I just ran into an odd problem & Google hasn't given me any answers. Strangely enough, I can't even find any mention of this problem, so I'm asking the Great Hive Mind:
I'm editing some video from a Panasonic GH2 DSLR. It's AVCHD, 1080 23.98p, and I'm doing an import w. transcode to DNxHD 115 on a MC 5.5.2 on Windows. Normally, everything works fine with clips of up to 20-25 minutes.
But the GH2 can record a single clip many hours long, by automatically making successive 4GB chunk (just like a nanoFlash or a KiPro). And when you import/transcode successive 4GB files and string them out in the timeline, all the frames are there. But the first frame or two after the cut often show macroblock errors. Visually, this looks sorta like an uncorrectable dropout on a digital videotape, and it's always in areas of motion or picture change. And even though it's just a frame or two, it's really noticable, like a big honking dropout.
I'm guessing that the camera is *not* understanding the long-GOP cadence, which *should* tell it to write a new chunk starting at an I-frame. Instead, it's hitting the 4GB limit at a random frame, so the new chunk may start with a P or B frame, which gives the macroblock errors. (BTW, the successive chunks, played back in-camera, show no macroblock errors at the file boundaries, so I know the original long-GOP data are all there.)
So I'm *guessing* that to solve this problem, I need a software tool that does the following:
* Open up the 1st & 2nd files.
* Parse the encoded bitstream to find the first I-frame of the 2nd file.
* Re-write the 2nd file starting at the I-frame.
* Re-write the 1st file, with the orphaned P & B frames (from the 2nd file) appended at the end, where they belong.
* Rinse & repeat wherever there's a 4GB break.
Anybody know of such a tool? Or any other solution?
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