Newest 'libx264' Questions - Stack Overflow

Les articles publiés sur le site

• Is Electron using a custom-licensed libx264 variant ?

  13 septembre 2016, par JohnW

  Electron is providing a few variants of FFmpeg.

  The variant I have seems to handle H264 just fine, which it does using libx264 apparently.

  The question is simple: Do electron developers have a special deal with VideoLan to provide an MIT licensed FFmpeg with x264?

  I am asking because VideoLan seems to dual-license libx264 (GPL and custom license) so it is possible that there is a deal.

  According to this link however the answer may very well be "no".

• Is Electron using a custom-licensed libx264 variant ?

  13 septembre 2016, par JohnW

  Electron is providing a few variants of FFmpeg.

  The variant I have seems to handle H264 just fine, which it does using libx264 apparently.

  The question is simple: Do electron developers have a special deal with VideoLan to provide an MIT licensed FFmpeg with x264?

  I am asking because VideoLan seems to dual-license libx264 (GPL and custom license) so it is possible that there is a deal.

  According to this link however the answer may very well be "no".

• Can x264 be used from Java code via JNI to decrease the resolution of RTMP streams ? [on hold]

  5 septembre 2016, par Orr151

  I would like to implement a custom RTMP transcoder to HLS format in Java. As the repackaging itself seems to be relatively clear and doable in Java, then I found the modification of the video resolution a bit challenging in Java. My plan is to avoid using existing solutions like FFmpeg or at least minimize the amount of 3rd party frameworks/tools integrated with my component.

  After some research it seems that reusage of JCodec and Xuggler can be challenging as both project are idle for a while. Also I'm not sure if their performance is acceptable. That's why I would like to integrate directly with x264 library via JNI from Java code.

  Is integration with x264/libx264 from Java code to decrease resolution/bitrate doable and is it a good idea? Could you please suggest any other solutions?

  Thanks!

• screen recording and video encoding with ffmpeg

  2 septembre 2016, par Alexander M.

  1.we need to record screenshots into video with 2-3 fps. Quality - the minimum possible to make text on the screen readable, 256 colors. It is important to reduce the output video file size as much as possible.

  2.we've made a lot of tests, and currently the most suitable way is to make screenshots every 300-500msec, save them in PNG, then run ffmpeg to encode to H.267 with these params:

  ffmpeg -f image2 -i "C:\png5min\image%04d.png" -y -an -vcodec libx264 -preset veryfast -crf 30 "C:\output.mp4"
  

  3.is it the best way to get minimum output size with 2-3fps screencast?

  4.the output file plays very quickly, codec by default concerns that images represent 25fps. But they are 2fps actually. Ok, but if we try to decrease the output frame rate, output file size increases for about twice!! (from 3mb to 6mb for a 3m:26s video). And if we set the output frame rate as 2 - video does not play frames at all or plays just 2 frames for 3mins...:

  -r 2 -f image2 -i "C:\png5min\image%04d.png" -y -an -vcodec libx264 -preset veryfast -crf 30 -r 2 "C:\image5min_2fps_crf30_test__R2-2.mp4"
  

  so, how can we just add some latency after each frame without increasing the output file size???

• screen recording and video encoding with ffmpeg

  2 septembre 2016, par Alexander M.

  1.we need to record screenshots into video with 2-3 fps. Quality - the minimum possible to make text on the screen readable, 256 colors. It is important to reduce the output video file size as much as possible.

  2.we've made a lot of tests, and currently the most suitable way is to make screenshots every 300-500msec, save them in PNG, then run ffmpeg to encode to H.267 with these params:

  ffmpeg -f image2 -i "C:\png5min\image%04d.png" -y -an -vcodec libx264 -preset veryfast -crf 30 "C:\output.mp4"
  

  3.is it the best way to get minimum output size with 2-3fps screencast?

  4.the output file plays very quickly, codec by default concerns that images represent 25fps. But they are 2fps actually. Ok, but if we try to decrease the output frame rate, output file size increases for about twice!! (from 3mb to 6mb for a 3m:26s video). And if we set the output frame rate as 2 - video does not play frames at all or plays just 2 frames for 3mins...:

  -r 2 -f image2 -i "C:\png5min\image%04d.png" -y -an -vcodec libx264 -preset veryfast -crf 30 -r 2 "C:\image5min_2fps_crf30_test__R2-2.mp4"
  

  so, how can we just add some latency after each frame without increasing the output file size???