Inpoint and outpoint settings

Oct 13, 2025 by wbrum.org 39 views

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Introduction

Concatenating multiple video files into a single file is a common task in video editing and processing. FFMPEG is a powerful, open-source multimedia processing tool that can be used to concatenate videos. However, users have reported issues where the concatenated video is longer than expected. In this article, we will discuss the possible causes of this issue and provide solutions to resolve it.

Understanding the Problem

When concatenating multiple video files, FFMPEG reads the input files and creates a new output file. However, if the input files have different frame rates, resolutions, or codecs, it can lead to unexpected behavior. In some cases, the concatenated video may be longer than expected due to the following reasons:

Different frame rates: If the input files have different frame rates, FFMPEG may not be able to accurately calculate the duration of the concatenated video.
Resolution differences: If the input files have different resolutions, FFMPEG may not be able to accurately calculate the duration of the concatenated video.
Codec differences: If the input files have different codecs, FFMPEG may not be able to accurately calculate the duration of the concatenated video.
Inpoint and outpoint settings: If the inpoint and outpoint settings are not correctly set, it can lead to unexpected behavior.

Analyzing the Issue

To analyze the issue, we need to examine the input files and the FFMPEG command used to concatenate them. In this case, we are using the following video list:

Video List

file 'C:\Users\X\Documents\test\input.mp4'
inpoint 00:00:02.7650000
outpoint 00:00:04.7650000

The FFMPEG command used to concatenate the video files is:

FFMPEG Command

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v ...

Possible Causes

Based on the FFMPEG command and the video list, there are several possible causes of the issue:

Incorrect inpoint and outpoint settings: If the inpoint and outpoint settings are not correctly set, it can lead to unexpected behavior.
Different frame rates: If the input files have different frame rates, FFMPEG may not be able to accurately calculate the duration of the concatenated video.
Resolution differences: If the input files have different resolutions, FFMPEG may not be able to accurately calculate the duration of the concatenated video.
Codec differences: If the input files have different codecs, FFMPEG may not be able to accurately calculate the duration of the concatenated video.

Solutions

To resolve the issue, we need to examine the input files and the FFMPEG command used to concatenate them. Here are some possible solutions:

Solution 1: Correct Inpoint and Outpoint Settings

If the inpoint and outpoint settings are not correctly set, it can lead to unexpected behavior. To resolve this issue, we need to ensure that the inpoint and outpoint settings are correctly set.

Solution 2: Use the Same Frame Rate

If the input files have different frame rates, FFMPEG may not be able to accurately calculate the duration of the concatenated video. To resolve this issue, we need to use the same frame rate for all input files.

Solution 3: Use the Same Resolution

If the input files have different resolutions, FFMPEG may not be able to accurately calculate the duration of the concatenated video. To resolve this issue, we need to use the same resolution for all input files.

Solution 4: Use the Same Codec

If the input files have different codecs, FFMPEG may not be able to accurately calculate the duration of the concatenated video. To resolve this issue, we need to use the same codec for all input files.

Solution 5: Use FFMPEG's -t Option

FFMPEG's -t option can be used to specify the duration of the output file. To resolve this issue, we can use the -t option to specify the duration of the output file.

Solution 6: Use FFMPEG's -ss Option

FFMPEG's -ss option can be used to specify the start time of the output file. To resolve this issue, we can use the -ss option to specify the start time of the output file.

Conclusion

Concatenating multiple video files into a single file is a common task in video editing and processing. However, users have reported issues where the concatenated video is longer than expected. In this article, we discussed the possible causes of this issue and provided solutions to resolve it. By examining the input files and the FFMPEG command used to concatenate them, we can identify the possible causes of the issue and resolve it using the solutions provided.

Additional Tips

Here are some additional tips to help you resolve the issue:

Use the -v verbose option: The -v verbose option can be used to display detailed information about the FFMPEG command and the input files.
Use the -loglevel option: The -loglevel option can be used to specify the level of detail in the FFMPEG log output.
Use the -f option: The -f option can be used to specify the format of the output file.
Use the -c option: The -c option can be used to specify the codec of the output file.

FFMPEG Command Examples

Here are some FFMPEG command examples that demonstrate how to use the solutions provided:

Example 1: Correct Inpoint and Outpoint Settings

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v -c:v libx264 -c:a aac -b:v 500k -b:a 128k -t 00:00:10 output.mp4

Example 2: Use the Same Frame Rate

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v -c:v libx264 -c:a aac -b:v 500k -b:a 128k -r 30 output.mp4

Example 3: Use the Same Resolution

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v -c:v libx264 -c:a aac -b:v 500k -b:a 128k -s 1920x1080 output.mp4

Example 4: Use the Same Codec

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v -c:v libx264 -c:a aac -b:v 500k -b:a 128k output.mp4

Example 5: Use FFMPEG's -t Option

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v -c:v libx264 -c:a aac -b:v 500k -b:a 128k -t 00:00:10 output.mp4

Example 6: Use FFMPEG's -ss Option

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v -c:v libx264 -c:a aac -b:v 500k -b:a 128k -ss 00:00:02 output.mp4

By using the solutions provided and the FFMPEG command examples, you can resolve the issue of the concatenated video being longer than expected.

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Introduction

Q: What are the possible causes of the concatenated video being longer than expected?

A: The possible causes of the concatenated video being longer than expected include:

Incorrect inpoint and outpoint settings: If the inpoint and outpoint settings are not correctly set, it can lead to unexpected behavior.
Different frame rates: If the input files have different frame rates, FFMPEG may not be able to accurately calculate the duration of the concatenated video.
Resolution differences: If the input files have different resolutions, FFMPEG may not be able to accurately calculate the duration of the concatenated video.
Codec differences: If the input files have different codecs, FFMPEG may not be able to accurately calculate the duration of the concatenated video.

Q: How can I resolve the issue of the concatenated video being longer than expected?

A: To resolve the issue of the concatenated video being longer than expected, you can try the following solutions:

Correct inpoint and outpoint settings: Ensure that the inpoint and outpoint settings are correctly set.
Use the same frame rate: Use the same frame rate for all input files.
Use the same resolution: Use the same resolution for all input files.
Use the same codec: Use the same codec for all input files.
Use FFMPEG's -t option: Use FFMPEG's -t option to specify the duration of the output file.
Use FFMPEG's -ss option: Use FFMPEG's -ss option to specify the start time of the output file.

Q: How can I use FFMPEG's -t option to resolve the issue?

A: To use FFMPEG's -t option to resolve the issue, you can add the -t option to the FFMPEG command followed by the duration of the output file. For example:

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v -c:v libx264 -c:a aac -b:v 500k -b:a 128k -t 00:00:10 output.mp4

Q: How can I use FFMPEG's -ss option to resolve the issue?

A: To use FFMPEG's -ss option to resolve the issue, you can add the -ss option to the FFMPEG command followed by the start time of the output file. For example:

ffmpeg -y -safe 0 -f concat -i output.txt -map 0:v -c:v libx264 -c:a aac -b:v 500k -b:a 128k -ss 00:00:02 output.mp4

Q: What are some additional tips to help me resolve the issue?

A: Here are some additional tips to help you resolve the issue:

Use the -v verbose option: The -v verbose option can be used to display detailed information about the FFMPEG command and the input files.
Use the -loglevel option: The -loglevel option can be used to specify the level of detail in the FFMPEG log output.
Use the -f option: The -f option can be used to specify the format of the output file.
Use the -c option: The -c option can be used to specify the codec of the output file.

Q: Can you provide some FFMPEG command examples to help me resolve the issue?

A: Here are some FFMPEG command examples that demonstrate how to use the solutions provided: