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• Encode iOS compatible h264 audio stream with FFMPEG

  11 octobre 2014, par beamformer

  I am using FFMPEG with Python to encode a low bit rate version of videos that I import. I would like the output to be playable on several devices, including Roku and iOS. This link states that Apple supports H264 High profile, level 4.1 and MP3 audio.

  ffmpeg -preset veryslow -y -profile:v high -level 4.0 -movflags +faststart -codec:a libmp3lame -qscale:a 2 -s 1280x720 out.mp4

  The resulting videos play fine in an HTML5 browser on a computer. However, on the iPhone the video appears but the audio stream does not play. Is there an issue with the mp3 settings ?

  From ffprobe :

  [STREAM]
  
  index=1
  
  codec_name=mp3
  
  codec_long_name=MP3 (MPEG audio layer 3)
  
  profile=unknown
  
  codec_type=audio
  
  codec_time_base=1/44100
  
  codec_tag_string=mp4a
  
  codec_tag=0x6134706d
  
  sample_fmt=s16p
  
  sample_rate=44100
  
  channels=1
  
  channel_layout=mono
  
  bits_per_sample=0
  
  id=N/A
  
  r_frame_rate=0/0
  
  avg_frame_rate=0/0
  
  time_base=1/44100
  
  start_pts=-1105
  
  start_time=-0.025057
  
  duration_ts=2321489
  
  duration=52.641474
  
  bit_rate=94949
  
  max_bit_rate=N/A
  
  bits_per_raw_sample=N/A
  
  nb_frames=2016
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  DISPOSITION:dub=0
  
  DISPOSITION:original=0
  
  DISPOSITION:comment=0
  
  DISPOSITION:lyrics=0
  
  DISPOSITION:karaoke=0
  
  DISPOSITION:forced=0
  
  DISPOSITION:hearing_impaired=0
  
  DISPOSITION:visual_impaired=0
  
  DISPOSITION:clean_effects=0
  
  DISPOSITION:attached_pic=0
  
  TAG:language=und
  
  TAG:handler_name=SoundHandler
  
  [/STREAM]

  I tried using AAC, but did not get good results with the native FFMPEG encoder

• FFMPEG Re-muxing .MKV to MP4\MV4 while retaining Dolby Digital Plus JOC [closed]

  31 décembre 2020, par David F

  My ask is, does anyone have any knowledge of how to remux and keep Enhanced AC-3 with Joint Object Control with FFMPEG.

  


  I would be grateful if anyone could help me out here. I'm remuxing a number of video files from .MKV to .MP4\M4V so they play on the Apple platform (including the TV App). It's important NOT to convert, but to remux.

  


  I have achieved the ability to remux 4K HDR with Dolby Digital Plus in a .MKV to 4K HDR with Dolby Digtial 5.1. MP4. The issue is retaining the Dolby Digital Plus. This contains the ATMOS information for object based sound.

  


  The media players on Apple reports Dolby Digital Plus for the .MKV and Dolby Digital 5.1 for .MP4. I know Dolby Labs to allow free remuxing of Dolby Digital Plus/ Atmos with sample code and information they have uploaded onto Github for developers.

  


  I'm using FFMPEG with the following command :-

  


  ffmpeg -i original.mkv -c:v copy -c:a eac3 -tag:v hvc1 output.mp4

  


  Resulting output from MediaInfo (note .MKV contains only 1 video and 1 audio track)

  


  Audio -----Original.mkv

  


  

  • ID : 2

  


  • Format : E-AC-3 JOC

  


  • Format/Info : Enhanced AC-3 with Joint
Object Coding

  


  • Commercial name : Dolby Digital Plus with Dolby
Atmos

  


  • Codec ID : **A_**EAC3

  


  • Duration : 51 min 51 s

  


  • Bit rate mode : Constant

  


  


  Audio ----- Remuxed.mp4

  


  

  • ID : 2

  


  • Format : E-AC-3

  


  • Format/Info : Enhanced AC-3

  


  • Commercial name : Dolby Digital Plus

  


  • Codec ID : ec-3

  


  • Duration : 51 min 51 s

  


  • Bit rate mode : Constant

  


  


  The remux operation finished in about 1 minute for a 8Gb 4k video file, so I know there is no reencoding.

  


  I can see that .mp4 can take E-AC-3 Joint Object Control (JOC) with the demo files from Dolby labs.

  


  I've also remuxed an MKV to MKV and able to see the same result. The JOC markings have been removed with FFMPEG

  


  Thanks in advanced.

  


  David

  


• What is the difference between yuv420p and yuv420p(tv) ?

  9 novembre 2018, par Aleksandr Shemetillo

  I am trying to implement Fairplay ready browser player (Apple’s DRM).
  A stream that has h264(Main) yuv420p(tv) settings becomes non-working after drm decryption (crashed picture of green color). Converting again the video with a "Main" ffmpeg profile changes the setting to a simple yuv420 and this solves the problem.
  Please explain the difference.
  Or maybe some other changes I don’t see can happen during the conversion ?

  Of course, since we are talking about Fairplay, the problem is observed in Safari on Os X