mp4 plays but no audio

[ted_simple]

Now I've read a lot here and I've tried Quicktime 6, mpegable ds decoder and 3ivx directshow filters.
They all work more or less (i like 3ivx best), but NONE of them plays the audio.

However the camera application on the ppc can playback video and audio.

What the hell is this? And I dont like Motion JPEG avi cause it's too big.

Converting also seems to be no option: I tried Riverpast Video Cleaner and a heavily upgraded virtual dub mod, but they can't even read the video. Quicktime Pro 6 can at least import the video, but no audio again.

Any ideas?

[ted_simple]

If someone wants to do more research, here are two good sites concerning mp4 players:
http://www.audiocoding.com/wiki/index.php?page=Software+Audio+Players+for+Windows
http://www.rarewares.org/

I've now tried WinMPG Video Convert and the Philips Platform4 Player - only video, as always.

I suppose the audio codec used is not the mp4 AAC LC (low complexity) codec because that's the most common one which can be played back by any mp4 player.

btw, mp4UI shows me a video and a audio stream (like most othre applications), but I can only export the video file and there is no information on the audio codec used, seems to be unknow to any program.

I tried several recorded mp4 files, always the same, and they DO playback video+audio on the ppc.

[ted_simple]

That's about 100 kB/s so I can hardly record more than 5 min. But hey who needs to? At least it can be converted by quicktime uncompressed avi export in no time, and then encoded to whatever you want.

More annoying is the fact that I need to remember getting the file off the pocket pc pretty soon because otherwise I will run out of space. I'd prefer taking a series of snapshots and carrying them around with me.

Well copying the file via USB will take almost as long as the video duration is, and a storage card can't be used because it decreases the recording frame rate significantly.

Motion MJPEG also seems to catch more redundant frames (the same picture in two frames) than mp4, but it's still okay.

[Rudegar]

cant you just record to your device and then copy the recording to your sd card manualy ?

[ted_simple]

Yes I thought of that, it would approximately take the same time as the video duration is. If you really need to do another recording while on the go, you can do that to free your memory.

btw, I chose divx5 250 kbit CBR + mp3 in virtual dub, only took a few seconds to encode a minute and now I've got a file that can be played back equally well on both machines. I'm using beta player for pocketpc, and it plays fine in fullscreen using the ati imageon chipset. File size is comparable to choosing the mp4 format in the first place.

[ted_simple]

mp4 video+audio works with quicktime!! hooray!!
Quicktime always told me it couldn't find the software needed on the server.
But when I opened the mp4 file today, the automatic download of the audio codec succeded.
Even with disabled firewall qt couldn't download the software before. Strange.

And I can export it to uncompressed avi if I need to edit the file with other programs.