Wednesday, July 22, 2015

PE 13/13.1: HD Timeline Rendered Files Format Changes

INTRODUCTION

When the Premiere Elements Timeline content is Timeline rendered to get the best possible preview of it in the Edit area monitor, the project generates preview files which are automatically saved to the computer hard drive. These preview files are all in video format whether the file rendered on the Timeline is a video or still. Typically, the generalization is made that
  • For SD project, the preview file is DV.AVI 4:3 or 16:9
  • For HD project, the preview file is HD MPEG2.MPEG with a companion .XMP file
The Timeline Rendering Quality preference can change the resolution of the HD project's preview file from 960 x 540 to 1920 x 1080, but has no effect on the 720 x 480 resolution of the SD project's preview file. The DV.AVI and MPEG2.MPEG preview files contain no audio component.

 ISSUE

MediaInfo video audio properties readout program was used to examine more deeply the properties of the Premiere Elements 12/12.1 versus 13/13.1 preview files. According to these MediaInfo readouts, Premiere Elements 13/13.1 preview file format from HD projects is significantly different than that used in Premiere Elements 12/12.1. The format of the preview files from SD project appears to remain the same in 12/12.1 and 13/13.1. This blog post will document the format changes found in the Premiere Elements 13/13.1 HD project's preview files.

CHANGES FOUND

For NTSC AVCHD Full HD1080i30 Project HD Preview Files
Timeline Render Quality = High quality, Slow speed....
  • 13/13.1 Format = AVC* whereas 12/12.1 Format = MPEG2 (MPEG-PS)
  • 13/13.1 Bitrate = 60.0 Mbps Constant whereas 12/12.1 Bitrate = 31.1 Mbps max VBR
  • 13/13.1 Scan Type = Progressive whereas 12/12.1 Scan Type = Interlaced with Scan Order = Top Field First
All these 12/12.1 and 13/13.1 preview files have resolution of 1920 x 1080. And, frame rate is 29.97 frames per second. Display Aspect Ratio is 16:9. All have MPEG file extension.


For NTSC AVCHD Full HD1080i30 Project HD Preview Files
Timeline Render Quality = Draft quality, High Speed
  • 13/13.1 Format = AVC* whereas 12/12.1 Format = MPEG2 (MPEG-PS)
  • 13/13.1 Bitrate = 15.5 Mbps Constant whereas 12/12.1 Bitrate = 7768 Kbps max VBR
  • 13/13.1 Scan Type = Progressive whereas 12/12.1 Scan Type = Interlaced with Scan Order = Top Field First
All these 12/12.1 and 13/13.1 preview files have resolution of 960 x 540 and frame rate is 29.97 frames per second. Display Aspect Ratio is 16:9.All have MPEG file extension.


For NTSC DSLR 1080p DSLR 1080p30@29.97 Project HD Preview Files
Timeline Render Quality = High quality, Slow speed....
  • 13/13.1 Format = AVC* whereas 12/12.1 Format = MPEG2 (MPEG-PS)
  • 13/13.1 Bitrate = 60.0 Mbps Constant whereas 12/12.1 Bitrate = 31.1 Mbps max VBR
All these 12/12.1 and 13/13.1 preview files have resolution of 1920 x 1080 and frame rate 29.970 progressive frames per second. Display Aspect Ratio is 16:9. All have MPEG file extension.


For NTSC DSLR 1080p DSLR 1080p30@29.97 Project HD Preview Files
Timeline Render Quality = Draft quality, High speed
  • 13/13.1 Format = AVC* whereas 12/12.1 Format = MPEG2 (MPEG-PS)
  • 13/13.1 Bitrate = 15.5 Mbps Constant whereas 12/12.1 Bitrate = 7768 Kbps max VBR
All these 12/12.1 and 13/13.1 preview files have resolution of 960 x 540 and frame rate 29.970 progressive frames per second. Display Aspect Ratio is 16:9. All have MPEG file extension

COMMENTARY

The most surprising observation is that the Premiere Elements 13/13.1 preview file is the same whether the project settings are for 1080i or 1080p which is not the case in Premiere Elements 12/12.1. See Figure 1 for 13/13.1 comparison of preview file from its NTSC AVCHD Full HD 1080i30 project and from its NTSC DSLR 1080p DSLR 1080p39@29.97 project.

Figure 1. Premiere Elements 13/13.1 Comparison Of Preview File From HD Project With Interlaced Versus Progressive Frame Rate. Timeline Render Quality = High Quality, Slow Speed.




The preview files from Premiere Elements 13/13.1 PAL HD projects also are affected as described for the NTSC counterparts (not all projects tested so far).

The reasons for these changes are not understood at this time. We have not picked up on any visual benefits of these changes related to the actual Edit area previewing.

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* The codec utility named GSpot identifies the video compression as "Codec = H.264 with Name = H.264/AVC".


Work in progress.


ATR



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