Excessive Bitrate?

[joshbm]

Hi all,

Well I just created a CBR 8.25 mbps video and I try importing it into muxman and it refuses to run... I also have a 1536 kbps PCM audio file. How high can the video bitrate run on a DVD?

I don't know if this is related but: Also I tried Ifoedit, it works and I burnt the DVD and tried playing it on 4 different DVD players... 2 out of the 4 worked. All 4 are compatable with the media I burnt it to (it is what I normally use). Any ideas why the other 2 didn't (just went to reauthor and added video and audio)?

M2V File specs:
16:9
23.976 (pulldown added to 29.97)

Thanks,
joshbm

[Sir Didymus]

This is from DVD Demystified...

[img=http://img299.imageshack.us/img299/1186/image15ez.th.gif] (http://img299.imageshack.us/my.php?image=image15ez.gif)

The absolute (instantaneous) maximum for the video bitrate is 9.8 Mbps.
The total of video + all of the audio strams + all of the supictures + all of the real time text presentation control information (PCI) is the "famous" 10.08 Mbps.

There is most probably something wrong with your assets. Not sure about, but double check in your situation the way pulldown has been added to the video.

Also there are all around some excellent free encoders (Qenc, HC) and some other commercial ones (CCE in primis, or Canopus Procoder, supposedly better for interlaced material) that will provide to you surely compliant video streams. In this case I would recommend using VBR, also in the case you don't worry about the space, since it would be very helpful for keeping the average bitrate down to more "orthodox" values ~4 or even ~5 Mbps. This way you keep an overall excellent quality, with peak bitrate really high, up to the maximum, that is in your case ~ 8 Mbps, considering the PCM audio, but only when such bitrate is necessary, i.e. in the action scenes...

In any case my suggestion is to stay on what Muxman tells you. If the application refuses to mux your streams, change the streams, in order to remove the cause of the trouble, do not change the authoring application...

What is the error message provided by Muxman ?

Cheers,
SD

[mpucoder]

Also make sure you are using the latest version of MuxMan (0.15g), there were a couple problems in older versions. One problem gave a false "excessive bitrate" message even though the mux worked, and the other problem halted the mux when it could have continued.
But a combined constant bitrate of 9.786 is probably too high after adding all the overhead (NAV packs, PES headers, padding stream, LPCM alignment filler, etc). The GOP structure will influence the overhead, it should be as long as allowable (18 NTSC frames, or 15 PAL frames) to keep the overhead low.
The overhead on the audio is constant, every 2048 byte pack contains 2008 bytes of audio. So while 48000 * 32 = 1536000, after packetizing it rises to 1566597.61, or roughly 1.566Mbps
And DVDDemystified's graphic on bitrate is a little misleading. The system multiplex bitrate is 10.08, including the DSI information which that graphic implies gets siphoned off. So 10.08 should be shown as the bitrate after error correction.

[mpucoder]

Just in case anyone would like to know just how high the instantaneous video bitrate can go (and why VBR is the preferred method). In a buffered system such as the standard model for a DVD player, which all authoring programs use to multiplex and all players must comply with as a minimum of performance, the instantaneous peak bitrate would be achieved with a single frame using the entire buffer. This is possible with a low enough average bitrate leading up to the peak, and sufficient time to fill the buffer (MuxMan and many others allow more than enough time to fill the buffer). As you can see by the graphic above, the buffer is 232KB, or 237568 bytes. A little overhead to prevent accidental buffer overflow is allowed, so the maximum most authoring programs will place in the buffer is 237560 bytes. Using the NTSC framerate gives us an instantaneous bitrate of 237560 * 8 * 29.97 = 56,957,385.6bps Of course after the buffer is completely emptied like that the following frames are restricted to less than the bitrate the system can deliver in order to refill the buffer to a safer level.

[Sir Didymus]

...And DVDDemystified's graphic on bitrate is a little misleading. The system multiplex bitrate is 10.08, including the DSI information which that graphic implies gets siphoned off...

Thanks for the clarification mpucoder!
...and agreed... I was aware of this: its evident that PCI+DSI (the DVD system overhead) are always present into the muxed stream, so both of them, into the graphic, should have been showed as present into the track buffer...

That's a little mistake into a nice book...