Using goldwave to autotrim and concatenate audio tracks.

GoldWave general discussions and community help
Post Reply
jibanes
Posts: 3
Joined: Sun Nov 08, 2009 9:37 pm

Using goldwave to autotrim and concatenate audio tracks.

Post by jibanes »

Hello,

I am recording audio with a Sony PCM-D50 recorder with a 16GB sony memory stick pro duo (which, when coupled with the internal 4GB flash memory of the recorder gives me roughly 20GB of storage). This recorder uses a Fat filesystem on the memory stick to store data, which can be later on read either through the recorder's USB slot or using a memory card reader.

This is a pretty good recorder, therefore I usually record on 48 kHz/24 bits, which allows me to store roughly 1 hour per GB of storage space. Because of some limitations (Fat or Wav, I'm unsure, maybe either or both), the recorder can not store wav files bigger than 2GB, although, this is not really a problem since the recording doesn't stop when the file reaches its maximum file storage size, a new file is simply created and the recording goes on. Filenames are as such: 091108_1.wav, 091108_2.wav, 091108_3.wav, etc. Most obviously, the "last" file usually has a size smaller than 2GB.

Because my recordings are usually 4-5 hours long (sometimes even longer), it's not uncommon that I end up with 4-5 files to concatenate, also, because the recorder doesn't do "sync rec" (well they say it does, but trust me, it doesn't work, even with a good cutoff filter either set to 75Hz or 150Hz) I usually have a "blank" (sometimes 10 minutes long) in front of the first track and another "blank" at the end of the last.

What I would like to achieve here, using Goldwave, is to trim the first track to remove the prepended blank, then trim the last track to remove the appended blank, then concatenate all the tracks and encode the output as a mp3 file (because it would, in all logic, be too big to leave it as a wav) which I think should be 44.1 kHz/16 bits (using the lame library of course).

This raises some questions:
* Is it possible to automate this using goldwave, if so, how?
* Would it be possible to perform these tasks on a machine, running xp sp3 with roughly 3GB of ram? Or, simply put, a machine with less memory available than the sum of all the wav files. I assume here than disk space is not a concern, although, I would like to ask, how much termporary disk storage space is necessary per each GB of wav file to be processed?

Finally, please note that for obvious sound quality considerations, the mp3 encoding should take place in the last step only, while it is possible (and easy) to concatenate mp3 files, this would involve a "two round" encoding which would drastically lower the quality of the final output.

Let me know what you think,
Jerome

cdeamaze
Posts: 87
Joined: Thu Oct 05, 2006 3:19 pm

Re: Using goldwave to autotrim and concatenate audio tracks.

Post by cdeamaze »

48 kHz/24 bits, which allows me to store roughly 1 hour per GB of storage space.
You are absolutely right in your observation. This follows from simple arithmetic: 48000*24/8*3600*2=1.0368 GB
Because of some limitations (Fat or Wav, I'm unsure, maybe either or both), the recorder can not store wav files bigger than 2GB
This is the famous 2GB "FAT barrier": (2^16)*(2^15)=2^31=2GB
To overcome this barrier, different file formats such as FAT32 or NTFS format can be used. I have never tried this before, not sure if it will work for your memory stick. but you can also change from wave to mp3 when you record. See below.
Because my recordings are usually 4-5 hours long (sometimes even longer), it's not uncommon that I end up with 4-5 files to concatenate
Get yourself a tool such as "Easy Hi-Q Recoder". It is free for trial and $30 if you like it and decide to buy. You can decide when and where to record and in what format(MP3 in your case). If you choose to record in mp3 instead of wave, your file size will be a lot less than the magic number 2GB, you have only 1 file and nothing to concatenate. You will still need to get rid of silence, but that part should be easy. Instead of frequency, you can also use amplitude(or signal strenth) like "remove if it less than -23db". GoldWave will have 4-5 files in this case because it uses wave format.

References:
why are my files so big?
How to cut file size by sampling freq, bit rate, stereo/mono

jibanes
Posts: 3
Joined: Sun Nov 08, 2009 9:37 pm

Re: Using goldwave to autotrim and concatenate audio tracks.

Post by jibanes »

Because my recordings are usually 4-5 hours long (sometimes even longer), it's not uncommon that I end up with 4-5 files to concatenate
Get yourself a tool such as "Easy Hi-Q Recoder". It is free for trial and $30 if you like it and decide to buy. You can decide when and where to record and in what format(MP3 in your case). If you choose to record in mp3 instead of wave, your file size will be a lot less than the magic number 2GB, you have only 1 file and nothing to concatenate. You will still need to get rid of silence, but that part should be easy. Instead of frequency, you can also use amplitude(or signal strenth) like "remove if it less than -23db". GoldWave will have 4-5 files in this case because it uses wave format.
This wouldn't work for me, let me explain why. I'm trying to get the best quality possible, therefore, recording in MP3 or preprocessing Wav->MP3 before editing it (or not) with GoldWave would intruduce a "lossy" compression, degrading the sound quality, I would rather concatenate several 2GB Wav files and maintain the audio quality to its best before finally encoding the final result as an mp3 file. The less lossy compressions you do through your audio processing the best the final quality will be. Here, by doing only one lossy compression, I maintain the audio quality through the processing phase, should I precompress the files in MP3 or record directly in MP3, I will lose some signal quality.

Therefore, I am still looking for a solution here.

cdeamaze
Posts: 87
Joined: Thu Oct 05, 2006 3:19 pm

Re: Using goldwave to autotrim and concatenate audio tracks.

Post by cdeamaze »

I'm trying to get the best quality possible
If quality is your top concern, then obviously recording in mp3 is out. But you can still look into the possibility:
(i) Using FAT32 instead of FAT, this will cut your files from 4-5 to 2-3.
I suppose your memory stick can have that option(my flash drive can be in either FAT or FAT 32), make sure your recorder flash memory has that capability.
(ii)Consider 44.1K 16-bit(CD quality) recording instead of 48K 24-bit.
You probably incur no loss in quality if your final product is in mp3 form, a saving of 40%

If you can do both, your files will be reduce to 2 files from 4-5, which is 50-60% reduction. and you only need to concatenate once.
_______________________________________________
Because my recordings are usually 4-5 hours long (sometimes even longer), it's not uncommon that I end up with 4-5 files
Q: just curious if each hour recording is 1GB, and each file is 2GB, how can 4-5 hours recording takes 4-5 files? Shouldn't it be 8-10 hours recording takes 4-5 files? :D

jibanes
Posts: 3
Joined: Sun Nov 08, 2009 9:37 pm

Re: Using goldwave to autotrim and concatenate audio tracks.

Post by jibanes »

(i) Using FAT32 instead of FAT, this will cut your files from 4-5 to 2-3.
I suppose your memory stick can have that option(my flash drive can be in either FAT or FAT 32), make sure your recorder flash memory has that capability.
Not possible as the recorder doesn't have a FAT32 driver.
(ii)Consider 44.1K 16-bit(CD quality) recording instead of 48K 24-bit.
You probably incur no loss in quality if your final product is in mp3 form, a saving of 40%
Saving 40% of space won't change the original problem which is that I will have several files to concatenate and autotrim.
If you can do both, your files will be reduce to 2 files from 4-5, which is 50-60% reduction. and you only need to concatenate once.
I do not intend to change the process itself, not minimize the quality of the final product or save disk space, I would just like to know if an automated solution to my problem is possible, and if so, how?
Q: just curious if each hour recording is 1GB, and each file is 2GB, how can 4-5 hours recording takes 4-5 files? Shouldn't it be 8-10 hours recording takes 4-5 files? :D
I have used those words: "Because my recordings are usually 4-5 hours long (sometimes even longer), it's not uncommon that I end up with 4-5 files to concatenate,"

As I mentioned ("sometimes even longer") some recordings are 10 hours long, therefore creating 4-5 files of 2GB to concatenate, others, the shortest ones are 4-5 hours long, leading to 2-3 files to concatenate.

Can someone please let me know if it's possible to automate such process?

GoldWave Inc.
Site Admin
Posts: 4005
Joined: Wed Mar 10, 2004 6:43 pm
Location: St. John's, NL
Contact:

Re: Using goldwave to autotrim and concatenate audio tracks.

Post by GoldWave Inc. »

File size isn't an issue if you are using GoldWave on a recent computer with NTFS and you don't have RAM storage turned on (it is off by default). The size of the file can be larger than 4GB. There'd only be a problem if you tried to store the concatenated file back on the memory stick or if you used the Wave format (which is limited to 4GB).

You can use the File Merger tool in GoldWave and save the final file on your hard drive in any of the formats that support large files (FLAC, WMA, Ogg, MP3, ...).

Before merging the files, you can use the Batch Processing feature to Auto Trim leading and trailing silences from each file (use the Add Edit button to add Auto Trim on the Process tab).

Chris

Post Reply