Video/Audio Syncing Issues

[ThinkDifferent]

I thought I'd report back with the results of my tests regarding the video/audio syncing issues I've encountered since updating to ffmpegX 0.0.9v.

I can now say that no matter the method I try, I cannot get the video and audio to sync properly in any of ffmpegX's outputs (AVI, MPEG4, AVC, etc.). Opening the output from ffmpegX in QuickTime Pro shows that the compressed video and audio are always of different lengths. Further, sometimes the video is longer than the audio, while other times the audio is longer than the video, so there's no consistency. I should also state that I never had this issue using ffmpegX 0.0.9u. In fact, in one of my tests I used the exact same VOB source that v0.0.9u had output a perfectly in-sync AVI. But, after converting that same VOB using v0.0.9v with the same settings, the output was always out of sync. Again, opening the output from ffmpegX 0.0.9v in QuickTime Pro shows video and audio of different lengths whereas opening the output from ffmpegX 0.0.9u shows video and audio of exact equal lengths.

I really am at a loss and don't know what to do next. The only two things that I changed since things were working perfectly for me were updating to QuickTime 7.0.4 and ffmpegX 0.0.9v. I even went so far as to reinstall the older versions of mencoder and mplayer since on the ffmpegX "What's New" page it says you DO NOT need the new versions while on the "Download" page it says you DO (confusing, eh?). I wish I would have kept a copy of 0.0.9u so I could test it now but, alas, in my haste to upgrade I did not.

Suggestions anyone? Major?

(And, yes, the video/audio are out of sync even when viewing in other apps and on other devices, so I know it's not just an issue with QuickTime.)

Thanks in advance.

[rumplestiltskin]

All results from the same source file or from different source files? Did you try converting an older source file (that had converted properly with the older version of ffmpegX)?

[ThinkDifferent]

rumple,

All results from the same source file or from different source files?

Both. (This is after about 2 weeks of testing.) I'm an analyst by trade, so my testing was pretty inclusive and fairly meticulous. Eventually, I ended up using an older VOB that I converted perfectly using ffmpegX 0.0.9u for all my testing thinking that eventually it would work. But, even it did not.

Did you try converting an older source file (that had converted properly with the older version of ffmpegX)?

Yes. (See above.)

Think

[rumplestiltskin]

Hmmm. I'm running 10.2.5 / ffmpegX .9v / QuickTime 7.0.4 "Pro" and the latest mpeg2 codec.

The only time I've seen sync issues (and I don't doubt you at all) is when the source file also has them -or- the framrate of the source is so goofy that only VLC can play it. At that point, however, nothing (VLC export, MPEG Streamclip, ffmpegX, QT Pro export, etc.) will resolve the issue. But, as I indicated above, this seems to be specific to a source file and not to a trancoding app like ffmpegX.

Next step I'd recommend would be to create a new user account to see if something in your prefs, etc. is pooched. After that, an "archive & install".

[ThinkDifferent]

rumple,

I'm running 10.3.9 / ffmpegX .9v / QuickTime 7.0.4 "Pro" and the latest mpeg2 codec. The only two things I changed was upgrading from .9u to .9v and QuickTime from 7.0.1 to 7.04.

I can also now confirm that converting other VOB files that previously worked using ffmpegX .9u don't work now either. I know that the source files are good, because, like I said previously, I used them to create working AVI files under fffmpegX .9u. That's what's so frustrating.

I like your "create a new user account" idea. I think I'll try that next. I'd hate to run an "archive and install" if I don't have to.

For my own ease of mind, can you please confirm for me that converting a VOB to an AVI (using ffmpegX .9v and all the default settings) results in a file with equal Video and Audio lengths. I've been examining each output by opening the AVI in QuickTime and selecting the "Show Movie Properties" selection from the "Window" menu (or Cmd-J).

Thanks,
Think

[ThinkDifferent]

Update:

- Creating and using a different user account didn't work. I still got the same results.
- Uninstalling and reinstalling ffmpegX .9v didn't resolve the problem either.
- Neither did reinstalling QuickTime 7.0.1.

This is becoming very frustrating. ffmpegX is one of my favorite apps, and one that I recommend to all my fellow Mac users. So, it's really disheartening that I've hit this snag.

Think

[rumplestiltskin]

Checking the VOB>AVI(DivX) now. This is the standard setting that ffmpegX suggests when you launch the app and then drop a file into the source box. Should be done in about 15 minutes and I'll post the result at that time.

[rumplestiltskin]

Finished encoding but with a few errors noted (copied from the "info" window below).

Difference of .52 second between video and audio in 40:30 VOB length.

I'll try another codec and report again.

(info code follows):
Forcing output fourcc to 58564944 [XVID]
Building audio filter chain for 48000Hz/2ch/s16be -> 48000Hz/0ch/s8...
Building audio filter chain for 48000Hz/2ch/s16be -> 48000Hz/2ch/s16be...
VDec: vo config request - 720 x 480 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
SwScaler: FAST_BILINEAR scaler, from Planar YV12 to Planar YV12 using AltiVec
videocodec: libavcodec (640x352 fourcc=58564944 [XVID])
1 duplicate frame(s)!
Writing AVI header...
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.
Skipping frame!
Skipping frame!
Skipping frame!
a52: CRC check failed!
Skipping frame!
Skipping frame!
Skipping frame!
a52: error at resampling
a52: CRC check failed!
a52: error at resampling
a52: CRC check failed!
Skipping frame!
a52: error at resampling
a52: CRC check failed!
Flushing video frames
Writing AVI index...
Fixing AVI header...
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.
Video stream: 123.951 kbit/s (15493 B/s) size: 37662536 bytes 2430.806 secs 58289 frames
Audio stream: 96.000 kbit/s (12000 B/s) size: 29175840 bytes 2431.320 secs
Encoding completed on Sat Mar 18 23:03:12 MST 2006

[rumplestiltskin]

I should point out that the encoding I did used mencoder. I'm trying it again using ffmpeg and will report when done.

[rumplestiltskin]

Okay; VOB>AVI (ffmpegX) yields the following:

video: 40:31.51
audio: 40:31.10

I can't say whether this difference was present in the older version or not because I normally go from AVI to H264 (iPod).

I used 100kbps simply to speed up this testing process. Here's the data from the "info" window:

Input #0, mpeg, from '/Volumes/Secondary Internal HD/myDVD/VIDEO_TS/VTS_01_1.VOB':
Duration: 00:40:31.3, start: 0.268267, bitrate: 3532 kb/s
Stream #0.0[0x1e0], 23.98 fps: Video: mpeg2video, yuv420p, 720x480, 2994 kb/s
Stream #0.1[0x80]: Audio: ac3, 48000 Hz, stereo, 448 kb/s
Output #0, avi, to '/Volumes/Secondary Internal HD/Serial Lover(DVD).mpg.DVD/VIDEO_TS/VTS_01_1.VOB.ff.avi':
Stream #0.0, nan fps: Video: mpeg4, yuv420p, 640x352, q=2-15, 100 kb/s
Stream #0.1: Audio: mp3, 48000 Hz, stereo, 64 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Stream #0.1 -> #0.1
video:37272kB audio:18993kB global headers:0kB muxing overhead 6.713734%
bench: utime=1099.793s
Encoding completed on Sat Mar 18 23:27:58 MST 2006

[ThinkDifferent]

Thanks, rumple. Your results appear to be similiar to my own and confirm there's an issue no matter whether you use mencoder or ffmpeg.

Before the ffmpegX .9v release my video and audio were outputting to identical lengths down to the hundredth of a second using VOB>AVI. Now, there's always a difference. I've tried the default settings, changing bitrates, using different codecs, using different source files, and the list goes on. It always results in the video and audio tracks being different lengths. What really clinched it for me was when I found an old VOB on my drive that I had used previously and began using it for testing. As I stated before, it converted perfectly under ffmpegX .9u. Now, no matter what I try, it's always out of sync. And, the longer the file, the more out of sync it gets.

Thanks again for taking the time to test.

[rumplestiltskin]

Just ran the same test using .9uR2 and found exactly the same result (same mencoder engine as used in .9v).

I'm now encoding the same VOB using MPEG Streamclip 1.61 and will report as soon as it's done.

[rumplestiltskin]

Same issue (approx .5 second difference) converting the same VOB to AVI using MPEG Streamclip. That uses its own engines so I'm afraid we're back to the beginning. This may simply be a bad VOB (in my case).

[ThinkDifferent]

rumple,

This may simply be a bad VOB (in my case).

Before you jump to that conclusion, try converting that same VOB to an MPEG-4 H.264 file in MPEG Streamclip 1.6b1. You might be surprised (as I was) to find that it outputs an AVC (H.264) with video and audio of exact equal lengths. Using MPEG Streamclip, I can convert any of my VOBs to AVC with the video and audio syncronized perfectly. That's more than I could do with ffmpegX .9v. However, when I take that AVC file and try to convert it to an AVI in ffmpegX, guess what... video and audio get out of sync.

I can't test the AVI output of Streamclip because I have no way to output the audio as MP3. It doesn't show up as an option. Do you happen to know how one goes about getting MPEG Streamclip to use MP3 as the audio output for AVI's?

Thanks again for all your help.

By the way, here are the results I'm getting with a test file:

Source VOB: 5:10.9 mins
AVC Conversion: Video (MPEG-4 H.264) = 5:10.9 mins, Audio (AAC) = 5:10.9
AVI Conversion: Video (3ivx D4 4.5.1) = 5:10.8, Audio (MP3) = 5:11.3

[laserheart]

Is anyone else getting these types of errors when encoding in ffmpegx?

What does this mean?

--------------

[mpeg2video @ 0x444b70]concealing 45 DC, 45 AC, 45 MV errors
[mpeg2video @ 0x444b70]ac-tex damaged at 44 29
[mpeg2video @ 0x444b70]concealing 45 DC, 45 AC, 45 MV errors
[mpeg2video @ 0x444b70]ac-tex damaged at 44 29
[mpeg2video @ 0x444b70]concealing 45 DC, 45 AC, 45 MV errors
[mpeg2video @ 0x444b70]concealing 1 DC, 1 AC, 1 MV errors
[mpeg2video @ 0x444b70]invalid mb type in P Frame at 44 29
[mpeg2video @ 0x444b70]concealing 45 DC, 45 AC, 45 MV errors