Sunday, November 1, 2015

PE: Videomerge Produced Transparency Lost In 4K (3840 x 2160) Sized Export

INTRODUCTION

Premiere Elements 12/12.1, 13/13.1, and 14 have QFHD project presets and XAVC-S export presets for 4K (3840 x 2160) video. And, each version includes the Videomerge effect under its Expert workspace fx Effects/Keying. Videomerge has been described as an automatic version of the keying effect named ChromaKey. The keying effects have been used in green screen projects to convert a color in the image to transparency.


ISSUE

When Videomerge is used to convert a color to transparency in an image to allow for replacement background in that image, the preview in the Edit area looks fine. However, when that Timeline content is exported to file AVCHD.mp4 or XAVC-S.mp4 with 4K 3840 x 2160 export settings, the transparency in that image is lost, and the export file displays the image with its original colored background. 

The study results point to this issue being exclusive to Videomerge and the 4K 3840 x 2160 export in Premiere Elements 12/12.1, 13/13.1, and 14. It is independent of codec (AVCHD vs XAVC-S), project preset (1920 x 1080p30 vs 3840 x 2160p30), and resolution of the import* (1920 x 1080 vs 3840 x 2160). The problem does not exist if ChromaKey or Difference Matte replaces Videomerge in these studies.

STUDIES, DETAILS & RESULTS

The following is a list of the studies done to arrive at the above ISSUE details...
Premiere Elements 13/13.1**
Windows 7 Professional SP1 64 bit
With imported images 1920 x 1080 or 3840 x 2160
Pumpkin on green background on Video 2 and Videomerge applied
Leaves background on Video 1
Player for export: either VLC Player of QuickTime Player 7.7.8.

XAVC-S.MP4 Series Export

TEST 1

Project Preset = NTSC/AVCHD/QFHD 16x9 29.97
Publish+Share = Computer/XAVC-S with Presets = MP4 H.264 3840 x 2160 29.97 30 Mbps

Preview = Image with replacement background displaying
Export = Image with original green colored background displaying
Result = Failure

TEST 2
Project Preset = NTSC/AVCHD/QFHD 16x9 29.97
Publish+Share = Computer/XAVC-S with Presets = MP4 H.264 3840 x 2160 29.97 30 Mbps, but changed 3840 x 2160 to 1920 x 1080 in Advanced Button/Video Tab of preset

Preview = Image with replacement background displaying
Export = Image with replacement background displaying
Result = Success

AVCHD.MP4 Series Export

TEST 3
Project Preset = NTSC/AVCHD/QF 16x9 29.97
Publish+Share = Computer/AVCHD with Presets = MP4 H.264 1920 x 1080p30, but changed 1920 x 1080 to 3840 x 2160 in Advanced Button/Video Tab of preset
Preview = Image with replacement background displaying
Export = Image with original green colored background displaying
Result = Failure

TEST 4
Project Preset = NTSC/AVCHD/QF 16x9 29.97
Publish+Share = Computer/AVCHD with Presets = MP4 H.264 1920 x 1080p30 and left as is.
Preview = Image with replacement background displaying
Export = Image with replacement background displaying
Result = Success

Other Defining Tests

TEST 5, 6, 7, and 8
Repeat of  TESTs 1, 2, 3, and 4, except ChromaKey replaced Videomerge.
Results = All Success

TEST 9, 10, 11, and 12
Repeat of TESTs 1, 2, 3, and 4, except Difference Matte replaced Videomerge
Results = All Success

ADDITIONAL TESTS
Repeat of TESTs 1 through 12, same except Project Preset = NTSC/DSLR/1080p/DSLR 1080p30@ 29.97 instead of NTSC/AVCHD/QFHD 16x9 29.97
Repeat of TESTs 1 through 12, same except resolution of Timeline image was 1920 x 1080 instead of 3840 x 2160
Results = Same As Results From TESTs 1 through 12.

SOLUTION

Based on the above considerations and results, the conclusion is to use ChromaKey or Difference Matte and not Videomerge to create transparency in Timeline images destined for export with the 4K sizing of 3840 x 2160 in Premiere Elements 12/12.1, 13/13.1, and 14.

No advanced export settings were found to resolve the Videomerge 4K 3840 x 2160 export issue.

__________________________________________________________________________________
*Results were independent of whether Videomerge, ChromaKey, or Difference Matte was applied to Timeline video or still.
**The results were randomly confirmed in Premiere Elements 14 on Windows 10 64 bit using Export & Share/Devices/Computer 4K Ultra HD 3840 x 2160 or HD 1080 1920 x 1080 choices as well as Export & Share/Devices/Custom choices. The results were also randomly confirmed in Premiere Elements 12/12.1 on Windows 7 64 bit using  Publish+Share choices similar to those used in the studies reported above for Premiere Elements 13/13.1 on Windows 7 64 bit.

 
ATR