TMPgenc MPEG-2 Encoding question at DVinfo.net

Matt Vanecek · March 4th, 2007, 10:43 AM

Howdy, y'all

I have Adobe Premiere 1.5.1, Encore 1.5.x, and TMPeg Xpress 4.0. I bought TMPgenc because it generates a noticeably better picture than the MainConcept encoder included with Adobe, and because I don't have the $2K to get the encoder I almost really want (or $50K to get the encoding system I *really* want!).

I'm noticing when watching resulting DVDs that the video has occasional freeze-frames. E.g., on scenes where somebody is turning or something, if I step through the video (with the player remote control), where the video appears to "jump," there are two frames repeated. Over a 114 minute video, I see maybe 8 such repeated-frame occurrences.

I'm using the DVD standard template, with the bitrate set to whatever my bitrate calculator spits out. For 114 minutes, I get about 4800. However, I've noticed the same jumps on higher bitrate (around 6000) video, too (I see the repeated frame problem on all my TMPgenc video). The input video (DV AVI, progressive 16x9) does not exhibit the repeated frames.

I have scrubbed the m2v file, and the repeated frames are in there, so it's not a player problem (plus I tried 3 different players).

Is there some secret to get TMPgenc to not do this frame repeating thing? Right now I'm trying a generic MPEG-2 encode with custom GOP, etc., but is this something others have encountered and worked through, with TMPgenc or other encoders? I really don't want to return to using MainConcept because the picture is poor relative to TMPgenc, but I'd sure like to get rid of the odd repeated frames...

Audio (encode separately from PPro) remains in sync throughout the video, so I'm not *losing* frames...

Thanks,
Matt

Robert M Wright · March 4th, 2007, 11:47 AM

If you take 29.97fps video and convert it to 30fps video, by repeating 1 out of every 1000 frames, you would get around 8 repeated frames in 114 minutes (if I did the rough math in my head close to right). Could that be what's happening?

Matt Vanecek · March 4th, 2007, 12:52 PM

I don't know. I specify 29.97 on all the frame rate fields. I can't imagine that an encoder would arbitrarily round up to 30 without publishing somewhere that's what it was doing. That would be a pretty crappy piece of software, and I would want my money back...

Scrubbing through the original AVI and the .m2v, I can see where a frame is skipped in the .m2v, and then a frame that is repeated twice. It's almost like TMPgenc is saying, "Oops, I missed one, let me just repeat one and maybe they won't notice...".

Thanks,
Matt

Matt Vanecek · March 4th, 2007, 10:26 PM

Well, I tried a customized render, and had the same problem. I tried a 1-I, 5-P GOP structure, and changed some other optimizations, and I get the same exact dropped frame and repeated frame. Is there some formula I'm missing here to successfully convert a DV AVI to an MPEG-2 file? How can MainConcept encode this file without dropping/repeating frames, albeit with a lower-quality picture? If anybody has any configuration tricks for TMPGenc, I'd appreciate it. I've been through several Websites, which tell me to do what I'm already doing...

Thanks,
Matt

March 4th, 2007, 10:43 AM	#1
Matt Vanecek Major Player Join Date: Jul 2005 Location: Denton, TX Posts: 334	TMPgenc MPEG-2 Encoding question Howdy, y'all I have Adobe Premiere 1.5.1, Encore 1.5.x, and TMPeg Xpress 4.0. I bought TMPgenc because it generates a noticeably better picture than the MainConcept encoder included with Adobe, and because I don't have the $2K to get the encoder I almost really want (or $50K to get the encoding system I really want!). I'm noticing when watching resulting DVDs that the video has occasional freeze-frames. E.g., on scenes where somebody is turning or something, if I step through the video (with the player remote control), where the video appears to "jump," there are two frames repeated. Over a 114 minute video, I see maybe 8 such repeated-frame occurrences. I'm using the DVD standard template, with the bitrate set to whatever my bitrate calculator spits out. For 114 minutes, I get about 4800. However, I've noticed the same jumps on higher bitrate (around 6000) video, too (I see the repeated frame problem on all my TMPgenc video). The input video (DV AVI, progressive 16x9) does not exhibit the repeated frames. I have scrubbed the m2v file, and the repeated frames are in there, so it's not a player problem (plus I tried 3 different players). Is there some secret to get TMPgenc to not do this frame repeating thing? Right now I'm trying a generic MPEG-2 encode with custom GOP, etc., but is this something others have encountered and worked through, with TMPgenc or other encoders? I really don't want to return to using MainConcept because the picture is poor relative to TMPgenc, but I'd sure like to get rid of the odd repeated frames... Audio (encode separately from PPro) remains in sync throughout the video, so I'm not losing frames... Thanks, Matt

March 4th, 2007, 11:47 AM	#2
Robert M Wright Inner Circle Join Date: Jan 2006 Location: Minnesota (USA) Posts: 2,171	If you take 29.97fps video and convert it to 30fps video, by repeating 1 out of every 1000 frames, you would get around 8 repeated frames in 114 minutes (if I did the rough math in my head close to right). Could that be what's happening?

March 4th, 2007, 12:52 PM	#3
Matt Vanecek Major Player Join Date: Jul 2005 Location: Denton, TX Posts: 334	I don't know. I specify 29.97 on all the frame rate fields. I can't imagine that an encoder would arbitrarily round up to 30 without publishing somewhere that's what it was doing. That would be a pretty crappy piece of software, and I would want my money back... Scrubbing through the original AVI and the .m2v, I can see where a frame is skipped in the .m2v, and then a frame that is repeated twice. It's almost like TMPgenc is saying, "Oops, I missed one, let me just repeat one and maybe they won't notice...". Thanks, Matt

March 4th, 2007, 10:26 PM	#4
Matt Vanecek Major Player Join Date: Jul 2005 Location: Denton, TX Posts: 334	Well, I tried a customized render, and had the same problem. I tried a 1-I, 5-P GOP structure, and changed some other optimizations, and I get the same exact dropped frame and repeated frame. Is there some formula I'm missing here to successfully convert a DV AVI to an MPEG-2 file? How can MainConcept encode this file without dropping/repeating frames, albeit with a lower-quality picture? If anybody has any configuration tricks for TMPGenc, I'd appreciate it. I've been through several Websites, which tell me to do what I'm already doing... Thanks, Matt