An alternative strategy could be to use ffmpeg to transcode flv into mp3. The real challenge is to find a recent compiled executable that support the Nellymoser/ Speex (assuming that the source is the user mic).
From: [email protected] [mailto:[email protected]] On Behalf Of Jeff Ramin Sent: Wednesday, November 18, 2009 12:37 AM To: Open Source Flash Mailing List Subject: [osflash] flv file format question I want to read an FLV file for the purpose of transcoding the audio, and I'm using classes from the red5 project to iterate through the tags in the file. The section of the http://osflash.org/flv page on audio states: FLV Tag 0x08: AUDIO The first byte of an audio packet contains bitflags that describe the codec used, with the following layout: Name Expression Description soundType (byte & 0×01) » 0 0: mono, 1: stereo soundSize (byte & 0×02) » 1 0: 8-bit, 1: 16-bit soundRate (byte & 0x0C) » 2 0: 5.5 kHz, 1: 11 kHz, 2: 22 kHz, 3: 44 kHz soundFormat (byte & 0xf0) » 4 0: Uncompressed, 1: ADPCM, 2: MP3, 5: Nellymoser 8kHz mono, 6: Nellymoser, 11: Speex The rest of the audio packet is simply the relevant data for that format, as per a SWF <http://osflash.org/swf> SoundStreamBlock. However, when I dump the first few bytes of audio data from consecutive tags, I see this pattern: tag 1: b2 2a d7 5b tag 2: b2 2a d7 5a tag 3: b2 2a d7 5a tag 4: b2 2a d7 5a It seems there is more header data than a single byte. Is anybody familiar with FLV file formats and audio data (speex encoded, in this instance) that could clear this up for me? Thanks. -- Jeff Ramin Software Engineer Singlewire Software PO Box 46218 Madison, WI 53744-6218 Phone Direct - 608.298.1024 www.singlewire.com
_______________________________________________ osflash mailing list [email protected] http://osflash.org/mailman/listinfo/osflash_osflash.org
