How to save incoming h264 stream without re-encoding?

Wed May 16 11:28:12 PDT 2012

Thank you for the suggestions Rufael and Tiago.

I tried writing the H264 stream to an mp4 file with mp4mux. My strategy for
developing this receive and write script is to write a single test script
is to see if a particular mux can write a file directly from the output of
rtph264depay and then, if it works, integrate the mux into the network
receive and write script.

My test script for writing to an mp4 file was:
gst-launch-0.10 v4l2src ! queue ! 'video/x-raw-yuv,width=640,height=480' !
x264enc bitrate=500 speed-preset=superfast tune=zerolatency ! rtph264pay !
rtph264depay ! mp4mux ! filesink location=video.mp4

This wrote a file but the file was 0 bytes in size.

If you were to take out the "rtph264pay ! rtph264depay" part:
gst-launch-0.10 v4l2src ! queue ! 'video/x-raw-yuv,width=640,height=480' !
x264enc bitrate=500 speed-preset=superfast tune=zerolatency ! mp4mux !
filesink location=video.mp4

It writes a file that takes up space, but when playing the file my media
player says it doesn't contain playable streams (I'm closing the script
with ctrl + c by the way).

When I test the matroskamux element:
gst-launch-0.10 v4l2src ! queue ! 'video/x-raw-yuv,width=640,height=480' !
x264enc bitrate=500 speed-preset=superfast tune=zerolatency ! rtph264pay !
rtph264depay ! matroskamux ! filesink location=video.mkv

I get a file that is 0 bytes in size.

Removing the "rtph264pay ! rtph264depay" part of the script produces a
playable file (although the playhead progress is not liner, it starts in
the middle and slows down increasingly as it approaches the end of the
movie).

Adding in "ffdec_h264 ! ffmpegcolorspace" to the script:

gst-launch-0.10 v4l2src ! queue ! 'video/x-raw-yuv,width=640,height=480' !
x264enc bitrate=500 speed-preset=superfast tune=zerolatency ! rtph264pay !
rtph264depay ! ffdec_h264 ! ffmpegcolorspace ! matroskamux ! filesink
location=video.mkv

Produces a playable (but very large file).

Extending this to the network receive script:
gst-launch-0.10 udpsrc multicast-group=224.1.1.1 auto-multicast=true
port=5010 caps='application/x-rtp, media=(string)video,
clock-rate=(int)90000, encoding-name=(string)H264,
sprop-parameter-sets=(string)\"Z0KAHukBQHpCAAAH0AAB1MAIAA\\=\\=\\,aM48gAA\\=\",
payload=(int)96, ssrc=(uint)3315029550, clock-base=(uint)3926529534,
seqnum-base=(uint)45576' ! gstrtpjitterbuffer drop-on-latency=true
latency=500  ! rtph264depay ! ffdec_h264 ! ffmpegcolorspace ! matroskamux !
filesink location=video.mkv

Produces a playable, but large file. This "works" but is an ineffective
solution because uncompressed video is too large.

If I try to add in a x264 encode before the matroskamux, to compress the
video, after it has been received:
gst-launch-0.10 udpsrc multicast-group=224.1.1.1 auto-multicast=true
port=5010 caps='application/x-rtp, media=(string)video,
clock-rate=(int)90000, encoding-name=(string)H264,
sprop-parameter-sets=(string)\"Z0KAHukBQHpCAAAH0AAB1MAIAA\\=\\=\\,aM48gAA\\=\",
payload=(int)96, ssrc=(uint)3315029550, clock-base=(uint)3926529534,
seqnum-base=(uint)45576' ! gstrtpjitterbuffer drop-on-latency=true
latency=500  ! rtph264depay ! ffdec_h264 ! x264enc ! matroskamux ! filesink
location=video.mkv

This produces a playable, compressed video file (although the playhead
progress is not liner, it starts in the middle and slows down increasingly
as it approaches the end of the movie). But this is an inelegant solution
because I needed to decompress, then re compress the video as it comes in.

There must be a way to take the incoming H264 stream and write it directly
to a file.

On Tue, May 15, 2012 at 10:02 AM, Tiago Katcipis <katcipis at inf.ufsc.br>wrote:

> Hi,
>
> On Tue, May 15, 2012 at 8:43 AM, Rufael Mekuria <R.N.Mekuria at cwi.nl>wrote:
>
>> I don't think its such a good idea to save H.264 to avi, I would
>> recommend trying mp4mux and save to mp4 instead,
>>
>
> There is also Matroska:
>
>
> http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-matroskamux.html
>
> Best regards,
> Tiago Katcipis
>
>
>>
>> hope it helps, with me this works fine.
>>
>> best,
>>
>> Rufael
>>
>> ----- Oorspronkelijk bericht -----
>> Van: "garrett" <weaverg at email.arizona.edu>
>> Aan: gstreamer-devel at lists.freedesktop.org
>> Verzonden: Dinsdag 15 mei 2012 04:00:28
>> Onderwerp: Re: How to save incoming h264 stream without re-encoding?
>>
>> I'm trying to do the exact same thing. I stumbled upon a heap of
>> unanswered
>> threads like these on my search, so I'll bump this one because it's most
>> similar to what I want to do.
>>
>> I'm trying to transmit H264 video in RTP packets, over UDP and then on the
>> receiving end reconvert the packets into an H264 stream and both output
>> the
>> stream with ximagesink and save the h264 stream into a file.
>>
>> I can output the live stream to ximagesink just fine. Saving the stream
>> is a
>> whole different ordeal. No matter what I do, I cannot save a stream to a
>> file.
>>
>> I'll start by posting my transmit script.
>> gst-launch-0.10 v4l2src ! queue ! 'video/x-raw-yuv,width=640,height=480' !
>> x264enc bitrate=500 speed-preset=superfast tune=zerolatency ! queue !
>> rtph264pay ! udpsink host=224.1.1.1 port=5010 auto-multicast=true
>>
>> This is my most desired receiving script (it's supposed to both show the
>> video in a window and write the video to an avi file):
>> gst-launch-0.10 udpsrc multicast-group=224.1.1.1 auto-multicast=true
>> port=5010 caps='application/x-rtp, media=(string)video,
>> clock-rate=(int)90000, encoding-name=(string)H264,
>>
>> sprop-parameter-sets=(string)\"Z0KAHukBQHpCAAAH0AAB1MAIAA\\=\\=\\,aM48gAA\\=\",
>> payload=(int)96, ssrc=(uint)3315029550, clock-base=(uint)3926529534,
>> seqnum-base=(uint)45576' ! gstrtpjitterbuffer drop-on-latency=true
>> latency=500  ! rtph264depay ! tee name=videosrc \
>> videosrc. ! queue ! ffdec_h264 ! ffmpegcolorspace ! ximagesink sync=false
>> \
>> videosrc. ! queue ! avimux ! filesink location=video.avi
>>
>> Unfortunately that doesn't work, doesn't throw any errors, but it doesn't
>> bring up the video window nor does it try to write a file. If I take out
>> the
>> last line (the tee for printing out the file), it does bring up the video
>> window. If I take out the second to last line (the tee for displaying the
>> window) it creates the file, but it's zero bytes in size.
>>
>> My scripts do depend on the elements rtph264pay and rtph264depay which are
>> poorly documented. I thought that perhaps the output of rtph264depay
>> doesn't
>> output an h264 format avimux likes. So I ran this script:
>> gst-launch-0.10 v4l2src ! queue ! 'video/x-raw-yuv,width=640,height=480' !
>> x264enc bitrate=500 speed-preset=superfast tune=zerolatency ! rtph264pay !
>> rtph264depay ! avimux ! filesink location=video.avi
>>
>> Which doesn't work, it only writes a file of zero bytes large, but if I
>> took
>> out the "rtph264pay ! rtph264depay !" part, it works fine. But what's
>> more?
>> If I add "ffdec_h264 ! ffmpegcolorspace !" between rtph264depay and avimux
>> it does write a file (albeit a very large file).
>>
>> But then if I try to run this script as the receive script (just to try to
>> write a file):
>> gst-launch-0.10 udpsrc multicast-group=224.1.1.1 auto-multicast=true
>> port=5010 caps='application/x-rtp, media=(string)video,
>> clock-rate=(int)90000, encoding-name=(string)H264,
>>
>> sprop-parameter-sets=(string)\"Z0KAHukBQHpCAAAH0AAB1MAIAA\\=\\=\\,aM48gAA\\=\",
>> payload=(int)96, ssrc=(uint)3315029550, clock-base=(uint)3926529534,
>> seqnum-base=(uint)45576' ! gstrtpjitterbuffer drop-on-latency=true
>> latency=500  ! rtph264depay ! ffdec_h264 ! ffmpegcolorspace ! tee
>> name=videosrc \
>> videosrc. ! queue ! avimux ! filesink location=video.avi
>>
>> It does not work. So what is the deal here? Is there any way to write
>> video
>> from a h264 stream?
>>
>> --
>> View this message in context:
>> http://gstreamer-devel.966125.n4.nabble.com/How-to-save-incoming-h264-stream-without-re-encoding-tp1559487p4633660.html
>> Sent from the GStreamer-devel mailing list archive at Nabble.com.
>> _______________________________________________
>> gstreamer-devel mailing list
>> gstreamer-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>> _______________________________________________
>> gstreamer-devel mailing list
>> gstreamer-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>
>
>
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>
>

-- 
*W.A. Garrett Weaver *
weaverg at email.arizona.edu
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/gstreamer-devel/attachments/20120516/c405dc0a/attachment.htm>