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• Seeking CLI Tool for Creating Text Animations with Easing Curves [closed]

  15 novembre 2023, par anonymous-dev

  I'm working on a video project where I need to animate text using various easing curves for smooth and dynamic transitions with the terminal. Specifically, I'm looking to apply the following easing curves to text animations :

  


  bounceIn
bounceInOut
bounceOut
decelerate
ease
easeIn
easeInBack
easeInCirc
easeInCubic
easeInExpo
easeInOut
easeInOutBack
easeInOutCirc
easeInOutCubic
easeInOutCubicEmphasized
easeInOutExpo
easeInOutQuad
easeInOutQuart
easeInOutQuint
easeInOutSine
easeInQuad
easeInQuart
easeInQuint
easeInSine
easeInToLinear
easeOut
easeOutBack
easeOutCirc
easeOutCubic
easeOutExpo
easeOutQuad
easeOutQuart
easeOutQuint
easeOutSine
elasticIn
elasticInOut
elasticOut
fastEaseInToSlowEaseOut
fastLinearToSlowEaseIn
fastOutSlowIn
linearToEaseOut
slowMiddle


  


  My initial thought was to use ffmpeg for this task, however, it appears that ffmpeg may not support these advanced easing curves for text animation.

  


  I am seeking recommendations for a command-line interface (CLI) tool that can handle these types of animations.

  


  Key requirements include :

  


  

  • Easing Curve Support : The tool should support a wide range of easing curves as listed above.

  


  • Efficiency : Ability to render animations quickly, preferably with performance close to what I can achieve with ffmpeg filters.

  


  • Direct Rendering : Ideally, the tool should render animations in one go, without the need to write each individual frame to disk.

  


  • Should work with transformations such as translate, scale and rotate. For example a text translates from a to b with a basing curve applied to the transition.

  


  


  I looked into ImageMagick, but it seems more suited for frame-by-frame image processing, which is not efficient for my needs.

  


  Could anyone suggest a CLI tool that fits these criteria ? Or is there a way to extend ffmpeg's capabilities to achieve these animations ?

  


• What video format will allow Android MediaPlayer.seekTo() to reliably provide frame-accurate scrubbing ?

  8 juillet 2015, par Tim Closs

  We have an iOS app that we are currently rebuilding for Android. The app relies on being able to scrub video with frame accuracy. We have 3D animations that are rendered out as single frames ; we build subsets of frames into lots of small (1-2 second) videos ; and the app provides the ability to scrub those videos and see each individual frame.

  The MP4 videos we initially created work fine on iOS. When we tried to get them working on Android (using the MediaPlayer class), we entered a world of pain ! What we need to do is find a video format that will play and allow frame-accurate scrubbing across all Android devices, using MediaPlayer.seekTo(). Initially we are targetting Android 3.0 and above, but we probably want to stretch back to 2.3.3 after our initial release. Here’s what I’ve discovered so far :

  (A) Android claims that H264 "baseline profile" should be supported everywhere : (URL). However, within that, there are dozens of other settings that may or may not be supported. Is there a more fine-grained list anywhere ? Currently we are converting to H264 within an MP4 container.

  (B) I haven’t yet seen an Android device that will accurately scrub H264 files without inserting keyframes ("intra frames"). iOS will happily take H264 files without keyframes and provide accurate scrubbing. It seems that, to allow accurate scrubbing, we need to insert a keyframe for every frame of the video (the relevant ffmpeg setting is "-g 1"). This significantly increases the file size.

  (C) However, inserting a keyframe for every frame results in a video that will not play at all on the Samsung Galaxy Note 3 (Snapdragon chipset I believe). Reducing the keyframes to every second frame or above seems to work (ffmpeg setting "-g 2").

  To summarise :
  MediaPlayer.seekTo() seems very dependent on the video format, and varies across devices. Is this the intention ? Is there a base level of behaviour that seekTo() is supposed to provide, regardless of format ?

  What video format that will allow frame-accurate scrubbing (using MediaPlayer.seekTo()) across all Android devices (at least for 3.0 and above ?)

• aarch64 : Use regular hwcaps flags instead of HWCAP_CPUID for CPU feature detection...

  14 février 2024, par Martin Storsjö

  aarch64 : Use regular hwcaps flags instead of HWCAP_CPUID for CPU feature detection on Linux
  This makes the code much simpler (especially for adding support
  
  for other instruction set extensions), avoids needing inline
  
  assembly for this feature, and generally is more of the canonical
  
  way to do this.
  The CPU feature detection was added in
  
  493fcde50a84cb23854335bcb0e55c6f383d55db, using HWCAP_CPUID.
  The argument for using that, was that HWCAP_CPUID was added much
  
  earlier in the kernel (in Linux v4.11), while the HWCAP flags for
  
  individual features always come later. This allows detecting support
  
  for new CPU extensions before the kernel exposes information about
  
  them via hwcap flags.
  However in practice, there's probably quite little advantage in this.
  
  E.g. HWCAP2_I8MM was added in Linux v5.10 - long after HWCAP_CPUID,
  
  but there's probably very little practical cases where one would
  
  run a kernel older than that on a CPU that supports those instructions.
  Additionally, we provide our own definitions of the flag values to
  
  check (as they are fixed constants anyway), with names not conflicting
  
  with the ones from system headers. This reduces the number of ifdefs
  
  needed, and allows detecting those features even if building with
  
  userland headers that are lacking the definitions of those flags.
  Also, slightly older versions of QEMU, e.g. 6.2 in Ubuntu 22.04,
  
  do expose support for these features via HWCAP flags, but the
  
  emulated cpuid registers are missing the bits for exposing e.g. I8MM.
  
  (This issue is fixed in later versions of QEMU though.)
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] libavutil/aarch64/cpu.c