id	summary	reporter	owner	description	type	status	priority	component	version	resolution	keywords	cc	blockedby	blocking	reproduced	analyzed
1843	wav file fmt block size could be 16 for formatid==pcm	cgo		"Summary of the bug:
ffmpeg produces wav files with a 18 bytes size fmt section (hardcoded in libavformat/riff.c:ff_put_wav_header()). Some software expect the header size to be 16 bytes if wFormatTag is 1 (pcm), as the standard suggests that.
The header size could be 16 for the casual pcm streams, skipping the two optional fields at the end of the fmt section.
This can enhance support for legacy and poorly-written software.

How to reproduce:
{{{
% ffmpeg -i in.wav out.wav
% hexdump out.wav | head -2
0000000 4952 4646 0344 0000 4157 4556 6d66 2074
0000010 0012 0000 0001 0001 1f40 0000 3e80 0000
          ^^__ there !
ffmpeg version 1.0 and git master.
built on archlinux
}}}

Thank you"	defect	closed	minor	avformat	git-master	invalid	wav				0	0