[FFmpeg-devel] RTP mark bit not passed to parse_packet

Alexandre FERRIEUX - FT/RD/SIRP/ASF/SOFTL alexandre.ferrieux
Thu Jan 15 14:15:52 CET 2009

Ronald S. Bultje wrote:
> Hi,
> On Thu, Jan 15, 2009 at 4:13 AM, Alexandre FERRIEUX -
> FT/RD/SIRP/ASF/SOFTL <alexandre.ferrieux at orange-ftgroup.com> wrote:
>> In the process of writing an RTP depayloader for H263 (RFC2429, simple
>> follow-on packet mode), I see that the current API doesn't pass the RTP
>> Mark bit (buf[1]&0x80) to the payload handler callback.
> I have a local patch that saves the M-bit as 0x100 in the flags field
> (flags |= (buf[1] & 80) << 1) in the flags field, which is passed on
> to the parse_packet() functions. See my recent X-QT patch, which
> includes it (IIRC). We could consider making >=0x100 (e.g. 0xFF00) an
> official "format-specific" flag mask (in avformat.h), and then using
> 0x100 as RTP_FLAG_M_BIT (in rtp_internal.h).

Yes, I'd love to see this committed :)

FWIW, instead of

	flags |= (buf[1] & 0x80) << 1

I'd prefer the more readable variant:

	if (buf[1] & 0x80) flags |= RTP_FLAG_M_BIT;



More information about the ffmpeg-devel mailing list