[FFmpeg-devel] add MJPEG support into RTP output

Luca Abeni lucabe72
Mon Apr 12 08:38:32 CEST 2010

On 12/04/10 06:32, Nash Tsai wrote:
>> Section 3.1.9 "JPEG Payload":
>> "The data following the RTP/JPEG headers is an entropy-coded segment
>> consisting of a single scan.  The scan header is not present and is
>> inferred from the RTP/JPEG header. ... "
> By capture the RTP packet with Wireshark, if the RTP payload type is
> 26 the wireshark packet analyzer will assume that JPEG RTP Header is
> required.

The "JPEG RTP header" (I assume you mean the payload header, here?) is 
needed. What needs to be removed is an header which is part of the JPEG 
bitstream, referred as "scan header" in the RFC.
This header is generated by the (M)JPEG encoder, and needs to be removed 
by the packetiser in order to generate a valid "MJPEG in RTP" stream 
(such header will be added back by the depacketiser when receiving the 
RTP stream). The patch that has been posted does not do anything 
similar, and as a result vlc generates a lot of errors when trying to 
decode the stream.


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