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• ffmpeg crashes on crossfades between 3 clips if 2 clips coming from same input file [closed]

  14 avril 2020, par Erik

  I observed that ffmpeg 4.2.2 (macOS) crashes in particular cases of crossfades between clips, if one clip comes from file 1.dv, and two clips are cut out of file 2.dv, as shown below :

  



  ffmpeg -f lavfi -i color=black:size=720x576:duration=11:rate=25 -i 1.dv -i 2.dv -filter_complex "\
    [1:v]trim=5:10,setpts=expr=PTS-STARTPTS,yadif,fade=alpha=1:d=2:st=3:type=out,setpts=expr=PTS-STARTPTS,fifo[s5];\
    [2:v]split=2[s7][s8];\
    [s7]trim=5:10,setpts=expr=PTS-STARTPTS,yadif,fade=alpha=1:d=2:type=in,fade=alpha=1:d=2:st=6:type=out,setpts=expr=PTS-STARTPTS+(3/TB),fifo[s15];\
    [s8]trim=12:17,setpts=expr=PTS-STARTPTS,yadif,fade=alpha=1:d=2:type=in,setpts=expr=PTS-STARTPTS+(6/TB),fifo[s22];\
    [0:v][s5]overlay=eof_action=repeat[s6];\
    [s6][s15]overlay=eof_action=repeat[s16];\
    [s16][s22]overlay=eof_action=repeat[s24];\
    [1:a]atrim=5:10,asetpts=expr=PTS-STARTPTS[s26];\
    [2:a]asplit=2[s27][s28];\
    [s27]atrim=5:10,asetpts=expr=PTS-STARTPTS[s30];\
    [s28]atrim=12:17,asetpts=expr=PTS-STARTPTS[s33];\
    [s26][s30]acrossfade=d=2[s31];\
    [s31][s33]acrossfade=d=2[s36]" \
     -map "[s24]" -map "[s36]" -ab 128k -acodec aac -crf 23 -movflags faststart -preset medium -tune film -vcodec libx264 -aspect 1024:576 out.mp4 -y


  



  The order makes a difference : if the two clips from 2.dv are used first and then the clip from 1.dv is appended, everything works fine. Also, if all clips are coming from different files.

  



  ffmpeg 3.4.6 (ubuntu 18.04) shows no issues in any case.

  



  A self-compiled ffmpeg version N-97322-gb1699f4 (commit 2020-04-13) works with short clips as above, but crashes if one of the two clips taken from 2.dv is getting longer. In my tests 1500 frames (64 sec) is OK, 1700 (68 sec) leads to a segmentation fault. That is, if you replace in the command line above :

  



  

  • [s7]trim=5:10... -> [s7]trim=0:68 and accordingly

  


  • [s27]atrim=5:10... -> [s27]atrim=0:68

  


  



  Interestingly, the length of the clip taken from 1.dv does not play a role.

  



  The ffmpeg output shows about 20 times :

  



  frame=    0 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x  


  



  before it continues (seg fault case) :

  



  frame=    4 fps=0.3 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   24 fps=1.6 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   25 fps=1.5 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   34 fps=1.9 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   36 fps=2.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   39 fps=2.1 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   40 fps=2.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   40 fps=2.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   40 fps=1.9 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    



  



  success case :

  



  frame=    5 fps=0.4 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   42 fps=3.2 q=28.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   53 fps=3.9 q=28.0 size=       0kB time=00:00:00.36 bitrate=   2.9kbits/s speed=0.0264x    
frame=   65 fps=4.6 q=28.0 size=       0kB time=00:00:00.84 bitrate=   1.2kbits/s speed=0.0594x 
...   


  



  Slightly older versions included in the newest MacOS builds from zeranoe.com (git-2020-04-13-59e3a9a) and evermeet.cx (N-97308-g14dd0a9057-tessus, from 2020-04-12) are working nicely - also on my production cases (longer clips).

  



  Any feedback would be appreciated !

  


• SVT-AV1 Vertical 4k video

  14 avril 2020, par Dmitry Maksakov

  I have a vertical 4k video captured on my phone with the following parameters (ffprobe) :

  



  Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/smpte170m), 3840x2160, 71980 kb/s, SAR 1:1 DAR 16:9, 59.96 fps, 60 tbr, 90k tbn, 180k tbc (default)
Metadata:
  rotate          : 90
  creation_time   : 2020-04-03T17:17:11.000000Z
  handler_name    : VideoHandle
Side data:
  displaymatrix: rotation of -90.00 degrees


  



  When I try to transcode it to av1 with svt_av1

  



  ffmpeg -i video.mp4 -c:v libsvt_av1 -y output.webm


  



  I am getting

  



  Error instance 1: Source Height must be less than 2160
[libsvt_av1 @ 0x5614a858c400] Error setting encoder parameters: bad parameter (0x80001005)
Segmentation fault


  



  How could I encode such videos ?

  


• Picking the right gpu for ffmpeg decoding/encoding with nvidia/cuda

  14 avril 2020, par Reza Mir

  I am writing code using ffmpeg/nvidia/cuda library to decode and encode some video. I am trying to pick one specific GPU for decoding/encoding among some existing GPUs installed on the system. Here is the list of existing GPUs :

  



   nvidia-smi 
Tue Apr 14 00:14:59 2020       
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 440.64.00    Driver Version: 440.64.00    CUDA Version: 10.2     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|===============================+======================+======================|
|   0  GeForce RTX 208...  On   | 00000000:1A:00.0 Off |                  N/A |
| 41%   33C    P8    20W / 260W |      0MiB / 11019MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
|   1  GeForce GTX 108...  On   | 00000000:1B:00.0 Off |                  N/A |
| 41%   65C    P2   182W / 250W |   7167MiB / 11178MiB |     53%      Default |
+-------------------------------+----------------------+----------------------+
|   2  GeForce GTX 108...  On   | 00000000:1E:00.0 Off |                  N/A |
| 14%   55C    P2    61W / 250W |   1943MiB / 11178MiB |     26%      Default |
+-------------------------------+----------------------+----------------------+
|   3  Quadro P5000        On   | 00000000:3D:00.0 Off |                  Off |
| 26%   33C    P8     6W / 180W |      1MiB / 16278MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
|   4  TITAN RTX           On   | 00000000:3E:00.0 Off |                  N/A |
| 41%   38C    P0    72W / 280W |      0MiB / 24220MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
|   5  TITAN RTX           On   | 00000000:41:00.0 Off |                  N/A |
| 40%   32C    P8    14W / 280W |      0MiB / 24220MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+



  



  I would like to pick GPU #3 in my code and use it for decoding. I am using h264_nvenc and h264_cuvid as encoder and decoder in my program and setting the options of decoder/encoder using the following code :

  



  av_opt_set(decoder_context->priv_data, "gpu", "Quadro P5000", 0);


  



  But this code doesn't pick Quadro GPU for decoding/encoding. Instead, it always goes to GPU #4 in my test :

  



  nvidia-smi pmon | grep tx
    4      20096     C    22     3    44    16   tx            
    4      20096     C    26     4    49    17   tx            
    4      20096     C    25     4    49    17   tx