Variable Bitrate Setting Ignored on HEVC Export

[TheTooleMan]

After updating Premiere Pro and Media Encoder to version 24.4.1, exported HEVC videos are not conforming to the bit rate I specified in the export settings when selecting "VBR, 1-PASS" in the bit rate settings.

For the past few years, I have been using the same settings without issue. See the screenshot of the Premiere Pro export settings for details.

Prior to the update, these settings produced an MP4 file with a bit rate of approximately 5 Mbps. After the update, the MP4 file has a bit rate of about 3.5 Mbps. This occurs regardless of the bit rate specified by the slider control on the export settings dialog. Even setting the slider to its maximum value, 50 Mbps, produced a video file with a bit rate of approximately 3.5 Mbps.

Further tests reveal that when selecting CBR, the output MP4 video conforms to the bit rate I set with the slider control.

This issue is seen when exporting from Premiere Pro 24.4.1 or Media Encoder 24.4.1.

[Kevin-Monahan]

Hi @TheTooleMan,

I read your bug report. Thanks for the info. The team might need more info. See: How do I write a bug report?

I hope we can help you.

Thanks,
Kevin

[mayjain]

Hi @TheTooleMan,

Sorry for the issue. Can you please try the latest beta build once ? I believe this is fixed in the beta builds.
Please let us know how it goes in beta builds.

Thanks,
Mayjain

[TheTooleMan]

Thank you for the reply. I will give the beta a try and post back.

(Sorry for the delayed response. Seems I am not getting an email when there's activity on my post.)

[TheTooleMan]

Same problem in the Premiere Pro BETA (Version 24.6.0 BETA (Build 23). I am following the template from "How do I write a bug report" to help your debugging.

• Issue - exported hardware-encoded HEVC videos do not conform to the bit rate I specified in the export settings when selecting "VBR, 1-PASS" in the bit rate settings.
  
• Adobe Premiere Pro version number: 24.4.1 (Build 2) and the beta version 24.6.0 BETA (Build 23). The issue also occurs in Media Encoder version 24.4.1 (Build 2) on exported video from Premiere Pro
  
• Operating system - Windows 10 Pro version 22H2
  
• System Info: CPU, GPU, RAM, HD:

  • CPU: Intel(R) Core(TM) i7-10700K CPU @ 3.80GHz 3.79 GHz

  • GPU and Driver Version: NVidia GeForce GTX 1650 Studio Driver version 555.99

  • RAM: 16.0 GB

  • Hard Drive: all are internal drives for use with Premiere Pro. C: 1TB SSD NVMe, NTFS. D: 1TB SATA HDD, NTFS. E: 1TB exFAT SSD

• Video format (input video, edited on timeline):

  Type: QuickTime Movie
  File Size: 13.29 GB
  Image Size: 1108 x 720
  Frame Rate: 29.97
  Source Audio Format: 48000 Hz - 16-bit - Stereo
  Project Audio Format: 48000 Hz - 32 bit floating point - Stereo
  Total Duration: 00:45:59:10
  Pixel Aspect Ratio: 1.0
  Alpha: None
  Color Space: Rec. 709
  Color Space Override: Off
  Input LUT: None

  QuickTime Details:
  Movie contains 1 video track(s), 1 audio track(s), 0 closed caption track(s), and 1 timecode track(s).

  Video:
  There are 82780 frames with a duration of 1/29.97th.

  Video track 1:
  Duration is 0:46:02:02
  Average frame rate is 29.98 fps

  Video track 1 contains 1 type(s) of video data:

  Video data block #1:
  Frame Size = 1108 x 720
  Compressor = Apple ProRes 422 LT
  Quality = Most (5.00)

  Audio:
  Audio track 1 contains 1 type(s) of audio data:

  Audio data block #1:
  Format = 16 bit - Stereo
  Rate = 48000 Hz
  Compressor = sowt

  Timecode:
  Timecode track 1 contains 1 type(s) of data:

  Timecode data block #1:
  Start Time = 00:00:00:00
  Reel name =

• Workflow details: Single camera sequence with a few edits. Adjustment layers are used for Lumetri color. (This same workflow has been in use for about two years without problems being reported here.)
  
• Steps to reproduce - (Very important!)
  1. In Edit workspace, finalize edits and color adjustments2. Save Premiere Pro project3. Click "Export" 4. In Export workspace, select format: HEVC (H.265), Frame Size: Full HD (1920x1080), Frame Rate: 29.97, Aspect: Square Pixels, Render at Maximum Depth - yes, Use Maximum Render Quality - yes, Time interpolation: Frame Sampling, Performance: Hardware Encoding, profile: Main 10, level: 4.1, tier: High, Export color space: Rec.709, HDR Graphics White: (match source), Bitrate Encoding VBR, 1 pass, target bitrate 5 Mbps, Quality Highest (slowest)
• Expected result - exported video should have bitrate close to 5 Mbps
  
• Actual result -  exported video bitrate is about 3.5 Mbps. NOTE: the bitrate of the exported video remained at about 3.5 Mbps regardless of the setting of the Target Bitrate slider. Even setting the Target Bitrate to 50 Mbps did not change the bitrate of the exported video.
  

Hope that helps. I'll be glad to furnish more information if it will aid your process.

[TheTooleMan]

Has there been any progress on this bug since I posted the bug report last week?

[TheTooleMan]

It's been six weeks, maybe seven. Any chance a fix is in the works? I think there may be an issue with ProRes, too...

[Sumeet Kumar Choubey]

Hi TheTooleMan,

Sorry for the delay. We will get it checked. Could you please confirm if this is happening specifically with VBR, 1 pass exports? Does exporting with VBR, 2 pass result in a bitrate closer to the Target Bitrate?

Thanks,

Sumeet

[TheTooleMan]

By @TheTooleMan

It occurs on 1-pass VBR. There is no 2-pass VBR option for HEVC Hardware encoding.

[moritzk95890100]

Same issue here, was there ever a fix for this?