HDV Editing Workflow on the PC
-FOR PRODUCERS- We've been working with JVC's flavor of the HDV format (720/30p) for about a year now, and in the beginning the prospect of editing HDV was murky at best. As a service to the HDV community, we thought it would be extremely helpful to share the editing workflow we have developed over the course of the past year.
HARDWARE
First, lets review our editing workstation's specs:
Pentium IV 3.0 GHZ, 800MHZ FSB
1 GB RAM, Dual Channel DDR266
160GB IDE Boot Drive
250GB SATA Video Drive (16 MB Buffer)
250GB External Firewire Drive (for Archiving/Backup)
Windows XP Professional SP1
ATI Radeon 9200SE 128MB Dual-Head Video Card
(2) 19" CRT Monitors
Please note that this workstation is the result of a recent upgrade, for the majority of the past year we have been editing on an AMD Athlon XP 2000+, which shows that even a modest PC can be used to edit HDV using our workflow (albeit slowly).
SOFTWARE
The foundation of our workflow is Sony Vegas, and the cornerstone is Cineform ConnectHD. This killer combo provides, in our opinion, the most bang for your HDV editing buck. The secret to ConnectHD is that it converts the MPEG2 files from the camera into CFHD .avi files. Why is this necessary, you may ask? Because editing MPEG2 files at HD resolutions is sloooow, and MPEG2 doesn't hold up to multi-generation editing well at all. Cineform's CFHD is a dream codec - it is lossless, has modest bandwidth requirements (variable bit-rate, 40Mbps - 70Mbps), and requires a relatively modest amount of CPU power to encode/decode. Furthermore, because of its high bitrate overhead (50Mbps vs 19Mbps for the source files) and intraframe compression (each frame stands alone), the same file can be encoded over and over with no generation loss. This last attribute is essential to our workflow, as you will soon find out.
WORKFLOW
1) Capture the footage -- We use HDLink (the capture and conversion program included with ConnectHD) to capture the .M2T files from the JVC HD10U. We suggest capturing the .M2T files first, and then doing the conversion to the CFHD .avi format later.
2) Review and log the .M2T files -- Windows Media Player can play the .M2T files without any trouble, so you can log and rename the files rather quickly. Then delete or set aside the bad takes.
3) Convert to CFHD -- Use HDLink to convert only the good takes to Cineform's CFHD .avi format. This will save you disk space and time. Cineform suggests using the "medium" setting for the conversion, and we concur. We did several in-house tests of "medium" vs. "large", and the results were nearly identical. However, the "large" files are HDCAM size, which creates a bandwidth and storage problem for most editing workstations.
4) Create Vegas Projects -- Make sure your Vegas project is set at 1280x720, progressive scan, square pixel, 48khz sample rate. Also, do yourself a favor, split your project up into easily digestible pieces. We have found that 20-minute projects work well (3 projects for an hour show, 6 projects for a 2 hour show). Not only does this give you more manageable timelines, but it also helps you creatively as well. Finally, set the "Dynamic RAM Preview" to 0, unless you plan on using that feature. This feature does not improve performance at all, and actually can hinder performance by taking memory away from Vegas and the rest of the computer.
5) Start Editing in Vegas -- During your first pass concentrate on laying the clips on the timeline, using simple cross-fades, and getting everything in the right place. Don't bog down the project with effects and filters yet. Set the preview window to "Preview - Auto", and use a half or quarter-size window. You should be able to maintain realtime performance throughout the entire first pass this way.
6) Apply Filters and Effects -- When possible we suggest applying filters and effects to the source files, and then rendering out "fixed" versions of those source files to be used in your projects. For example, say you have a file called "source.avi" that needs color correction. This source file is referenced several times throughout your project. Simply create a new temporary project with only "source.avi" on the timeline. Apply the correction, and then render the entire timeline to "source-fixed.avi" using the Cineform codec**. There is no need to save the temporary project unless you need to modify the correction later on. Then use the "replace media" function in the media pool to replace all instances of "source.avi" with "source-fixed.avi" in your project. This is where the CFHD format's resistance to generation loss comes in really handy.
7) Render -- Apply any effects you couldn't accomplish via #6, and then render each project using the Cineform codec. Review the renders and make changes if necessary. Once you are satisfied with the individual pieces, create a new MASTER project and stitch the rendered pieces together on the timeline. Render the MASTER project to your "final" Cineform .avi.
8) Chroma-Noise Removal -- We run our "final" Cineform .avi through VirtualDub for chroma-noise removal. We use the chroma-noise removal plugin (http://www.ifrance.com/freevcr/virtualdub/cnr-en.html) along with the Temporal Smoother set to 2. Set the compression to Cineform, click "Save As", and wait for it to render. On our new editing workstation it renders at about 7 fps. The result is your HD "MASTER".
9) Render Distribution Files -- Your HD Master can be fed into any encoding application that works with .avi's and can handle HD input resolutions. Your options are pretty limitless here: DVD, Windows Media 9, DivX, Quicktime, or even back to MPEG2-TS. Note that if someone wants to purchase your HD content for use in their HD projects that both Cineform (Windows only) and MPEG2-TS are viable options. If you choose Cineform, make sure to include the demo-version of ConnectHD (or tell them where to get it), which will allow them to decode your files and use them in their editing program. If you choose MPEG2-TS, you may want to change the extension to .MPG, as some editing programs will ignore files with the .M2T extension.
10) Cleanup and Archive -- At this point you can likely trash all of the .M2T files (assuming you have the source tapes for backup) as well as any .avi files you didn't end up using. Archive the remaining .avi files, the Vegas projects, the Master, and any other media files used in the project.
SUMMARY
Again, I have to re-iterate the importance of Cineform's multi-generation performance with respect to our workflow. I have yet to encounter a codec that holds up this strongly over so many renders. It is a real joy to work with.
Although this workflow applies specifically to footage shot with JVC HD10U, there is no reason it cannot be applied directly to the Sony FX-1 as well. Thus, we hope this article proves valuable to both current and prospective HDV producers and editors.
**Cineform / Vegas Bug and Workaround -- There is a rendering bug that could potentially make step 6 a nightmare, so please take note of this. When you render "source-fixed.avi", and then do the replace media function, you will notice strange problems start popping up in your project. Specifically, transitions involving "source-fixed.avi" will no longer render properly. However, there is a work-around. Before you render "source-fixed.avi", apply a "dummy-effect" to the entire temp project. You have to do this via the preview window, not on an individual video track. For example, add a contrast/brightness filter and set the contrast-center to 0.51 (which effectively does nothing). This will force Vegas to render the Cineform .avi file correctly, and "source-fixed.avi" will not give you trouble later on.
by Ben Buie
HARDWARE
First, lets review our editing workstation's specs:
Pentium IV 3.0 GHZ, 800MHZ FSB
1 GB RAM, Dual Channel DDR266
160GB IDE Boot Drive
250GB SATA Video Drive (16 MB Buffer)
250GB External Firewire Drive (for Archiving/Backup)
Windows XP Professional SP1
ATI Radeon 9200SE 128MB Dual-Head Video Card
(2) 19" CRT Monitors
Please note that this workstation is the result of a recent upgrade, for the majority of the past year we have been editing on an AMD Athlon XP 2000+, which shows that even a modest PC can be used to edit HDV using our workflow (albeit slowly).
SOFTWARE
The foundation of our workflow is Sony Vegas, and the cornerstone is Cineform ConnectHD. This killer combo provides, in our opinion, the most bang for your HDV editing buck. The secret to ConnectHD is that it converts the MPEG2 files from the camera into CFHD .avi files. Why is this necessary, you may ask? Because editing MPEG2 files at HD resolutions is sloooow, and MPEG2 doesn't hold up to multi-generation editing well at all. Cineform's CFHD is a dream codec - it is lossless, has modest bandwidth requirements (variable bit-rate, 40Mbps - 70Mbps), and requires a relatively modest amount of CPU power to encode/decode. Furthermore, because of its high bitrate overhead (50Mbps vs 19Mbps for the source files) and intraframe compression (each frame stands alone), the same file can be encoded over and over with no generation loss. This last attribute is essential to our workflow, as you will soon find out.
WORKFLOW
1) Capture the footage -- We use HDLink (the capture and conversion program included with ConnectHD) to capture the .M2T files from the JVC HD10U. We suggest capturing the .M2T files first, and then doing the conversion to the CFHD .avi format later.
2) Review and log the .M2T files -- Windows Media Player can play the .M2T files without any trouble, so you can log and rename the files rather quickly. Then delete or set aside the bad takes.
3) Convert to CFHD -- Use HDLink to convert only the good takes to Cineform's CFHD .avi format. This will save you disk space and time. Cineform suggests using the "medium" setting for the conversion, and we concur. We did several in-house tests of "medium" vs. "large", and the results were nearly identical. However, the "large" files are HDCAM size, which creates a bandwidth and storage problem for most editing workstations.
4) Create Vegas Projects -- Make sure your Vegas project is set at 1280x720, progressive scan, square pixel, 48khz sample rate. Also, do yourself a favor, split your project up into easily digestible pieces. We have found that 20-minute projects work well (3 projects for an hour show, 6 projects for a 2 hour show). Not only does this give you more manageable timelines, but it also helps you creatively as well. Finally, set the "Dynamic RAM Preview" to 0, unless you plan on using that feature. This feature does not improve performance at all, and actually can hinder performance by taking memory away from Vegas and the rest of the computer.
5) Start Editing in Vegas -- During your first pass concentrate on laying the clips on the timeline, using simple cross-fades, and getting everything in the right place. Don't bog down the project with effects and filters yet. Set the preview window to "Preview - Auto", and use a half or quarter-size window. You should be able to maintain realtime performance throughout the entire first pass this way.
6) Apply Filters and Effects -- When possible we suggest applying filters and effects to the source files, and then rendering out "fixed" versions of those source files to be used in your projects. For example, say you have a file called "source.avi" that needs color correction. This source file is referenced several times throughout your project. Simply create a new temporary project with only "source.avi" on the timeline. Apply the correction, and then render the entire timeline to "source-fixed.avi" using the Cineform codec**. There is no need to save the temporary project unless you need to modify the correction later on. Then use the "replace media" function in the media pool to replace all instances of "source.avi" with "source-fixed.avi" in your project. This is where the CFHD format's resistance to generation loss comes in really handy.
7) Render -- Apply any effects you couldn't accomplish via #6, and then render each project using the Cineform codec. Review the renders and make changes if necessary. Once you are satisfied with the individual pieces, create a new MASTER project and stitch the rendered pieces together on the timeline. Render the MASTER project to your "final" Cineform .avi.
8) Chroma-Noise Removal -- We run our "final" Cineform .avi through VirtualDub for chroma-noise removal. We use the chroma-noise removal plugin (http://www.ifrance.com/freevcr/virtualdub/cnr-en.html) along with the Temporal Smoother set to 2. Set the compression to Cineform, click "Save As", and wait for it to render. On our new editing workstation it renders at about 7 fps. The result is your HD "MASTER".
9) Render Distribution Files -- Your HD Master can be fed into any encoding application that works with .avi's and can handle HD input resolutions. Your options are pretty limitless here: DVD, Windows Media 9, DivX, Quicktime, or even back to MPEG2-TS. Note that if someone wants to purchase your HD content for use in their HD projects that both Cineform (Windows only) and MPEG2-TS are viable options. If you choose Cineform, make sure to include the demo-version of ConnectHD (or tell them where to get it), which will allow them to decode your files and use them in their editing program. If you choose MPEG2-TS, you may want to change the extension to .MPG, as some editing programs will ignore files with the .M2T extension.
10) Cleanup and Archive -- At this point you can likely trash all of the .M2T files (assuming you have the source tapes for backup) as well as any .avi files you didn't end up using. Archive the remaining .avi files, the Vegas projects, the Master, and any other media files used in the project.
SUMMARY
Again, I have to re-iterate the importance of Cineform's multi-generation performance with respect to our workflow. I have yet to encounter a codec that holds up this strongly over so many renders. It is a real joy to work with.
Although this workflow applies specifically to footage shot with JVC HD10U, there is no reason it cannot be applied directly to the Sony FX-1 as well. Thus, we hope this article proves valuable to both current and prospective HDV producers and editors.
**Cineform / Vegas Bug and Workaround -- There is a rendering bug that could potentially make step 6 a nightmare, so please take note of this. When you render "source-fixed.avi", and then do the replace media function, you will notice strange problems start popping up in your project. Specifically, transitions involving "source-fixed.avi" will no longer render properly. However, there is a work-around. Before you render "source-fixed.avi", apply a "dummy-effect" to the entire temp project. You have to do this via the preview window, not on an individual video track. For example, add a contrast/brightness filter and set the contrast-center to 0.51 (which effectively does nothing). This will force Vegas to render the Cineform .avi file correctly, and "source-fixed.avi" will not give you trouble later on.
by Ben Buie
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