Re-encoding Videos

Re-encoding within the Encord platform is only available to Enterprise customers. Contact [e-mail] for more information.

Encord automatically checks all uploaded videos for re-encoding, a process that ensures they meet our platform’s requirements. This prevents frame synchronization issues and guarantees accurate labels.

If a video requires re-encoding, a red badge on the file icon indicates the number of issues. You can view each issue by selecting the file and checking the details pane or by hovering over the badge.

How to Re-Encode

You can Re-encode your videos in the Files or Datasets interfaces, but we strongly recommend doing so at the Files level. Videos re-encoded at the Folder level can be used in any Project, while those re-encoded at the Dataset or Project level are restricted to their associated resources.

Re-encode from Folders

Re-encoding is only available to Enterprise customers. Contact [e-mail] for more information.

1. Go to Index > Files. A list of all Folders available appears on the Files page.

2. Go into the Folder where the video you want to re-encode resides.

3. Perform one of the following:

• Right-click the video and select Re-encode and select the type of re-encoding to perform.
• Select one or more videos and click Actions > Re-encode and select the type of re-encoding to perform.

4. Check the progress of the re-encoding job by clicking the bell icon in the top-right of the app.

When the process is complete a new video file with the word “normalized” appended to the name appears in the folder. For example, if you re-encoded snowboard.mp4, the new video is snowboard_normalized.mp4.

Re-encode from Datasets

Re-encoding is only available to Enterprise customers. Contact [e-mail] for more information.

1. Go to Index > Datasets. A list of all Datasets available appears on the Datasets page.

2. Go into the Dataset where the video you want to re-encode resides.

3. Select one or more videos.

4. Click Re-encode and select the type of re-encoding to perform.

5. Check the progress of the re-encoding job by clicking the bell icon in the top-right of the app. The number displayed in red signifies how many new notifications you have.

When the process is complete a new video file with the word “normalized” appended to the name appears in the folder. For example, if you re-encoded snowboard.mp4, the new video is snowboard_normalized.mp4.

Types of Re-encoding

Automatically fix detected issue

Re-encode (Auto): Encord performs a spot fix for any detected encoding issues. This is quicker than a full re-encoding, but for some issues, a full re-encoding is required.

Force full re-encoding

Re-encode (Full): Encord performs a full re-encoding of the video to a specific frame rate and video codec, regardless of the issues detected. This method ensures all issues are resolved, but it can take significantly more time to perform.

Re-encode Locally

Some cases, such as corrupted metadata, might require you to re-encode your data locally before uploading them to the Encord platform.

Use the following ffmpeg command, replacing video.mp4 with the name of the file you want to re-encode, and re-encoded-video.mp4 with the name you want the re-encoded file to have:

ffmpeg -err_detect aggressive -fflags discardcorrupt -i video.mp4 -r 30 -c:v libx264 -movflags faststart -an -tune zerolatency re-encoded-video.mp4

Since browsers require a constant frame rate, we apply the -r 30 flag (30 fps). Verify your video’s frame rate and adjust the value accordingly. We recommend using the average frame rate of your video to set the constant rate (rounded to the nearest whole number).

You can figure out the average frame rate of your video with this command:

ffprobe -v 0 -select_streams v:0 -show_entries stream=r_frame_rate -of default=noprint_wrappers=1:nokey=1 video.mp4 | bc -l

You may need to install ffprobe & bc

Here is a summary of the various flags:

• -err_detect aggressive: Improves error detection during decoding.
• -fflags discardcorrupt: Discards corrupted packets to maintain integrity.
• -r 30: This sets the frame rate to a constant 30 frames per second (FPS). Feel free to adjust 30 to your desired frame rate.
• -c:v libx264: Specifies the H.264 codec for video re-encoding.
• -movflags faststart: Optimizes for web playback by moving moov metadata to the beginning of the file.
• -an: This ensures the audio is removed from the re-encoded video.
• -tune zerolatency: Configures for low-latency encoding scenarios.