HDR Video Encoding Issues

2024-10-20 10:06 UTC gpt-4o-canmore Open in ChatGPT ↗

The error you’re seeing (“10-bit encode not supported”) is because the input video is in a 10-bit color format, typical for HDR content. NVIDIA’s H.264 NVENC encoder, which is used by h264_nvenc, does not support encoding in 10-bit color depth, especially for H.264 codec. This is often the reason why HDR content throws an error during processing.

You have a few options to solve this problem:

1. Convert to 8-bit Color Depth (Loss of HDR)

You can convert the 10-bit HDR video to 8-bit, effectively discarding the HDR data. This is useful if you don’t need HDR output and want compatibility with h264_nvenc.

Here’s how you can modify your command:

ffmpeg -y -vsync 0 -hwaccel cuda -hwaccel_output_format cuda -i "C:\Users\Uncharted Limbo\Downloads\ACT_01-HAN_01-CENTER.MOV" -c:v h264_nvenc -vf "scale_cuda=1920:1080, format=yuv420p, fps=30" "C:\Users\Uncharted Limbo\Downloads\ACT_01-HAN_01-CENTER.mp4"

Explanation:

format=yuv420p: This option forces the conversion to 8-bit color space, which is compatible with H.264.

2. Encode Using H.265 (HEVC) for 10-bit Support

If you want to keep the HDR and the 10-bit color depth, you should use H.265 (HEVC) encoding instead of H.264. The NVIDIA HEVC encoder (hevc_nvenc) does support 10-bit color depth.

Here’s the modified command:

ffmpeg -y -vsync 0 -hwaccel cuda -hwaccel_output_format cuda -i "C:\Users\Uncharted Limbo\Downloads\ACT_01-HAN_01-CENTER.MOV" -c:v hevc_nvenc -profile:v main10 -vf "scale_cuda=1920:1080, fps=30" "C:\Users\Uncharted Limbo\Downloads\ACT_01-HAN_01-CENTER.mp4"

Explanation:

-c:v hevc_nvenc: This uses the HEVC codec, which can support 10-bit encoding.
-profile:v main10: The main10 profile is specifically for 10-bit color depth.

3. Software Encoding with `libx265` (Slower but High Quality)

If you don’t have a powerful GPU or prefer high-quality encoding and don’t mind slower processing, you can use software encoding with libx265. This will allow for 10-bit encoding and HDR support, but will be significantly slower than hardware encoding.

ffmpeg -y -i "C:\Users\Uncharted Limbo\Downloads\ACT_01-HAN_01-CENTER.MOV" -c:v libx265 -preset medium -crf 23 -vf "scale=1920:1080, fps=30" -x265-params profile=main10 "C:\Users\Uncharted Limbo\Downloads\ACT_01-HAN_01-CENTER.mp4"

Explanation:

-c:v libx265: This uses the x265 encoder, which has 10-bit color depth support.
-preset medium: Adjusts the encoding speed/quality tradeoff (change to slow or faster if needed).
-crf 23: Adjusts the quality (lower means better quality but larger file size).
-x265-params profile=main10: Ensures 10-bit color depth encoding.

Summary

To convert to 8-bit color, use the format=yuv420p with h264_nvenc.
To preserve 10-bit HDR, use hevc_nvenc with profile=v main10 for hardware-accelerated encoding.
For high-quality but slower encoding, use libx265.

If you want to preserve HDR and 10-bit color depth, it’s generally best to use hevc_nvenc or libx265.

To convert all clips in a folder from H.265 to H.264 while ensuring compatibility (such as using an 8-bit color depth and a widely supported profile like yuv420p), you can use a batch script along with FFmpeg. This script will go through each video file in a directory and convert it appropriately.

Below, I’ll provide a Windows batch script that can accomplish this. If you’re on Linux or macOS, the equivalent shell script is also included.

Batch Script for Windows (.bat)

This script will:

Convert all .mp4 and .mov files in the folder.
Re-encode from H.265 (HEVC) to H.264.
Ensure the output is in yuv420p format for compatibility.

Create a .bat file with the following contents:

@echo off
set input_folder="C:\Users\Uncharted Limbo\Downloads\input"
set output_folder="C:\Users\Uncharted Limbo\Downloads\output"

rem Create the output folder if it doesn't exist
if not exist %output_folder% mkdir %output_folder%

rem Loop through all .mov and .mp4 files in the input folder
for %%f in (%input_folder%\*.mov %input_folder%\*.mp4) do (
    echo Processing %%f...
    ffmpeg -y -i "%%f" -c:v libx264 -preset medium -crf 23 -pix_fmt yuv420p -c:a aac -b:a 128k "%output_folder%\%%~nf_converted.mp4"
)

echo Conversion completed.
pause

Explanation:

set input_folder: Path to your input folder with H.265 files.
set output_folder: Path where converted H.264 files will be saved.
ffmpeg -y -i "%%f": The -y flag overwrites output files if they already exist.
-c:v libx264: Use the H.264 codec.
-preset medium: Controls encoding speed vs. compression (can be set to slow for higher quality or faster for quicker processing).
-crf 23: Sets quality (lower values yield better quality, typically between 18-28).
-pix_fmt yuv420p: Converts to an 8-bit color format for maximum compatibility.
-c:a aac -b:a 128k: Ensures audio is encoded to AAC at 128kbps.

Shell Script for Linux/macOS

If you are on Linux or macOS, you can use a similar script in shell script format:

Create a .sh file with the following contents:

#!/bin/bash

input_folder="/home/uncharted_limbo/input"
output_folder="/home/uncharted_limbo/output"

# Create the output folder if it doesn't exist
mkdir -p "$output_folder"

# Loop through all .mov and .mp4 files in the input folder
for file in "$input_folder"/*.mov "$input_folder"/*.mp4; do
    if [ -f "$file" ]; then
        echo "Processing $file..."
        ffmpeg -y -i "$file" -c:v libx264 -preset medium -crf 23 -pix_fmt yuv420p -c:a aac -b:a 128k "$output_folder/$(basename "$file" .mov)_converted.mp4"
    fi
done

echo "Conversion completed."

Explanation:

The Linux/macOS script has a similar workflow as the Windows batch script.
The mkdir -p "$output_folder" creates the output folder if it doesn’t exist.
The for loop goes through each .mov and .mp4 file in the input_folder.
"$(basename "$file" .mov)" extracts the base filename, allowing conversion and renaming (in this case to "_converted.mp4").

Ensure Compatibility Tips

H.264 codec (libx264): Ensure the codec used is H.264 (libx264), as it’s the most widely compatible codec for playback on devices and browsers.
Pixel Format (yuv420p): Setting -pix_fmt yuv420p ensures the color space is limited to 8-bit, which is standard and avoids compatibility issues when played on older devices.
Audio Codec (aac): Re-encode the audio with aac codec, which is also a very compatible format for most devices.
Bitrate and CRF: If you want a consistent output quality, use -crf 23. You can lower this to 18-20 for higher quality or increase to 25-28 for smaller files with some quality compromise.

This approach should allow you to convert all your H.265 video clips to H.264 while maximizing playback compatibility across devices, including older ones.