From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Date: Thu, 08 Jul 1999 11:46:38 +0000 Subject: Re: Microsoft RIFF, WAVE audio data, 1 bit, mono 8000 Hz Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sound@vger.kernel.org > I have a (free) voice mail service that provides the messages in a wav > file which file(1) specifies as: Dial it up and send it a steady tone square wave at about 1KHz. If my guess to the format is right then you will get back something vaguely like FF,00,FF,00,FF,00,FF,00 THen you can figure the bitendianness they use. Basically its exactly what it sounds like - single bit above/below threshold values. So you'd do while(len) { uchar i=*data++; int ct; for(ct=0;ct<8;ct++) { if(i&0x80) play8bit(0xFF); else play8bit(0x00); i<<=1; } len--; }