How to use the command 'transcode' (with examples)

The ’transcode’ command is used for transcoding video and audio codecs, as well as converting between different media formats. It provides a flexible and powerful way to manipulate media files, including the ability to stabilize footage, remove camera shakes, transform videos, and resize them. This article will walk you through each use case with examples.

Use case 1: Create stabilization file to be able to remove camera shakes

Code:

transcode -J stabilize -i input_file

Motivation: When capturing footage with a handheld camera or any unstable mounting, camera shakes can be inevitable. These shakes can distract the viewers and degrade the overall quality of the video. By creating a stabilization file, you can effectively remove these unwanted movements and produce smoother footage.

Explanation:

• transcode: The command itself.
• -J stabilize: The -J option tells ’transcode’ to perform a specific job, and in this case, it is the ‘stabilize’ job which creates a stabilization file.
• -i input_file: The -i option specifies the input file to be stabilized.

Example output: The stabilization process will analyze the input video file and generate a stabilization file that can be used in subsequent transformations or processing steps.

Use case 2: Remove camera shakes after creating stabilization file, transform video using XviD

Code:

transcode -J transform -i input_file -y xvid -o output_file

Motivation: After creating the stabilization file in the previous step, we can now remove the camera shakes and transform the video using a specific video codec. In this case, XviD codec is used for compression, which may result in smaller file sizes without significant loss in visual quality.

Explanation:

• -J transform: The ‘-J’ option tells ’transcode’ to perform the ’transform’ job, which removes camera shakes and applies transformations to the video.
• -i input_file: The ‘-i’ option specifies the input file to be processed.
• -y xvid: The ‘-y’ option specifies the output video codec to be used. In this case, XviD codec is selected for compression.
• -o output_file: The ‘-o’ option specifies the output file name to be saved.

Example output: After removing the camera shakes and transforming the video using the XviD codec, the output file will be generated with a smoother and more stabilized motion, thanks to the stabilization file created in the previous step.

Use case 3: Resize the video to 640x480 pixels and convert to MPEG4 codec using XviD

Code:

transcode -Z 640x480 -i input_file -y xvid -o output_file

Motivation: Resizing videos and converting them to a specific codec is often necessary to match certain requirements, such as compatibility with devices or platforms. In this case, we want to resize the video to 640x480 pixels and convert it to the MPEG4 codec using XviD.

Explanation:

• -Z 640x480: The ‘-Z’ option specifies the desired output resolution of the video. In this case, we want to resize it to 640x480 pixels.
• -i input_file: The ‘-i’ option specifies the input file to be processed.
• -y xvid: The ‘-y’ option selects the output video codec to be used, which is XviD codec in this case.
• -o output_file: The ‘-o’ option specifies the output file name to be saved.

Example output: After resizing the video and converting it to the MPEG4 format using the XviD codec, the output file will have a resolution of 640x480 pixels and a smaller file size compared to the original, while maintaining a visually acceptable quality.

Conclusion:

The ’transcode’ command provides a versatile set of features for manipulating video and audio files. Whether you need to stabilize footage, remove camera shakes, transform videos, or resize them to fit certain requirements, ’transcode’ can be an invaluable tool in your media processing workflow. Experimenting with its various options and understanding the transformation process will help you achieve your desired results efficiently.