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Topic: bzip2 compressed 6GB/10GB non-compliant WAVs (Read 6246 times) previous topic - next topic
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bzip2 compressed 6GB/10GB non-compliant WAVs

These files can be used for testing lossless or lossy encoders and also other applications that accept WAV files as input, and that also handle extra RIFF chunks in some way. They were created with Audition 2.0 and are digitally silent, hence they compress to only a few KB. RIFFs have a 4GB chunk limit and Audition places the extra audio into extra chunks which result in WAV files not being standard-compliant.

Some audio software have problems handling these files, either crash or add the extra data as uncompressed meta data etc, because these big files are so rare, I guess, and therefore it's not common to test for this special condition. And since not everyone developing such encoders or audio processing applications has access to Audition 2.0, I've uploaded them here:


The first file is 10 hours long and when uncompressed about 6GB big:
Code: [Select]
10h00m00s.wav.bz2            :  4,92 KB         (5.047 bytes)
10h00m00s.wav (uncompressed) :  5,91 GB (6.350.402.770 bytes)
[attachment=2955:attachment]


The second file is 16 hours and 40 minutes long and when uncompressed about 10 GB big:
Code: [Select]
16h40m00s.wav.bz2            :  7,82 KB          (8.014 bytes)
16h40m00s.wav (uncompressed) :  9,85 GB (10.584.002.780 bytes)
[attachment=2956:attachment]

For bzip2 binaries have a look at the official website: http://www.bzip.org/
Or for maybe some of the enhanced builts that can be found via http://en.wikipedia.org/wiki/Bzip2#Implementations

Unfortunately, bz2 is not recognised as a legit file extension by the forum software. (admins, fix this please! it's just the lovely bzip2.) That's why I took the freedom to rename the files to WAV and upload them anyway. Make sure to remove the ".wav" before uncompressing them or it might not work... 

One tip: in case you are on a Windows machine with NTFS partitions, you can use compressed folders to work with these files. NTFS' compression works quite well with these big empty files, too, and only a few KB of real disc space will be used. NTFS' compression is also quite faster than bzip2 by the way...  so your worries that may arise while you're waiting for bzip2 to uncompress should not apply to NTFS' compression. A fast machine is still recommended, or at least fast enough to handle the heavy IO-load of big files.

bzip2 compressed 6GB/10GB non-compliant WAVs

Reply #2 –
For decompression... I don't really know.

But for compression of such files (many many zeros, nothing but zeros) I don't recommend WinRAR. It started to produce a large archive of several MBs from these files above.

I guess 7z uses a compression method quite similar to bzip2, therefore try to use this for compressing such files.

bzip2 compressed 6GB/10GB non-compliant WAVs

Reply #3 –
7zip is the shiznit

you can throw winrar/winzip/winwhatever out


later

bzip2 compressed 6GB/10GB non-compliant WAVs

Reply #4 –
The Riff length is (2^32 - 1), or -1. There are 2 data chunks, each is just under the max allowed. Compliant RIFF program will only read the first data chunk, it is a small fix to allow reading of this file as it should be, which would not break anything.

It is a good test, thanks for the file (one that takes just 24 kb in a compressed folder, so good to have around).

bzip2 compressed 6GB/10GB non-compliant WAVs

Reply #5 –
Quote from: xmixahlx on
7zip is the shiznit

you can throw winrar/winzip/winwhatever out


later

7z is cool but not all-around better. Raw audio samples, for example, compress much better with RAR, for some reason! Also, RAR has a major edge in resource usage - and support.

Ogg Vorbis has several advantages over MP3 yet still MP3 is dominant, don't forget that...