[flac-dev] Two questions

Martijn van Beurden mvanb1 at gmail.com
Wed Aug 4 19:38:49 UTC 2021

Op ma 2 aug. 2021 om 17:40 schreef Federico Miyara <fmiyara at fceia.unr.edu.ar>:
> Dear All,
> 1) Is there a way to get the audio size (number of samples) and other information, such as number of channels, from a flac file without fully decoding it?
> I've found that the WAV header is replicated after the "riffRIFF" keyword, but I don't seem to be able to predict where it is located or whether it is safe or not to asume that the first time such keyword appears is the correct one, and if there is an upper bound for its location; for instance, some text such as the name of a song or some comment could contain that keyword, even if it is unlikely. The information preceding the  "reference libFLAC 1.3.3" encoder version seems to be non-text information.

If you are looking for a tool, take a look at the metaflac command
line utility. metaflac --list file.flac returns all metadata in a FLAC

> 2) I decode using the option --skip=0 --until=1. I would expect to get a wav file with only 1 sample, but I get 3 samples.

Strange, I am not able to replicate that behaviour. When I use flac -d
--skip 0 --until 1 file.flac I get a WAV file with a single sample per
channel. I tested with a mono and a stereo file. Can you perhaps share
the full command line you're using?

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