Sony725 tips - CDR, VCD, SVCD, GOP etc

[tnuro]

I own a Sony725 and I'm presenting a few tips for owners of this & similar machines, since there are a few curly problems to watch out for. These notes are probably applicable to some other players too. The Sony seems to be a pretty good machine once you find the tips for it. I started off thinking it was horrible, now I think its a danm fine machine even if a little old now. It seems to handle higher bitrates off cdrs than some of my friends machines by at least 50% or more.


(i) The machine officially does not support CDR or CDRW.,
Many players also do not, but its widely known that if you find the right brand & dye colour, it will play CDR & CDRW. I use Princo, but pretty much any silvery dye will work for my 725. It seems to be able to handle bitrates right upto 3000kbps & possibly beyond (I haven't tested that high yet...soon!)

(ii) The 725 officially only supports (X)VCD. Through a few postings around the place, you can fool it into playing (X)SVCD too. All you need to do is encode as mpeg2, then use the Simple Multiplex tool in tmpgenc (or any equivalent feature in other tools) to re-multiplex the mpeg2 stream as an mpeg1 stream. Make sure you select the Type correctly - should be mpeg1 VCD or non-standard mpeg1 VCD. If you choose anything else it will not work since the Sony725 only knows about VCD. You then burn this resulting file as a VCD setup (in Nero or you favourite burner prog), and the 725 will play it fine....as long as you follow (iii) &(iv)

(iii) the GOP structure becomes crucial on the 725 when creating the (X)SVCD above. In tmpgenc, make sure that the option "Output interval of sequence header" is NOT 0. 0 means that the GOP header will only appear once at the beginning of the file, and the 725 will corrupt its screen permanently if you ff/fr, unless you restart the film from the beginning. Its best to make this '1', you get no corruption at all. Larger intervals will result in corruption for a small number of frames before the header is picked up again. The header takes very little space, so '1' is OK. My guess is that the Sony 'forgets' its playing an mpeg2 file when you ff/fr since its been fooled into thinking its playing an mpeg1. THis option can be left on for (X)VCD since it started playing the file as a genuine (X)VCD.

(iv) Detect Scene Change should be turned off for Sony725. When enabled, this feature will break the GOP sequence (or structure) and place an I frame at scene changes to improve quality. The improvement is not large, and is short lived anyway (a few frames). Many players can handle this but the Sony725 will occasionally have a 1 frame hold at some scene changes (see my other postings in https://www.videohelp.com/phpBB/viewtopic.php?t=59895)

(v) chaptering works fine for the Sony725 for either VCD or SVCD (cool)

(vi) I almost always use high res encoding 720x480/720x576 at about 1800kbps average or higher depending on length of film. I prefer this higher res even if it does mean I have split a movie across 2 cds. The standard res for VCD of 352x288/352x240 or for SVCD 480x576/480x480 just looks a bit too blurry for me.


That's about it. Any issues/tips about quality are really meant for the encoding forum so I'll leave that for you to discover. I like tmpgenc the best for encoding. I haven't tried subtitling or any audio improvements (SVCD audio) yet, its my next area to research

Hope this is useful.
cheers

[Rafta21]

Hi,

I also have a Sony 725, but I have some strange problem with it. I finally found a CD-RW which is accepted by my player. I can use VCDs and with the trick you metioned I can ply even SVCDs. But due to the reason that I only can use this special CDs which has a storage capacity of 650MB I have to merge and cut the movies which I get from my friends. When I merge and cut the movie in TMPGenc everything is OK. After I burned the Movie (with Nero 5) on the CD and want to play it on the Sony, in the middle of the movie the syncronisation of the audio starts to get wrong although it was fine on the computer. This doesn´t happen with each movie but with almost every second one. Do you know an advice?
THX

[Dave B]

Does the Sony support VBR MPEG-1 streams? I have got them to play but it produced audio sync problems. I have only ever had good results with CBR.

Does the SVCD remux trick allow you to play variable bitrate video without audio problems?

What is the advantages in using a remuxed SVCD over a high bitrate & resolution MPEG-1?

[tnuro]

Rafta - yes, there are problems with the 725 if you use the 'auto' option for VBV buffer size in tmpgenc. Simpy type '112' in there for every type of (s)vcd you create and your audio sync problems should dissappear. If not, then your sync problems are probably wrong at the source somehow (maybe a problem with some other tool you're using maybe). Of course, if the movie is already encoded with auto from your friends then you can't just simply remux - you will have to re-encode the movie to fix this problem.
As for the 650MB thing - I have used many different brands of cdrw that are all 80 minute and they all work - its strange that you are having problems as all cdrw cd's are the same dye - its only cdr's that you have to be picky about. I use Princo CDRW & CDR's, but there are plenty of other silver (white) dye cdr's that work too, as I have tested them.

DaveB - yes, the 725 handles VBR perfectly for both mpeg1 & mpeg2, just adhere to the advice about VBV buffer size and you shouldn't have a problem. 112KB is the standard for SVCD, whereas the auto option causes problems. Technically, there is no such thing as CBR, as its just a constrained form of VBR, so ALL players will support VBR, its just the limits of the VBR that the players will vary on.