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• FFMPEG Options to increase framebuffer (allow in memory processing) ? [closed]

  28 mars 2021, par GitM

  I convert regulary my video files to current codecs.

  


  I use this to convert video files for apple tv :
ffmpeg -i video_file.abc -c:v libx265 -crf 27 -c:a aac -b:a 128k -tag:v hvc1 video_file_updatedt.mp4

  


  ... and this to convert audio files to ogg :
ffmpeg -i audio_file.abc -c:a libvorbis -q:a 4 audio_file_updated.ogg

  


  Does anyone know how to apply FFMPEG on in-memory files, or is there an option to increase the frame buffer ?

  


• Why iFrame is a good idea

  15 octobre 2009

  I’ve seen some hilariously uninformed posts about the new Apple iFrame specification. Let me take a minute to explain what it actually is.

  First off, as opposed to what the fellow in the Washington Post writes, it’s not really a new format. iFrame is just a way of using formats that we’ve already know and love. As the name suggests, iFrame is just an i-frame only H.264 specification, using AAC audio. An intraframe version of H.264 eh ? Sounds a lot like AVC-Intra, right ? Exactly. And for exactly the same reasons - edit-ability. Whereas AVC-Intra targets the high end, iFrame targets the low end.

  Even when used in intraframe mode, H.264 has some huge advantage over the older intraframe codecs like DV or DVCProHD. For example, significantly better entropy coding, adaptive quantization, and potentially variable bitrates. There are many others. Essentially, it’s what happens when you take DV and spend another 10 years working on making it better. That’s why Panasonic’s AVC-Intra cameras can do DVCProHD quality video at half (or less) the bitrate.

  Why does iFrame matter for editing ? Anyone who’s tried to edit video from one of the modern H.264 cameras without first transcoding to an intraframe format has experienced the huge CPU demands and sluggish performance. Behind the scenes it’s even worse. Because interframe H.264 can have very long GOPs, displaying any single frame can rely on dozens or even hundreds of other frames. Because of the complexity of H.264, building these frames is very high-cost. And it’s a variable cost. Decoding the first frame in a GOP is relatively trivial, while decoding the middle B-frame can be hugely expensive.

  Programs like iMovie mask that from the user in some cases, but at the expensive of high overhead. But, anyone who’s imported AVC-HD video into Final Cut Pro or iMovie knows that there’s a long "importing" step - behind the scenes, the applications are transcoding your video into an intraframe format, like Apple Intermediate or ProRes. It sort of defeats one of the main purposes of a file-based workflow.

  You’ve also probably noticed the amount of time it takes to export a video in an interframe format. Anyone who’s edited HDV in Final Cut Pro has experienced this. With DV, doing an "export to quicktime" is simply a matter of Final Cut Pro rewriting all of the data to disk - it’s essentially a file copy. With HDV, Final Cut Pro has to do a complete reencode of the whole timeline, to fit everything into the new GOP structure. Not only is this time consuming, but it’s essentially a generation loss.

  iFrame solves these issues by giving you an intraframe codec, with modern efficiency, which can be decoded by any of the H.264 decoders that we already know and love.

  Having this as an optional setting on cameras is a huge step forward for folks interested in editing video. Hopefully some of the manufacturers of AVC-HD cameras will adopt this format as well. I’ll gladly trade a little resolution for instant edit-ability.

• Detect rotation angle and rotate final video using ffmpeg version 2.8

  9 novembre 2017, par Hemant Kumar

  I used to work on ffmpeg 2.2 until now and was detecting rotation angle of video uploaded from android / iPhone mobiles and rotate the resulting video so that it run perfectly on a correct angle.

  But since I have updated the ffmpeg to version 2.8 I am getting this rotation problem. My queries are not rotating the videos as they were earlier.

  Here’r the commands I was using :

  To check rotation angle :

  ffprobe -of json -show_streams {$input} | grep rotate

  below is my final command to convert a video to mp4

  "ffmpeg -i {$input} -strict -2 -vcodec libx264 -preset slow -vb 500k -maxrate 500k -bufsize 1000k -vf 'scale=-1:480 ".fix_video_orientation($input)."' -threads 0 -ab 64k -s {$resolution}  -movflags faststart -metadata:s:v:0 rotate=0 {$output}";

  "fix_video_orientation" function is given below. It detect the angle of rotation of the initial video and output optimal option for rotating the final video.

  function fix_video_orientation($input){
  
  
  
  $return= ", transpose=1 ";
  
  
  
  $dd= exec("ffprobe -of json -show_streams  {$input}   | grep rotate");
  
  
  
  if(!empty($dd)){
  
  
  
  $dd=explode(":",$dd);
  
  $rotate=str_replace(",","",str_replace('"',"",$dd[1]));
  
  
  
  if($rotate=="90")return $return;
  
  
  
  else if ($rotate=="180") return ", transpose=2,transpose=2 ";
  
  
  
  else if($rotate == "270") return ", transpose=2 ";
  
  }

  Currently above script is supporting "flv","avi","mp4","mkv","mpg","wmv","asf","webm","mov","3gp","3gpp" extensions, also the script is supporting the resulting .mp4 file to play on all browsers and devices.

  Now the ffprobe command is not returning rotation angle and so a portrait video if uploaded from iphone is showing as landscape on the website.

  Output console of ffprobe command :

  ffprobe version N-77455-g4707497 Copyright (c) 2007-2015 the FFmpeg developers
  
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04)
  
  configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --mandir=/usr/share/man --enable-avresample --disable-debug --enable-nonfree --enable-gpl --enable-version3 --enable-libopencore-amrnb --enable-libopencore-amrwb --disable-decoder=amrnb --disable-decoder=amrwb --enable-libpulse --enable-libdcadec --enable-libfreetype --enable-libx264 --enable-libx265 --enable-libfdk-aac --enable-libvorbis --enable-libmp3lame --enable-libopus --enable-libvpx --enable-libspeex --enable-libass --enable-avisynth --enable-libsoxr --enable-libxvid --enable-libvo-aacenc --enable-libvidstab
  
  libavutil 55. 11.100 / 55. 11.100
  
  libavcodec 57. 20.100 / 57. 20.100
  
  libavformat 57. 20.100 / 57. 20.100
  
  libavdevice 57. 0.100 / 57. 0.100
  
  libavfilter 6. 21.101 / 6. 21.101
  
  libavresample 3. 0. 0 / 3. 0. 0
  
  libswscale 4. 0.100 / 4. 0.100
  
  libswresample 2. 0.101 / 2. 0.101
  
  libpostproc 54. 0.100 / 54. 0.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/standard/PORTRAIT.m4v':
  
  Metadata:
  
  major_brand : qt
  
  
  
  minor_version : 0
  
  compatible_brands: qt
  
  
  
  creation_time : 2016-02-03 05:25:18
  
  com.apple.quicktime.make: Apple
  
  com.apple.quicktime.model: iPhone 4S
  
  com.apple.quicktime.software: 9.2.1
  
  com.apple.quicktime.creationdate: 2016-02-03T10:52:11+0530
  
  Duration: 00:00:03.34, start: 0.000000, bitrate: 7910 kb/s
  
  Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 63 kb/s (default)
  
  Metadata:
  
  creation_time : 2016-02-03 05:25:18
  
  handler_name : Core Media Data Handler
  
  Stream #0:1(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 720x1280 [SAR 1:1 DAR 9:16], 7832 kb/s, 29.97 fps, 29.97 tbr, 600 tbn, 50 tbc (default)
  
  Metadata:
  
  creation_time : 2016-02-03 05:25:18
  
  handler_name : Core Media Data Handler
  
  encoder : H.264
  
  Stream #0:2(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
  
  Metadata:
  
  creation_time : 2016-02-03 05:25:18
  
  handler_name : Core Media Data Handler
  
  Stream #0:3(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
  
  Metadata:
  
  creation_time : 2016-02-03 05:25:18
  
  handler_name : Core Media Data Handler
  
  Unsupported codec with id 0 for input stream 2
  
  Unsupported codec with id 0 for input stream 3

  If latest version of ffmpeg (2.8) is used to auto rotate the video, can you please suggest me what option I need to add or remove from my final command.