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FFmpeg 4.0 released

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Re: FFmpeg 4.0 released

#51

Post by danneu »

peterburkimsher wrote: post #50
always_good wrote: post #49

Earlier quoted context omitted.

Brilliant. Would you mind sharing it?

There's actually several scripts: burn the subtitles into the movie as hard-subs, extend the subtitles by 1 second, make clips of each subtitle, make headings, and combine the clips with the headings. These are my rough notes I made at the time (you could skip the Pingtype steps if you're not trying to make bilingual language learning material). https://github.com/pingtype/pingtype.github.io/blob/master/d...

Wow, that's great.

Here's my attempt at building something for language learning since my listening skills trail so far behind my reading skills: https://www.danneu.com/slow-spanish/

It parses this painstakingly created file: https://github.com/danneu/slow-spanish/blob/a455da3a230632c2...

Unfortunately it's really hard to generate the source material (timestamping a transcript).

So my idea was to upload some slow-speaking audio to Youtube and let it autogen its .srt subtitle files. The subtitles don't come out perfectly, but it's the timestamp data I'm after since the goal is a UI that makes it easy to replay and scrub around spoken audio.

Re: FFmpeg 4.0 released

#52

Post by peterburkimsher »

danneu wrote: post #51
peterburkimsher wrote: post #50

Earlier quoted context omitted.

There's actually several scripts: burn the subtitles into the movie as hard-subs, extend the subtitles by 1 second, make clips of each subtitle, make headings, and combine the clips with the headings. These are my rough notes I made at the time (you could skip the Pingtype steps if you're not trying to make bilingual language learning material). https://github.com/pingtype/pingtype.github.io/blob/master/d...

Wow, that's great. Here's my attempt at building something for language learning since my listening skills trail so far behind my reading skills: https://www.danneu.com/slow-spanish/ It parses this painstakingly created file: https://github.com/danneu/slow-spanish/blob/a455da3a230632c2... Unfortunately it's really hard to generate the source material (timestamping a transcript). So my idea was to upload some slow-spe…

Using YouTube to generate the timestamps is a really good idea!

I'm manually recording timestamps while I read/listen to the Bible, verse by verse. Every time I click pause in Pingtype's Media Viewer, it logs the time. It's painstaking, but I'm trying to study each verse while I read anyway, so it's good to let me pause regularly.

There's a lot of LRC data for songs that are used in KTV/Karaoke. You just need to find a good data source for Spanish. In my opinion, listening to music and singing along in church helped my Chinese much more than textbooks. I still lack confidence speaking, but my listening improved a lot when my regular playlist became majority-Chinese (I listen to iTunes all day).

Re: FFmpeg 4.0 released

#53

Post by the8472 »

scottlamb wrote: post #27
Cogito wrote: post #20

Love ffmpeg! I was trying to do something the other day and couldn’t figure it out, if anyone has any ideas. The end goal is to provide a set of video files, with time stamps for each, splicing them into one file while removing parts I don’t want. That is straightforward enough, as long as you’re willing to re-encode the whole file. Otherwise, it seems like ffmpeg is restricted to make cuts at key frames. It’s rare f…

Depending on the container format, you may not need to re-encode anything. .mp4 supports "edit lists". You can create a .mp4 file that starts at the latest key frame Afraid I don't know how to do what you want with the ffmpeg commandline tool, though, either by partial re-encoding or by edit lists.

mkv can do something similar with chapter lists

Re: FFmpeg 4.0 released

#54

Post by phoenix24 »

Quick Question,

For a personal project, I would like to generate videos to visualize the evolution of our git repository.

Is ffmpeg the best approach to programmatically create videos? What is the state of java, python or go bindings for such a usecase?

Or should I use OpenGL for this particular use?

I'm new to this, so any help and guidance would be great for me to get started.

Thanks!

Re: FFmpeg 4.0 released

#55

Post by terminalcommand »

phoenix24 wrote: post #54

Quick Question, For a personal project, I would like to generate videos to visualize the evolution of our git repository. Is ffmpeg the best approach to programmatically create videos? What is the state of java, python or go bindings for such a usecase? Or should I use OpenGL for this particular use? I'm new to this, so any help and guidance would be great for me to get started. Thanks!

If you want to try out golang, go has an amazing gif library built-in.

Here is a nice excerpt out of a tutorial exercise from the book The Go Programming Language: http://www.informit.com/articles/article.aspx?p=2453564&seqN...

Re: FFmpeg 4.0 released

#56

Post by ZenoArrow »

phoenix24 wrote: post #54

Quick Question, For a personal project, I would like to generate videos to visualize the evolution of our git repository. Is ffmpeg the best approach to programmatically create videos? What is the state of java, python or go bindings for such a usecase? Or should I use OpenGL for this particular use? I'm new to this, so any help and guidance would be great for me to get started. Thanks!

Have you considered using Gource?

http://gource.io/

As an example, here's a video covering 22 years of the evolution of Python:

http://youtu.be/cNBtDstOTmA

Re: FFmpeg 4.0 released

#57

Post by phoenix24 »

ZenoArrow wrote: post #56
phoenix24 wrote: post #54

Quick Question, For a personal project, I would like to generate videos to visualize the evolution of our git repository. Is ffmpeg the best approach to programmatically create videos? What is the state of java, python or go bindings for such a usecase? Or should I use OpenGL for this particular use? I'm new to this, so any help and guidance would be great for me to get started. Thanks!

Have you considered using Gource? http://gource.io/ As an example, here's a video covering 22 years of the evolution of Python: http://youtu.be/cNBtDstOTmA

Thank you for pointing me to gource, but I wanted to understand it as a general approach which would be a better build it via libffmpeg or opengl.

I'm keen on building something, and extending to other use cases like embedding photographs, milestones and other major events involving our business unit.

Re: FFmpeg 4.0 released

#58

Post by cup-of-tea »

chatmasta wrote: post #44
cup-of-tea wrote: post #33

Earlier quoted context omitted.

Yes. PPA and Docker are great but compiling isn't too difficult and worth remembering how to do it.

The initial compile isn’t bad but the second you want to render some font on a video with ffmpeg on Ubuntu, good luck with that

Are the fonts compiled in?

Re: FFmpeg 4.0 released

#59

Post by izacus »

no_u wrote: post #14

Couldn't find a PPA or a docker image for it, would I need to install it from source? I would really like to test AV1 with it.

The canonical way is just to grab the static build from the home page. You don't need a full OS container image to run a single binary.

Re: FFmpeg 4.0 released

#60

Post by Bromskloss »

stirner wrote: post #34
gusfoo wrote: post #4

If you're reading this, FFmpeg developers, please accept my thanks for your work. You have become a "Category Killer"[1] in command-line video tomfoolery. [1] http://www.catb.org/esr/writings/homesteading/cathedral-baza...

Not just command line. libav* is used in pretty much everything that deals with arbitrary AV formats/codecs.

What is the current relationship between Libav and FFmpeg? I could never figure out which one I should support when there was a falling out, and things might even have changed since then.
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