Is it possible to manipulate audio channels in AVI files using avisyth?

[digicube]

Is it possible to manipulate audio channels in AVI files using avisyth without extracting the WAV files?

I have several AVI videos where the left channel is much louder than the right. Mono tapes played on a Stereo equipment most likely. Is it possible to correct this without extracting the WAV files using Avisynth? I will also need to use the TRIM() function to select which audio to manipulate.

It seems most solutions I've found require extracting the WAV files and using WAVSOURCE(), AUDIODUB(), GETCHANNEL(). NORMALIZE().

[sneaker]

WavSource() can open AVI files. As can AviSource(), ffaudiosource(), lwlibavaudiosource(), dss2(), DirectShowSource() and maybe a few others I forgot.

[digicube]

But AUDIODUB doesn't support AVIs which is needed to merge the video and audio together.

[sneaker]

AudioDub() works with any video and audio. It doesn't even know about the source file formats.

[digicube]

Does GetChannel() work with AVI?

[sneaker]

GetChannel() works with any audio. It doesn't even know about the source file formats.

(I hope you see the pattern here. Only the source filter needs to know a file format. Other filters grab the uncompressed video or audio data coming from the previous filter. They don't care if the source was AVI or something else...)

[digicube]

I'm trying to normalize the audio channels separately using the example from http://avisynth.nl/index.php/Normalize

video = AviSource("video.avi")
left_ch = GetChannel(video,1).Normalize
right_ch = GetChannel(video,2).Normalize
return AudioDub(video, MergeChannels(left_ch, right_ch))

I get this error. Getchannel: Attempted to request a channel that didn't exist.

My AVI file is a Type 2 DV file. Here is the MediaInfo.

General
Format                         : AVI
Format/Info                    : Audio Video Interleave
Commercial name                : DV
Format profile                 : OpenDML
File size                      : 24.9 GiB
Duration                       : 2h 3mn
Overall bit rate mode          : Constant
Overall bit rate               : 28.9 Mbps

Video
ID                             : 0
Format                         : DV
Duration                       : 2h 3mn
Bit rate mode                  : Constant
Bit rate                       : 24.4 Mbps
Encoded bit rate               : 28.8 Mbps
Width                          : 720 pixels
Height                         : 480 pixels
Display aspect ratio           : 4:3
Frame rate mode                : Constant
Frame rate                     : 29.970 fps
Standard                       : NTSC
Chroma subsampling             : 4:1:1
Bit depth                      : 8 bits
Scan type                      : Interlaced
Scan order                     : Bottom Field First
Compression mode               : Lossy
Bits/(Pixel*Frame)             : 2.357
Time code of first frame       : 00:55:49;05
Time code source               : Subcode time code
Stream size                    : 24.8 GiB (100%)

Audio
ID                             : 0-0
Format                         : PCM
Muxing mode                    : DV
Muxing mode, more info         : Muxed in Video #1
Duration                       : 2h 3mn
Bit rate mode                  : Constant
Bit rate                       : 1 536 Kbps
Encoded bit rate               : 0 bps
Channel(s)                     : 2 channels
Sampling rate                  : 48.0 KHz
Bit depth                      : 16 bits
Stream size                    : 1.32 GiB (5%)
Encoded stream size            : 0.00 Byte (0%)

[poisondeathray]

Does info() report 2 ch audio ?

AVISource("video.avi")
Info()

[digicube]

It says no audio.


[Attachment 41103 - Click to enlarge]

[sneaker]

Try (one of) the source filters I mentioned in post #2.

[poisondeathray]

So there is no audio, at least "heard" by your AVISource VFW system

Is there audio when you use VLC, MPCHC etc... ?

This is bizarre:

Bit rate                       : 1 536 Kbps
Encoded bit rate               : 0 bps

Stream size                    : 1.32 GiB (5%)
Encoded stream size            : 0.00 Byte (0%)

Makes me think something is corrupted, at least with this video

Try another source filter as sneaker mentioned, and also test a different sample from that batch

[digicube]

Yeah it's the files that is the problem. I use TRIM() to select a section of the videos and everything is working now. Thank for the help.

The files plays fine on VLC and MPCHC though, so they are not corrupt.