Interlaced AVCHD files crash in Vista

[WorBry]

I'm having a problem opening interlaced AVCHD clips from both Panasonic and Canon camcorders on my Vista laptop. The mts files open OK on my PC running XP Pro, but in Vista, File Explorer crashes as soon as I open the BDMV Stream folder containing the files, as does every media player and AV application I've tried to open them with. Tried first converting the mts files to mkv and mp4 on my XP Pro PC, but Vista doesnt seem to like them either.

If it's of any relevance, I have both CoreAVCPro and DivX H264 decoders installed on both machines, with CoreAVCPro set as preferred encoder. I also have the Vista codecs pack installed on my laptop, but with FFDShow H264/AVC decoder disabled.

Any ideas what the cause of the problem might be?

I might add that progressive AVCHD clips from the same camcorders open without any problem.

Cheers.

[Selur]

Any idea what the source of the problem might be?
used Splitter&Decoder
(Haalis Splitter and ffdshow work fine here)

[WorBry]

Yes, thanks, the interlaced files appear to open OK with FFDShow H.264/AVC (ffmpeg-mt). Guess I could have tried that before :rolleyes:

But how come progressive AVCHD clips opened OK with CoreAVC?

[Selur]

just because a decoder works fine with progressive material doesn't mean it can handle interlaced material fine too. ;)

[WorBry]

One of the reasons I've been looking at these clips is that (pursuant to eventally purchasing an AVCHD camcorder) I've seen many anecdotal comments on video forums stating that (at least some) AVCHD camcorders employ PAFF interlace encoding. Some even state that PAFF is specifically applied to b-frames only.

Seems a bit unlikely to me, and I suspect these folks are mistakenly applying the term PAFF to conventional (non-adaptive) field-based interlacing. Even so, I'd satisfy my curiosity about this.

DGAVCIndex tells me that the Frame Structure of my sample 1080/50i AVCHD clips (from the new Panasonic HMC-41) is Fields(TFF), but I'm wondering if there is an application (analyzer) out there that can identify and distinguish PAFF from conventional field interlace on a frame-by-frame basis.

Edit: Just tried a demo version of one professional H.264 analyzer (H.264Vista), but it promptly crashes when I try to open the interlaced mts files or extracted H.264 streams.

[poisondeathray]

HMC40/HMC150 North American versions shoot conventional interlaced fields, not MBAFF or PAFF, not sure about Euro spec versions

streameye can tell you if it's MBAFF

[WorBry]

Well, it's definitely not MBAFF - DGAVCIndex tells me that.

Cant imagine that the European camcorder models are any different from the N. American in this respect.

[Mr VacBob]

"Fields" picture structure is PAFF - there's no such thing as "conventional" interlacing, only frame structure (MBAFF) and field structure (PAFF).

And field structure isn't historically conventional anyway; MPEG-2 supported both, but the field-picture mode seems to have been rare.

[poisondeathray]

"Fields" picture structure is PAFF - there's no such thing as "conventional" interlacing, only frame structure (MBAFF) and field structure (PAFF).

And field structure isn't historically conventional anyway; MPEG-2 supported both, but the field-picture mode seems to have been rare.

My understanding is the term PAFF (picture adaptive field frame) can include a mixture frames and fields, whereas "conventional" interlacing is fields only, not a mixture. Are you saying this is not true?

[Mr VacBob]

Yes. Just because it has adaptive in the name doesn't mean you have to adapt. x264 doesn't in its MBAFF mode.

[poisondeathray]

Yes. Just because it has adaptive in the name doesn't mean you have to adapt. x264 doesn't in its MBAFF mode.


OK, that makes sense, thanks.

In that case, in regards to the original topic, the HMC40/150 in interlaced mode uses PAFF, and is never adaptive.

@WorBry: if you "play" a stream in dgavcindex, a true PAFF stream that actually uses the "adaptive" function will flicker the label "frames" and "fields" as it plays in the display window in the "frame struct" heading. You can test on this sample, for example:
http://x264.nl/h.264.samples/premiere-paff.ts

Also, not sure if you ware aware, but DGAVCIndex has a well known issue when decoding interlaced AVC content (you get pixellation in scenes) especially from AVCHD cameras.

[WorBry]

In that case, in regards to the original topic, the HMC40/150 in interlaced mode uses PAFF, and is never adaptive.

Seems a bit of a contradiction in terms, but like you say, I guess it makes sense. You might say then that uses PAFF syntax, just as x264 uses MBAFF syntax without being macroblock adaptive.

If you "play" a stream in dgavcindex, a true PAFF stream that actually uses the "adaptive" function will flicker the label "frames" and "fields" as it plays in the display window in the "frame struct" heading. You can test on this sample, for example:
http://x264.nl/h.264.samples/premiere-paff.ts

The HMC-41 1080/50i samples dont do that, so for sure the PAFF is not adaptive.

Also, not sure if you ware aware, but DGAVCIndex has a well known issue when decoding interlaced AVC content (you get pixellation in scenes) especially from AVCHD cameras.

No, I didnt know that; something to be aware of.

Seems that PAFF also presents problems for MKVMerge and MP4Box:

http://forum.doom9.org/showthread.php?p=1340818#post1340818

If I do eventually go for one of these Pana camcorders, the 720/50p recording capability will certainly be a major factor.