Mpeg1 max bitrate question

[leonb]

Hi

I have a problem when making higher bitrate (>1150) vcd's. When bbmpeg mux my a/v files , I get the following errors:

......
......
video PTS (132876.00ms) underflow at pack 17003 by 94230.67ms
video DTS (132909.37ms) underflow at pack 17007 by 94250.63ms
3900 video underflows (SCR >= PTS or DTS)

NOTE: The resulting file may not play back correctly.
Try reducing the video bitrate or increasing the video and
audio startup delays.
.............................
.............................

The resulting mpeg file plays very jerky in both my computer and standalone dvd player. The dvd player can play up to 6000 kbps svcd files, so I don't think it is high bitrate that makes it choke.

The bitrate of the video file is between 1000-2000 kbps (VBR).
Does the mpeg1 spec have a max bitrate one can not go higher than, or what is the problem?

When I mux the same a/v files in TMPEG , the playback gets better but it is still jerky.

I think it must be the muxing process that cause the errors/jerkiness. Should one change the buffer sizes in bbmpeg setting when using higher(vbr) mpeg1 bitrates, or what?

Thanks for any help.

[Clixo]

as far as i know ( please correct me if i am wrong ) and vcd will have a cbr video stream with 1150bts and one or two audio streams of 224 bts , this will be for a standard but if you want a non standard vcd also known as xvcd you can play with the bitrates as you whant but also with all the riscs that it implies. question have you used cce or tmpeg encoder to make the video stream ? it is said that tmpeg is better to make mpeg1 streams. also have you played the video stream befoure it was muxed, only to chech if befoure the muxing process it was better ?

[leonb]

Hi
I tested both cce and tmpg, and get the same errors. I will try to play video file on its own and see what happens.

[Daagar]

I believe in the advanced options for bbMpeg, you need to set the 'Forced MUX rate' to 0 from whatever its default value is. This should get rid of those errors, and hopefully help the stuttering problem.

[Plantaman]

@Daagar: same problem here. Besides setting the forced mux rate to "0", what else should be selected? Mpeg-1 or VCD? VBR? Add SVCD scan offsets? etc, etc, etc...
I've been multiplexing my MPEG-2 encoded files to MPEG-1 VCD in TMPG, but I wanted to do it with bbMPEG within DVD2SVCD, so that it could manage the VBR better...

Thanks in advance!

@clixomano: sempre ouvi dizer dizer que o CCE era pior que o TMPG a encodar mpeg-1, mas uma vez tentei usar o TMPG para isso no DVD2SVCD e ficou péssimo, péssimo, péssimo... viva o CCE, e viva a nossa selecção :D