HuffYUV sound & pic problems

[Meeper]

I downloaded and installed the HuffYUV codec, along with the Flying Dutchman's (?) unlock utility. Everything installed fine as far as I can tell, with some good and some bad results through AVI_IO.

Good: excellent quality captures, with no frames dropped at 352x288.

Bad: the AVI playback is very jumpy, even though there are no frames dropped. This wouldn't be a problem (who wants to view the files as AVIs?), except that it is still slightly evident after it has been encoded to MPEG 1 or 2 - the jumps appear to be frame forward jumps, as opposed to pauses. Also the sound comes out very 'burbly', but I have no problems when using the MJPEG codec.

Any ideas on how to solve the problems?

[Dr Mordrid]

HuffYUV is not really a PLAYBACK format.

It's for capture, lossless editing and exporting to another codec (i.e. MPEG-1/2/4 or PICVideo MJPeg @quality 20) with the highest possible quality.

Dr. Mordrid


[This message has been edited by Dr Mordrid (edited 29 August 2000).]

[Meeper]

That's why I wasn't bothered that the AVI file wouldn't play smoothly. The problem is that the resulting MPEG file is still slightly jumpy.

Any idea why I have problems with the sound when capturing with HuffYUV?

[Sillyname]

Just a hunch but how high are your audio levels? Sometimes extremely high levels can cause more trouble than just audio distortion. Are you interleaving your audio?

------------------
Deep is not the root word of depression.

[Meeper]

The line-in level is quite high (as in 'nearly at max'), because if it is set any lower when capturing using MJPEG you can hardly hear a thing. I'll try lowering the level when capturing with HuffYUV to see if that helps matters.

Interleaved audio? Erm, wassat then?

[Meeper]

I tried altering the sounds levels (even down to zero), but the picture problems are still the same. I then uninstalled Huff, and tried a straight YUV capture - the sound & pic problems were still there. So the problem isn't with the HuffYUV codec, but the vid tools. I had the 1.54 installed, so I got rid of it and installed 1.52 - still the same sound and pic problems with the YUV capture.

Any ideas?

[Marijn]

Hi,

I may not have an answer, but yesterday I was recording YUY2 with HuffYUV recompression with Ulead MSP vidcap. When I started the recording I had forgotten that the recording volume was set too high. So I openend up the volume settings from the taskbar and lowered them. MSP reported 0 dropped frames, so I thought every thing went fine. But when I encoded the file to MPEG I say the the file jumped a little forward at the moments I had opened the volumesettings and again when I had closed them.

The only conclusion I can think of is that the number of dropped frames isn't correctly reported. But I haven't tried much with this as a second try worked out just fine. (I don't have time to try all this)

Maybe your system isn't capable of handling the datastream for some reason. Does recording at fullsize MJPEG give any problems?

Marijn

[Meeper]

Nope, no problems in either Avi_IO or PC-VCR. I can record 25fps at 704x576 at 6.6:1 compression ratio (the highest available to me at that capture size), with no dropped frames or sound problems.

What is the "Matrox YUY2 -> force Keyflags" option for? I've tried captures with it selected and deselected, and it makes no difference. It would be nice to know how it should ideally be set though. ;o)

[Meeper]

Hmmm, some very odd developments here. I downloaded & installed the DivX codec, and did a YUY2 capture using DixV as the compressor. The sound still turned out burbly, and the video quality was awful - but there was no jumping in the frames!

[Eric VanHeest]

What happens if you export the audio as a WAV file? That is, is the bad audio inherent in the captured PCM data, or is something about the A/V format causing problems? What audio format do you use for capture (raw PCM? compressed on-the-fly?)

[Flying dutchman]

Meeper,

the "Keyflags" option is needed only if you capture into raw, native YUY2 ( -> not HuffYuv!). The Matrox YUY2 codec is very buggy, among other things it doesn't save the frames as keyframes. This means that applications such as Premiere can't directly seek to a given frame, instead they have to parse the whole file (which takes ages).
The Keyflags option in Avi_io merely corrects this issue... But as I said, it is not needed with HuffYuv (but it doesn't hurt either)

[Meeper]

Originally posted by Eric VanHeest:
What happens if you export the audio as a WAV file? That is, is the bad audio inherent in the captured PCM data, or is something about the A/V format causing problems? What audio format do you use for capture (raw PCM? compressed on-the-fly?)

The exported WAV file sounds exactly the same as the video file soundtrack. I record using AVI_IO (as Virtual Dub drops huge amounts of frames), and the only sound compression available for me to use is the PCM option. I've no idea if it's raw or compressed.


(Thanks for the keyflags info FD)

[Fred H]

Try 11025 Hz audio (PCM)

[Meeper]

Nope, no joy. The sound is still the same.

I've stripped the sountrack from a vid capture, and converted it to MP3 if anyone wants to listen to it (371K). Well you never know, some people can tell you what's wrong with your car engine by listening to it. ;o)
http://website.lineone.net/~steve.hay/strack.mp3

[Eric VanHeest]

Does your audio line in have these effects when recording audio without video, using a program such as Cool Edit (or even Windows skanky sound recorder) ? What sound board or chip are you using? I've had problems with some machines' internal sound cards until I turned off some ridiculous settings in the drivers for their boards (boards that have no "line-in" and instead only a microphone jack are particularly annoying about it).