Burn VTT Subtitles MP4

2024-04-15 11:33 UTC gpt-4 Open in ChatGPT ↗

To burn a VTT subtitle file onto an MP4 video using FFmpeg on Windows, you need to ensure that the VTT file is compatible and that you have FFmpeg installed on your system. Here’s a basic command to get this done:

Open your command prompt in Windows.
Navigate to the directory where your video file and subtitle file are located, or specify the full path to these files in the command.
Use the following FFmpeg command:

ffmpeg -i input.mp4 -vf "subtitles=subtitle.vtt" -c:v libx264 -c:a copy output.mp4

Here’s a breakdown of the command:

-i input.mp4: Specifies the input video file.
-vf "subtitles=subtitle.vtt": Applies the subtitles filter to burn the VTT subtitles onto the video. Replace subtitle.vtt with the path to your subtitle file if it’s not in the same directory or if it has a different name.
-c:v libx264: Specifies the video codec. libx264 is a common choice for H.264 encoding.
-c:a copy: Copies the original audio without re-encoding.
output.mp4: Specifies the name of the output file.

Make sure that the subtitle file format (VTT in this case) is supported by FFmpeg’s subtitles filter. If you encounter issues with direct VTT support, it might be necessary to convert the VTT to another format like SRT.

If you need to install FFmpeg or require any other specifics on this process, feel free to ask!

If VTT subtitles are supported by FFmpeg, the command I provided will work directly to burn the subtitles into the video file. Here’s a recap and additional details for a successful execution:

1. Ensure FFmpeg is Installed

Make sure that FFmpeg is installed on your Windows machine. You can verify this by running ffmpeg -version in the command prompt. If it’s not installed, you will need to download and set it up from the FFmpeg official website.

2. Prepare Your Files

Place the video file (input.mp4) and the VTT subtitle file (subtitle.vtt) in the same directory for simplicity, or be ready to specify their full paths in the command.

3. Run the Command

Open the Command Prompt and navigate to the directory containing your files. Run the following command:

ffmpeg -i input.mp4 -vf "subtitles=subtitle.vtt" -c:v libx264 -c:a copy output.mp4

Explanation of the Command

-i input.mp4: Specifies your input video file.
-vf "subtitles=subtitle.vtt": The filter graph (-vf) applies the subtitles filter to burn the .vtt subtitles onto the video. Make sure the subtitle file name matches what you have.
-c:v libx264: Uses the libx264 encoder to encode the video, which is widely compatible with various devices and players.
-c:a copy: Copies the audio stream from the original file without re-encoding, preserving the original audio quality.
output.mp4: This is your output file with the subtitles burned in.

4. Execute and Verify

After running the command, FFmpeg will process the input file and the subtitle file to create a new video file (output.mp4) that has the subtitles hardcoded onto it. This process can take some time depending on the video length and your system’s performance.

5. Troubleshooting

If you encounter any errors regarding the subtitle file (like format issues), you may need to check the subtitle file for correctness or convert it to a different format like SRT, which is generally well supported.

Using this method, you can seamlessly integrate subtitles into your video, making them a permanent part of the video stream that is visible on all devices and players. If you run into any specific issues or need further customization, such as adjusting font size or subtitle position, you can explore additional FFmpeg subtitle filter options.

here is what I am getting C:\Users\elean>ffmpeg -i D:\TEACHING\UAL\recordings\Sorted\week6_1.mp4 -vf “subtitles=D:\TEACHING\UAL\recordings\Sorted\week_6_2.vtt” -c:v libx264 -c:a copy D:\TEACHING\UAL\recordings\Sorted\week6_1_subs.mp4 ffmpeg version 6.0-essentials_build-www.gyan.dev Copyright (c) 2000-2023 the FFmpeg developers built with gcc 12.2.0 (Rev10, Built by MSYS2 project) configuration: —enable-gpl —enable-version3 —enable-static —disable-w32threads —disable-autodetect —enable-fontconfig —enable-iconv —enable-gnutls —enable-libxml2 —enable-gmp —enable-lzma —enable-zlib —enable-libsrt —enable-libssh —enable-libzmq —enable-avisynth —enable-sdl2 —enable-libwebp —enable-libx264 —enable-libx265 —enable-libxvid —enable-libaom —enable-libopenjpeg —enable-libvpx —enable-libass —enable-libfreetype —enable-libfribidi —enable-libvidstab —enable-libvmaf —enable-libzimg —enable-amf —enable-cuda-llvm —enable-cuvid —enable-ffnvcodec —enable-nvdec —enable-nvenc —enable-d3d11va —enable-dxva2 —enable-libmfx —enable-libgme —enable-libopenmpt —enable-libopencore-amrwb —enable-libmp3lame —enable-libtheora —enable-libvo-amrwbenc —enable-libgsm —enable-libopencore-amrnb —enable-libopus —enable-libspeex —enable-libvorbis —enable-librubberband libavutil 58. 2.100 / 58. 2.100 libavcodec 60. 3.100 / 60. 3.100 libavformat 60. 3.100 / 60. 3.100 libavdevice 60. 1.100 / 60. 1.100 libavfilter 9. 3.100 / 9. 3.100 libswscale 7. 1.100 / 7. 1.100 libswresample 4. 10.100 / 4. 10.100 libpostproc 57. 1.100 / 57. 1.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ‘D:\TEACHING\UAL\recordings\Sorted\week6_1.mp4’: Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2 creation_time : 2024-04-12T09:05:39.000000Z Duration: 00:04:46.46, start: 0.000000, bitrate: 337 kb/s Stream #0:00x2: Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080, 272 kb/s, 16 fps, 16 tbr, 10k tbn (default) Metadata: creation_time : 2024-04-12T09:05:39.000000Z vendor_id : [0][0][0][0] Stream #0:10x1: Audio: aac (LC) (mp4a / 0x6134706D), 16000 Hz, mono, fltp, 63 kb/s (default) Metadata: creation_time : 2024-04-12T09:05:39.000000Z vendor_id : [0][0][0][0] Stream mapping: Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264)) Stream #0:1 -> #0:1 (copy) Press [q] to stop, [?] for help [Parsed_subtitles_0 @ 0000011842a8ef00] Unable to parse option value “TEACHINGUALrecordingsSortedweek_6_2.vtt” as image size Error applying option ‘original_size’ to filter ‘subtitles’: Invalid argument Error reinitializing filters! Failed to inject frame into filter network: Invalid argument Error while processing the decoded data for stream #0:0 Conversion failed!

The error you’re encountering indicates that there’s a problem with the path of the subtitle file in the subtitles filter. In FFmpeg, paths that contain colons (:) or are not properly escaped can lead to issues because colons are used to separate different options within filters. This seems to be happening with your path that includes the drive letter (D:).

To resolve this, you should escape the colon and the backslashes in the path to the subtitle file within the FFmpeg command. Here’s how you can modify your command to correctly specify the path on a Windows system:

ffmpeg -i "D:\TEACHING\UAL\recordings\Sorted\week6_1.mp4" -vf "subtitles='D\:/TEACHING/UAL/recordings/Sorted/week_6_2.vtt'" -c:v libx264 -c:a copy "D:\TEACHING\UAL\recordings\Sorted\week6_1_subs.mp4"

Here’s what changed:

The paths are enclosed in quotes to ensure they are processed as a single argument.
The subtitle file path uses a forward slash (/) and the drive letter colon is escaped as D\:/ which FFmpeg can handle more reliably.

This should help FFmpeg correctly locate and apply the subtitle file to your video. Make sure the subtitle file name and path are exactly correct.

To concatenate a set of MP4 videos into one using FFmpeg, you have a couple of options depending on the format and codec of the videos. If all videos are encoded with the same codec, you can use the concat demuxer, which is generally the recommended method as it does not re-encode the videos, thus preserving the original quality.

Using the Concat Demuxer

Create a text file listing all the videos: Create a text file (e.g., filelist.txt) and list each video file on a new line with the format file 'path/to/file.mp4'. Here’s an example of what the content of filelist.txt might look like:
```
file 'video1.mp4'
file 'video2.mp4'
file 'video3.mp4'
```
Run the FFmpeg command: Use this command to concatenate the videos:
Terminal window
```
ffmpeg -f concat -safe 0 -i filelist.txt -c copy output.mp4
```
Here’s what each option means:
- -f concat: Tells FFmpeg to use the concat demuxer.
- -safe 0: Allows file paths that might otherwise be considered unsafe.
- -i filelist.txt: Specifies the input file list.
- -c copy: Copies the video and audio streams without re-encoding.

Using the Concat Protocol (if videos are exactly the same in codec/format)

If the concat demuxer approach doesn’t work (e.g., due to different codecs or settings in the videos), and you are sure that all video files are encoded exactly the same way (same codec, same frame rate, same bitrates, etc.), you can use the concat protocol:

Run the FFmpeg command:
Terminal window
```
ffmpeg -i "concat:video1.mp4|video2.mp4|video3.mp4" -c copy output.mp4
```
This method is simpler but less flexible and can cause issues if the videos are not encoded identically.

General Advice

Check Codec Compatibility: Make sure all videos use the same codecs, resolution, and frame rates.
Backup Originals: Always keep a backup of the original files in case something goes wrong during the concatenation process.
Test After Processing: Check the output video to ensure the concatenation process went smoothly and that there are no playback issues.

If you need help creating the file list or have specific requirements (like re-encoding the videos into a single format), let me know, and I can guide you through those steps!