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FFmpeg 4.3

ffmpeg.org

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Re: FFmpeg 4.3

#211

Post by thallian »

sandreas wrote: post #201
thallian wrote: post #105

Earlier quoted context omitted.

The amount of time I spent on correcting wrong chapter marks (like the first four books of the Wheel of Time) is masochistic. But I am absolutely happy that I have the possibility of doing so after the conversion :)

Maybe you would like to try m4b-tool chapter-adjustment by musicbrainz id or silence-detection? :-) Disclaimer: I'm the author - https://github.com/sandreas/m4b-tool I once planned a chapter database ( https://www.chapter-db.org ) to collect work like yours, provide an online chapter editor and bind an api to m4b-tool, but i did not have the time to finish the project.

Oh, very interesting, thanks for the hint :D

Re: FFmpeg 4.3

#212

Post by tambourine_man »

amyjess wrote: post #76
tambourine_man wrote: post #9

ffmpeg is amazing, but it’s like tar on steroids: I can never remember the right incantation. Google is required for even the simplest of things. I don’t know if it’s their goal, but I’d love a more user friendly set of command line arguments.

You might want to look into Handbrake. I understand it's basically just a GUI frontend for ffmpeg.

I use it almost everyday.

Re: FFmpeg 4.3

#213

Post by tambourine_man »

zerocrates wrote: post #186
tambourine_man wrote: post #161

Earlier quoted context omitted.

ImageMagick's convert is much friendlier than ffmpeg: convert image.png image.jpg Does what it's suppose to and it's as simple as possible. Sure, you can get really fancy with resizing proportions but easy stuff should be easy.

I mean, ffmpeg -i something.avi something.mp4 works as well, but there's just _so_ many more options inherently involved in converting a video: most inputs and outputs will be at least 2 tracks, so that's 2 codecs, and the majority of containers used now (MP4, MKV, etc.) support all sorts of codecs, so while ffmpeg will "guess" what you want just like ImageMagick does in your short example, the chances that it guesse…

True, but that -i is telling. Remove it and it breaks spectacularly

Re: FFmpeg 4.3

#214

Post by vanderZwan »

chewzerita wrote: post #171
Cactus2018 wrote: post #100

Earlier quoted context omitted.

i'm thinking it's audio only. Maybe it's hiding here? https://soundcloud.com/oliviernijs

My guess is this one: https://soundcloud.com/oliviernijs/perdag1900

That's seven in the afternoon, I guess I misremembered! Thank you so much for finding it! :)

EDIT: This is six in the morning, maybe I heard that version https://soundcloud.com/oliviernijs/perdag600

Re: FFmpeg 4.3

#215

Post by jokoon »

I wonder how hard it would be to build a video editing suite with FFMPEG

Avidemux is nice, but currently I only see vinci as an alternative to premiere.

Re: FFmpeg 4.3

#216

Post by ctrager »

I've been feeling stupid these past few days because I've been using ffmpeg for the first time. I've been trying to take an rtsp stream from a security camera and transcode it, restream it, to something that can be viewed in an html video tag. It works, with poor quality, in Firefox, but in Chrome just a green screen. (I also tried using vlc/cvlc's streaming). I've been feeling stupid because of all the copy/pasting from the web into the command line without understanding what I was doing.

Re: FFmpeg 4.3

#217

Post by boomboomsubban »

touisteur wrote: post #200
strombofulous wrote: post #173

Earlier quoted context omitted.

Why do you need to be rich for gnuplot? Aren't gnu things generally GPL?

Sorry it was a bit tongue in cheek. On many systems I work with and have to debug, gnuplot won't be already installed (and won't be installable on a system not connected to the Internet) so 'rich' would be 'flush in packages with a full system available'. Sometimes, even imagemagick isn't there, but rsvg-convert is, you can still do amazing things with just bash+curl+svg...

Apparently gnuplot is unrelated to GNU, and the original developers were making a pun on "newplot." It's license is a bit complicated, which is why most systems don't have it.

Re: FFmpeg 4.3

#218

Post by bsenftner »

If anyone is compiling their own version for use with IP video streams, here is a modification that adds to the av_read_frame() function a call to the avformat interrupt callback.

https://gist.github.com/bsenftner/ba3d493fa36b0b201ffd995e8c...

This effectively adds the ability to monitor the IP stream for unexpected termination.

The current implementation of av_read_frame() will hang if, for example, a human trips over a camera's cables and the stream abruptly terminates. Without modification to the API, this change to av_read_frame() calls the avformat interrupt callback each loop through av_read_frame()'s reading of packets. All the callback needs to do is look at the time, and signal error if the time between callbacks exceeds something reasonable.

I am not sure why, but this change was not accepted by the ffmpeg developers. I find it essential for working with IP video and IP video cameras.

Re: FFmpeg 4.3

#219

Post by sandreas »

thallian wrote: post #118
anderspitman wrote: post #113

Earlier quoted context omitted.

Heh, I just started The Dragon Reborn on my 3rd read-through. I have noticed the chapters aren't right, but it hasn't really bothered me. What does your workflow look like when fixing these? Is there a way to share chapter corrections so others can apply them to their files?

I have the corresponding ebooks too, so I open up the whole audiobook as one file and guess where the chapters are from the waveform. I listen to the guess and compare to the ebook, checking whether I am too far or too early. Once I find the correct position (and I got quite good at spotting it from the waveform), I set a marker and start with the next chapter. In the end I split it along the markers. I was planning…

Well, if you own the epub, you could try to find out the whole length of the audiobook, then extract the whole text of the epub splitted by chapters and then relatively match the text length to the audio length and put the chapters where the nearest silence is (chapter 2 is at 3.3845% of the whole text, so seek for a silence around 3.3845% of the audio length)

I got some pretty good matches with m4b-tool here, while it does not work for all audio books (you need the latest pre-release for this very experimental undocumented feature!):

  # try to match my-book.epub on my-audiobook.m4b
  # ignore first, second and last two epub-chapters for the match (dedication etc.)
  # split chapters into sub chapters to ensure they are between 5 and 15 minutes
  # create a backup of the original chapters (done automatically)
  m4b-tool chapters -v --epub=my-book.epub --epub-ignore-chapters=0,1,-1,-2 --max-chapter-length=300,900 "my-audiobook.m4b"

  # omg it did not work and messed up all chapters, please restore the original chapters
  m4b-tool chapters -v --epub-restore "my-audiobook.m4b"

  # ok, lets only dump the findings in chapter.txt format to do it manually
  m4b-tool chapters -v --epub-dump --epub=my-book.epub my-audiobook.m4b

Re: FFmpeg 4.3

#220

Post by touisteur »

boomboomsubban wrote: post #217
touisteur wrote: post #200

Earlier quoted context omitted.

Sorry it was a bit tongue in cheek. On many systems I work with and have to debug, gnuplot won't be already installed (and won't be installable on a system not connected to the Internet) so 'rich' would be 'flush in packages with a full system available'. Sometimes, even imagemagick isn't there, but rsvg-convert is, you can still do amazing things with just bash+curl+svg...

Apparently gnuplot is unrelated to GNU, and the original developers were making a pun on "newplot." It's license is a bit complicated, which is why most systems don't have it.

Or the IT security guys that expertly hand-picked all your available packages for minimum attack surface removed it (but let imagemagick... after some time you stop asking some questions :-)
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