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• Missing functions in new version of FFmpeg

  25 avril 2013, par Asik

  I am upgrading a wrapper around ffmpeg to the most recent version of the library. Some functions have been renamed or replaced. For the most part I've been able to found equivalents easily, but the following two are giving me trouble :

  av_abort_set_callback
  
  av_abort_default_callback

  I could not find these functions by searching online, so what happened to them and what should they be replaced with now ?

  Here is a copy of the header file "abort.h" where they were located :

  /* 
  
   * This file is part of FFmpeg. 
  
   * 
  
   * FFmpeg is free software; you can redistribute it and/or 
  
   * modify it under the terms of the GNU Lesser General Public 
  
   * License as published by the Free Software Foundation; either 
  
   * version 2.1 of the License, or (at your option) any later version. 
  
   * 
  
   * FFmpeg is distributed in the hope that it will be useful, 
  
   * but WITHOUT ANY WARRANTY; without even the implied warranty of 
  
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
  
   * Lesser General Public License for more details. 
  
   * 
  
   * You should have received a copy of the GNU Lesser General Public 
  
   * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 
  
   */
  
  
  
  #ifndef AVUTIL_ABORT_H
  
  #define AVUTIL_ABORT_H
  
  
  
  /** 
  
   * Causes abnormal program termination. By default, av_abort_callback calls 
  
   * abort() from the stdlib. This behavior can be altered by setting a 
  
   * different av_abort callback function. 
  
   */
  
  
  
  void av_abort_internal(void);
  
  void av_abort_set_callback(void (*)(void));
  
  void av_abort_default_callback(void);
  
  
  
  #define av_abort()    do { av_log(NULL, AV_LOG_ERROR, "Abort at %s:%d\n", __FILE__, __LINE__); av_abort_internal(); } while(0)
  
  
  
  #endif /* AVUTIL_ABORT_H */

• What is the best solution to convert old videos to newer more optimised formats ? [on hold]

  9 septembre 2019, par Jack

  Not too sure if this is the wrong place - please move it as I couldn’t find a more suitable network

  I have loads of media (Movies, TV Shows) as well as home videos (old VHS stuff ripped using some awful VHS to digital kit)

  Most of the movies/TV shows are in H264 (MP4/MKV containers) format, however some older ones are in AVI and WMV - I’d like to convert these into either H264 or a newer format (HEVC ?) To save some disk space and also because WMVs and AVIs are getting harder to deal with nowadays. I’m concerned about losing quality and am wondering what would be the best compromise in terms of converting these to HEVC/MPEG4’s encoder quality settings as compared to the data savings.

  The media collection of TV shows/movies, I don’t mind too much about losing some quality but the home videos/VHS tapes I have in old file formats, the storage factor for these is less important but I was wondering what I’d need to do to convert old AVI’s/MPEG2’s to MPEG4/HEVC - mainly if it is possible to convert one of these old video files to a newer format, without loss of quality, I thought the newer video encoding’s had lossless and lossy compression, but I could be completely wrong and don’t know much about video codecs.

  I was more curious on the best solution to do this as, Googling it gives me loads of commercial software and I’d rather have something which I can use command line/programmatically against my entire libraries. I also couldn’t find anything on these commercial sites about the technicals of re-encoding video so, was wondering if anyone had any experience with any command line applications/have an understanding of the video codecs.

• Camera2 video recording with custom resolutions ?

  14 avril 2020, par Chitrang

  Currently, I am following google's sample code in Kotlin for Camera2 API. Everything seems working fine in terms of video recording. However, I do have different requirements for my project as listed below.

  



  I need to record a video in three possible ways 640 x 640(square), Y x 640(portrait), or 640 x Y(landscape) in portrait screen where Y is a number less than 640. 

  



  640 x 640(square) :
I have Samsung S9+ which supports only one resolution with 1:1 aspect ration which is 384x384, but when I post on Instagram they create a video with 720 x 720 resolution with good quality. So the question is how Instagram is enlarging a low-resolution video without losing quality ?

  



  W ? x 640(portrait) :
I need to find out an equal or high resolution with the closest matching aspect ratio and later on, I can run the FFmpeg command to match with the required size, right ?

  



  640 x H ?(landscape) :
I can follow the same thing as in the portrait use case. However, the real question is how to record a video in the landscape if your screen is in Portrait orientation ?

  



  I have already researched a lot on each use case and now open for any possible solutions like FFMpeg, OpenGL, MediaMuxer, MediaCodec or anything else ?

  



  Any hint, links or suggestion would be highly appreciated. Thanks in advance.