  I've used ffmpeg to experiment with changing the aspect ratio, changing the resolution, and setting the SAR and DAR, all without success.

  


  This can't be a resolution issue, as I've exported 720p and 1080i, plenty of pixels but all produce roughly the same result - a small image that doesn't fill the window, and ditto on the TV. The original recording is only 704x576 but fills the window. Also the aspect ratio of the original recording is 16:9 (VLC agrees) but the actual measured AR of the screen image is closer to 2.04:1.

  


  I'm hoping that while this could be an OpenShot issue, the cause of the problem should be visible to ffprobe and perhaps fixable with ffmpeg. Help wil be appreciated.

  


• FFMPEG drops supposedly corrupt frames from original video while transcoding using h264 encoder

  19 février 2019, par t6nand

  I am using h264 for optimising MP4 for web. I have a video which has some supposedly corrupt frame(s) within it’s initial 1-2 seconds. (Frame provided below)

  On transcoding using :

  ffmpeg -i orig.mp4 -c:v libx264 -crf 25 -vf scale="-2:min(ih\,720)" -b:v 600K -g 90 -c:a libfdk_aac output.mp4

  The output MP4 has these frames dropped out and I have my output with it’s start about 1 to 2 seconds delayed from original video, thus resulting in overall less time duration in output video.

  Moreover, most media players also skip these frames in playback (like quicktime player, etc). But VLC media player was able to play this video without skipping these frames.

  Is there a way to not drop frames using ffmpeg ? And if possible is it possible to identify and fix these frames in a video ?

  Note : I tried encoding same video using AWS Elastic transcoder which actually fixed these frames (Frame provided below) :
  

  Note : Original video can be found here -
  https://drive.google.com/file/d/0B9VkhR9Zu60ybXFDeno3RGpQTUE/view?usp=sharing
  Video transcoded by AWS Elsatic transcoder can be found here -
  https://drive.google.com/file/d/0B9VkhR9Zu60yWUVHQk5MTk05QVk/view?usp=sharing

  EDIT1 : As suggested by @Mulvya in comments, TS-transcoded video can be found here - (https://drive.google.com/file/d/0B9VkhR9Zu60yU0t6T0dMME9ZMmc/view?usp=sharing)