Cannot parse while doing a first pass output to null

[smacz42]

When passing the first pass arguments to ffmpeg (-pass 1 -f null /dev/null), there is no time/speed recorded for the analysis:

Input #0, matroska,webm, from '2021-03-18 19-23-22.mkv':                                                                                                                                                                                      
  Metadata:                                                                                                                                                                                                                                   
    ENCODER         : Lavf58.45.100                                                                                                                                                                                                           
  Duration: 01:55:39.95, start: 0.000000, bitrate: 2828 kb/s                                                                                                                                                                                  
    Stream #0:0: Video: h264 (High), yuv420p(tv, bt709, progressive), 852x480, 60 fps, 60 tbr, 1k tbn, 120 tbc (default)                                                                                                                      
    Metadata:                                                                                                                                                                                                                                 
      DURATION        : 01:55:39.950000000                                                                                                                                                                                                    
    Stream #0:1: Audio: aac (LC), 44100 Hz, stereo, fltp (default)                                                                                                                                                                            
    Metadata:                                                                                                                                                                                                                                 
      title           : Track1                                                                                                                                                                                                                
      DURATION        : 01:55:39.864000000                                                                                                                                                                                                    
    Stream #0:2: Audio: aac (LC), 44100 Hz, stereo, fltp                                                                                                                                                                                      
    Metadata:                                                                                                                                                                                                                                 
      title           : Track2                                                                                         
      DURATION        : 01:55:39.864000000                                                                             
Stream mapping:                                                                                                        
  Stream #0:0 -> #0:0 (h264 (native) -> vp9 (libvpx-vp9))                                                                                                                                                                                     
Press [q] to stop, [?] for help                                                                                        
[libvpx-vp9 @ 0x560317566b80] v1.9.0    
Output #0, null, to '/dev/null':                                                                                                                                                                                                                Metadata:                                                                                                                                                                                                                                       encoder         : Lavf58.45.100                                                                                                                                                                                                               Stream #0:0: Video: vp9 (libvpx-vp9), yuv420p, 852x480, q=-1--1, 512 kb/s, 60 fps, 60 tbn, 60 tbc (default)                                                                                                                               
    Metadata:                           
      DURATION        : 01:55:39.950000000                                                                             
      encoder         : Lavc58.91.100 libvpx-vp9                                                                                                                                                                                              
    Side data:                          
      cpb: bitrate max/min/avg: 742000/256000/512000 buffer size: 0 vbv_delay: N/A
frame=52437 fps=384 q=0.0 Lsize=N/A time=00:00:00.00 bitrate=N/A speed=   0x    

This goes on for as long as the frames are being processed.

ffpb doesn't seem to be able to report on this, and just sits at 0% for the entirety of the first pass:

2021-03-18 19-23-22.mkv:   0%|                                | 0/416340 [03:56<?, ? frames/s]

Which, it doesn't fail to pass any arguments, etc. so it's technically working, it just can't get any info from ffmpeg to display. Is there something that I'm missing that could be passed to enable status on firstpass analysis?

[althonos]

This is strange, I can't reproduce on my machine. With a random Matroska file, and the latest ffpb (0.4.1):

$ ffpb -i The\ Strokes.mkv -pass 1 -f null /dev/null

I get a smooth progress bar as expected. I suppose the issue here could appear with specific file formats / codecs.