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• HEVC with Alpha Encoding on Windows

  14 juillet 2023, par CodeVortex

  I know, this question has been asked before, but most of the answers to them are very old.

  


  Actually, I am developing a website which uses transparent videos. So, I am using .webm format for them. However, as you know it is not possible to run .webm with transparency on Apple products. So, after researching on internet(stackoverflow etc), I found a solution that I should convert my video into a series of PNGs and then convert them into HEVC with alpha channel. However, according to the research I done, only the Apple hardware can properly encode HEVC with alpha channel.

  


  I am a newbie to these codecs and formats stuff. So, I think that I read somewhere that latest versions of FFMPEG can also encode HEVC with alpha. However, being a noob I can't figure out any way to write a command for this purpose. Being a beginner with almost non-existent skills in this field of expertise, it is nearly impossible for me to understand the documentations correctly. I also tried using shutterencoder and some other tools but failed.

  


  Although, there is a quicktime .mov solution but with that the file size becomes too large for my 10 sec video, almost 334 mb and as you know this size is too large for a animation video on a landing-page style basic website.

  


  So, now my question is there any way to properly encode HEVC with alpha on Windows or Linux to maintain transparency ?

  


  If this is not possible, then is there any other way to create such transparent videos on Windows or Linux which can be played on browsers of Apple devices ?

  


  I am stuck on this for 3 days, So, any type of help is greatly regarded. I am also providing the link to my videos, if someone wants to take a closer look on codes and formats of these videos : Videos Link

  


  P.S : if anyone with a mac device can encode these transparent videos for me, then that would be best and I shall be very grateful to you

  


• Http live stream video segmenting. non-Mac approach

  20 juin 2012, par Agzam

  Anyone knows a good way to use http live streaming tools on non-Mac platforms ?
  Can you tell me at least if there's good alternatives ? I need mediafilesegmenter and mediastreamvalidator.

  Or maybe anyone has a source code or something like that...

  UPD : I've tried different segmenters, most of them are based on Carson's open-sourced segmenter. Now the difference between Apple's mediafilesegmenter and this one, that it takes only a transport stream, not just any video. And I need to segment h264 videos.
  When I use ffmpeg to convert h26s to mpeg-ts I'm getting much bigger files in the end. Even if I try to preserve same audio codec (aac) it changes video codec form avc to mpeg-ts.

  Damn I hate Apple. How can they propose that thing as a standard if they don't even provide workarounds for another platforms.

  I still need to find a way to segment h264 videos, and keep in the segmented files avc and aac codecs.

• ffmpeg messing up audio when copying PCM streams

  2 juin 2022, par lioumens

  I'm using ffmpeg to compress videos, but when trying to copy the audio stream from one video file using the same codec and container, the audio is completely corrupted and unusable.

  


  The video I'm trying to compress has stream data :

  


  $ ffprobe -hide_banner -i testing.mov
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'testing.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 0
    compatible_brands: qt
    creation_time   : 2019-04-25T05:37:35.000000Z
    com.apple.quicktime.make: Apple
    com.apple.quicktime.model: MacBookPro15,2
    com.apple.quicktime.software: Mac OS X 10.14.2 (18C54)
    com.apple.quicktime.creationdate: 2019-04-25T00:28:40-0500
  Duration: 00:06:35.75, start: 0.000000, bitrate: 66117 kb/s
  Stream #0:0[0x1](und): Video: prores (Standard) (apcn / 0x6E637061), yuv422p10le(tv, smpte170m/bt709/bt709, progressive), 1280x720, 65923 kb/s, 29.01 fps, 29.01 tbr, 30k tbn (default)
    Metadata:
      creation_time   : 2019-04-25T05:37:35.000000Z
      handler_name    : Core Media Video
      vendor_id       : appl
      encoder         : Apple ProRes 422
  Stream #0:1[0x2](und): Audio: pcm_s16be (lpcm / 0x6D63706C), 8000 Hz, 1 channels, s16, 128 kb/s (default)
    Metadata:
      creation_time   : 2019-04-25T05:37:35.000000Z
      handler_name    : Core Media Audio
      vendor_id       : [0][0][0][0]


  


  Just working with the audio, I tried to copy the audio into a separate file with ffmpeg -i testing.mov -vn -channel_layout mono -c:a copy tmp.mov, which results in a video file with stream data :

  


  $ ffprobe -hide_banner -i tmp.mov
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'tmp.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf59.16.100
  Duration: 00:06:35.26, start: 0.018000, bitrate: 128 kb/s
  Stream #0:0[0x1]: Audio: pcm_s16be (twos / 0x736F7774), 8000 Hz, mono, s16, 128 kb/s (default)
    Metadata:
      handler_name    : Core Media Audio
      vendor_id       : [0][0][0][0]


  


  It seems the only difference when copying the audio is the original says pcm_s16be (lpcm / 0x6D63706C) while the resulting audio has pcm_s16be (twos / 0x736F7774). My understanding is that twos is Apple Quicktime's FOURCC identifier for signed 16 bit big-endian., which is correct and shouldn't affect the audio.

  


  It seems another forum user had a similar issue, but they were using a hex editor to directly manipulate bits, which I'm not comfortable doing. Is there a fix from within ffmpeg ?

  


  EDIT :
I've uploaded a sample of the clip that has this problem.