Command-line vs GUI Audio File Merging Tools
The differences between using command-line or a GUI-based tools are similar across applications, but the command-line is especially useful for file merging since many GUI-based tools for audio files are limited in function and availability (especially for free versions).
Advantages – faster execution, all tasks can be completed by executing a single script, flexibility/customization (adding tools, changing options, etc.), free, uses less system resources
Disadvantages– requires coding or understanding code, takes more time and effort to configure, less intuitive
Advantages – quicker learning curve, more intuitive visually and for multitasking, more complete viewing and listing of information, easier switching between commands
Disadvantages – slower execution (additional programs are often required for processing ID3 tags or to repair VBR headers), requires more system resources (video, drivers, mouse, etc.), limited options for advanced tasks (especially for free versions), limited availability of free versions
The command-line tools used in this guide are:
MP3Wrap (ver 0.5) – Wraps two or more mp3 files into a single file. The command-line executable is mp3wrap.exe
ID3 mass tagger (ver 0.78) – Copies the ID3 tag to the merged file. This is the download link for the older freeware version, which is the version used in this guide. A newer version (1.21.25) is available here for both 32-bit and 64-bit systems, but it non-free shareware. It includes a GUI and a command-line version.
MP3Val (ver 0.1.8) – Validates and fixes MPEG stream, frame, and header errors. Includes both GUI and command-line versions. The command-line executable is mp3val.exe.
Because MP3Wrap strips and replaces the ID3 tags with its own information, ID3 is used to copy the tags from one of the files. MP3Val repairs any errors in the pre-merged files copied into the merged file or produced during the merging process.
Command syntax as used in this guide:
MP3 files can be merged using either the Windows command-line or with MP3wrap. The syntax for merging mp3 files at the command-line in Windows:
copy /b file1.mp3+file2.mp3+file3.mp3 outputfile.mp3
/b = binary file
mp3wrap outputfile.mp3 file1.mp3 file2.mp3 file3.mp3
additional commands for MP3Wrap: mp3wrap_cmd_help:
Syntax to copy the ID3 tags from input file1 to the output file with ID3:
id3.exe -D file1.mp3 outputfile.mp3
-D = duplicate tags from filename
additional commands for ID3: id3_078_help
Fix and Validate
Syntax to fix and validate the output file with MP3Val:
mp3val outputfile.mp3 -f -nb -si
-f = try to fix errors
-nb = delete .bak files (suitable with -f)
-si = suppress INFO messages
additional commands for MP3Val: mp3val_cmd_help
Merging mp3 Files: Process
If using the provided batch file (see below), two steps are required.
1. Prepare the mp3 files
Ensure that the mp3 files to be merged have the same frequency, bitrate, and MPEG coding and layering. Otherwise, the output file may contain non-apparent errors, even if no errors were displayed during the merging process.
2. Drag and drop the mp3 files onto the batch file to merge
Drag and drop the mp3 files all at once and in the order to be processed onto the batch file. Rename/renumber the files as necessary to obtain the right order.
How the Batch File Processes the Files
- Displays the order of the mp3 files to be processed
- Asks the user to select between merging the files with the Windows command-line or MP3Wrap
- Merges the mp3 files into a temp file “temp_MP3WRAP.mp3”
- Transfers the ID3 tags from the first mp3 file to the temp file with ID3
- Fixes and validates the temp file with MP3Val
- Renames the temp file to the first mp3 file and appends “_merged” to the file name
Example Batch File:
Be sure to change the extension to “bat” before using.
blogferret.com – id3.exe – ideal tool for tagging and renaming MP3 files
alexenglish.info – Concatenating MP3 Files in Linux
cephas.net – Merge multiples MP3 files into one
ghacks.net – ID3 Mass Tagger