Gop too long error in TDA when using CCE Basic and pulldown.exe

[mcpogue]

When I use CCE Basic to encode a 23.976fps elementary stream and then use pulldown.exe (or DGPulldown) to convert to 29.97, I get an error in TDA reporting that the GOP length is too long and I can't author. I don't understand how I can have a stream with legal GOP sizes before pulldown and afterward the GOPs are too long. HELP!

[fritzi93]

When I see that error, I just hit ignore. Don't recall it ever causing a problem.

[mcpogue]

Ignoring doesn't work, TDA completes in seconds and doesn't output working VOBs

[fritzi93]

Ignoring doesn't work, TDA completes in seconds and doesn't output working VOBs

Dunno what to tell you, usually the too-long GOP warning can be ignored. Someone else will no doubt have suggestions.

[manono]

I don't understand how I can have a stream with legal GOP sizes before pulldown and afterward the GOPs are too long.

Because applying pulldown to a 23.976fps progressive stream increases the GOP length. Go into the Advanced screen of CCE. I bet you have N/M set for 5. That's only OK if you're encoding for 29.97fps with no pulldown. When encoding for 23.976fps with pulldown afterwards, N/M should be set for 4 (and M for 3).

[mcpogue]

Thanks for the replies. The strange thing is, when you use a 15
frame GOP in TMPGenc and set 3:2 pulldown playback TDA has no difficulty...wonder why?

[manono]

I don't use TMPGEnc, so I'm only guessing, but if you tell TMPGEnc to apply the pulldown within the encoder, it may be figuring the GOP length after the pulldown, and maybe that's why 15 is OK. Either that or you're wrong. Because CCE doesn't work that way. It wants N/M=4 for 23.976fps progressive whether pulldown is applied during the encoding or afterwards. At least that's what I gather from the convoluted English used in the CCE manual. I apply pulldown afterwards, like you, and if the GOP length is 15 before pulldown, then after pulldown you've got a non-compliant video stream