BUG: Adobe Media Encoder 2026 – H.264 exports use incorrect color metadata and produce visible color shifts at certain resolutions

Product: Adobe Media Encoder 2026
Related application: Adobe After Effects 2026
Operating system: Windows 10
Encoding: H.264, Software Encoding, VBR 2-Pass
Severity: High – Incorrect color reproduction in professional video delivery workflows

Issue Summary

Adobe Media Encoder 2026 produces visibly incorrect colors and inconsistent color space metadata when exporting H.264 videos at certain non-standard resolutions.

The issue appears to depend on the H.264 output resolution, rather than the source video's color metadata or encoding settings.

At 1920 × 1080, the H.264 output is correctly tagged as Rec.709 (1-1-1) and visually matches the reference.

At 1536 × 576, Media Encoder produces an H.264 file tagged as 5-5-5 instead of Rec.709 (1-1-1). The resulting video appears noticeably darker and more saturated.

This happens even though the Export Color Space setting explicitly displays Rec.709.

The issue is consistently reproducible.

Steps to Reproduce

Test 1 – Standard HD resolution

1. Create an After Effects composition at 1920 × 1080, 25 fps.

2. Set the After Effects working color space to sRGB IEC61966-2.1.

3. Export the composition as Apple ProRes 422 HQ using Rec.709 Gamma 2.4 as the output color profile.

4. Import the ProRes file into Adobe Media Encoder.

5. Export as H.264 using:

   • Resolution: 1920 × 1080

   • Frame rate: 25 fps

   • Encoding: Software Encoding

   • Bitrate Encoding: VBR, 2-Pass

   • Export Color Space: Rec.709

6. Inspect the resulting H.264 file using FFprobe and compare its appearance with the reference.

Result:

• Color metadata: Rec.709 (1-1-1)

• Colors visually correct

• No noticeable gamma or saturation shift

Test 2 – Non-standard resolution

1. Create an After Effects composition at 1536 × 576, 25 fps.

2. Use the same working color space and export settings.

3. Export as Apple ProRes 422 HQ.

4. Import the ProRes file into Adobe Media Encoder.

5. Export as H.264 using the same encoding settings, with the output resolution set to 1536 × 576.

6. Inspect the resulting H.264 file.

Result:

• Color metadata: 5-5-5 instead of Rec.709 (1-1-1)

• Video appears darker and more saturated

• Export Color Space still displays Rec.709 in Media Encoder

Additional Tests Performed

To isolate the issue, several additional tests were conducted.

A. Correcting the ProRes color metadata

The problematic 1536 × 576 ProRes file was found to contain the following metadata:

• color_space: smpte170m

• color_transfer: bt709

• color_primaries: smpte170m

Using FFmpeg and the prores_metadata bitstream filter, the ProRes file was corrected to:

• color_space: bt709

• color_transfer: bt709

• color_primaries: bt709

After Effects correctly recognized the modified file as Rec.709.

However, Adobe Media Encoder still produced an H.264 file tagged as 5-5-5, with the same visible color shift.

This indicates that correcting the ProRes source metadata alone does not resolve the problem.

B. Scaling a working ProRes source using FFmpeg

A correctly tagged 1920 × 1080 ProRes file was resized externally using FFmpeg to 1536 × 576 and encoded again as ProRes 422 HQ.

The resulting file was then exported through Adobe Media Encoder.

Result:

• H.264 output at 1536 × 576: 5-5-5 metadata

• Visible darkening and increased saturation

This reproduced the issue independently of the original After Effects export at 1536 × 576.

C. Changing only the H.264 output resolution

The same 1536 × 576 ProRes source was exported through Adobe Media Encoder at 1920 × 1080 instead.

Result:

• H.264 output correctly tagged as Rec.709 (1-1-1)

• Colors visually correct

This is the most significant finding.

Changing the output resolution changes the resulting color metadata and visible color reproduction, even when the source file remains the same.

D. Software encoding and H.264 profile settings

The issue persists when using:

• Software Encoding

• H.264 High Profile

• H.264 Level 4.1

• VBR 2-Pass

Changing the H.264 profile and level does not resolve the problem.

E. Encoding with FFmpeg/libx264

The same problematic ProRes source was encoded directly to H.264 using FFmpeg/libx264 with explicit Rec.709 color metadata.

Result:

• Correct Rec.709 metadata

• Visually correct colors

• No comparable darkening or saturation shift

This provides a working alternative encoding path.

Expected Behavior

Adobe Media Encoder should respect the selected Rec.709 export color space regardless of output resolution.

When exporting SDR H.264 video from a properly color-managed Rec.709 source, the output should retain consistent color reproduction and appropriate color metadata.

Non-standard resolutions must not automatically cause an unexpected switch to Rec.601-related color metadata or visibly different color reproduction.

Actual Behavior

Adobe Media Encoder appears to change its H.264 color handling depending on the output resolution.

At 1536 × 576:

• The exported file is tagged as 5-5-5.

• The video appears darker and more saturated.

• The Export Color Space setting still displays Rec.709 and cannot be changed.

• Correcting the source ProRes metadata does not fix the issue.

At 1920 × 1080:

• The exported file is tagged as Rec.709 (1-1-1).

• The video visually matches the reference.

Professional Impact

This issue is particularly serious for Digital Out-of-Home (DOOH), digital signage, LED displays, and other professional workflows requiring non-standard output resolutions.

Publishers frequently require exact pixel dimensions, meaning users cannot simply change the output resolution to avoid the problem.

The issue can result in incorrect brand colors and inconsistent visual appearance across deliverables, even when identical export presets are used.

It also makes batch rendering unreliable because different output resolutions may silently produce different color characteristics.

Request

Please investigate whether Adobe Media Encoder incorrectly selects or applies color space metadata or color conversion based on the H.264 output resolution.

In particular:

1. Why does a 1536 × 576 H.264 export receive 5-5-5 metadata despite Rec.709 being displayed as the export color space?

2. Why does exporting the same source at 1920 × 1080 produce correct Rec.709 metadata and visual appearance?

3. Is there a way to explicitly force Rec.709 primaries, transfer characteristics, and matrix coefficients for H.264 exports at arbitrary resolutions?

A fix would be highly valuable for professional multi-resolution delivery workflows.

I can provide sample ProRes source files, resulting H.264 exports, FFprobe metadata, and detailed reproduction steps if needed.