- Posts: 7
- Joined: Sun Feb 03, 2013 2:11 pm
I've seen a number of posts already talking about the Intensity Shuttle's "gradual video-audio out of sync" issue. As a user who suffers this as well, I dug into the problem and found the cause of the it:
As the capturing goes, the Intensity constantly and randomly creates "redundant" frames for the video (like 0.x second tiny loops), which cumulatively makes the video length longer then it should be. For example, if the final clip should be 1:00:00 long, the video length may be 1:03:24 and the audio length is 1:00:00. This looks very much like a "sync" issue but actually it is not. The video footage is inaccurate, but the problem actually lies within the sound capturing process.
The reason why these tiny loops occur may be that Media Express is trying to match the video and audio by somewhat "resampling" the video. I own both a Pro and a Shuttle. When capturing with Virtualdub, the sound capturing with the Pro is flawless while that with the Shuttle is constantly being resampled. The tempo and pitch is all over the place. If I check the "Use Hi-Fi Audio Levels" option in the control panel, which is enabled by default when capturing through analog with the Pro, the sound will be full of noises. The reason why I bought me a Shuttle is that SD content captured by the Pro is full of artifacts: jagged edges.
I also tried different codecs for capturing. Surprisingly, the MJPEG codec causes more "redundancy" than the 8-bit and 10-bit uncompressed ones. So I believe it has very little, if there is some, to do with the PC spec rather than the codec itself. More specifically, it maybe is the codec's compatibility with the device (the onboard analog device chip) since the footage captured with the Pro is perfect. Also, it has nothing to do with the input source. Whether it is interlaced or progressive, SD or HD, component or HDMI, the problem persists.
I noticed that if I use analog inputs with the shuttle, the "HDMI Audio & Analog RCA Audio" option and the "Component Video & Analog RCA Audio" option in the control panel will actually provide the same functionality. If I use analog inputs with the Pro, then only the "Component Video & Analog RCA Audio" option will work correctly, as the option indicates. It seems that the Pro deals with digital and analog inputs separately but the Shuttle utilizes a somewhat "hybrid" method. Since digital and analog contents are on different clocks, this can cause the sync problem that the Pro will not incur. But neither the device driver nor the Media Express seems to adjust it accurately.
In terms of the compatibility issues among the codecs installed on the computer, I clean installed the Windows 7 64-bit OS with necessary drivers only, and the problem is still there.
These are all that I found out, does anyone here has a clue how to fix it? Much appreciated.
As the capturing goes, the Intensity constantly and randomly creates "redundant" frames for the video (like 0.x second tiny loops), which cumulatively makes the video length longer then it should be. For example, if the final clip should be 1:00:00 long, the video length may be 1:03:24 and the audio length is 1:00:00. This looks very much like a "sync" issue but actually it is not. The video footage is inaccurate, but the problem actually lies within the sound capturing process.
The reason why these tiny loops occur may be that Media Express is trying to match the video and audio by somewhat "resampling" the video. I own both a Pro and a Shuttle. When capturing with Virtualdub, the sound capturing with the Pro is flawless while that with the Shuttle is constantly being resampled. The tempo and pitch is all over the place. If I check the "Use Hi-Fi Audio Levels" option in the control panel, which is enabled by default when capturing through analog with the Pro, the sound will be full of noises. The reason why I bought me a Shuttle is that SD content captured by the Pro is full of artifacts: jagged edges.
I also tried different codecs for capturing. Surprisingly, the MJPEG codec causes more "redundancy" than the 8-bit and 10-bit uncompressed ones. So I believe it has very little, if there is some, to do with the PC spec rather than the codec itself. More specifically, it maybe is the codec's compatibility with the device (the onboard analog device chip) since the footage captured with the Pro is perfect. Also, it has nothing to do with the input source. Whether it is interlaced or progressive, SD or HD, component or HDMI, the problem persists.
I noticed that if I use analog inputs with the shuttle, the "HDMI Audio & Analog RCA Audio" option and the "Component Video & Analog RCA Audio" option in the control panel will actually provide the same functionality. If I use analog inputs with the Pro, then only the "Component Video & Analog RCA Audio" option will work correctly, as the option indicates. It seems that the Pro deals with digital and analog inputs separately but the Shuttle utilizes a somewhat "hybrid" method. Since digital and analog contents are on different clocks, this can cause the sync problem that the Pro will not incur. But neither the device driver nor the Media Express seems to adjust it accurately.
In terms of the compatibility issues among the codecs installed on the computer, I clean installed the Windows 7 64-bit OS with necessary drivers only, and the problem is still there.
These are all that I found out, does anyone here has a clue how to fix it? Much appreciated.