On Wed, Jun 25, 2014 at 01:05:50AM +0100, Ken Moffat wrote: > On Fri, Jun 20, 2014 at 02:12:41AM +0100, Ken Moffat wrote: > > > > After two days of intermittent banging my head against a keyboard / > > googling / cursing, I have now got a process of preparing the > > individual clips with ffmpeg to a position where it might be usable. > [...] > > > > What I have done for now is to keep the audio as .wav, and called > > it a .mkv file because it clearly isn't mp4. Xine only plays the > > video from this. The benefit of this is that the although even the > > video has now grown by 67ms, the audio has only grown by 69ms so the > > relative loss of sync is 2ms for this clip. > > > > Still need to do similar things to at least one other clip (but > > I think I now understand the process, and on a good day I can > > remember how the ffmpeg options fit together), and prepare at least a > > title image, then I will find out if I can successfully convert it > > all to mp4 and upload it to youtube : for the moment, I am sort-of > > expecting that to fail, in which case I will be in mega-sulk mode in > > a few days :-( > > > > And now getting very close to mega-sulk mode, and I have not even > got as far as trying to upload to youtube. > [ ... ] > > So, last night I did a quick test with the first two clips, using > -preset ultrafast for a single pass encoding. That worked, although > the video quality on one clip was noticeably worse than with the > -preset veryslow two-pass encoding. > [ ... ] > I can almost remember how I felt the last time I eventually gave up > trying to edit my clips (that was apparently with ffmpeg-0.7.4). I > hesitate to say "suggestions welcome" because some suggestions will > undoubtedly upset me, but has anyone here edited .mov video clips > into a single video using _recent_ ffmpeg ? > At last, a *progress* report -
Came back to this on Monday. At last I have some success to report (but I also realise that I've got to review almost everything I've done along the way - the ffmpeg wiki https://trac.ffmpeg.org/wiki/Encode/H.264 suggests many of the settings I have used are suboptimal). Anyway, my example is now at https://www.youtube.com/watch?v=VmfYQKvmGSQ (views from a train on the Arosa line of the RhB in Switzerland). I'm sure very few people here will find the subject interesting, but there we are. Perhaps the captions at start and end might raise a smile. I am sort-of hoping to document how to do this in a hint (ffmpeg is a fast-moving target, I've only done this on 2.2.2 which is already "old"), but the process is somewhat tedious and involved [ that maybe will not deter BLFS users ]. The worst part is putting the processed clips back together. For example, the command to create this video from only 5 parts was like: ffmpeg -i start-caption.mkv -i clip1.mkv -i clip2.mkv \ -i clip3.mkv -i end-caption.mkv \ -filter_complex '[0:0] [0:1] [1:0] [1:1] [2:0] [2:1] [3:0] [3:1] [4:0] [4:1] concat=5:v=1:a=1 [v] [a]' \ -map '[v]' -map '[a]' -s 1280x720 \ -vcodec libx264 -tune film -b:v 7000k \ -acodec libfdk_aac -cutoff 16000 -b:a 128k -y \ outfile.mkv and those parameters for -filter_complex will get longer for each additional file :-( Also, it re-encodes when doing this, which I had hoped to avoid - turns out only straight mp4 can be concatenated, but I took the opportunity to change the audio to aac ready for upload. I also tried mkvmerge from mkvtoolnix-7.0.0 but it did not work for me, so I guess I'll file a general bug and see if my use-case is valid. <sigh/> With luck, I might finish my film for that line (perhaps another 10 clips / 7 minutes) sometime this year :) ĸen -- Nanny Ogg usually went to bed early. After all, she was an old lady. Sometimes she went to bed as early as 6 a.m. -- http://lists.linuxfromscratch.org/listinfo/blfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
