[MPlayer-users] Error messages when encoding HDTV

[Steven M. Schultz]

On Fri, 26 Dec 2003, Adam Nielsen wrote:

> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> > > > size restrictions for MP at ML or MPEG1 exceeded! (1920x1088).000 [834:102]
> 
> > I think it's exeeding MPEG1 limits, as they are quite low

	MPEG1 is limited to around 4096x4096 or so ;)

	When people say "MPEG1 is limited" what they are really talking about
	is the VCD format which uses a very restricted subset of MPEG-1
	called CPB ("Constrained Parameters Bitstream") and that is limited 
	to 1152 Kbits/s, constant bitrate, 396 macroblocks/frame, and so on.

> That's what I gathered, but why would it print this when it's an MPEG-2 
> stream?  Unless it means that it's either exceeding MPEG1 specs or MPEG-2's 
> MP at ML specs?

	It is printing those messages out (and I have seen them too) because
	MPEG-2 streams are characterized by "Level" and "Profile with Level" .
	MP at ML means 'main profile' at 'mail level'.

	Low Level = MPEG1 Constrained Parameter Bitstream, up to 352x288 at
	    30 frames/sec, maximum of 4Mb/s

	Main Level = MPEG2 Constrained Parameter Bitstream, up to 720x576 at
	     30 frames/sec, maximum of 15-30Mb/s

	High 1440 Level = up to 1440x1088 at up to 60 frames/sec and intended
	     for HDTV applications, maximum bitrate is 60 to 80 Mb/s

	High Level = up to 1920x1088 at up to 60 frames/sec and intended for
	     HDTV, max bitrate is 80 to 100Mb/s

	The various profiles ("SP", "MP", "MVP", "422P") specify additional
	features and/or restrictions ("422P" adds 4:2:2 to the High and Main
	profiles for example).

	So if a player is geared towards MP at ML then it will complain when
	given a MP at HL stream

> I don't know whether this message causes any frames to be skipped though (my 
> computer is waaay to slow to decode HDTV in realtime, and the resolution is 
> too high for the xv overlay of my GF2 anyway) so I guess as long as all the 

	On my nvidia 5200 I use '-vc ffmpeg12mc' and the clip plays smoothly
	and without dropping any frames (and uses almost no cpu time since
	the decoder in the video card is doing most of the work).

	I was using a Matrox card until a few weeks ago but those all have
	a Xv overlay of only 1024x1024 where the nvidia GF4 and up are
	around 2048x2048.

> frames are displayed it wouldn't matter.  Does anyone who has a fast enough 
> PC know whether any frames are dropped?

	HDTV resolution in software only playback is slow even on a Athlon
	2800 (well, it's a dual but that doesn't matter for this).  

	Cheers,
	Steven Schultz