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Topic: AIFF codec ID "raw"? (Read 4972 times) previous topic - next topic
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AIFF codec ID "raw"?

News to me that this exists, but I got ffmpeg to produce it by ffmpeg -i 8bitfile.wav -codec copy 8bitfile.aiff
MediaInfo recognizes it as AIFF little/unsigned with codec ID "raw". foobar2000 plays it.
I have a hard time finding any info on that type, but I saw this screenshot from macOS suggesting that unsigned 8-bit AIFF(-C, then?) is actually a thing ... since when, then?


(And ... macOS doesn't do sowt for 24 or 32 bits?)

Re: AIFF codec ID "raw"?

Reply #1 –
Plot thickens. Not much use in searching apple.com for AIFF/AIFC, but then there is the QuickTime format:
https://developer.apple.com/documentation/quicktime-file-format/sound_sample_descriptions updates from https://developer.apple.com/standards/qtff-2001.pdf

  • NONE: now relegated to "This format descriptor should not be used, but may be found in some files." Right, insinuating that the developers should be blamed for adhering to Apple's 2001 document. Other formats are marked as obsolete, but this is not.
  • raw: 8-bit unsigned, like WAVE does for 8-bit
  • twos, a.k.a. "k16BitBigEndianFormat". That's some description. Says it is stored in 16-bit big-endian, but also says in a parenthesis that 8-bit ranges -128 to 127.
  • sowt: the next in the table, here they found out they don't need the parenthesed part - thus leaving it unclear whether it can at all be used for 8-bit signals. Isn't that quite far off best practice for documentation?
  • then fl32 fl64 in24 in32. On page 17 it says that endianness defaults to big.

Also size fields are unsigned, with a field for extended to 2^32 or more.  No wonder then that there show up AIFF files with unsigned chunk size past 2 GiB. (For all that I know, Apple could have explicitly allowed that once upon a time, only to remove it from their website.)