Blackmagic Forum

I downloaded two videos from my Wyze v2 cam (4.9.6.241) to my iPhone photo album, and then AirDropped them to my Mac (10.14.6) so I could put them together. There I imported them into DaVinci Resolve (17.1.1), and some bizarre bug resulted in the audio turning into what sounds like a Nintendo soundtrack

This is my first post, so I can't post URLs, but you can replace the DOTs with .s, or perhaps some kind soul can comment on this with the corrected URLs:

https://wwwDOTyoutubeDOTcom/watch?v=lKhKscwpFqI

The 2 original video files are here:

https://wwwDOTkanDOTorg/download/GraymondAscends.MP4

https://wwwDOTkanDOTorg/download/Graymo ... Whisps.MP4

The original video files play properly in QT Player (10.5) or VLC (3.0.12). VLC reports the audio as 16-bit, 8 kHz mono PCM ALAW (alaw). When imported into DaVinci the audio goes adorably awry!

I'm curious if this is a repeatable bug.

edit: fixed "alaw" (stupid auto-correct!)

https://www.kan.org/download/GraymondAscends.MP4
https://www.kan.org/download/GraymondDropsWhisps.MP4


Don't have a solution, obviously resolve doesn't like that audio codec so you'd have to convert it to something else. (no need to convert the video, just the audio).

For instance with ffmpeg :

Code: Select all

ffmpeg -i GraymondAscends.MP4 -c:v copy -ar 48000 -c:a pcm_s24le GraymondAscends.mov

You've discovered a hidden plugin. The undocumented nintendoFX feature

RikshaDriver wrote:You've discovered a hidden plugin. The undocumented nintendoFX feature

smunaut wrote:Don't have a solution, obviously resolve doesn't like that audio codec so you'd have to convert it to something else. (no need to convert the video, just the audio).

For instance with ffmpeg :

Code: Select all

ffmpeg -i GraymondAscends.MP4 -c:v copy -ar 48000 -c:a pcm_s24le GraymondAscends.mov

Thanks for the tip, and for posting my links.

Is there a place to submit a bug request?

Is 16-bit, 8 kHz mono PCM ALAW (alaw) a common codec/format for audio that Resolve should be . . . resolving?

I've never seen that codec used before ... didn't even know you could do 16 bit non linear ...

smunaut wrote:I've never seen that codec used before ... didn't even know you could do 16 bit non linear ...

I wondered whether VLC was reporting it correctly, so I tried ffplay:

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Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/steven/Desktop/temp/DeleteMe/GraymondAscends.MP4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isom
  Duration: 00:00:36.80, start: 0.000000, bitrate: 786 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080, 722 kb/s, 15 fps, 15 tbr, 90k tbn, 30 tbc (default)
    Metadata:
      encoder         : JVT/AVC Coding
    Stream #0:1(und): Audio: pcm_alaw (alaw / 0x77616C61), 8000 Hz, 1 channels, s16, 64 kb/s (default)
   3.07 A-V: -0.023 fd=  19 aq=   15KB vq=  167KB sq=    0B f=0/0   

Resolve will not read an 8khz audio file and automatically resample it to 48k. You will have to do it in something like Handbrake or Shutter Encoder.

smunaut wrote:

Code: Select all

ffmpeg -i GraymondAscends.MP4 -c:v copy -ar 48000 -c:a pcm_s24le GraymondAscends.mov

Yup! After a quick transcode, Resolve can import them properly:

TheWaterbug wrote:Is there a place to submit a bug request?

Is 16-bit, 8 kHz mono PCM ALAW (alaw) a common codec/format for audio that Resolve should be . . . resolving?

The recent update to 17.2 does not fix this bug/omission.