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Stuttering Transcoded Video When Played Back in Avid 5.5.1 from G-Raid Drive Firewire 800
Hello,
I am editing a short film that was shot on Canon 5D cameras in 23.98 HD and recorded sound on a separate deck (I don’t have the name of the deck that the sound man was using). I setup my Avid project as 1080p/23.98 Color SPace YCbCr 709. All of the sound files(48k) from the sound man when imported into my avid play perfectly. I linked the AMA folder in Avid and pointed it to my camera files (these camera files also had recorded sound from the microphone on the cameras) which were on a 2TB G-Drive connected to my MacBook Pro Laptop (6 GB of RAM/Graphics Display Card is NVIDIA GeForce 8600M GT) using a FW 800 cable. The footage was then transcoded to DNxHD 36 (HD1080p). Once the camera files were transcoded I played them back in the avid and the picture and recorded sound from the camera stuttered with sound dropouts occurring as well. I then sub clipped just the picture and auto synced those clips with the separate sound files from the sound man (these sound files are in a separate folder which also live on the same G-Drive as the camera files). When I played back the synced clips the picture and sound continued to stutter. I spoke to a friend of mine who owns a computer store and he tole me the issue was the G-Drive that it was too slow to playback HD footage. He told me I should use a G-RAID drive. I bought a G-Raid drive and brought it home and copied the Avid Media File Folder from the G-Drive over to the new G-Raid drive and hooked it up to my computer using FW 800. The synced files when played back in the Avid continued to stutter with sound dropouts. I feel that the issue is that the FW 800 cable is not giving me enough throughput to play the files in real time with out any stuttering or dropouts. If I purchase an e-Sata card and connect the drive using e-Sata will that solve the stuttering and dropout issue? Please advise ASAP. I am under a tight deadline. Thank you.
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15 Replies
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I suspect the FW800 is your bottleneck in this scenario. I have had success in the past with DNxHD 36 synced dailies off of a FW800, but you are flirting with the the total throughput available to you. When you load a clip in the timeline, the colored bars in the timecode ribbons indicate whether there is a throughput problem. If I remember correctly, blue bars indicate drive is too slow for the given operation. Red is effects, and yellow is a warning that frames may drop.
Also, is your timeline set to green/yellow?
Michael
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Hi Michael,
When I cut a clip into the timeline I do not see any colored ribbons in the timeline. Is there a setting that I need to select from the hamburger menu on the timeline in order to see those settings ? And yes it was set to green/yellow at the bottom of the timeline. I also tried green and I tried yellow and the video stuttered in all three settings. Any thoughts or solutions would be helpful. Thank you for your initial response.
Judd -
Basic question, but when you transcoded, were you presented with a frame rate mismatch in the dialog window? I asked because a frame rate mismatch might cause motion artifacts if the camera original frame rate does not match the timeline frame rate. Just something to check.
And you’re sure it is DNxHD 36? Is the drive full? Are you using any third party hardware for I/O?
Michael
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In answer to your question, no. When I transcoded camera files to DnX36 HD, I was not presented with a dialog box suggesting a frame rate mismatch. When I play the original camera files through quicktime on the desktop the inspector tells me that the format of the clips are H.264, 1920×1080, Linear PC, 16 bit little-endian signed integer, 48000 Hz, Stereo (L R) FPS: 23,98
Data Size: 60.8 MB and Datat Rate 45.03 Mbit/s. I am beginning to think my issue will be solved once I connect the FW drive via eSata instead of FW 800. Do you agree?Judd
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That would certainly be the place the start if you have eSATA available to you.
Michael
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Thank you Michael. I really appreciate your help. I will check back on this thread if I have any other issues.
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Some preliminary trouble shooting might save you some money as well. As you have already spent money on 1 drive that didn’t fix the problem, before you spend more money you should confirm the media is good. (My guess is the firewire is the problem- although at DNX36 i would’ve thought playback should work), but i would copy a transcoded video file to your local drive. Put it in the proper folder structure and get that one file into your project. If it plays back fine, then you know your transcodes are good, and the problem probably lies with the throughput. Troubleshooting should always have a logical checklist of what does work, to be able to identify what doesn’t work. Never hurts to check the source media first.
Glenn
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Hi Michael, I think I have solved the issue without using an eSata card. When I was playing the clips last night the G-Raid drive that was accessing the media files only had the Avid Media File folder on it which contained the MXF files. Before I went to bed last night I copied over all of the original camera files and the original sound files on to the G-Raid drive as well. THis morning, everything seemed to play normally with out any stuttering or dropouts. So I guess my friend was right, that I needed to have everything coming from the G-Raid drive NOT the G-Drive. Do you have any thoughts on this work around? Let me know if you have a chance. Thanks again for your help!!!
Judd
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FW even on a non-raid drive should be fine in DNx. I’ve even cut a couple projects in 115 on a G-Drive with FW800 when the files came to me that way and I had no time to transcode.
You couldn’t multicam with that set up, but straight cuts shouldn’t be a problem.
eSata is a good solution but many cards don’t seem to be stable on Mac. I installed a the Esata card from Sonnet technologies and it was great for the most part but I’ve heard of nightmares on other Mac Pro systems.
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A raid will be faster than a single drive, you just might want to backup. I have to say though, having used 30+ G-tech RAids/drives in the past year, only one ever failed and it was right out of the box, a mini which was a new release of theirs.
I’m still surprised you had trouble with a drive, but at least now things work.
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