[MEncoder-users] Lots of decoder errors

[James Hastings-Trew]

James Hastings-Trew wrote:
> I'm re-encoding from a bluray source, and the codec of the video stream 
> in the m2ts file is h264. Couple of things I have noticed - mplayer 
> cannot play the video stream from these kinds of m2ts files, but is able 
> to play vc1 and mpeg2 content from them just fine. So I have to extract 
> the video stream to a raw h264 file with eac3to, and then encode it from 
> there. During encoding, I sometimes get errors that look like these:
>
> [h264 @ 00D857C0]concealing 38 DC, 38 AC, 38 MV errors  A-V:0.000 [5204:0]
> [h264 @ 00D857C0]left block unavailable for requested intra mode at 0 340]
> [h264 @ 00D857C0]error while decoding MB 0 34, bytestream (td)
> [h264 @ 00D857C0]concealing 2040 DC, 2040 AC, 2040 MV errors
> [h264 @ 00D857C0]top block unavailable for requested intra4x4 mode -1 at 
> 101 17
> [h264 @ 00D857C0]error while decoding MB 101 17, bytestream (td)
> [h264 @ 00D857C0]concealing 1988 DC, 1988 AC, 1988 MV errors
> [h264 @ 00D857C0]top block unavailable for requested intra4x4 mode -1 at 
> 93 17
> [h264 @ 00D857C0]error while decoding MB 93 17, bytestream (td)
> [h264 @ 00D857C0]concealing 1996 DC, 1996 AC, 1996 MV errors
> [h264 @ 00D857C0]top block unavailable for requested intra4x4 mode -1 at 
> 37 34
> [h264 @ 00D857C0]error while decoding MB 37 34, bytestream (td)
> [h264 @ 00D857C0]concealing 2040 DC, 2040 AC, 2040 MV errors
> [h264 @ 00D857C0]left block unavailable for requested intra mode at 0 440]
> [h264 @ 00D857C0]error while decoding MB 0 44, bytestream (td)
> [h264 @ 00D857C0]concealing 889 DC, 889 AC, 889 MV errors
> [h264 @ 00D857C0]concealing 279 DC, 279 AC, 279 MV errors-V:0.000 [5100:0]
> [h264 @ 00D857C0]error while decoding MB 70 34, bytestream (td)00 [5100:0]
> [h264 @ 00D857C0]concealing 2040 DC, 2040 AC, 2040 MV errors
> [h264 @ 00D857C0]left block unavailable for requested intra4x4 mode -1 
> at 0 25
> [h264 @ 00D857C0]error while decoding MB 0 25, bytestream (td)
> [h264 @ 00D857C0]concealing 1129 DC, 1129 AC, 1129 MV errors
> [h264 @ 00D857C0]left block unavailable for requested intra4x4 mode -1 
> at 0 25
> [h264 @ 00D857C0]error while decoding MB 0 25, bytestream (td)
> [h264 @ 00D857C0]concealing 1129 DC, 1129 AC, 1129 MV errors
> [h264 @ 00D857C0]concealing 1332 DC, 1332 AC, 1332 MV errors0.000 [5005:0]
>
> I'm not familiar enough with this to know if these are serious errors or 
> just Mencoder being over-informative.
Follow up: watching the resulting encode shows that these are indeed 
visible errors. Some colored macroblocks and at least one case of 
massive smearing. Darn it. Admittedly my version of Mencoder was a tad 
elderly, so I've updated to the latest SVN and see if it has any better 
luck decoding the source properly.