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• avutil/frame : Rename av_frame_side_data_get and add wrapper for it

  22 mars 2024, par Andreas Rheinhardt

  avutil/frame : Rename av_frame_side_data_get and add wrapper for it
  av_frame_side_data_get() has a const AVFrameSideData * const *sd
  
  parameter ; so calling it with an AVFramesSideData **sd like
  
  AVCodecContext.decoded_side_data (or with a AVFramesSideData * const
  
  *sd) is safe, but the conversion is not performed automatically
  
  in C. All users of this function therefore resort to a cast.
  This commit changes this : av_frame_side_data_get() is renamed
  
  to av_frame_side_data_get_c() ; furthermore, a static inline
  
  wrapper for it name av_frame_side_data_get() is added
  
  that accepts an AVFramesSideData * const * and converts this
  
  to const AVFramesSideData * const * in a Wcast-qual safe way.
  This also allows to remove the casts from the current users.
  Reviewed-by : Jan Ekström <jeebjp@gmail.com>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] doc/APIchanges
  • [DH] libavcodec/libsvtav1.c
  • [DH] libavcodec/libx264.c
  • [DH] libavcodec/libx265.c
  • [DH] libavutil/frame.c
  • [DH] libavutil/frame.h

• Can't get CBR when converting MP4 to Mono MP3

  28 octobre 2022, par GDP

  Having read at least a dozen other answers, it seems that the b:a 96k parameter should be producing a MP3 with a constant bitrate (CBR), yet I can only get Variable bitrates.

  


  The latest variation of ffmpeg that comes closest is below. I don't believe I'm missing anything, so are the other values interfering ?

  


  UPDATE : replace input/output with the latest results.

  


  From MediaInfo :

  


  General
Complete name                            : C:\3024.mp3
Format                                   : MPEG Audio
File size                                : 124 MiB
Duration                                 : 2 h 59 min
Overall bit rate mode                    : Variable
Overall bit rate                         : 96.0 kb/s
Track name                               : My Title
Writing library                          : LAME3.100
major_brand                              : mp42
minor_version                            : 0
compatible_brands                        : mp42mp41

Audio
Format                                   : MPEG Audio
Format version                           : Version 1
Format profile                           : Layer 3
Duration                                 : 2 h 59 min
Bit rate mode                            : Variable
Bit rate                                 : 96.0 kb/s
Channel(s)                               : 1 channel
Sampling rate                            : 44.1 kHz
Frame rate                               : 38.281 FPS (1152 SPF)
Compression mode                         : Lossy
Stream size                              : 124 MiB (100%)
Writing library                          : LAME3.100


  


  ffmpeg -i 3024.mp4 -metadata title="My Title" -vn -ar 44100 -ac 1 -b:a 96k 3024.mp3

  


  ffmpeg version 4.1.1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 8.2.1 (GCC) 20190212
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --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-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '20221011_regular_3024.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41
    creation_time   : 2022-10-12T06:53:10.000000Z
  Duration: 02:59:59.36, start: 0.000000, bitrate: 1297 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1280x720 [SAR 1:1 DAR 16:9], 1198 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 60k tbc (default)
    Metadata:
      creation_time   : 2022-10-12T06:53:10.000000Z
      handler_name    : ?Mainconcept Video Media Handler
      encoder         : AVC Coding
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 93 kb/s (default)
    Metadata:
      creation_time   : 2022-10-12T06:53:11.000000Z
      handler_name    : #Mainconcept MP4 Sound Media Handler
Stream mapping:
  Stream #0:1 -> #0:0 (aac (native) -> mp3 (libmp3lame))
Press [q] to stop, [?] for help
Output #0, mp3, to '20221011_regular_3024.mp3':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41
    TIT2            : Regular Meeting on Tuesday, October 11th, 2022
    TSSE            : Lavf58.20.100
    Stream #0:0(eng): Audio: mp3 (libmp3lame), 44100 Hz, mono, fltp, 96 kb/s (default)
    Metadata:
      creation_time   : 2022-10-12T06:53:11.000000Z
      handler_name    : #Mainconcept MP4 Sound Media Handler
      encoder         : Lavc58.35.100 libmp3lame
size=  126556kB time=02:59:59.36 bitrate=  96.0kbits/s speed= 126x
video:0kB audio:126555kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000393% ```


  


• Trouble with CoCCA Registry

  7 octobre 2012, par Multimedia Mike — General

  I’ve been rather despondent all week. People who see me daily could readily identify this fact. Unfortunately, the exact reason was difficult to adequately explain. The problems that nerds deal with…

  When A Domain Expires
  As a few people noticed, the multimedia.cx domain and all of it’s subdomains didn’t work this last week. The problem started on Monday, October 1. Whose fault ? Well, fundamentally, I neglected to renew the domain name in time. However, I prefer to place the blame on the .cx domain registrar, CoCCA Registry. You see, they have never developed the technology to email a domain holder with a notice that their domain is about to expire or has already expired.

  This domain is the only one I have ever held so I don’t have a lot of experience in this matter. I wondered if I was crazy for thinking it would be normal for a registrar to send an email or 2 with status updates about your domain. I get the impression from speaking with others that this is indeed normal. I have 3 different email addresses listed under my account at the registrar– 2 at multimedia.cx and a backup gmail account. I checked spam folders after this incident. Then I remembered that I have never received any email notifications from them (although password reset emails show up, so that part thankfully works). Also, their support emails are black holes.

  So, I guess the moral is : be wary of dealing with CoCCA Registry. However, they seem to be the only way to register domains under a wide variety of uncommon country codes.

  By Friday, the domain appeared to have been reinstated, even through the status was officially listed as “renewal-pending” according to the web-based management console. Eventually, as cached DNS results started to time out throughout the day, I started seeing subdomains come back. I excitedly used the ‘dig’ command to count down the seconds until gamemusic.multimedia.cx was accessible on the network I was on (the number after the domain name is the time-to-live or ‘TTL’ value) :

  $ dig +nocmd gamemusic.multimedia.cx +noall +answer
  gamemusic.multimedia.cx. 3      IN      A       174.143.152.251
  $ dig +nocmd gamemusic.multimedia.cx +noall +answer
  gamemusic.multimedia.cx. 2      IN      A       174.143.152.251
  $ dig +nocmd gamemusic.multimedia.cx +noall +answer
  gamemusic.multimedia.cx. 1      IN      A       174.143.152.251
  $ dig +nocmd gamemusic.multimedia.cx +noall +answer
  gamemusic.multimedia.cx. 12962  IN      A       207.45.186.114
  

  Finally, today (Saturday), I received a receipt confirming that the domain has been renewed.

  8 Years Old
  Incidentally, happy eighth birthday to multimedia.cx. It was September, 2004 when I decided to branch out from a simple ISP-based web presence.

  People often ask why I went with the .cx TLD. When I decided I wanted a proper domain name 8 years ago, I found that multimedia.X was already taken for just about every TLD value of X. .cx was a notable exception and was distinctive enough (speaking of .X, though, I see that multimedia.xxx is still up for grabs as of this writing ; I imagine that would come with a whole other set of problems).

  It’s funny that tech nerds often rail against outsourcing too much — email, storage, computing power, web hosting — all to some type of cloud provider under the premise that it could easily be taken away. But this episode teaches me that even having your own domain name is no guarantee of a solid online presence.

  Meanwhile, I have taken proactive steps to avert this same situation from arising again :

  
  
  

  Barring a lack of automated emails from the registrar, I hope a Google Calendar reminder set up a month ahead of expiration will do the trick.