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• Why Do Some of the Codecs in FFMPEG's Supported Codec List Show "encoders :" or "decoders :" in Parenthesis ?

  4 mai 2020, par spaceman

  If you open the Command Prompt, and run ffmpeg -codecs,
  
you will get a long list of Codecs that FFMPEG supports.

  



  Here's a small sample of the list :

  



   DEV.L. h261                 H.261
 DEV.L. h263                 H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2
 D.V.L. h263i                Intel H.263
 DEV.L. h263p                H.263+ / H.263-1998 / H.263 version 2
 DEV.LS h264                 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (encoders: libx264 libx264rgb)
 D.V.LS hevc                 H.265 / HEVC


  



  Now If you briefly go over the whole list,
  
you see that most Codecs in this list appear with their Name and Description,
  
but some of the Codecs also include parenthesis in the Description, and in the parenthesis,
  
they specify "encoders :" or "decoders :".

  



  For example :

  



  1)

  



   DEV.LS h264                 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (encoders: libx264 libx264rgb)


  



  2)

  



   DEVILS jpeg2000             JPEG 2000 (decoders: jpeg2000 libopenjpeg) (encoders: jpeg2000 libopenjpeg)


  



  3)

  



   DEV.L. msmpeg4v3            MPEG-4 part 2 Microsoft variant version 3 (decoders: msmpeg4) (encoders: msmpeg4)


  



  4)

  



   DEA.L. aac                  AAC (Advanced Audio Coding) (encoders: aac libvo_aacenc)


  



  5)

  



   DEA.L. amr_nb               AMR-NB (Adaptive Multi-Rate NarrowBand) (decoders: amrnb libopencore_amrnb) (encoders: libopencore_amrnb)
 DEA.L. amr_wb               AMR-WB (Adaptive Multi-Rate WideBand) (decoders: amrwb libopencore_amrwb) (encoders: libvo_amrwbenc)


  



  My question :

  



  Why do some Codecs have those parenthesis, specifying Encoders/Decoders,
  
while other (in fact : most) codecs don't have these parenthesis ?

  


• Build h323plus support h264 and h263

  8 février 2019, par Ильдар Нурмухаметов

  Try build H323Plus(latest version) with support H263 and H264 codes.

  From config.log found error :

  /usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /tmp/ccLlS6ND.o: in function `main':
  
  conftest.c:(.text.startup+0x7): undefined reference to `h263p_encoder'
  
  collect2: error: ld returned 1 exit status

  It seems h263p_encoder not found from avcodec.

  FFmpeg(latest 4 version ) build with params :

  --enable-libx264 --enable-libxvid --enable-libx265 --enable-gpl --disable-x86asm --enable-shared --prefix=/usr --libdir=/usr/lib64

  This codecs I see from FFmpeg. If execute command ffmpeg —codecs :

  DEV.L. h263                 H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2 (decoders: h263 h263_v4l2m2m ) (encoders: h263 h263_v4l2m2m )
  
  D.V.L. h263i                Intel H.263
  
  DEV.L. h263p                H.263+ / H.263-1998 / H.263 version 2
  
  DEV.LS h264                 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (decoders: h264 h264_v4l2m2m h264_cuvid ) (encoders: libx264 libx264rgb h264_nvenc h264_v4l2m2m nvenc nvenc_h264 )

  Can any help please. I try build project from Ubuntu 18.04 and Opensuse 15.0

• What version of ffmpeg is bundled inside electron ?

  7 août 2020, par greghmerrill

  The prebuilt electron binaries for Windows include the file ffmpeg.dll. How can I determine what version of the underlying ffmpeg library is actually compiled to produce this dll ? I need this information to understand what known vulnerabilities (CVE's, etc) might be in a given version of electron via ffmpeg.

  



  As I understand it, the ffmpeg dll itself is taken from https://github.com/electron/nightlies/releases/ when I download my dependencies (I'm using electron-prebuilt-compile). But I'm not getting a clear picture of what the source for that binary is. I think it might be from https://chromium.googlesource.com/chromium/third_party/ffmpeg/ but then I'm not clear on the relationship of that repo with the original ffmpeg repo (e.g. how often are fixes merged from the ffmpeg repo to the chromium third-party repo, etc.)

  



  I tried searching the content of the dll as per cody's suggestion, but no luck :

  



  $ strings ffmpeg.dll  | grep -i ffmp
FFmpeg video codec #1
Huffyuv FFmpeg variant
Not yet implemented in FFmpeg, patches welcome
C:\projects\libchromiumcontent\src\out-x64\static_library\ffmpeg.dll.pdb
ffmpeg.dll


$ strings ffmpeg.dll  | grep -i version
H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2
MPEG-4 part 2 Microsoft variant version 1
MPEG-4 part 2 Microsoft variant version 2
MPEG-4 part 2 Microsoft variant version 3
H.263+ / H.263-1998 / H.263 version 2
On2 VP6 (Flash version)
On2 VP6 (Flash version, with alpha channel)
old standard qpel (autodetected per FOURCC/version)
direct-qpel-blocksize bug (autodetected per FOURCC/version)
edge padding bug (autodetected per FOURCC/version)
strictly conform to a older more strict version of the spec or reference software
minor_version
premiere_version
quicktime_version
Assume this x264 version if no x264 version found in any SEI