MP4 from Zi8 Audio Sync Problem

WD Legacy Products WD TV Live & Live Plus
1

Hi, this is my first post so please go easy.

I am having problems playing files from my Kodak Zi8 on the WDTV Live. The file plays ok, but the audio falls out of sync. This is the media file…

Format                           : MPEG-4
Format profile                   : QuickTime
Codec ID                         : qt  
File size                        : 1.22 GiB
Duration                         : 24mn 49s
Overall bit rate                 : 7 020 Kbps
Movie name/More                  : KODAK Zi8 Pocket Video Camera
Encoded date                     : UTC 2010-03-05 13:26:16
Tagged date                      : UTC 2010-03-05 13:29:09
Writing library                  : Apple QuickTime 7.6.5
com.apple.quicktime.player.movie : (Binary)
Origin                           : Digital Camera
AMBA                             :

Video
ID                               : 1
Format                           : AVC
Format/Info                      : Advanced Video Codec
Format profile                   : Main@L4.2
Format settings, CABAC           : Yes

Format settings, ReFrames        : 4 frames
Format settings, GOP             : M=3, N=15
Codec ID                         : avc1
Codec ID/Info                    : Advanced Video Coding
Duration                         : 24mn 49s
Bit rate mode                    : Variable
Bit rate                         : 6 887 Kbps
Maximum bit rate                 : 12.8 Mbps
Width                            : 1 280 pixels
Height                           : 720 pixels
Display aspect ratio             : 16:9
Frame rate mode                  : Variable
Frame rate                       : 36.690 fps
Original frame rate              : 29.970 fps
Minimum frame rate               : 19.982 fps
Maximum frame rate               : 59.960 fps
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.204
Stream size                      : 1.19 GiB (98%)
Language                         : English
Encoded date                     : UTC 2009-12-25 13:31:15
Tagged date                      : UTC 2010-03-05 13:29:09

Audio
ID                               : 2
Format                           : AAC
Format/Info                      : Advanced Audio Codec
Format profile                   : LC
Codec ID                         : 40
Duration                         : 24mn 32s
Bit rate mode                    : Constant
Bit rate                         : 128 Kbps
Channel(s)                       : 2 channels
Channel positions                : Front: L R
Sampling rate                    : 48.0 KHz
Compression mode                 : Lossy
Stream size                      : 22.5 MiB (2%)
Language                         : English
Encoded date                     : UTC 2009-12-25 13:31:15
Tagged date                      : UTC 2010-03-05 13:29:09

Hope someone can help :slight_smile:

2

Interesting.  I have a Zi8, too, and don’t have that issue.

One thing I note is the bizarre framerate:   36.69 fps?? 

Here’s one of mine for comparison:   The frame rate is a correct 29.97 fps.

If the WDTV is unable to handle the VARIABLE frame-rate yours has, then out-of-sync audio is a likely result.

I am unaware of any settings in the Zi8 that allow for a change in constant / variable framerate…

General
Complete name : 560_0207.MOV
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt
File size : 87.0 MiB
Duration : 56s 957ms
Overall bit rate : 12.8 Mbps
Movie name/More : KODAK Zi8 Pocket Video Camera
Encoded date : UTC 2010-05-24 17:32:23
Tagged date : UTC 2010-05-24 17:32:23
Origin : Digital Camera
AMBA :

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4.2
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Format settings, GOP : M=3, N=15
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 56s 957ms
Bit rate mode : Variable
Bit rate : 12.7 Mbps
Maximum bit rate : 15.8 Mbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.459
Stream size : 86.1 MiB (99%)
Title : Ambarella AVC / Ambarella AVC
Language : English
Encoded date : UTC 2010-05-24 17:32:23
Tagged date : UTC 2010-05-24 17:32:23

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 56s 810ms
Bit rate mode : Constant
Bit rate : 128 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 888 KiB (1%)
Title : Ambarella AAC / Ambarella AAC
Language : English
Encoded date : UTC 2010-05-24 17:32:23
Tagged date : UTC 2010-05-24 17:32:23
3

I also have the same issue with files with a constant frame rate of 29.97 fps. Could it be anything to do with the fact that the files are a collection of different files that have been cobbled together?

4

Quite possible.

One way to tell is if the audio de-sync occurs at the break between two original “chunks.”

How are you concatenating the files?

5

I used QuickTime Pro. I will have a go with the original files and see if that makes any difference.

6

The original smaller files work fine, it’s only the edited full length clip that has the audio sync problem. Is this because I edited it in QuickTime Pro? Did I make elementary mistakes while doing so? Should I have used Media Impression instead? Thanks in advance

7

I have no idea about that, sorry…   Never modified my original files.