[Libav-user] get mpeg4 streams with rtsp protocol

Thu Jun 16 00:17:21 CEST 2011

I have tried that. On some cameras, such as the axis, that does make
the errors go away (but causes video delay). On others, like the
panasonic, it doesn't work because they don't support TCP mode. Also,
I don't think sending RTP over TCP is very efficient when bandwidth is
limited and could cause delay. I could be wrong, but I'm under the
impression that RTP was designed to work with UDP datagrams.

On Wed, Jun 15, 2011 at 4:11 PM, av_vince [via libav-users]
<ml-node+3600712-1203814277-245513 at n4.nabble.com> wrote:
>
>
> 2011/6/15 luke <[hidden email]>
>>
>> I'm having this same problem with two axis ip cameras and two panasonic ip
>> cameras!! The video gets messed up with ghosting and other artifacts,
>> especially in the lower half. The console spits out hundreds of errors
>> each
>> minute.
>>
>> To reproduce the error, go to: http://ffmpeg.zeranoe.com/builds/ and get
>> the
>> latest 32 bit static build for, (the one I have is 1929807). Then open a
>> IP
>> camera rtsp stream via ffplay. If you don't have one, I found one that's
>> accessible online that you can access using:
>>
>> ffplay rtsp://195.200.199.8/mpeg4/media.amp
>>
>> There will be a lot of errors in the output console for ffplay.
>>
>> A few years ago we used some older versions that didn't have any mpeg4
>> errors, but they had another problem that caused the video to timeout
>> after
>> 1 minute. So it seems like the timeout problem was fixed, but replaced by
>> this mpeg4 issue. There is a post in the ffmpeg group that describes the
>> same issue. And another one here:
>> http://web.archiveorange.com/archive/v/yR2T4qtfjQ1es89IeoVN .
>>
>> It's not just ffplay either. I tried it with several example apps like the
>> ffmpeg sdl tutorial here: http://dranger.com/ffmpeg/ and my own code -
>> they
>> all get the same mpeg4 errors. The common code for these apps is based on
>> av_open_input_file(), av_find_stream_info(), and av_read_frame().
>>
>> I've tried it on several different windows computers. I'm going to try it
>> on
>> Ubuntu tonight.
>>
>> Is there a chance that perhaps we just need a certain flag or option
>> enabled?
>>
>> I will look into the source code and see if I can find the bug, but I'm
>> pretty new with mpeg4 codec specifics so it would help a lot if someone
>> can
>> give me a better idea of where to look. I don't even know where to begin -
>> the rtp parsing or the mpeg4 decompression?
>>
>> BTW, the errors I'm getting look like:
>>
>> C:\ffmpeg\bin>ffplay rtsp://195.200.199.8/mpeg4/media.amp
>> ffplay version git-N-30344-g5501afa, Copyright (c) 2003-2011 the FFmpeg
>> develope
>> rs
>>  built on May 27 2011 22:37:57 with gcc 4.5.3
>>  configuration: --enable-gpl --enable-version3 --enable-memalign-hack
>> --enable-
>> runtime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r
>> --enable-libo
>> pencore-amrnb --enable-libopencore-amrwb --enable-libfreetype
>> --enable-libgsm --
>> enable-libmp3lame --enable-libopenjpeg --enable-librtmp
>> --enable-libschroedinger
>>  --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx
>> --enabl
>> e-libx264 --enable-libxavs --enable-libxvid --enable-zlib
>> --pkg-config=pkg-confi
>> g
>>  libavutil    51.  2. 2 / 51.  2. 2
>>  libavcodec   53.  6. 0 / 53.  6. 0
>>  libavformat  53.  2. 0 / 53.  2. 0
>>  libavdevice  53.  0. 0 / 53.  0. 0
>>  libavfilter   2. 11. 0 /  2. 11. 0
>>  libswscale    0. 14. 0 /  0. 14. 0
>>  libpostproc  51.  2. 0 / 51.  2. 0
>> [rtsp @ 01E57B60] Estimating duration from bitrate, this may be inaccurate
>> Input #0, rtsp, from 'rtsp://195.200.199.8/mpeg4/media.amp':
>>  Metadata:
>>    title           : Media Presentation
>>  Duration: N/A, start: 0.030000, bitrate: N/A
>>    Stream #0.0: Video: mpeg4, yuv420p, 352x288 [PAR 12:11 DAR 4:3], 100
>> tbr, 90
>> k tbn, 100 tbc
>> [mpeg4 @ 01E5BA40] ac-tex damaged at 16 4B vq=   17KB sq=    0B f=0/0
>> [mpeg4 @ 01E5BA40] Error at MB: 108
>> [mpeg4 @ 01E5BA40] concealing 44 DC, 44 AC, 44 MV errors
>> [mpeg4 @ 01E5BA40] 1. marker bit missing in 3. esc=    0B f=0/0
>> [mpeg4 @ 01E5BA40] Error at MB: 61
>> [mpeg4 @ 01E5BA40] concealing 110 DC, 110 AC, 110 MV errors
>> [mpeg4 @ 01E5BA40] concealing 49 DC, 49 AC, 49 MV errorsB f=0/0
>> [mpeg4 @ 01E5BA40] ac-tex damaged at 12 9   0KB sq=    0B f=0/0
>> [mpeg4 @ 01E5BA40] Error at MB: 219
>> [mpeg4 @ 01E5BA40] concealing 44 DC, 44 AC, 44 MV errors
>> [mpeg4 @ 01E5BA40] ac-tex damaged at 4 7    0KB sq=    0B f=0/0
>> [mpeg4 @ 01E5BA40] Error at MB: 165
>> [mpeg4 @ 01E5BA40] concealing 66 DC, 66 AC, 66 MV errors
>> [mpeg4 @ 01E5BA40] concealing 30 DC, 30 AC, 30 MV errorsB f=0/0
>> [mpeg4 @ 01E5BA40] ac-tex damaged at 5 5    0KB sq=    0B f=0/0
>> [mpeg4 @ 01E5BA40] Error at MB: 120
>> [mpeg4 @ 01E5BA40] concealing 287 DC, 287 AC, 287 MV errors
>> ...........
>> ...........
>> and billions more errors like that :-)
>>
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>
>
> Hi,
> if you add ?tcp in the end of URL I think that many of your
> problems are solved..
> ffplay rtsp://195.200.199.8/mpeg4/media.amp?tcp
>
>
>
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-- 
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-
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Luke Clemens
http://clemens.bytehammer.com

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