On Wed, Jun 24, 2020 at 3:41 AM Tom Sparks <tomasparks...@gmail.com> wrote:
> mkv is a better output format to use > Thanks for this Tom, can you expand on what the benefits are? I think I ended up with mov as it seemed to be the "natural" choice for apple prores content, but there was no thought went into it, just "what somebody said" :) > On 24/06/2020, Simon Roberts <si...@dancingcloudservices.com> wrote: > > Greetings all, I'm a pretty low-level ffmpeg user, just doing screen > > captures, compressions, and some simple format conversions. I have not > made > > much progress understanding more advanced key concepts; I apologize if > this > > is a basic question. > > > > I have a four-input video capture card, (Blackmagic DeckLink) and I > > successfully built ffmpeg with support for that. I can capture using the > > card, and I can run two captures concurrently as independent processes > > putting output into two different files. I haven't tried running all four > > at once (though that's my long-term goal, along with another four audio > > channels from a USB capture device). > > > > However, I would like to be able to put the multiple streams into a > single > > file. There are a couple of reasons for this, and if my expectations are > > misplaced, now's a great time to tell me. One is that I'd like the > > timecodes to be synchronized, another is that I'd prefer a single command > > to start everything, and end everything, at the same instant. This, I > hope > > will reduce the complexity of synchronizing the channels in later > editing. > > > > But I have no clue how to start with this. I tried simply adding more > input > > channels to my input specifications: > > > > ffmpeg -f decklink -i 'DeckLink Quad HDMI Recorder (1)' -f decklink -i > > 'DeckLink Quad HDMI Recorder (4)' -c:v copy -c:a copy -metadata > > title=DeckLinkCapture capture.mov > > > > But all I got was a ton of buffer overruns, and a file that ffprobe said > > only contained one video stream. > > > > I believe that .mov can hold multiple streams, but I have not particular > > reason for using that file format, other than I often use it when I go > with > > a prores compression. (I'm hoping that later in this project I might get > > enough CPU power to go that route, and reduce bandwidth and storage > > requirements to less insane levels) > > > > Can someone point me at a template for a command line that might do what > I > > need? If the explanation or resources might help me understand the > concepts > > better, that would be a bonus (and might result in my becoming a little > > more self-sufficient!) > > > > Cheers, > > Simon > > > > > > -- > > Simon Roberts > > (303) 249 3613 > > _______________________________________________ > > 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". -- Simon Roberts (303) 249 3613 _______________________________________________ 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".
