Changeing Dolby Atmos Audio-File from 23.946FPS to 24.000FPS. How ?

[Platos]

Is this possible with free Tools ? Could i do it with mkvtoolnix ?

Edit: 23.976FPS to 24.000FPS

[Horacistro]

It can be done with free tools like MKVToolNix. You just need to edit the frame rate from 23.976FPS to 24.000FPS. Open the file in MKVToolNix, select the "Tracks" section and change the frame properties under "Video" and you're done.

[Horacistro]

Thank you

[johns0]

That will only change the video frame rate,not the audio,that will have to be done with a audio editor that will change the audio fps while keeping it dolby atmos.

[Platos]

Does anyone know how to do that? I still did not find out it

[ProWo]

Is this possible with free Tools ? Could i do it with mkvtoolnix ?

Edit: 23.976FPS to 24.000FPS

You could change the videostream instead from 24 to 23.976 fps.
Can be done without reencode with mkvtoolnix or clever Ffmpeg-GUI.

[videoAI]

Changing the frame rate of a Dolby Atmos audio file from 23.946 FPS to 24 FPS involves a few steps. Since Dolby Atmos is primarily an audio format, the frame rate change typically affects the synchronization between the audio and video. Here’s a step-by-step guide to achieve this using FFmpeg:

### Convert the Frame Rate
Use FFmpeg to change the frame rate of the video file. Note that this process will re-encode the video, which may affect the quality slightly.

Here is the command to change the frame rate from 23.946 FPS to 24 FPS:

ffmpeg -i input.mkv -vf "fps=24" -c:v copy -c:a eac3 output.mkv

### Verify the Frame Rate
you can verify the frame rate of the output file:

ffmpeg -i output.mkv

This command will display information about the output file, including the frame rate.

### Sync Audio with Video
If the audio and video are out of sync after the conversion, you may need to adjust the audio delay. use FFmpeg to add a delay to the audio stream:

ffmpeg -i output.mkv -itsoffset 0.1 -i output.mkv -map 0:v -map 1:a -c:v copy -c:a eac3  synced_output.mkv

Explanation:
-itsoffset 0.1`: Adds a 0.1 second delay to the audio stream.

Is this possible with free Tools ? Could i do it with mkvtoolnix ?
Edit: 23.976FPS to 24.000FPS

[videoAI]

@Platos

Dolby Atmos is an advanced audio technology that provides an immersive, object-based audio experience. Unlike traditional channel-based audio formats, Dolby Atmos allows for the precise placement of sounds in a three-dimensional space, creating a more realistic and engaging listening environment. Here are some key parameters related to Dolby Atmos audio streams, including bit rate and audio sample rate:

### Bit Rate
The bit rate of a Dolby Atmos audio stream can vary depending on the specific use case and the encoding parameters. Dolby Atmos supports both lossy and lossless compression, and the bit rate can be adjusted to balance quality and file size.

- **Lossy Compression**: For streaming and consumer applications, Dolby Atmos often uses lossy compression to reduce file sizes. The bit rate can range from around 300 kbps to 768 kbps or higher, depending on the content and the desired quality.
- **Lossless Compression**: For high-fidelity applications, such as Blu-ray discs or archival purposes, Dolby Atmos can use lossless compression. The bit rate in this case can be much higher, often exceeding 1 Mbps.

### Audio Sample Rate
The audio sample rate refers to the number of samples of audio carried per second, measured in Hertz (Hz). Dolby Atmos supports various sample rates to accommodate different audio quality requirements:

- **48 kHz**: This is a common sample rate for Dolby Atmos content, especially for consumer applications and streaming services. It provides a good balance between quality and file size.
- **96 kHz**: This higher sample rate is used for high-fidelity applications, such as Blu-ray discs and professional audio production. It offers better audio quality but requires more storage and bandwidth.
- **192 kHz**: This is the highest sample rate supported by Dolby Atmos and is used for the most demanding audio applications, such as high-end audio systems and professional studios. It provides the best possible audio quality but at the cost of significantly larger file sizes.

### Other Key Parameters

- **Channels**: Dolby Atmos is an object-based audio format, meaning it can handle a variable number of audio objects and channels. The number of channels can vary widely depending on the content and the playback system. For example, a home theater setup might support 5.1.2 (5 full-bandwidth channels, 1 low-frequency effects channel, and 2 height channels) or 7.1.4 configurations.
- **Metadata**: Dolby Atmos includes metadata that describes the spatial positioning of audio objects. This metadata is essential for rendering the audio correctly in a Dolby Atmos-enabled playback system.
- **Bit Depth**: The bit depth refers to the number of bits used to represent each sample of audio. Dolby Atmos supports various bit depths, including 16-bit, 24-bit, and 32-bit. Higher bit depths provide better dynamic range and audio quality.

### Example of Encoding Dolby Atmos
Encoding Dolby Atmos audio typically requires specialized software and hardware. Here is a conceptual example using FFmpeg, although note that FFmpeg does not natively support Dolby Atmos encoding. This is for illustrative purposes only:

ffmpeg -i input.wav -c:a eac3 -b:a 768k -ar 48000 output.mka

In this command:
- `-i input.wav` specifies the input file.
- `-c:a eac3` sets the audio codec to E-AC-3, which is a common codec used for Dolby Atmos.
- `-b:a 768k` sets the audio bit rate to 768 kbps.
- `-ar 48000` sets the audio sample rate to 48 kHz.
- `output.mka` is the name of the output file in Matroska format, which supports Dolby Atmos.

For actual Dolby Atmos encoding, you would typically use Dolby's proprietary tools and software,
such as Dolby Media Producer or Dolby Atmos Mastering Suite.

P.S. The Dolby Atmos audio stream does not have a [FPS] parameter, FPS only applies to video streams.

[Platos]

Thanks, i will try that (but im not sure how fast i have time to do that )

[videoAI]

Several audio codecs support Dolby Atmos, including:

1. Dolby TrueHD with Dolby Atmos: This is a lossless audio codec that supports Dolby Atmos. It is commonly used in Blu-ray discs.

2. Dolby Digital Plus with Dolby Atmos: This is a lossy audio codec that supports Dolby Atmos. It is often used in streaming services and some Blu-ray discs.

3. Dolby Digital with Dolby Atmos: This is another lossy audio codec that supports Dolby Atmos. It is used in some streaming services and older Blu-ray discs.

4. Dolby AC-4 with Dolby Atmos: This is a next-generation audio codec that supports Dolby Atmos. It is designed to provide high-quality audio with efficient compression.

5. Dolby EAC3 with Dolby Atmos: This is a lossy audio codec that supports Dolby Atmos. It is used in some streaming services and broadcast applications.

To encode audio with Dolby Atmos using `ffmpeg`, you typically need to use a codec that supports Dolby Atmos, such as EAC3 or AC4. However, `ffmpeg` does not natively support encoding to Dolby Atmos codecs due to licensing restrictions. You would need to use specialized software or hardware encoders provided by Dolby for this purpose.

For example, to encode audio to Dolby Digital Plus with Dolby Atmos, you would typically use a tool provided by Dolby, such as the Dolby Media Producer software.

Thanks

[videoAI]

please read this:
dolby-digital-audio-in-ffmpeg

[johns0]

I really believe that ProWo's idea to change the video fps to 23.976 without any re-encoding would be much better than trying to alter the dolby atmos audio.