Hi there. I'm using DVD Decrypter to rip a DVD. The info file says there's an audio delay of -80ms. I then use dgindex to give me a avs file i can open in virtual dub. dgindex gives me a AC3 file with no delay (i.e. DELAY 0ms). my question is: does dgindex sense and fix the original delay of -80, or do i have to correct this in VirtualDub (i.e. interleaving dealy -80ms).
any help would be greatly appreciated.
Cheers, Sam
Some DVD already have delay = 0 usually you should see 'audio 80 ms corrected to 0 ms' if you the DVD had it.
If you set Output method : Decode AC3 tracks to WAV, the resulting WAV will automatcally have the A/V delay set to 0. Then you can encode it to AC3 or MP2 with FFMPEG GUI or to MP3 CBR with HeadAC3he. You can do this whan you want to make an AVI with MP3 sound.
If you want to make an AVI with AC3 sound, you can correct the A/V AC3 delay to 0 by loading the D2V with ReJig in IFO Mode keeping checked the box 'correct AC3 delay'.
Instead, if you wand to make a DVD and you have simply put 'Demux' for the trace in DGIndex (I use DVD2AVIDG, which is almost identical), the resulting delay (eg. 80 ms) can be inserted during authoring (so the resulting DVD has A/V delay = 0).
For example, you can set the delay (toghether with the stream language name, which is 'german' by default) in IFOEdit (DVD___DVD Author), once you load the AC3 stream and select it in the 'author' screen (the 'delay' box lights up).
From DGIndex help file:
============= Audio Menu Table of Contents =============
Output Method Table of Contents
Use this option to control audio processing.
Disable - Disables audio processing.
Demux Tracks - Demultiplex (Demux) the selected track(s).
Demux All Tracks - Demultiplex all the available audio tracks.
Decode AC3 Track to WAV - Decode the selected AC3 track to WAV.
DGIndex can demultiplex the following types of audio: LPCM, AC3, MPA, DTS, AAC.
Only AC3 tracks can be decoded to WAV. Use an external audio utility, such as BeSweet, to decode other audio types.
Demuxed audio files will be named after the project name and additional parameters of the audio format.
For example: "MyProject T01 3_2ch 448Kbps DELAY -248ms.ac3".
An important number is contained in the filename of the demultiplexed audio file: the delay correction for the audio relative to the video. In the example above, the audio delay correction is reported as -248 milliseconds. That means that the audio should be advanced by 248 milliseconds. The number -248 could thus be entered directly into VirtualDub's "Audio Skew Correction" edit box to achieve audio/video synchronization. Note that when AC3 tracks are decoded to WAV, their filenames do not contain a delay correction value because the correction is applied during decoding.
==================================================================
Tsk, tsk. You didn't look at the help file, isn't it?
thanks for your reply, but i'm still a little confused. i just want to know if dgindex senses and fixes the audio delay after i rip a dvd with DVD Decrypter (i.e. delay = -80ms). or do i have to wait till i use virtual dub to fix this delay myself. all i need is a yes or no answer.
cheers, sam
If you had read what I wrote, you'd have seen that when DGIndex (or DVD2AVI, or DVD2AVID) decompresses to WAV the AC3 stream, the resolting WAV has no delay since the delay correction is applied during the conversion'.
If you plan to extract an AC3 stream, use ReJig in IFO Mode checking the box 'correct AC3 delay' which makes the same to AC3 streams.
This way, both WAV (which you can later convert to MP3 [with HeadAC3he] or AC3 2ch [with FFMPEG GUI] ) and AC3 6ch will have delay=0 and you won't need to 'fix' them.
Ok, the jigsaw is starting to fall into place :) I use adobe audition to convert the AC3 into Wav. this makes it easy to normalise the volume. Would adobe audition also correct the delay as it converts the AC3 to wav.
Cheers, Sam
