Video Conversion....

[dsraa]

Hey guys, I just updated to 1.4 and I started converting my vids with gx transcoder

I used xvid video compression for video and mp3 compression for audio, but the audio is not syncing correctly.

Can you guys tell me how to fix this, and what compression or program is best????

AND DON'T TELL ME TO GO SEARCHING TELCOGUY, BECAUSE I DID ALREADY AND ALL I FOUND WAS SOME TOPICS THAT MERELY TALKED ABOUT THIS PROBLEM, BUT DIDN'T FIX IT, AND THEY ARE LIKE 3 MONTHS OLD!!

Any help would be greatly appreciated..

DSR

 

[Mudi]

Run the software patch that comes with your 1.4 patch. There should be a .bin, a .tar.gz, and a .gpu. You need to put the .tar.gz and the .gpu on the root of your SD card and run the .gpu from the Utilities menu.

xVid with mp3 is fine, but the 1.2 mplayer had problems with video/audio sync for some files for some reason.

 

[dsraa]

No, I did that already.

I converted a simpsons, familyguy, and ren&stimpy episodes, and all of them have the audio out of sync. have you tried any other options that work as well?

DSR

 

[k3nn]

Try DivX? *Shrugs*.

 

[TelcoLou]

AND DON'T TELL ME TO GO SEARCHING TELCOGUY, BECAUSE I DID ALREADY AND ALL I FOUND WAS SOME TOPICS THAT MERELY TALKED ABOUT THIS PROBLEM, BUT DIDN'T FIX IT, AND THEY ARE LIKE 3 MONTHS OLD!!

​

I won't tell you to search, but I will ask you to kindly not type with all caps ... and to put your topics in the right forums

 

[dsraa]

AND DON'T TELL ME TO GO SEARCHING TELCOGUY, BECAUSE I DID ALREADY AND ALL I FOUND WAS SOME TOPICS THAT MERELY TALKED ABOUT THIS PROBLEM, BUT DIDN'T FIX IT, AND THEY ARE LIKE 3 MONTHS OLD!!

​

I won't tell you to search, but I will ask you to kindly not type with all caps ... and to put your topics in the right forums

​

Thankyou for doing so, I appreciate it.

DSR

 

[Mudi]

That's odd... all my problems with video/audio sync were fixed by 1.4 firmware. Do they play in sync on a PC?

 

[dsraa]

That's odd... all my problems with video/audio sync were fixed by 1.4 firmware. Do they play in sync on a PC?

​

Actually, no.

I don't know what I'm doing wrong, can you tell me what options you use, and what program?

DSR

 

[xalres]

I use a program called DVDx to rip from DVD to .avi. The options are plentiful and it takes some trial and error to get the correct aspect ratio for the DVD you're trying to rip. Luckily you can stop the encoding process at any point and it still outputs a playable file. I use this to test-view any movies to see if they're squished or not. You'll want to use XVid or DivX encoding (it puts a little DivX logo in the corner of your movie for about 15 seconds when you do this though :angry: ).

Then, if the file is too big for my liking I use Pocket DivX to compress it even further. You'll want to select PC as your output resolution otherwise the aspect ratio is all wonky.

So far I haven't had any sync issues.

 

[Vimacs]

classic pebkac...
through, you may want to try another program,virtualdub and pocket divx are proven to work well.

 

[aapje89]

vemode also works very well, and is noob friendly.

 

[TheFr00n]

I don't know what I'm doing wrong, can you tell me what options you use, and what program?

Okay, if your audio is out of sync even when playing back on a PC, then I think I know what it is.

Are you using VBR mp3?

Because if you are, this is the problem. Now, I'm not saying you *can't* use VBR mp3, just that you have to be careful when you mux the audio and video streams.

You see, VBR audio is not officially supported in AVI files, so often the encoding program will rewrite the mp3 header when joining (muxing) the video and audio streams to make the final AVI file. This rewritten header follows the AVI standard, and assumes a constant bitrate in the audio. But because the bitrate of a VBR file fluctuates based on content, you get a progressive sync loss.

As far as the playback software is concerned, you are in sync, because if the audio were at constant bitrate, then for example at ten minutes into the video, you would be at so many samples into the audio. But because the bitrate of the audio fluctuates in VBR, you're actually somewhere else entirely.

So how do we fix this?

Well, the quickest fix would be to stop using VBR audio and encode at constant bitrate. But this solution is wasteful, both in filesize and quality (arguably not very wasteful but anyway).

I encode the audio separately to the video. To encode the video I use VirtualDubMod (get it at Doom9 in the software section, there are also good tutorials there). When you select your audio stream, VirtualDubMod will warn you of the problem, and allow you to rewrite the header (bad) or ignore it (good) which creates a slightly nonstandard AVI.

The GP2X has no problems playing AVIs with VBR audio, so you'll be okay.

Feel free to ask more questions if you get stuck, but I do urge you to read the tutorials at Doom9.

 

[dsraa]

I don't know what I'm doing wrong, can you tell me what options you use, and what program?

Okay, if your audio is out of sync even when playing back on a PC, then I think I know what it is.

Are you using VBR mp3?

Because if you are, this is the problem. Now, I'm not saying you *can't* use VBR mp3, just that you have to be careful when you mux the audio and video streams.

You see, VBR audio is not officially supported in AVI files, so often the encoding program will rewrite the mp3 header when joining (muxing) the video and audio streams to make the final AVI file. This rewritten header follows the AVI standard, and assumes a constant bitrate in the audio. But because the bitrate of a VBR file fluctuates based on content, you get a progressive sync loss.

As far as the playback software is concerned, you are in sync, because if the audio were at constant bitrate, then for example at ten minutes into the video, you would be at so many samples into the audio. But because the bitrate of the audio fluctuates in VBR, you're actually somewhere else entirely.

So how do we fix this?

Well, the quickest fix would be to stop using VBR audio and encode at constant bitrate. But this solution is wasteful, both in filesize and quality (arguably not very wasteful but anyway).

I encode the audio separately to the video. To encode the video I use VirtualDubMod (get it at Doom9 in the software section, there are also good tutorials there). When you select your audio stream, VirtualDubMod will warn you of the problem, and allow you to rewrite the header (bad) or ignore it (good) which creates a slightly nonstandard AVI.

The GP2X has no problems playing AVIs with VBR audio, so you'll be okay.

Feel free to ask more questions if you get stuck, but I do urge you to read the tutorials at Doom9.

​

Wow, thanks!!

DSR