aac alone is actually not a file format - it needs a container if you are not simply rendering it.
OpenAI doesn’t seem to know this, instead giving an ADTS stream in the file.
They use libfaac 1.30.
The AAC cannot be decoded by neroaacdec, instead giving a “moov box not found” error.
It lacks the metadata to determine the play time of a VBR file.
You could mux it into a mp4. Or just request a different format.
my audio:
ffprobe -v error -show_entries stream=codec_name,bit_rate,duration,r_frame_rate,avg_frame_rate -of default=noprint_wrappers=1 audio.aac
codec_name=aac
r_frame_rate=0/0
avg_frame_rate=0/0
duration=19.225456
bit_rate=51917
(the audio plays for 21s)
