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• HTML5 Video Compatibility (MP4, WEBM, OGG) in 2021

  19 juillet 2021, par William

  The support of HTML5 video has evolved a lot over the years. I am trying to understand whether the <video></video> element still needs to have three sources : MP4, WEBM, and OGG.

  


  There are a lot of answers throughout StackOverflow with deeply conflicting information - some of which say that you just need MP4 now, others say, MP4 and WEBM are enough, and then finally many say that you need all three (although many of those article are 10 years old).

  


  W3 suggests that either MP4 or WEBM alone would have universal support (Even though I found a 2011 article from Google saying that they would be removing support for MP4/H.264). Wikipedia paints a more complicated picture (as well as listing that Google Chrome does indeed support MP4/H.264). Azure Media services ONLY seems to allow output in MP4, which would suggest to me that MP4 must have widespread compatibility.

  


  Also see Example 1, Example 2, Example 3.

  


  Is there any definitive information on what video types to include in an HTML5 video player to achieve widespread compatibility ?

  


  Background : I am building a Content Management Platform that allows uploading videos. When a new video is uploaded, a conversion process kicks off to convert the video into the required formats. This takes time and CPU/Memory, so if it is possible I would like to convert uploaded videos into as few formats as possible.

  


  p.s. This question HAS been asked before, however, the fundamentals of playing video on the web continually evolve and most of the answers out there have become irrelevant.

  


• Build FFmpeg with libaom using MSYS

  21 février 2021, par Alexander Dyagilev

  I'm trying to build FFmpeg (version 4.3.1) with --enable-libaom for Windows using MSYS and Microsoft Visual C++.

  


  Configure script says : ERROR: aom >= 1.0.0 not found using pkg-config

  


  But I have libaom (built it from sources) and paths to it are specified :

  


  set INCLUDE=%INCLUDE%;%~dp0..\..\libaom-build\prebuilt\include;
set LIB=%LIB%;%~dp0..\..\libaom-build\prebuilt\windows\x64\lib;


  


  This is how I call the configuration script :

  


  ./configure --prefix=$PWD/../../prebuilt/windows/x64 --toolchain=msvc --extra-cflags="-MD" --arch=x64 --disable-x86asm --disable-iconv --disable-network \
--enable-filter=stereo3d --enable-libmp3lame --enable-libaom --enable-libdav1d \
--extra-cflags="-I$PWD/../../../zlib-build/prebuilt/include -I$PWD/../../../libpng-build/prebuilt/include -I$PWD/../../../lame-build/prebuilt/include -I$PWD/../../../libaom-build/prebuilt/include -I$PWD/../../../libdav1d-build/prebuilt/include" \
--extra-ldflags="-L$PWD/../../../lame-build/prebuilt/windows/x64/lib -L$PWD/../../../libaom-build/prebuilt/windows/x64/lib -L$PWD/../../../libdav1d-build/prebuilt/windows/x64/lib"


  


• Need help on handling MPEG4V1 data

  31 janvier 2021, par Gediminas

  I'm in situation where I need to get a chunk of MPEG4V1 (Microsoft MPEG-4 VKI
Codec V1) data located in the beginning of a packet (that was sent by some DVR unit).

  



  Packet structure looks something like this :

  



  

  • Compressed MPEG4 data.

  


  • Long integer - Number of events and tripwires.

  


  • Long integer - Number of events.

  


  • Event - Event's sequence.

  


  • Long integer - Number of tripwires.

  


  • Tripwire - Tripwires sequence.

  


  • Long integer - Cyclical redundant code (CRC).

  


  



  So there is no indication of how to know where does the MPEG4 data ends (Or is there ?),
and from where should I start reading this additional data like "Number of events and tripwires" and etc...

  



  I uploaded two packet's so you could see how the actual data looks like :
recvData1.txt,
recvData2.txt.

  



  I've tried to decode those packets using FFmpeg library with avcodec_decode_video function and by removing byte by byte from the end of my recvData buffer in a hope for any results,
  
but FFmpeg just allways returned with an error messages like this :

  



  


  "[msmpeg4v1 @ 038865a0] invalid startcode",
 "[msmpeg4v1 @ 038865a0] header damaged".

  


  



  I'm not that good specialist on knowing of how does the MPEG4 works from the inside,
but judging by the error messages it's clearly seen that I'm missing some data for decoding at the start of the buffer.

  



  So I'm not sure of what part / kind of MPEG data I'm getting here..
  
Maybe it's some kind of MPEG's "frame" data with it's "end" indication or something ?

  



  I've even compared the start of my recvData buffer to some of MPEG4V1 encoded video files I found on the net "http://www.trekmania.net/clips/video_clips4.htm" to check if the start of my buffer really contains the MPEG data ..and not some kind of DVR vendor specific stuff..

  



  And I noticed that there are about 20bytes of data 
(at the start of my packet data, and in .avi files right after about 180bytes..) 
that looks like some kind of header or something..

  



  Please check this image : "http://ggodis.gamedev.lt/stackOverflow/recvData.jpg"

  



  Maybe someone knows what this part of MPEG4V1 data represents ?

  



  P.S. ..I've checked the CRC values for my received packets and they were correct..