[FFmpeg-user] Can't write packet with unknown timestamp

[Mark Filipak]

What's going wrong with my remux? '-dn' tells ffmpeg to ignore data (stream 0, i.e., nav packets) 
yet I get "Timestamps are unset in a packet for stream 0".

Thanks,
Mark.

ffmpeg -i "concat:VTS_01_1.VOB|VTS_01_2.VOB|VTS_01_3.VOB|VTS_01_4.VOB|VTS_01_5.VOB|VTS_01_6.VOB" 
-map 0 -codec:v copy -codec:a copy -codec:s copy -dn "C:\AVOut\VTS_01_1.MKV" -y
ffmpeg version git-2020-04-20-cacdac8 Copyright (c) 2000-2020 the FFmpeg developers
   built with gcc 9.3.1 (GCC) 20200328
   configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls 
--enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype 
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg 
--enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt 
--enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp 
--enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib 
--enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc 
--enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --disable-w32threads 
--enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc 
--enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
   libavutil      56. 42.102 / 56. 42.102
   libavcodec     58. 80.100 / 58. 80.100
   libavformat    58. 42.100 / 58. 42.100
   libavdevice    58.  9.103 / 58.  9.103
   libavfilter     7. 79.100 /  7. 79.100
   libswscale      5.  6.101 /  5.  6.101
   libswresample   3.  6.100 /  3.  6.100
   libpostproc    55.  6.100 / 55.  6.100
Input #0, mpeg, from 
'concat:VTS_01_1.VOB|VTS_01_2.VOB|VTS_01_3.VOB|VTS_01_4.VOB|VTS_01_5.VOB|VTS_01_6.VOB':
   Duration: 01:06:28.82, start: 0.039456, bitrate: 12486 kb/s
     Stream #0:0[0x1bf]: Data: dvd_nav_packet
     Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, progressive), 720x480 [SAR 32:27 DAR 
16:9], Closed Captions, 29.97 fps, 59.94 tbr, 90k tbn, 59.94 tbc
     Side data:
       cpb: bitrate max/min/avg: 7500000/0/0 buffer size: 1835008 vbv_delay: N/A
     Stream #0:2[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s
Output #0, matroska, to 'C:\AVOut\VTS_01_1.MKV':
   Metadata:
     encoder         : Lavf58.42.100
     Stream #0:0: Video: mpeg2video (Main) (mpg2 / 0x3267706D), yuv420p(tv, progressive), 720x480 
[SAR 32:27 DAR 16:9], q=2-31, 29.97 fps, 59.94 tbr, 1k tbn, 90k tbc
     Side data:
       cpb: bitrate max/min/avg: 7500000/0/0 buffer size: 1835008 vbv_delay: N/A
     Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, fltp, 192 kb/s
Stream mapping:
   Stream #0:1 -> #0:0 (copy)
   Stream #0:2 -> #0:1 (copy)
Press [q] to stop, [?] for help
[matroska @ 000001b5fa53bac0] Timestamps are unset in a packet for stream 0. This is deprecated and 
will stop working in the future. Fix your code to set the timestamps properly
[matroska @ 000001b5fa53bac0] Can't write packet with unknown timestamp
av_interleaved_write_frame(): Invalid argument
frame=    4 fps=0.0 q=-1.0 Lsize=      15kB time=00:00:00.09 bitrate=1251.4kbits/s speed=3.76x
video:12kB audio:3kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Conversion failed!