Odd frame rate onversion audio sync problem

[flodisar]

Hi,
I have an AVI file which runs at 24.998 fps. If I simply encode it using TMPGenc or Mainconcept MPEG encoder or whatever else I get the audio out of sync. I have tried to use tools such as AVIfrate, but again when I change to 25fps the audio gets out of sync (gradually of course).
I have 10 files and I want to make DVDs of them, so I hope there is a simple solution/tool to fix this.

thankful for help.

[mikiem]

Try V/Dub, feeding it the avi and audio -- if existing orig. audio/video are in sync & same length?

[flodisar]

Thanks for your reply, but what exactly do you mean by feeding?
Yes, they are the same length and in sync.
I load the avi file into V/Dub. It is in 24.998 fps. What do I do next to get it in 25 fps and in sync?

Thankful for further help.

[Joakim_A]

I think that traditional tools expect an NTSC to be either 23.97 or 24 fps or possible 30 fps. A file with 24.998 fps I have never heard of. I would try to extract the audio separatly in GoldWave then increase the speed of the audio to 100.008% or change the time. You can do this under Effects menu>Pitch or use the Time Warp function. Then save it as a Wav and then use this Wav as a separate audio source when encoding in TMPGenc.

Hope it works!

[flodisar]

Thanks for the reply.
I will try that, but I think it is a PAL file because it is almost 25 fps.

[flodisar]

Have never used Goldwave before, but I thought of the sampling rate also... it is 44100 original, will something bget wrong if I resaple it to 48000Hz? Does this matter if I want to make a DVD?

[mikiem]

"Thanks for your reply, but what exactly do you mean by feeding?
Yes, they are the same length and in sync.
I load the avi file into V/Dub. It is in 24.998 fps. What do I do next to get it in 25 fps and in sync? "

With mjpeg avi files, open them in VirtualDub, then under frame rate (part of video menu) set desired fps. May or may not work with other codecs & all file types (for example if you've got vbr mp3). At any rate, if V/Dub will handle it, haven't ever had any sync prob after altering fps.

Or might try altering the headers of the avi file, again depending on codecs used, to show 25 so hopefully encoding to mpg2 will not change fps. My understanding is this is sometimes done with 24 fps content, just played at 25, & while not absolutely correct, isn't noticed.

Or, might try DGPulldown.

RE: audio... the length of the audio file has to match the length of the video, but not being stored in frames like the video, converting fps often leaves existing audio alone. An audio editing prog will allow you to time stretch the audio if it's too short. Ideally you'd demux the audio first, encode the video, change the audio length if needed, then encode audio. Need separate for DVD anyway. & yes, you want your audio at 48 for DVD spec -- it might play at 44 or might not, depending on player.