Sorenson Squeeze compression causes sound to be not in sync with video

[psaad]

Hi Everyone,

Here's my problem.

After compressing a .mov file (2GIG) using the following modified preset in Sorenson Squeeze:
.flv VP6_768K_Stream
Frame size: 640x480
Display Aspect Ration Policy: Letter Box
Drop Frames to Maintain Data Rate: 90

My resulted .flv file's audio and video, when added in a flash file as a new (Actionscript-controlled) video, is not well synchronized.
Its starts synchronized and a few seconds after, the audio is unsynchronized from the video.

This happens when I play the flash file locally, its not even on a web server yet.

If it helps understand my problem:
The original .mov file was generated from an After effects edit I made. I compressed it into a .mov file using the Add to Render Queue, using the Animation preset for the Video Format. I made sure to keep the same fps setting at Medium quality.

But again, this issue does not happen to my original .mov file.

Did anyone encounter that issue when compressing a .mov file into a VP6 flv at 768k stream ? If so, do you know of a way to compress it so that sound and video always stay in sync?

I am using a MacBook Pro 15.4inch
Sorenson Squeeze 4.5.3
Flash CS3

Would appreciate any help possible.

Thanks.

Patrick

[guns1inger]

The issue is probably tied to the 90 frames dropped in order to mainatain the data you have requested. You might look for a setting that prohibits dropping frames, or try a higher bitrate.

[psaad]

The issue is probably tied to the 90 frames dropped in order to mainatain the data

I tried setting it to 20 frames instead, same thing happened... I thought this would help so that video and sound would stay in sync.. am I wrong here?

or try a higher bitrate.

All the data rate choices are confusing in Sorenson, im not sure what they all mean.

There's 768K Stream, which is the choice I took.
There's Total Data Rate: set by default to 661
There's Data Rate: set by default to 615
Also, the keyframe is set at each 45 frames

Does the bitrate correspond to any of these ?

Pat.

[guns1inger]

Bitrate = data rate

What is the framerate of the source ?

If you want your video to remain at the same framerate, you have to stop sorenson from dropping frames. I don't use it, so I don't know how you would do this.

[psaad]

I looked into the .mov file's Quicktime Movie Inspector and it says:

Data Rate: 73.10 mbits/s

Apple Format: Apple Animation, 640 x 480, Millions
16-bit Integer (Big Endian), Stereo, 44.100 kHz

FPS: 29.97

Data Size: 3.34 GB

It seems that the data rate setting in Sorenson Squeeze is much lower in order to reduce file-size. But how can I achieve a low size file while keeping a similar data rate? that seems impossible if so.

I can specify a Total Data Rate different then the default one, and I can also modify the Data Rate as well. What would be a good balance?

Again,

Total Data Rate: set by default to 661
Data Rate: set by default to 615

I looked up another forum and the user says that the issue lies with sorenson squeeze which just can't seem to handle keeping the audio on On2 VP6 codec. but then again, that wouldn't make sense that a software so powerful can't handle this simple task of syncing audio with video.

Flash video clips in sync lacks the ability to add watermarks to encoded videos

http://forums.creativecow.net/readpost/20/858764

[guns1inger]

Filesize = bitrate x running time. Universal rule of video compression.

In other words, make the bitrate higher, the file size will increase. Reduce the bitrate, you get a smaller file, but at some point you start to sacrifice quality. You cannot have a high bitrate and a small file without reducing the length of the video.

I can't really offer you any further help, other than to suggest perhaps you try an different encoder.

[psaad]

Thanks for your help guns1inger, I will give it another shot with a much higher bitrate ... see if I can fix my issue this time.

Regards,
Patrick from Montreal

[psaad]

Thanks for your help guns1inger, I will give it another shot with a much higher bitrate ... see if I can fix my issue this time.

Regards,
Patrick from Montreal

Actually,

I just noticed that there is a different datarate for the audio that is used for compression:

By default for the audio: compressed to:

Fraunhofer MP3
Data Rate: 48kbps

if the datarate, in this case, is different then the video could that cause an out of sync ?

[psaad]

It seems the problem lies with Sorenson Squeeze 4.5.3...as I said earlier, the out of sync problem does not occur in Sorenson Squeeze 5(trial version)

I found a version of Adobe CS3 Flash Encoder and used it to compress it to 700kbs OnVP6 and it worked like a charm