Re: scripts for processing mov files into something for youtube

What an epic!

I thought I had a hard time learning all the switches in sox, lame, and 
mpg123.
Regards
Kali

On Fri, 1 Aug 2014, Ken Moffat wrote:

> On Wed, Jul 16, 2014 at 05:22:45PM +0100, Ken Moffat wrote:
>
> Moving to chat, it's probably a bit too far beyond BLFS to keep it
> on support :)  So, I'll keep the whole of this for context.
>
>> 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
>
> So, I reworked what I was doing (changed to single-pass encodes, and
> eventually to just playing with the crf value (I use x264 for
> video).  What I had originally done in 2011 was to use two-pass,
> play with presets, and change the size of the video buffer.  With
> ffmpeg-2.2.2 and recent x264 I find that specifying a crf makes a
> lot of difference to how long it takes, and how big the files are -
> playing with the video buffer size makes a minimal difference to
> those, but did reduce the quality, and playing with different
> presets seemed unhelpful.
>
> The scripts are now at
> https://github.com/zarniwhoop73/video-scripts and licensed under the
> WTFPL - if I had written any significant code, I would have used
> GPL, but this is 99% scraped from google's results.  The only part I
> think is an interesting hack is that I change any spaces in text
> (captions superimposed on the video) to non-break-space because I
> can't get my head around the quoting of shell variables used to make
> up video filter parameters in ffmpeg (double quotes, escaped or not,
> break it, and spaces in the text also broke it).
>
> So, now it is out there, I won't be writing a hint.
>
> Examples of the results are in my youtube files (user zarnimovies),
> e.g. Landwasser : http://youtu.be/FXcs9urpU5g for a short one
> (actually just one clip, no captions), and along the Engadin
> http://youtu.be/HVWBDRKFLXI for the most recent (27 files, including
> 'slide' captions and text overlays - I would not have fancied
> typing the merge command for this one ;)  As with my manually
> prepared version mentioned above, these are all trains/landscape,
> and variable quality.  So probably not interesting to most people.
> But I guess the scripts might be.  Mostly they use ffmpeg, with sox
> to handle fading the audio.
>
> A summary of how to use them follows - I guess that almost everyone
> who reads this far won't care, but this is -chat so here goes :
>
> My editing is now straightforward - list the clips, check duration
> / where to cut using vlc, cut with ffmpeg (i.e. copy the original
> mov file to a new name, specifying start/time as appropriate - for
> overlaid text I split a clip into before|text|after versions).
>
> Then, I use my video-summary script to confirm the length, and
> number of frames, for each clip.  That script uses MediaInfo-CLI.
> After that I can pass in values for video-fade-in/out (start frame
> and number of frames), volume (255=unchanged), text, audio fade
> (parms passed to sox, things like "h 2 0".  So simple, even I can
> do it.
>
> For "slides" I either take a still photo, or extract a png from
> the video, scrawl over it in the gimp, and use the slide script to
> create an mkv file of a specified duration, with silence.
>
> Then I use the merge script, perhaps with a title (in fact,
> youtube seems to ignore titles in the video itself), and see how
> little quality (high crf setting) I think I can get away with : I've
> got decent download speed from virginmedia, but the best upload is
> about 2Mbps (about 10.5MB/minute in practice), so large uploads are
> tedious.
>
> 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.
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