[FFmpeg-user] ffmpeg read from UDP/Port

Alex Lin op1031 at gmail.com
Wed Sep 24 00:05:38 CEST 2014 

Hi Maziar,

I am implementing the client. Before the server sends video stream to me,
it sends a SIP INVITE with SDP which describes the video stream.
Once I get the SIP INVITE, I can create a SDP file according to the SIP
packet and call ffmpeg to record the incoming video stream.

I have not programmed with html5 before, but I imagine there are packets to
describe the incoming video stream before the video actually arrives.
Otherwise, the server and the client must have already agreed on the video
type ahead of time.

Hope this helps,
AL

On Tue, Sep 23, 2014 at 11:16 AM, Maziar Mehrabi <mmehrabi at abo.fi> wrote:

> Hi,
>
> No problem, it was yourself who figured it out after all.
> I have a question still though. How do you transmit the SDP file to the
> client? I mean apparently for every stream you should have an SDP file
> generated and sent to the client before the client is able to play it.
> This problem is a major challenge if the client if going to play the stream
> in a browser using html5.
> So how do you manage this? Or do you think what solutions are there?
>
> Thank you,
> Maziar
>
>
> --
> Hälsningar,
> Maziar Mehrabi
>
> On Tue, Sep 23, 2014 at 8:19 PM, Alex Lin <op1031 at gmail.com> wrote:
>
> > Hi Maziar,
> >
> > I finally figured it out. Instead of using udp stream as input, I
> generated
> > a SDP file and use it as the input.
> > Prior to receiving the audio packets, I receive a SIP packet with SDP
> > payload. The SDP payload describes the IP/port of the video packet as
> well
> > as the format. I just created a SDP file with the content of the payload,
> > and FFmpeg was able to use it to receive and save the packets into a mpeg
> > file. (or play it)
> >
> > Thank you for your help!
> > AL
> >
> > On Mon, Sep 22, 2014 at 10:05 PM, Maziar Mehrabi <mmehrabi at abo.fi>
> wrote:
> >
> > > Hi,
> > >
> > > Try testing it over http first, rather than UDP or RTP. What I
> understand
> > > is that the errors somehow are related to audio channel, and RTP
> divides
> > > the media into two streams (one audio and one video) and sends them
> > through
> > > separate ports, so I guess you should have some sort of mechanism on
> the
> > > other end to capture and mix these two streams.
> > > One other way to test this idea is to use the -an option while you are
> > > streaming media, this option means "No Audio" and will just stream the
> > > video channel.
> > >
> > > if you please, keep me updated about your results.
> > >
> > > BR,
> > > Maziar
> > >
> > >
> > > --
> > > Hälsningar,
> > > Maziar Mehrabi
> > >
> > > On Tue, Sep 23, 2014 at 2:38 AM, Alex Lin <op1031 at gmail.com> wrote:
> > >
> > > > Hi Bill,
> > > >
> > > > >> I might be tempted to set both video and audio codec to copy, and
> > save
> > > > in a .TS file without -f at all.
> > > > I did a look search on google about .ts files. My understanding is
> > that,
> > > I
> > > > can use videosnarf to convert a packet trace to .TS file. Is that the
> > way
> > > > you have in mind as well?
> > > >
> > > > Thank you,
> > > > AL
> > > >
> > > > On Fri, Sep 19, 2014 at 12:19 PM, Bill Davidsen <davidsen at tmr.com>
> > > wrote:
> > > >
> > > > > Alex Lin wrote:
> > > > >
> > > > >> Hi all,
> > > > >>
> > > > >> I am using Windows 7 64 bit, and I downloaded the 64 bit version
> of
> > > > >> ffmpeg: ffmpeg-20140916-git-b76d613-win64-static.7z
> > > > >>
> > > > >> I have spent the entire day experimenting with ffmpeg today but I
> > > > haven't
> > > > >> quite figure out if ffmpeg is the right solution to my problem
> yet,
> > > so I
> > > > >> would like to get some opinions.
> > > > >>
> > > > >> I am receiving H264 encoded packets through RTP with sample rate
> of
> > > > >> 90,000,
> > > > >> and I need to record these packets. The file format doesn't really
> > > > matter
> > > > >> at this point.
> > > > >>
> > > > >> Currently, I have a server sending the H264 packets to port 50002
> of
> > > my
> > > > >> machine (192.168.1.200), so I run the following ffmpeg command on
> my
> > > > >> machine:
> > > > >>
> > > > >> ffmpeg -i udp://192.168.1.200:50002 -f mp4 hello.mp4
> > > > >>
> > > > >
> > > > > I might be tempted to set both video and audio codec to copy, and
> > save
> > > in
> > > > > a .TS file without -f at all.
> > > > > If that works you can capture the information and then play with it
> > > from
> > > > > the file. I am a Linux user,
> > > > > so you may need guidance for Windows issues from an expert, but if
> > you
> > > > can
> > > > > capture the data you
> > > > > eliminate some possible problems by not reformatting the data at
> > > capture.
> > > > >
> > > > >
> > > > >> Then the following shows
> > > > >>
> > > > >> ffmpeg version N-66289-gb76d613 Copyright (c) 2000-2014 the FFmpeg
> > > > >> developers
> > > > >>    built on Sep 15 2014 22:11:04 with gcc 4.8.3 (GCC)
> > > > >>    configuration: --enable-gpl --enable-version3
> > --disable-w32threads
> > > > >> --enable-avisynth --enable-bzlib --enable-fontconfig
> --enable-frei0r
> > > > >> --enable-gnutls --enable-iconv --enable-libass --enable-libbluray
> > > > >> --enable-libbs2b --enable-libcaca --enable-libfreetype
> > --enable-libgme
> > > > >> --enable-libgsm --enable-
> > > > >> libilbc --enable-libmodplug --enable-libmp3lame
> > > > --enable-libopencore-amrnb
> > > > >> --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus
> > > > >> --enable-librtmp --enable-libschroedinger --enable-libsoxr
> > > > >> --enable-libspeex --enable-libtheora --enable-libtwolame
> > > > >> --enable-libvidstab --enable-libvo-aacenc --
> > > > >> enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx
> > > > >> --enable-libwavpack --enable-libwebp --enable-libx264
> > --enable-libx265
> > > > >> --enable-libxavs --enable-libxvid --enable-decklink --enable-zlib
> > > > >>    libavutil      54.  7.100 / 54.  7.100
> > > > >>    libavcodec     56.  1.100 / 56.  1.100
> > > > >>    libavformat    56.  4.101 / 56.  4.101
> > > > >>    libavdevice    56.  0.100 / 56.  0.100
> > > > >>    libavfilter     5.  1.100 /  5.  1.100
> > > > >>    libswscale      3.  0.100 /  3.  0.100
> > > > >>    libswresample   1.  1.100 /  1.  1.100
> > > > >>    libpostproc    53.  0.100 / 53.  0.100
> > > > >>
> > > > >> The server starts sending video packets, and nothing happens on
> the
> > > > >> command
> > > > >> prompt with the ffmpeg command.
> > > > >> The server stops sending video packets, and nothing happens still
> (I
> > > > >> waited
> > > > >> for at least 5 minutes), so I pressed Ctrl+C, then I see this
> > > > >>
> > > > >> udp://192.168.1.200:50002: Invalid data found when processing
> input
> > > > >> Received signal 2: terminating.
> > > > >>
> > > > >> am I using ffmpeg correctly? and are the H264 packets I am
> receiving
> > > not
> > > > >> supported?
> > > > >> I have looked around and did not see any debug log generated by
> > > ffmpeg,
> > > > so
> > > > >> I don't really know where else to look.
> > > > >> If it is necessary, I can provide a packet capture with the H264
> > > > packets.
> > > > >>
> > > > >>
> > > > > --
> > > > > bill davidsen <davidsen at tmr.com>
> > > > >   CTO TMR Associates, Inc
> > > > > Unsigned numbers may not be negative. However, unsigned numbers may
> > be
> > > > > less than zero for suffiently large values of zero.
> > > > >
> > > > >
> > > > > _______________________________________________
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