Which MAX. Bitrate to use if not using Audio ??

[Betamax]

Hi All,

Do you know which is the maximum bitrate I could use for either VCD/SVCD (compliant bitrates) if I'm not using an audio-stream (so only 1 video-stream)?

The point is that if had 4seconds of video, encoded this into either MPeG-1 or MPeG-2, the final (cue-)bin data is less than 4seconds because the audio is missing.

I assume that the max. bitrate of 1150kbps for VCD and 2520kbps for SVCD is accurate if there was an audio-stream encoded using 224kbps.
So my question is, what bitrates could I use for VCD/SVCD if I encode the stream using CBR and am not using any audio-stream and still have at least 4seconds of raw (bin/cd)-image data if the v

(If I knew the algorithme's used in any bitrate-calculator I could figure it out myself).

Tx if you can help me.

[Cobra]

I think the max bitrate for SVCD is 2700Kbps - I'm not too sure about VCD though.

As I say, not sure about that so try it and use a CD-RW, just in case!

Hope this helps!

CobraDMX

[Betamax]

Tx CobraDMX,
I played around and it seems that for SVCD-CBR, I even could go upto 3000kbps (without the audio, so video only) and my standalone DVD-player accepted the mpeg-stream.

Still figuring out for VCD.


To get at least 4seconds RAW material, I must have a MPeG of at least 300 lba-blocks in size (lba : 1 sector at a CD, raw=2352bytes, mpeg=2324bytes), so I must play around to get this size by enlarging the play-length of the source stream.
It's for a new addition to VCDwizard, in which I would be able to create some kind of photo-cd's. So startingpoint is from an Image (which is 1 frame).
I must figure out somekind of algorithm to get this 300lba size while this 300lba is seen from the target mpeg view, while I must enter all settings (amount of frames to create for the source YUV file) at the very beginning after I've converted the image to a YUV file (containing 1 frame).
This is even before the mpeg-encoder has created the GOP's (IBBPBB...), while the size of a I-, B- and P-packet differs as well!

Anyone has an idea for the max-bitrate of VCD (without the audio)?

(almost forgot to mention, that a single mpeg-track at a S/VCD must be at leat 4seconds -so 300lba- in size)

[i_am_dave]

I've run SVCD - VBR bitrate up to 3600 before. Playback gets a little jerky on my Apex player. I think the real limitation that comes into play is in how fast you player can read from CD.

[Cornucopia]

Betamax, I'm surprised. I thought you would know this one already.

Anyway,
You're confusing me with 3 requisites that are somewhat at odds with each other...

1. As per spec, (S)VCD tracks MUST be >/= 4 seconds.

2. As per spec, "Trackable" mpegs MUST include video+audio, even if the audio is silence.

3. But, you want mpegs that aren't limited by the 4 second rule, and don't have to include the audio.

If you truly are working on a PhotoVCD solution (YEAH! ), it would make sense to me to do most of these as segments, not sequences. At least with segments, you have a choice between V only, A only, or AV -- as long as they're all muxed program/system streams. Also, with segments, you don't have the 4 second limitation. The limitation then is, IIRC, 1 segment = 2324 bytes. The time this takes up will depend on bitrate and control info.

Did this help?

Scott