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• FFmpeg : What re-encoding settings can be used to achieve results similar to Google Drive's video processing ?

  4 août 2023, par Mycroft_47

  Context :

  


  I have a large collection of videos recorded by my phone's camera, which is taking up a significant amount of space. Recently, I noticed that when I uploaded a video to Google Drive and then downloaded it again using IDM (by clicking on the pop-up that IDM displays when it detects something that can be downloaded here's what i mean), the downloaded video retained the same visual quality but occupied much less space. Upon further research, I discovered that Google re-encodes uploaded videos using H.264 video encoding, and I believe I can achieve similar compression using FFmpeg.

  


  Problem :

  


  Despite experimenting with various FFmpeg commands, I haven't been able to replicate Google Drive's compression. Every attempt using -codec:v libx264 option alone resulted in videos larger than the original files.

  


  While adjusting the -crf parameter to a higher value and opting for a faster -preset option did yield smaller file sizes, it unfortunately came at the cost of a noticeable degradation in visual quality and the appearance of some visible artifacts in the video.

  


  Google Drive's processing, on the other hand, strikes a commendable balance, achieving a satisfactory file size without compromising visual clarity, (I should note that upon zooming in on this video, I observed some minor blurring, but it was acceptable to me).

  


  Note :

  


  I'm aware that using the H.265 video encoder instead of H.264 may give better results. However, to ensure fairness and avoid any potential bias, I think the optimal approach is first to find the best command using the H.264 video encoder. Once identified, I can then replace -codec:v libx264 with -codec:v libx265. This approach will ensure that the chosen command is really the best that FFMPEG can achieve, and that it is not solely influenced by the superior performance of H.265 when used from the outset.

  


  Here's the FFMPEG command I am currently using :

  


  ffmpeg -hide_banner -loglevel verbose ^
    -i input.mp4 ^
    -codec:v libx264 ^
    -crf 36 -preset ultrafast ^
    -codec:a libopus -b:a 112k ^
    -movflags use_metadata_tags+faststart -map_metadata 0 ^
    output.mp4


  


  





  


  


  


  


  


  


  


  



  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  Video file	Size (bytes)	Bit rate (bps)	Encoder	FFPROB - JSON
  Original (named 'raw 1.mp4')	31,666,777	10,314,710	!!!	link
  Without crf	36,251,852	11,805,216	Lavf60.3.100	link
  With crf	10,179,113	3,314,772	Lavf60.3.100	link
  Gdrive	6,726,189	2,190,342	Google	link

  


  


  Those files can be found here.

  


  Update :

  


  I continued my experiments with the video "raw_1.mp4" and found some interesting results that resemble those shown in this blog post, (I recommend consulting this answer).

  


  In the following figure, I observed that using the -preset set to veryfast provided the most advantageous results, striking the optimal balance between compression ratio and compression time, (Note that a negative percentage in the compression variable indicates an increase in file size after processing) :


  


  In this figure, I used the H.264 encoder and compared the compression ratio of different outputted files resulting from seven different values of the -crf parameter (CRF values used : 25, 27, 29, 31, 33, 35, 37),


  


  For this figure, I've switched the encoder to H.265 while maintaining the same CRF values used in the previous figure :


  


  Based on these results, the -preset veryfast and a -crf value of 31 are my current preferred settings for FFmpeg, until they are proven to be suboptimal choices.
As a result, the FFmpeg command I'll use is as follows :

  


  ffmpeg -hide_banner -loglevel verbose ^
    -i input.mp4 ^
    -codec:v libx264 ^
    -crf 31 -preset veryfast ^
    -codec:a libopus -b:a 112k ^
    -movflags use_metadata_tags+faststart -map_metadata 0 ^
    output.mp4


  


  Note that these choices are based solely on the compression results obtained so far, and they do not take into account the visual quality of the outputted files.

  


• ffmpeg : Convert a legally purchased video on Google

  24 avril 2020, par Heycava

  I've bought a video on the Google Play Store. I need to have it on my computer in order to edit it for a video montage. But Google says "Important : You cannot download movies and TV shows onto a PC, Mac, and other laptops or computers."

  



  The video has a YouTube link. As I paid for it, I can watch it. I've managed to get the video part and the audio thanks to some web tools.
The video is a .webm file and the audio a .m4a file.

  



  I can hear the audio with VLC but I can't watch the video. Even if VLC displays "21:42" for the timecode.

  



  Here are informations for the webm file (from MediaInfo) :

  



  General
Complete name                            : XXX\videoplayback.webm
Format                                   : WebM
Format version                           : Version 4 / Version 2
File size                                : 357 MiB
Duration                                 : 21 min 42 s
Overall bit rate                         : 2 301 kb/s
Writing application                      : google/video-file
Writing library                          : google/video-file

Video
ID                                       : 1
Format                                   : VP9
Codec ID                                 : V_VP9
Duration                                 : 21 min 42 s
Bit rate                                 : 2 203 kb/s
Width                                    : 854 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 23.976 (24000/1001) FPS
Bits/(Pixel*Frame)                       : 0.224
Stream size                              : 342 MiB (96%)
Language                                 : English
Default                                  : Yes
Forced                                   : No


  



  It seems to be a good video file.

  



  I wanted to convert it with some video converters but none of them works. So I've tried to download ffmpeg, I renamed the video to "video.webm" and tried a lot of commands. But none of them worked.

  



  Here are informations from ffprobe command :

  



  C:\Users\XXX\Downloads\ffmpeg-20200424-a501947-win64-static\bin>ffprobe -i video.webm


  



  Results :

  



  ffprobe version git-2020-04-24-a501947 Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 42.102 / 56. 42.102
  libavcodec     58. 81.100 / 58. 81.100
  libavformat    58. 42.101 / 58. 42.101
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 79.100 /  7. 79.100
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
[vp9 @ 00000284720d5f40] Invalid frame marker
    Last message repeated 111 times
[vp9 @ 00000284720d5f40] Profile 4 is not yet supported
[vp9 @ 00000284720d5f40] Invalid frame marker
    Last message repeated 6 times
[matroska,webm @ 00000284720cd840] decoding for stream 0 failed
[matroska,webm @ 00000284720cd840] Could not find codec parameters for stream 0 (Video: vp9 (Profile 0), none, 854x480): unspecified pixel format
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, matroska,webm, from 'video.webm':
  Metadata:
    encoder         : google/video-file
  Duration: 00:21:42.05, start: 0.000000, bitrate: 2301 kb/s
    Stream #0:0(eng): Video: vp9 (Profile 0), none, 854x480, SAR 1:1 DAR 427:240, 23.98 fps, 23.98 tbr, 1k tbn, 1k tbc (default)
    Metadata:
      enc_key_id      : [24 characters I prefer not to display]


  



  If ever I initiate a conversion, I get :

  



  [vp9 @ 0000019038a80980] Invalid frame marker
[vp9 @ 0000019038c0fe40] Invalid frame marker
[vp9 @ 0000019038c193c0] Invalid frame marker
[vp9 @ 0000019038c1e780] Invalid frame marker
[vp9 @ 0000019038c29100] Invalid frame marker
[vp9 @ 0000019038c324c0] Invalid frame marker
[vp9 @ 0000019038c3d480] Invalid frame marker
[vp9 @ 0000019038c47280] Invalid frame marker
Error while decoding stream #0:0: Invalid data found when processing input
[vp9 @ 0000019038c4c080] Invalid frame marker
Error while decoding stream #0:0: Invalid data found when processing input
[vp9 @ 0000019038a80980] Invalid frame marker


  



  etc.
Then :

  



  Error while decoding stream #0:0: Resource temporarily unavailable
    Last message repeated 243 times
Error while decoding stream #0:0: Resource temporarily unavailabletrate=  -0.0kbits/s speed=N/A
    Last message repeated 306 times
Error while decoding stream #0:0: Resource temporarily unavailabletrate=  -0.0kbits/s speed=N/A
    Last message repeated 190 times


  



  I've already checked on the Internet solutions for the raised issues :

  



  

  • Invalid frame marker

  


  • unspecified pixel format

  


  • Consider increasing the value for the 'analyzeduration' and 'probesize' options

  


  



  But it didn't work in my case.

  



  Obviously, I can watch the video on YouTube when I'm logged into my purchase account. I presume they have a high level security algorithm, that's why I can't do nothing. Mayve there is something with the "enc_key_id" in the metadata, they get it and the video can only be read with it. I don't know.

  



  I find it unacceptable not to be able to use freely my purchased videos.

  



  Would anyone have an idea ?

  


• Presentation of Piwik’s collaborative translations platform : oTrance [Interview]

  19 avril 2013, par matt — Community, translation

  Piwik enables domain administrators, hobbyists, power users, personal website builders and everyone in between to access enormous amounts of data for website analytics. To support all those users, Piwik needs to be available in a number of different languages. From the start, we made internationalization (i18n) part of Piwik’s DNA. There are now dozens active volunteers who help make sure each language is well represented in the latest official release of Piwik. As of now, Piwik is available in 48 languages.

  Recently a new tool became available that makes the translation of Piwik much easier. The software we are using is an open source platform called oTrance. It has made our translation architecture more robust, and it allows us to expedite the timely delivery of high quality and up-to-date translations to the thousands of people who rely on Piwik every day.

  We’ve met with oTrance creator and lead developer Daniel Schlichtholz who answered a few questions for us.

  1. What is oTrance ?
  2. What sets oTrance apart from the other ways to manage translations ?
  3. Now that oTranCe 1.0 is out, what will you be working on next ?

  What is oTrance ?

  oTranCe is the short form of “Online Translation Center”. It was born because I needed a translation platform for my project MySQLDumper.

  Many languages have been added by the community and manual maintenance became more and more time consuming. I wanted to change that. So I searched for an existing platform I could use and tested a lot of approaches. To put a long story short : none of the given solutions satisfied my needs.

  From the view of a translator maintaining a language should be as easy as possible. In most cases they have to install a program on their local machine or the workflow was too difficult. A translator doesn’t want to struggle with technical things ; he just wants to translate the phrases and wants to know the progress.

  That’s the main goal we want to reach : to make the translation process as easy as possible.

  What sets oTrance apart from the other ways to manage translations ?

  Ease of use is one advantage of oTranCe compared to other solutions. Another advantage is that project administrators can install oTranCe on their own server – so nobody is dependant of a third party provider.

  We love to get feedback from other users. User feedback influences the way oTranCe is developed. We believe that this way oTranCe satisfies the requirements of the real world.

  We also have extensive user documentation, in our “Working with oTranCe” wiki. We try to document use cases in an understandable way. We don’t write down marketing buzz words, but try to explain the use from the view of the user/administrator.

  Now that oTranCe 1.0 is out, what will you be working on next ?

  The language files can be exported to version control and oTranCe can commit changes to the target repository. Currently we support export to Subversion, and we are working on a Git export adapter, which will be released soon.

  Another issue we are trying to solve is the context problem. When your project uses many different phrases the translator often doesn’t know in which context the current phrase is used. Version 1.1.0 (not released yet, but you can grab the latest developer version from GitHub) introduces the oTranCe-connector. The idea behind it : a small plug in grabs the used phrases/keys on the current page, and on click this list is submitted to oTranCe, where the translator can edit the words. This way the translator knows in which context these phrases are used. I wrote a small plug in for OXID eShop. Since it is really easy to implement, my hope is that other plug ins for other applications will be added by the community.

  Matthieu : Congratulations Daniel for having created such an awesome Translation Platform. At Piwik we are really thankful for oTranCe, which has resulted in much better translation process, and happier translators. Keep up the good work !

  If you are a Piwik user, and if you want to participate in translating Piwik, please sign up for an account on oTrance and become part of the team making Piwik available in more languages across the world.