Could low SVCD bitrate cause freezes ?

[dvbr]

Hi,

I'm trying to convert a DVD of 02:20 h to SVCD splited in 2 discs.

I'm setting CCE2.5 with 3 pass, 1000 min, 1300avg, 2400max, image quality priority 17, no antinoise. Other as usual: progressive, linear quantizer, zigzag scan, no audio
I using bbMpeg to audio and mux, with audio at 224, mux rate 8000, startup delays 180 all, buffer video 256kb, buffer audio 8kb

The problem is:
When play in a Samsung 811 random freezes occur, no matter in action scenes (high bitrate) or slow scenes.

I'm asking this 'cause I have made other SVCDs with higher bitrate min 1600, max 2600 + 224 audio and they work well.

Thanks

[xzarkad]

Yes you are correct. A lower bitrate can cause freezes on standalone players. When the bitrate is too low, the picture can be ahead of the sound (the player notices this, you won't). The player then has to stop the image till it's synchonized with the sound again.

[dvbr]

Hi,

The other posts were lost, but I've tested more and seems that it happens only when mux is done with the bbMpeg. I tested with I-Author muxer and it seems to be ok.

I tried changing the buffers sizes of the bbMpeg muxer, the mux rate with no success. I use the bbMpeg muxer because you can split the video, with I-Author you need to split before, both video and audio.

Thanks

[RoopeT]

A lower bitrate can cause freezes on standalone players. When the bitrate is too low, the picture can be ahead of the sound (the player notices this, you won't). The player then has to stop the image till it's synchonized with the sound again

I have seen this with most of my encodes on my Philis DVD 622 too ...
Why this happens? If the video and audio is encoded and multiplex according to SVCD specs, shouldn't it play on a SVCD compliant DVD player? I mean that to my knowledge thre's no minimum video bitrate in the specs, and the disc can be up to 100 minutes long ... still I can't play these discs on my player!

[sue denim]

Hi !

Everybody in the industry that I've spoken to on the subject of lowbitrates on SVCD, seems to recommend that it shouldn't drop below 1000kb/sec !!
The SVCD spec is not at all clear on this matter

I'm not trying to say this is totally right according to specs, but it's just what info I've managed to gain over the last few months on the subject.
My Pioneer DV-444 has the same problem with lowbitrates.

BTW - just in case you're interested ..... the Ligos LSX-Encoder has a SERIOUS problem with padding the low bitrate setting. Therefore, I recommend not buying/using this encoder if you want 'jitter' free disks!

Hope this helps a bit.

Sue xxx

[RoopeT]

seems to recommend that it shouldn't drop below 1000kb/sec !!

Thanks for this info, this is what I was suspecting already. I asked about this about 6 months ago (I think on Dooms forum, but didn't get any answers, so I though my promlems lay somewhere else).

With the first few SVCD rips I did ~2 years ago I used LSX, but I haven't been playing with that for a while. I didn't have an player back then but used my H+ decoder card for SVCD playback (without promlems) . Now I've found out these discs won't work with my Philips DVD.

[sue denim]

Hey, glad to be of service!

I'll tell you one invaluable little tip ........ download Bitrate Viewer (check the Tools section <--)
When you've done an encode, run it through Bitrate Viewer to REALLY see what's going on with your MPEG encode!

I think you'll find that most of your files that were encoded with LSX will drop to around 200kb/s in the black bits - NOT GOOD AT ALL!!!

Good luck ....... Sue xxx :P

[agent374]

I'm new to encoding via CCE myself and I'm not sure if this works (yet). I have encoded a 500kbps min 1500kbps avg 2500kbps movie in CCE (final fantasy) and muxed via bbmpeg successfully (watched it on my apex all the way through both SVCD discs). Perhaps you could solve your mux rate problems by setting it to zero in bbmpeg. I recall that setting it to zero forces bbmpeg to determine the best mux rate for the movie. Before, I would go with the default values (something along the line of 2300kbps) and would get frequent stutters in video playback. Haven't tried with 1300kbps avg movie yet, it may work. I'm just trying to point out another option using bbmpeg since I don't see anyone mentioning the auto mux rate setting.

[RoopeT]

I have bitrate viewer, but at least with the VBR VCD (MPG1 352x288) I really don't notice anything strange on the spots that hang the player.

The playback problems can't be solved by remuxing: I've tried TMPGEnc, BBMPG (also with auto setting), I-Author and Philips SVCD Designer.

When encoding standard SVCD resolution, the bitrate is less likely to drop below the minimum limit (whatever the exact value of it is). Also, with average 1500 kbs problems shouldn't arise yet, but when changing the average to something like 1200 kbs and resolution to 352x576 (or 352x288), the bitrate minimum will probably jump in at some point.

[dvbr]

Hi,

I've been testing again bbMpeg with auto mux rate (0) and got the freezes. But I confirmed that with I-Author muxer it works. With the CCE settings: 1200 min, 1300 avg, 2400 max , the size is 480x480. I could put 1:10 in a 700MB CDR, with audio at 224kbps. It's was possible because the video is 2.35:1, so almost the half area is black bars.
The I-Author send a alert about the A/V sync, probably because of some bitrate peak above 2400, but my player can play high bitrates.
I will try to put 2 audio tracks by setting the avg bitrate to 1100, and see if the I-Author muxer works.


Regards