[asterisk-users] video voicemail

[Jeff LaCoursiere]

On Mon, 15 Feb 2010, Tilghman Lesher wrote:

> On Monday 15 February 2010 14:09:38 Olle E. Johansson wrote:
>> 15 feb 2010 kl. 20.31 skrev Jeff LaCoursiere:
>>> Playing around with the Grandstream GXV3140.
>>>
>>> I'm interested in having the video voicemail clips emailed in a format
>>> that might be opened by Windows Media Player or even Quicktime.  Have
>>> been googling around a lot and have tried various bits of OSS to read the
>>> resulting .h264 file that asterisk is saving, but having absolutely no
>>> luck.  A video nut I know took a look at the file and said it had no
>>> header, and was actually convinced there was no video in it.
>>>
>>> Anyone else trying to do this?
>>
>> Asterisk is not saving a proper h.264 file, it's saving the raw RTP media.
>> I think that ffmpeg had a module that could handle this at some point in
>> time.
>>
>> Because of patents for H.264, we can't convert the media to anything
>> useful.
>
> IIRC, the actual format of the file is:
> 1-bit: full-frame marker
> 15-bits, unsigned: length of the RTP packet, in bytes
> RTP-data
> 1-bit: full-frame marker
> 15-bits, unsigned: length of the RTP packet, in bytes
> RTP-data
> (etc.)
>
> The format was designed to be easily convertable back into an RTP stream,
> because as the format does not include audio data, it was believed that it
> would never be useful outside of Asterisk's own usage.
>

Am I naive in assuming that I could extract the RTP data given the format 
above into something that is inherently h.264 encoded?

Cheers,

j