Philips DVP642 - numerous problems

[markalot]

Note: I messed up when encoding interlaced video (top frame first was set incorrectly)

All these problems solved, read the thread!

Howdy,

I purchased this player last week and I've discovered the following issues.

DIVX 5.2.1 Pro (I paid for it)
VirtualDub 1.6.2 (need support of DV AVI Type 1)
Lame MP3 ACM 3.96.1 (I use 192kbps CBR)
My player had been flashed to the latest (1109) rom.

My computer is an Athlon XP 2500+ with 1gb ram

1. B Frames (or bi-directional encoding) is not supported. If I encode with bidirectional encoding on, either using DIVX or using XVID with 1 consecutive B frame enabled, I get distortion in the video. The distortion is usually in the lower half of the picture and appears to be a different frame being flashed onto the picture. Bottom line, can't use B frames.

2. Interlaced DIVX not supported. I am taking DV AVI's from a Panasonic digital camcorder and backing them up using DIVX at a bitrate of 4000, home theater profile with B frames turned off. If I maintain interlace, which I want to do since these are backups, it appears the the 642 re-interlaces the interlaced video, producing an unwatchable blink and stutter effect. Using the same settings but de-interlacing all frames looks fine.

3. Even when I get everything looking right I still have the occasional audio sync problem. These sync issues don't seem to be consistent and sometimes are accompanied by brief dropouts or clicks in the audio.

Needless to say I'm pretty dissapointed that I paid a little extra for a name brand player and ended up a box that seems hyper sensitive and NOT fully DIVX compliant.

So, did I make any newbie mistakes that might be causing me problems? All I wanted to do was get a player that would play my DIVX backups of home videos so I wouldn't have to spend time making DVD's and dealing with the lower quality of MPEG2.

[rayray]

All I wanted to do was get a player that would play my DIVX backups of home videos so I wouldn't have to spend time making DVD's and dealing with the lower quality of MPEG2.

First up, I don't think DIVX has superior quality to MPEG2 at DVD bitrates. It's only at low bitrates that DIVX is better than MPEG2. If you make DVD at say 8000kb/s, I don't think a DIVX movie can be of better quality.

Don't worry, you're just going through what I've been through for the 642 a few months back when I first bought it. I'll try to answer your problems one by one :-

1) You must be encoding in 720x480 / 720x576 resolution. For some reason, Philips 642 doesn't handle full screen DVD resolution DIVX very well. Try encoding in say 640x432/640x512, then you won't have problems with b-frames. Alternatively, don't use b-frames and there won't be problem with the video. The problem always come in the same place in the video, so it has something to do with the 642 can't handle those b-frames or something.

2) I don't know the answer to that, as I never encode in interlaced format. What is the reason not to de-interlace it? I always thought de-interlaced material is better for compression.

3) The audio again could be inter-related to the screen resolution. Try encoding in smaller resolution and see if the audio still has problem.

Hope that answers some of your questions. I mainly use my 642 to view downloaded divx/xvid movies from the net, and it handled 99% of those movies.

[markalot]

Don't worry, you're just going through what I've been through for the 642 a few months back when I first bought it. I'll try to answer your problems one by one :-

1) You must be encoding in 720x480 / 720x576 resolution. For some reason, Philips 642 doesn't handle full screen DVD resolution DIVX very well. Try encoding in say 640x432/640x512, then you won't have problems with b-frames. Alternatively, don't use b-frames and there won't be problem with the video. The problem always come in the same place in the video, so it has something to do with the 642 can't handle those b-frames or something.

2) I don't know the answer to that, as I never encode in interlaced format. What is the reason not to de-interlace it? I always thought de-interlaced material is better for compression.

3) The audio again could be inter-related to the screen resolution. Try encoding in smaller resolution and see if the audio still has problem.

Hope that answers some of your questions. I mainly use my 642 to view downloaded divx/xvid movies from the net, and it handled 99% of those movies.

Thanks Ray.

I'll try encoding at a lower resolution to see if that fixes some of the problems. I can live with a slight loss in resolution if it means the videos will play correctly.

I want to keep the video interlaced so I don't lose any detail. AFAIK de-interlacing pretty much throws away 50% of the resolution in scenes with motion.

[rayray]

ok. I missed the part you mentioned about DV. If it's DV, you probably better off leaving it in interlaced. If you're using DIVX pro 5.2.1, I think there is an option to choose for preserving interlace, choose that option and you shouldn't worry about b-frames, as b-frames is not available for interlaced source. Your encoding is probably messed up anyway if you didn't choose the preserve interlace option, as DIVX will assume you have a progressive source.

[markalot]

Howdy,

I messed up. The 642 supports interlaced just fine. For some reason DIVX defaults to Top field first when preserving interlace, I needed to turn that off in order for it to work.

A video recorded interlaced, 4000kbps, 640x432 looked fine, but unfortunatly the audio was out of sync. I haven't had to to experiment with that yet, hopefully it's consistent and I can fix it by setting some delay's in virtual dub.

I'm currently experimenting with XVID to see how it plays.

[markalot]

Ok, all my problems have been solved.

1. 720x480 just doesn't work, with or without bframes, interlaced or not. 640x480 is fine, 640x432 is fine.

2. With the corrected resolution b-frames are not a problem.

3. DIVX 5.2.1 Pro 4000kbps + Lame mp3 192kbps has audio sync problems, but XVID at the same rates does not.

I find it ironic that i have to use XVID to get good results on a DIVX player!

The settings I used to get perfect playback:

Virtual dub 1.6.2
resize filter 640x432 (Lanzcos3)
Lame mp3 audio codec, 48khz, 192 kbps CBR
XVID:

Profile: DXN HT NTSC
Adaptive Quant. Interlaced Encoding
B-VOPs (don't think this matters for interlaced)
Max BVOPs: 2 (yes, 2 worked fine on deinterlaced content at the 640x432 res)

4000 kbps single pass

Looks great and has no audio sync issues. Any ideas why DIVX 5.2.1 would introduce sync issues? Not that it matters as I think XVID looks a lot better.