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• avformat/dovi_isom : Implement Dolby Vision configuration parsing/writing

  1er janvier 2022, par quietvoid

  avformat/dovi_isom : Implement Dolby Vision configuration parsing/writing
  Both parse/write implementations are based on mov/movenc.
  This only adds support for the "Dolby Vision configuration box".
  
  Other configuration boxes, such as
  
  "Dolby Vision enhancement layer configuration box" are not supported.
  The new functions will be used to implement parsing/writing the DOVI config
  
  for Matroska, as well as to refactor both mov/movenc to use dovi_isom functions.
  Signed-off-by : quietvoid <tcChlisop0@gmail.com>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavformat/dovi_isom.c
  • [DH] libavformat/dovi_isom.h

• avformat/mp3dec : replace SAME_HEADER_MASK with MP3_MASK

  11 novembre 2019, par Limin Wang

  avformat/mp3dec : replace SAME_HEADER_MASK with MP3_MASK
  mp3 header bitstream syntax :
  
  header()
  
  
  
      syncword   12bits bslsf
  
      id         1bit    bslsf
  
      layer      2bit    bslsf
  
      protection_bit 1bit bslsf
  
      bitrate_index 4bits bslsf
  
      sampling_frequency 2bits bslsf
  
      padding_bit  1bit bslsf
  
      private_bit 1bit bslsf
  
      mode 2bits bslsf
  
      mode_extension 2bits bslsf
  
      copyright 1bit bslsf
  
      original/home 1bit bslsf
  
      emphasis 2bits bslsf
  
  
  if the header is masking with MP3_MASK(0xFFFE0CCF), below fields will be cleared :
  
  protection_bit, bitrate_index, sampling_freqency, mode
  with SAME_HEADER_MASK(0xFFFE0C00), extra below fields will be cleared which didn't make
  
  sense :
  
  mode_extension, copyright, original/home, emphasis
  As the MP3_MASK is good for same mp3 header masking and is defined in the
  
  header, so it's preferable to remove SAME_HEADER_MASK to keep the masking same.
  Signed-off-by : Limin Wang <lance.lmwang@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavformat/mp3dec.c

• How to use ffmpeg to encode mp4 to mov

  19 avril 2017, par user1526912

  I trying to use ffmpeg to encode a video for the first time. Can anyone tell me the exact command to encode a video in the following format :

  Music Video HD Source Profile

  ● Apple ProRes 422 (HQ)
  ● VBR expected at 220 Mbps
  ● HD encoded dimensions accepted to support square pixel aspect ratios (PASP) :
  Encoded PASP Converted to ProRes From
  1920 x 1080 1:1 HDCAM SR, D5, ATSC
  1280 x 720 1:1 ATSC progressive

  ● HD encoded dimensions accepted to support non-square pixel aspect ratios (this allows you to send HD video in the native dimensions of your best original source, for example in HD broadcast dimensions*) :

  Encoded PASP Converted to ProRes From
  1440 x 1080 1:1.33333 XDCAM-HD, HDCAM
  1280 x 1080 1:1.5 DVCProHD interlaced
  960 x 720 1:1.33333 DVCProHD progressive

  Native frame rate of original source :

  ● 29.97 interlaced frames per second for video sourced
  ● 24 or 25 progressive frames per second for film sourced
  ● 23.976 progressive frames for inverse telecine sourced from film
  ● Telecine materials will not be accepted

  ● HD source may be delivered matted : letterbox, pillarbox, or windowbox.

  Music Video Audio Source Profile

  Stereo
  ● MPEG-1 layer II stereo
  ● 384 kpbs
  ● 48Khz
  ● Included in the same file as the delivered video