1

Topic: LSMASHAudioSource with Avisynth and 24bit audio

Hi, I am having a problem with LSMASHAudioSource decoding multichannel PCM 24bit audio in a Quicktime Prores file (same file with 16bit audio works fine).  When I try and decode using Avisynth all I get is white noise.

Here is my Avisynth script:

v = LSMASHVideoSource(source="iTunes_Test_File_Small.mov", format="YUY2")
a1 = LSMASHAudioSource(source="iTunes_Test_File_Small.mov", track=2)
a2 = LSMASHAudioSource(source="iTunes_Test_File_Small.mov", track=3)
a3 = LSMASHAudioSource(source="iTunes_Test_File_Small.mov", track=4)
a4 = LSMASHAudioSource(source="iTunes_Test_File_Small.mov", track=5)
a5 = LSMASHAudioSource(source="iTunes_Test_File_Small.mov", track=6)
a6 = LSMASHAudioSource(source="iTunes_Test_File_Small.mov", track=7)
a7 = LSMASHAudioSource(source="iTunes_Test_File_Small.mov", track=8)
a = MergeChannels(a1,a2,a3,a4,a5,a6,a7)
AudioDub(a,v)
ColorMatrix(mode="Rec.709->Rec.601", clamp=0)
Spline64Resize(720, 480)
AssumeFPS(2997, 125)

What am I doing wrong?

2

Re: LSMASHAudioSource with Avisynth and 24bit audio

May be LSMASHAudioSource doesn't support 24bit PCM.
Does the same happen when using LWLibavAudioSource?
If you upload a small sample somewhere and send me a link I can look into it some more.

3

Re: LSMASHAudioSource with Avisynth and 24bit audio

Hi Selur, I tried exactly the same thing with LWLibavAudioSource and no white noise, just good audio.
I have sent you a PM with a link to a small sample, if you could take a look I would really appreciate it.

Kind regards.

4

Re: LSMASHAudioSource with Avisynth and 24bit audio

I can reproduce the white noise problem. smile

LoadPlugin("G:\Hybrid\avisynthPlugins\LSMASHSource.dll")
LoadPlugin("G:\Hybrid\avisynthPlugins\ColorMatrix.dll")
v = LSMASHVideoSource(source="Small_Sample_24bit_Audio.mov", format="YUY2")
v = v.ColorMatrix(mode="Rec.709->Rec.601", clamp=0)
v = v.Spline64Resize(720, 480)
a1 = LWLibavAudioSource(source="Small_Sample_24bit_Audio.mov", stream_index=1)
a2 = LWLibavAudioSource(source="Small_Sample_24bit_Audio.mov", stream_index=2)
a3 = LWLibavAudioSource(source="Small_Sample_24bit_Audio.mov", stream_index=3)
a4 = LWLibavAudioSource(source="Small_Sample_24bit_Audio.mov", stream_index=4)
a5 = LWLibavAudioSource(source="Small_Sample_24bit_Audio.mov", stream_index=5)
a6 = LWLibavAudioSource(source="Small_Sample_24bit_Audio.mov", stream_index=6)
a7 = LWLibavAudioSource(source="Small_Sample_24bit_Audio.mov", stream_index=7)
a = MergeChannels(a1,a2,a3,a4,a5,a6,a7)
AudioDub(a,v)
AssumeFPS(2997, 125)

Seems to work fine. My guess is that LSMASHAudioSource doesn't support 24bit audio since it was mainly intended for MP4 input. smile

Cu Selur

5

Re: LSMASHAudioSource with Avisynth and 24bit audio

sad That makes me very sad. I need to open very large HD prores files, about 120 GB files, which if i use LWLibavAudioSource it then needs to index the files, which takes about 20 minutes! Unless there is a way to prevent that, or if you have another idea about how i can open and use audio and video prom prores files?

Kind regards.

6

Re: LSMASHAudioSource with Avisynth and 24bit audio

Hmmm,.. you can try if setting 'cache = true' helps, this way LWLibavAudioSource will create the index inside the RAM, which might speed up things, but it also could cause Avisynth to use too much RAM. (Using Avisynth/Avisynth+/Vapoursynth 64bit and a 64Bit LWLibavAudioSource might help with the general 32bit restriction, but RAM usage might still be huge.)

  • FFAudioSource requires an index.

  • qtinput requires Quicktime to be installed and also only does load the first audio stream iirc.

  • DirectShowSource requires appropriate Direct Show filters inside the system and also only does load the first audio stream

7

Re: LSMASHAudioSource with Avisynth and 24bit audio

Hi Selur, VFR maniac has very kindly, and very quickly, updated his builds of L-SMASH Source to fix this problem. Only problem is how to I get the LSMASHSource.dll, I can see the source over on GitHub, but am unsure of how to compile it. Could you point me in the right direction please?

Kind regards.

8

Re: LSMASHAudioSource with Avisynth and 24bit audio

Sorry, don't know of anyone who provides automatic builds from the latest git source.
the_weirdo offers new builds in his dropbox from time to time: http://www.dropbox.com/sh/3i81ttxf028m1 … asmwa?dl=0

There's also a L-SMASH Works Build Script over at https://github.com/drocon11/lw-build which is probably worth a try.
(never used it)

Cu Selur