On 9/29/23, Mark Filipak <markfilipak.i...@gmail.com> wrote: > On Fri, Sep 29, 2023 at 10:38 AM Reindl Harald <h.rei...@thelounge.net> > wrote: >> Am 29.09.23 um 16:33 schrieb Mark Filipak: >> > This is an ffmpeg architecture question, so I don't have a specific log. >> >> but you have real outputs >> >> > When concatenating involving only demuxing and muxing, I sometimes get >> > "buffer underflow". Why underflow? It's not a real time process. >> >> you are long enough on the list to know that copy&paste of the whole >> input/output is required > > Okay. I'll explain. When I tried > ffmpeg -i "concat:c:\1.mp4|2.mp4 .."
That is simple concat at file level, it almost never works correctly. Unless really streamed format is used, like mpegts. > and that failed on "duplicate MOOV Atom", I converted the MP4s, 1: to > MKVs, and 2: to MPEGs, and 3: to VOBs, and repeated with each of them. > In one of them I got "buffer underflow". Now I wonder what is wrong using concat demuxer. > > I woke up this morning -- I'm in the US -- asking myself, "buffer > underflow? How is that possible?" I don't remember which of the > concats: MKVs or MPEGs or VOBs, did that. So, I don't have a log. A > log should not be required to ask: "How is a buffer underflow possible > when it's not a real time process?" Buffer overflow - something is too big in size. So can not be put into buffer. Buffer underflow - something is too small in size. So there is unused, wasteful space left. Also could mean decoder and/or demuxer did not processed whole buffer. > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".