A HDPVRCapture user recently contacted our support team regarding an audio issue he was experiencing when using the ‘Split large recordings into multiple files’ feature (which can be found on the NETWORK panel of HDPVRCapture.)
The feature works by splitting large recordings into smaller ‘chunks’ while the application is capturing. For example, if you were capturing a one hour long session of gameplay, you can split this into 6 x 10 minute .m2ts files, rather that having one huge .m2ts file at the end.
The problem the user was experiencing was, if he played back the 10 minute .m2ts recordings in either VLC, QuickTime or imported the files into iMovie, the last 2 to 3 seconds of audio in each 10 minute ‘chunk’ would not play, almost as if the audio had not been captured.
This isn’t necessary the case, the audio is there, the issue appears to be with what VLC, QuickTime and iMovie are doing to the files when they are playing them back.
To get round this, we can use the ‘cat’ command in the Terminal window on the Mac to join the files back together so they play seamlessly, and with no missing audio issues.
Using the ‘cat’ Command
When you use the ‘split large recordings’ feature in the network panel, you will be left with .m2ts files that look something like this:
To join these individual files back together so that they playback seamlessly, we will use the ‘cat’ command in the Terminal window on your Mac (you can find the Terminal application in your Applications > Utilities > Terminal.app).
For the purpose of this example, the .m2ts files will have been saved in the Movies folder (the default location for HDPVRCapture). Also, do not worry if your Terminal command prompt looks different to the screenshots in the following example. Terminal command prompts can be customised to user preference, the commands you type should work exactly the same.
Open a Terminal window and type:
Then press the Enter key.
cd, or ‘change directory’ will change the current folder (or directory) in the terminal window to the Movies folder.
Once you have changed directory to the directory where your files are saved, type:
cat video.m2ts.001 video.m2ts.002 video.m2ts.003 video.m2ts.004 > joined-files.m2ts
Then press the Enter key.
In the above code example:
|cat||Is the command we wish to run.|
|video.m2ts.001||Is the name of the 10 minute file ‘chunk’ we wish to join together.|
|video.m2ts.002||Is the name of the 10 minute file ‘chunk’ we wish to join together.|
|video.m2ts.003||Is the name of the 10 minute file ‘chunk’ we wish to join together.|
|video.m2ts.004||Is the name of the 10 minute file ‘chunk’ we wish to join together.|
|>||Tells the cat command that we wish to send the output to a new file.|
|joined-files.m2ts||Is the name of our new file which will contain all the above files seamlessly joined together.|
Once the process is complete, you should now be able to playback the ‘joined-files.m2ts’ file without any audio issues.
Things to Remember
1. In the example above, you will need to replace ‘video.m2ts.001’, ‘video.m2ts.002’, ‘video.m2ts.003’, ‘video.m2ts.004’ with the names of your actual files that you wish to join together.
2. When naming the output file (in this case joined-files.m2ts) do not use the same name as one of the files you wish to join together. Your file will be overwritten, without any warning.