ffmpeg GOP size, 12 or 15?

[TugBoat]

So, I'm trying to determine why so many ffmpeg m2vs I'm importing into DVDSP2 fail to mux and then some that do crash DVD2oneX. I try to encode so DVD2oneX is not needed, but, sometimes....

Looking at the DVDSP manual, I see that the common GOP size for NTSC is 15 frames. PAL is 12 frames. So, I'm using NTSC, would it be better to set the Keyframe(I-Frame) interval to 15 instead of 12? I'm clueless. Does ffmpeg set it's GOP frame rate by the I-Frame interval? I haven't the faintest.

Also, I notice that some movie's display the pulsating phenomena. It appears to cycle every half second, is this related to the GOP size which is also about half a second? What could be causing this pulsating, that appears to be the video going out of focus and then coming back into focus rapidly? Any way to cure it?

Questions, questions, questions.....

[major]

The GOP size can be variable. It should be 18 max for mpeg-2 NTSC and 15 max for mpeg-2 PAL. Using 12 for both is OK. The keyframe interval is the GOP size.

About the pulsating issue, it depends from what you see. It can be the result of 3:2 pulldown, or the i-frame frequency in dark scenes, or something else. Without seeing a clip it's impossible to answer. Try changing settings to see if the effect changes (ie set gop size to 24 and check if the effect is slower).

[TugBoat]

This is getting extremely frustrating. I began this DVD Sunday, finished a DVD, and then noticed the pulsating in the first track. This is one of those that needs DVD2oneX.

I think I had to re-encode both files (the original is 2 AVIs) twice to get them by DVDSP & DVD2oneX Sunday. Then Jeanne came and my power was out for 36 hrs.

Yesterday I decided to use ffmpegX to convert the AVIs to hi-bitrate MPG4s to see if this would help. No error messages while converting to MPG4. I also threw in the letterboxing so I wouldn't have to worry about it later. So, then I used ffmpeg to convert from MPG4 to MPEG2.
The Progress report was uneventful;
Input #0, mov,mp4,m4a,3gp, from '/Volumes/Video/Movie2.mp4':
Duration: 01:20:42.9, bitrate: 2669 kb/s
Stream #0.0: Video: mpeg4, 720x400, 29.97 fps
Stream #0.1: Audio: mpeg4aac, 48000 Hz, stereo
Output #0, vob, to '/Volumes/Video/Movie/Movie2.mp4.ff.mpg':
Stream #0.0: Video: mpeg2video (hq), 352x480, 29.97 fps, q=1-8, 1415 kb/s
Stream #0.1: Audio: mp2, 48000 Hz, stereo, 224 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Stream #0.1 -> #0.1

I replaced the original m2vs with the new ones. They passed DVDSP without any problems. I have been unable to get them through DVD2oneX. I think I've re-encoded the second one about 5 times now. Each time, DVD2oneX crashes in a different place. If I try to run the same file through DVD2oneX, it will crash in the same place...everytime. I've tried all three Ratio choices, it seems that every new encode has a new bad spot.

I ran one of the failures back through ffmpeg;
Input #0, mpegvideo, from '/Volumes/Video/Movie2.m2v':
Duration: N/A, bitrate: N/A
Stream #0.0: Video: mpeg2video, 352x480, 29.97 fps
Output #0, vob, to '/Volumes/Video/Movie2.m2v.ff.mpg':
Stream #0.0: Video: mpeg2video (hq), 352x480, 29.97 fps, q=1-8, 1410 kb/s
Stream mapping:
Stream #0.0 -> #0.0
[mpeg2video @ 0x331210]rc buffer underflow
[mpeg2video @ 0x331210]concealing 63 errors
[mpeg2video @ 0x331210]Warning MVs not available
[mpeg2video @ 0x331210]qscale == 0
[mpeg2video @ 0x331210]concealing 66 errors
[mpeg2video @ 0x331210]qscale == 0
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]Warning MVs not available
[mpeg2video @ 0x331210]qscale == 0
[mpeg2video @ 0x331210]concealing 66 errors
[mpeg2video @ 0x331210]invalid mb type in P Frame at 0 29
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]concealing 66 errors
[mpeg2video @ 0x331210]invalid mb type in P Frame at 0 28
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]invalid mb type in P Frame at 21 29
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]concealing 66 errors
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 0
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 1
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 2
[mpeg2video @ 0x331210]ac-tex damaged at 0 3
[mpeg2video @ 0x331210]invalid mb type in I Frame at 16 4
[mpeg2video @ 0x331210]invalid mb type in I Frame at 6 5
[mpeg2video @ 0x331210]invalid mb type in I Frame at 10 6
[mpeg2video @ 0x331210]invalid mb type in I Frame at 12 7
[mpeg2video @ 0x331210]ac-tex damaged at 1 9
[mpeg2video @ 0x331210]invalid mb type in I Frame at 3 9
[mpeg2video @ 0x331210]ac-tex damaged at 3 12
[mpeg2video @ 0x331210]ac-tex damaged at 0 11
[mpeg2video @ 0x331210]ac-tex damaged at 0 12
[mpeg2video @ 0x331210]ac-tex damaged at 15 13
[mpeg2video @ 0x331210]ac-tex damaged at 0 14
[mpeg2video @ 0x331210]ac-tex damaged at 13 16
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 16
[mpeg2video @ 0x331210]ac-tex damaged at 0 17
[mpeg2video @ 0x331210]invalid mb type in I Frame at 1 18
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 19
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 20
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 21
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 22
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 23
[mpeg2video @ 0x331210]mb incr damaged
[mpeg2video @ 0x331210]ac-tex damaged at 6 25
[mpeg2video @ 0x331210]ac-tex damaged at 0 26
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 27
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 28
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 29
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 0
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 1
[mpeg2video @ 0x331210]ac-tex damaged at 0 2
[mpeg2video @ 0x331210]invalid mb type in I Frame at 4 3
[mpeg2video @ 0x331210]ac-tex damaged at 0 4
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 5
[mpeg2video @ 0x331210]invalid mb type in I Frame at 7 6
[mpeg2video @ 0x331210]ac-tex damaged at 2 7
[mpeg2video @ 0x331210]slice mismatch
[mpeg2video @ 0x331210]ac-tex damaged at 0 9
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 10
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 11
[mpeg2video @ 0x331210]invalid mb type in I Frame at 1 12
[mpeg2video @ 0x331210]ac-tex damaged at 5 13
[mpeg2video @ 0x331210]ac-tex damaged at 1 14
[mpeg2video @ 0x331210]ac-tex damaged at 0 15
[mpeg2video @ 0x331210]invalid mb type in I Frame at 15 16
[mpeg2video @ 0x331210]slice mismatch
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 18
[mpeg2video @ 0x331210]invalid mb type in I Frame at 4 19
[mpeg2video @ 0x331210]ac-tex damaged at 16 20
[mpeg2video @ 0x331210]ac-tex damaged at 0 21
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 22
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 23
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 24
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 25
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 26
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 27
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 28
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 29
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]concealing 66 errors
bench: utime=1762.880s

The last string of 'invalid mb type' is about where DVD2oneX would croak. So, then I ran the VOB from DVDSP that was killing DVD2oneX;
Input #0, mpeg, from '/Volumes/Video/Movie/VIDEO_TS/VTS_01_2.VOB':
Duration: 01:11:57.5, bitrate: 1593 kb/s
Stream #0.0: Video: mpeg2video, 352x480, 29.97 fps
Stream #0.1: Audio: ac3, 48000 Hz, stereo, 112 kb/s
Output #0, vob, to '/Volumes/Video/Movie/VTS_01_2.VOB.ff.mpg':
Stream #0.0: Video: mpeg2video (hq), 352x480, 29.97 fps, q=1-8, 1415 kb/s
Stream mapping:
Stream #0.0 -> #0.0
[mpeg2video @ 0x331210]rc buffer underflow
[mpeg2video @ 0x331210]concealing 6 errors
[mpeg2video @ 0x331210]Warning MVs not available
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]qscale == 0
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]Warning MVs not available
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 0
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 1
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 2
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 3
[mpeg2video @ 0x331210]invalid mb type in I Frame at 5 4
[mpeg2video @ 0x331210]invalid mb type in I Frame at 1 5
[mpeg2video @ 0x331210]invalid mb type in I Frame at 9 6
[mpeg2video @ 0x331210]mb incr damaged
[mpeg2video @ 0x331210]invalid mb type in I Frame at 5 8
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 9
[mpeg2video @ 0x331210]invalid mb type in I Frame at 8 11
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 11
[mpeg2video @ 0x331210]ac-tex damaged at 6 12
[mpeg2video @ 0x331210]ac-tex damaged at 0 13
[mpeg2video @ 0x331210]invalid mb type in I Frame at 2 14
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 15
[mpeg2video @ 0x331210]invalid mb type in I Frame at 1 16
[mpeg2video @ 0x331210]invalid mb type in I Frame at 11 17
[mpeg2video @ 0x331210]slice mismatch
[mpeg2video @ 0x331210]ac-tex damaged at 1 19
[mpeg2video @ 0x331210]ac-tex damaged at 0 20
[mpeg2video @ 0x331210]slice mismatch
[mpeg2video @ 0x331210]ac-tex damaged at 14 22
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 23
[mpeg2video @ 0x331210]invalid mb type in I Frame at 11 24
[mpeg2video @ 0x331210]invalid mb type in I Frame at 11 25
[mpeg2video @ 0x331210]invalid mb type in I Frame at 9 26
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 27
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 28
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 29
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]invalid mb type in P Frame at 21 27
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]concealing 63 errors
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 0
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 1
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 2
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 3
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 4
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 5
[mpeg2video @ 0x331210]ac-tex damaged at 0 6
[mpeg2video @ 0x331210]ac-tex damaged at 5 7
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 8
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 9
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 10
[mpeg2video @ 0x331210]ac-tex damaged at 15 11
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 12
[mpeg2video @ 0x331210]ac-tex damaged at 0 13
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 14
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 15
[mpeg2video @ 0x331210]ac-tex damaged at 0 16
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 17
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 18
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 19
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 20
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 21
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 22
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 23
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 24
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 25
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 26
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 27
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 28
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 29
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]concealing 66 errors
[mpeg2video @ 0x331210]concealing 66 errors
[mpeg2video @ 0x331210]concealing 63 errors
[mpeg2video @ 0x331210]invalid mb type in P Frame at 21 29
[mpeg2video @ 0x331210]concealing 2147483647 errors
[mpeg2video @ 0x331210]concealing 129 errors
[mpeg2video @ 0x331210]concealing 66 errors
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]qscale == 0
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]invalid mb type in P Frame at 21 27
[mpeg2video @ 0x331210]concealing 2147483647 errors
bench: utime=1598.630s
video:745520kB audio:0kB global headers:0kB muxing overhead 1.366852%

It's hard to believe that this actually came out of DVDSP. But it does match what the m2vs are showing. Note, the above m2v and VOB are from different encodes. So, at this point, I guess my only choice is to go back to the original AVI and hope that the pulsating doesn't reappear. At least I managed to get that through DVD2oneX Sunday. It's only the second MP4 that's giving problems now, I only had to re-encode the first MP4 twice before it passed.


Well, I encoded the original AVI again. It went through DVDSP without any problems, now DVD2oneX crashes in a new spot. Twice so far, in the same spot using different Ratios. Someone doesn't want me to burn this movie.....
another re-encode.......

[TugBoat]

OK, I give up. Everytime I encode the second clip, DVD2oneX finds a new place to crash. I don't know how it made it through Sunday. Could be that the I-Frames were set at 12 instead of 15 I dunno. I do know that I had pulsating with it set at 12 and I don't at 15. Also, DVDSP hasn't refused to mux a single file with the I-Frame set at 15. Course, I've only been working on three different files since then

I tried a different AVI, encoded to MPEG2 then ran it back through ffmpeg. I got two damaged ac-tex errors then a whole bunch of motion vector out of bounds errors. So. I tried turning off 4 motion vectors and trellis quantization and only left High Quaility enabled. Didn't help.

The last attempt killed DVD2one almost instantly. I ran the m2v back through and immediately got;
Input #0, mpegvideo, from '/Volumes/Video/Movie/Movie2.m2v':
Duration: N/A, bitrate: N/A
Stream #0.0: Video: mpeg2video, 352x480, 29.97 fps
Input #1, ac3, from '/Volumes/Video/Movie/Movie2.AC3':
Duration: 01:20:43.0, bitrate: 112 kb/s
Stream #1.0: Audio: ac3, 48000 Hz, stereo, 112 kb/s
Output #0, vob, to '/Volumes/Video/Movie/Movie2.m2v.ff.mpg':
Stream #0.0: Video: mpeg2video (hq), 352x480, 29.97 fps, q=1-8, 1320 kb/s
Stream #0.1: Audio: mp2, 48000 Hz, stereo, 224 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Stream #1.0 -> #0.1
[mpeg2video @ 0x331210]rc buffer underflow
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]Warning MVs not available
[mpeg2video @ 0x331210]concealing 132 errors
[mpeg2video @ 0x331210]Warning MVs not available
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 0
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 1
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 2
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 3
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 4
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 5
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 6
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 7
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 8
[mpeg2video @ 0x331210]invalid mb type in I Frame at 1 9
[mpeg2video @ 0x331210]ac-tex damaged at 12 10
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 11
[mpeg2video @ 0x331210]invalid mb type in I Frame at 3 12
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 13
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 14
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 15
[mpeg2video @ 0x331210]slice mismatch
[mpeg2video @ 0x331210]invalid mb type in I Frame at 13 17
[mpeg2video @ 0x331210]ac-tex damaged at 2 18
[mpeg2video @ 0x331210]ac-tex damaged at 3 19
[mpeg2video @ 0x331210]ac-tex damaged at 8 20
[mpeg2video @ 0x331210]invalid mb type in I Frame at 3 21
[mpeg2video @ 0x331210]ac-tex damaged at 1 22
[mpeg2video @ 0x331210]ac-tex damaged at 0 23
[mpeg2video @ 0x331210]ac-tex damaged at 4 24
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 25
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 26
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 27
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 28
[mpeg2video @ 0x331210]invalid mb type in I Frame at 0 29
[mpeg2video @ 0x331210]concealing 2147483647 errors

I killed it after that.
So, I guess I go back and re-encode these other four clips at a lower bitrate so I don't need DVD2oneX. This sucks.......

[major]

I'm not sure I understand your issue here. Is it that DVD2oneX is unable to process DVDSP output? Or that DVDSP is unable to mux ffmpeg output?

[TugBoat]

A little of both.

Right now I'm having a hard time understanding why ffmpeg finds so many errors in a file that it just created. It's obviously the errors that are causing DVDSP & DVD2oneX to fail. Fortunately it appears that DVDSP is a little more forgiving. I can survive without DVD2oneX but it sure made things easier. Especially when you're working on 5 or 6 different clips and trying to fit them on a DVDr :P

***************
It looks like you can drastically cut down the errors and get the files through DVD2oneX if you enable Two-pass encoding and keep the files less than 80 minutes. So far, everyone of the files I split and used Two-pass encoding on works. Usually the errors that would kill DVDSP & DVD2oneX came very close to the end of the file. We'll see 8)