In Vegas, NV carries forward last frame before black
Posted: Mon Aug 10, 2009 3:40 pm
I'm using Neat Video in Sony Vegas 6. Here is something that happened after applying NV that you will want to know about - or maybe it has already been reported.
I am aware of the problem concerning repeated frames where NV is being used in a project that contains transitions. The problem I describe below is somewhat different in that no transitions are included in the project where NV is used.
I describe the process below in a manner that allows you to repeat the process.
In step 1 of my process, I rendered a progressive PAL DV file of a complete video that includes several frames of solid color (black) in two places. I created the black frames with Vegas Solid Color media generator, using the preset value "black." The black generated media is inserted in video track 1, while the PAL source media is in track 2. The black media follows a non-black frame in the source media.
Also in step 1, I set a marker several frames after the last frame of the source media. Then I rendered the PAL DV output, including the empty frames at the end of the file up to the last marker. The last frame of the source media contained an image, as the source was cut before the final scene faded completely to black.
In step 2, I applied NV with Temporal Filter Radius set to 2 and Adaptive Filtration turned on. I created a new progressive PAL DV of the NV output. No other processing was done by Vegas in this step.
Looking at the output of step 2, I found that NV carried forward the last non-black frame through the black section of output video. The frame is repeated nearly exactly the same number of frames as there are black frames. (I say "nearly exactly" because the black frames dissolve to the video, and NV does not carry the last non-black frame past this point).
I also see that NV carried forward the last frame of the input file through the empty frames I left at the end of the project.
My hypothesis is that NV is somehow holding and repeating the last non-black frame it encountered, probably to apply it to processing of the next frame. While it may be a good idea to hold the frame in a buffer for comparison to the next frame, NV should not output the frame to fill the black areas of the video.
I hope this helps find a solution to the problem.
Let me know if more information is required.
TheTooleMan
I am aware of the problem concerning repeated frames where NV is being used in a project that contains transitions. The problem I describe below is somewhat different in that no transitions are included in the project where NV is used.
I describe the process below in a manner that allows you to repeat the process.
In step 1 of my process, I rendered a progressive PAL DV file of a complete video that includes several frames of solid color (black) in two places. I created the black frames with Vegas Solid Color media generator, using the preset value "black." The black generated media is inserted in video track 1, while the PAL source media is in track 2. The black media follows a non-black frame in the source media.
Also in step 1, I set a marker several frames after the last frame of the source media. Then I rendered the PAL DV output, including the empty frames at the end of the file up to the last marker. The last frame of the source media contained an image, as the source was cut before the final scene faded completely to black.
In step 2, I applied NV with Temporal Filter Radius set to 2 and Adaptive Filtration turned on. I created a new progressive PAL DV of the NV output. No other processing was done by Vegas in this step.
Looking at the output of step 2, I found that NV carried forward the last non-black frame through the black section of output video. The frame is repeated nearly exactly the same number of frames as there are black frames. (I say "nearly exactly" because the black frames dissolve to the video, and NV does not carry the last non-black frame past this point).
I also see that NV carried forward the last frame of the input file through the empty frames I left at the end of the project.
My hypothesis is that NV is somehow holding and repeating the last non-black frame it encountered, probably to apply it to processing of the next frame. While it may be a good idea to hold the frame in a buffer for comparison to the next frame, NV should not output the frame to fill the black areas of the video.
I hope this helps find a solution to the problem.
Let me know if more information is required.
TheTooleMan