Not an issue, just a question
kallekutta opened this issue · comments
Hello,
I'm having trouble understanding the usage of the option -c in sacd_extract. According to the manual it's used to: "convert DST to DSD". I have two questions.
First question
How can one know if the sacd iso is in DST? I have tried the option -P (display disc and track information) but it doesn't output that kind of information. Luckily with the help of foobar2000 and the foo_input_sacd plugin it's possible to identify which sacd isos are in DST. But without foobar2000, how can one identify this information and know when to use the -c option?
Second question
I did an experiment and extracted the first track of two different albums, one in DSD and the other in DST. I did the extraction to DSF with the -s option. First I extracted the DSD album with and without the -c option. I wanted to see if forcing DST conversion to an album not in DST had any effect. But both files turned out the same, so no difference when using the -c option on DSD albums. Then I tried the same thing with the DST album. This is where it gets weird. Both files also turned out the same. My expectation was that when extracting a DST album without the -c option would result in some kind of error or something. How is this possible? What exactly does the -c option do and when to use it?
Hello,
Sorry for late answer.
Even this option(and functionality) is created in original master repository, I will try to explain some things here:
Answer of Q1) this app does not have an option to notify the user of the presence (or not) of DST on an iso.
Answer of Q2) -c option is build only for using in conjunction of dsdiff ( or dsdiff-em) file extraction. This is useless for extracting dsf files. DSF files must be always decompressed (if DST is present on sacd, the decompression is made automatically).
Thank you very much for this valuable information.
I usually extract to DSF so that means I don't have to worry about the -c option.
However, I got curious to do my experiment again with this new information in mind. So this time I extracted the same two albums to dsdiff (option -p) and I can see a difference now for the DST compressed album. With the -c option it was decompressed and without it no decompression.
The DSD album though was the same with or without the -c option. That means telling the program to decompress a non-compressed album doesn't seem to cause any problem. So if my preferred extraction result is decompressed that means I don't need to know in advance if the album is compressed or not. It should be safe to use the -c option all the time on all types of albums. Is that a correct interpretation?
Yes, your interpretation is correct on dsdiff (or dsdiff-em) files. On dsf files the option -c is ignored.
Thank you very much for clearing this up. Now I don't have to check in foobar2000 if the album is compressed or not before doing the extraction. This will save me a lot of time. Thank you and have a nice day!