[MPlayer-dev-eng] Problem decoding a H.263+ stream

Michael Niedermayer michaelni at gmx.at
Sat Aug 24 10:56:01 CEST 2002


Hi

On Saturday 24 August 2002 01:51, Ross Finlayson wrote:
> [This is really a question for the developer(s) of the "ffmpeg" codec
> library, but Fabrice Bellard has not yet responded to my email to him.  So,
> I wonder if anyone on this mailing list is familiar with the "ffmpeg"
> H.263(+) decoding software, and can help me out here.]
>
> As you know, I have recently modified the "mplayer" media player to play
> RTP streams: <http://www.live.com/mplayer/>.  However, I find that when I
> try playing a H.263+ video stream, mplayer is crashing in the "ffmpeg"
> codec.  The problem is occurring halfway through the first video
> frame.  The codec successfully decodes about half of the macroblocks in the
> first frame (this first frame is an "I" frame, of course), but then
> encounters an error.
>
> The error is occuring in the call to get_vlc2() at line 2696 of
> "h263.c".  This call is returning -1, which causes the macroblock decode to
> fail, which subsequently triggers the error concealment code (which then
> causes a crash, because this is the first frame, and there's no 'previous'
> frame at this point).
hmm, i thought i fixed that (first frame=NULL thing)

>
> Unfortunately, I don't yet know enough about the H.263+ codec to know for
> sure why macroblock decoding is failing halfway through the first
> frame.  So, I wonder if anyone who's familiar with this code could find the
> time to build the new "mplayer" (with RTP streaming support), and
> demonstrate this error for themselves.
>
> If you build the LIVE.COM libraries and "mplayer" (following the
> instructions at <http://www.live.com/mplayer/>), and run
>      mplayer -fps 15
> rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov
> you should see the error occur.
doesnt seem to work, no audio/video shown at all, see attached log

and
mplayer -fps 15 
rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov -v 
-dumpstream crashed see attached log

[...]

Michael
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MPlayer CVS-020720-22:23-2.95.4 (C) 2000-2002 Arpad Gereoffy (see DOCS!)

CPU: Intel Celeron 2/Pentium III Coppermine,Geyserville (Family: 6, Stepping: 1)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 SSE

Reading /home/michael/.mplayer/codecs.conf: 38 audio & 105 video codecs
CommandLine:get_path('font/font.desc') -> '/home/michael/.mplayer/font/font.desc'
 '-fps' '15' 'rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov' '-v'
Using MMX (with tiny bit MMX2) Optimized OnScreenDisplay
Font /home/michael/.mplayer/font/font.desc loaded successfully! (191 chars)
Linux RTC init error: Device or resource busy
Using usleep() timing
get_path('input.conf') -> '/home/michael/.mplayer/input.conf'
Can't open input config file /home/michael/.mplayer/input.conf : No such file or directory
Can't open input config file /usr/local/share/mplayer/input.conf : No such file or directory
Falling back on default (hardcoded) input config

Playing rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov
Connected to server: darwin.horizonlive.com
Stream not seekable!
Sending request: DESCRIBE rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov RTSP/1.0
CSeq: 1
Accept: application/sdp


Received DESCRIBE response: RTSP/1.0 200 OK
Server: DSS/3.0.1 [v338]-Linux
Cseq: 1
Last-Modified: Wed, 26 Sep 2001 15:38:33 GMT
Cache-Control: must-revalidate
Content-length: 297
Date: Sat, 24 Aug 2002 08:38:40 GMT
Expires: Sat, 24 Aug 2002 08:38:40 GMT
Content-Type: application/sdp
x-Accept-Retransmit: our-retransmit
Content-Base: rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov/

v=0
s=/finlayson/sample-h263-ulaw-8000.mov
u=http:///
e=admin@
c=IN IP4 208.185.32.22
a=control:*
b=AS:528
a=range:npt=0-  37.40333
m=video 0 RTP/AVP 96
b=AS:464
a=rtpmap:96 H263-1998/90000
a=control:trackID=3
a=cliprect:0,0,180,240
m=audio 0 RTP/AVP 0
b=AS:63
a=control:trackID=4

Initiated "video/H263-1998" RTP subsession
Sending request: SETUP rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov/trackID=3 RTSP/1.0
CSeq: 2
Transport: RTP/AVP;unicast;client_port=32786-32787


Received SETUP response: RTSP/1.0 200 OK
Server: DSS/3.0.1 [v338]-Linux
Cseq: 2
Last-Modified: Wed, 26 Sep 2001 15:38:33 GMT
Cache-Control: must-revalidate
Session: 5503127402563450278
Date: Sat, 24 Aug 2002 08:38:40 GMT
Expires: Sat, 24 Aug 2002 08:38:40 GMT
Transport: RTP/AVP;unicast;client_port=32786-32787;source=208.185.32.22;server_port=6970-6971


Sending request: PLAY rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov/trackID=3 RTSP/1.0
CSeq: 3
Session: 5503127402563450278
Range: npt=0-


Received PLAY response: RTSP/1.0 200 OK
Server: DSS/3.0.1 [v338]-Linux
Cseq: 3
Session: 5503127402563450278
RTP-Info: url=trackID=3;seq=27224;ssrc=2085301520;rtptime=1579977641


==> Found video stream: 0
Initiated "audio/PCMU" RTP subsession
Sending request: SETUP rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov/trackID=4 RTSP/1.0
CSeq: 4
Transport: RTP/AVP;unicast;client_port=32788-32789


Received SETUP response: RTSP/1.0 200 OK
Server: DSS/3.0.1 [v338]-Linux
Cseq: 4
Last-Modified: Wed, 26 Sep 2001 15:38:33 GMT
Cache-Control: must-revalidate
Session: 1677976936956434817
Date: Sat, 24 Aug 2002 08:38:40 GMT
Expires: Sat, 24 Aug 2002 08:38:40 GMT
Transport: RTP/AVP;unicast;client_port=32788-32789;source=208.185.32.22;server_port=6970-6971


Sending request: PLAY rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov/trackID=4 RTSP/1.0
CSeq: 5
Session: 1677976936956434817
Range: npt=0-


Received PLAY response: RTSP/1.0 200 OK
Server: DSS/3.0.1 [v338]-Linux
Cseq: 5
Session: 1677976936956434817
RTP-Info: url=trackID=4;seq=43430;ssrc=1307817095;rtptime=577699790


==> Found audio stream: 0
[V] filefmt:21  fourcc:0x33363248  size:0x0  fps: 0.00  ftime:=0.0000
get_path('sub/') -> '/home/michael/.mplayer/sub/'
Detected audio codec: [ulaw] afm:5 (uLaw)
Initializing audio codec...
Opening audio decoder: [alaw] aLaw/uLaw audio decoder
dec_audio: Allocating 2048 + 65536 = 67584 bytes for output buffer
AUDIO: 8000 Hz, 1 ch, sfmt: 0x10 (2 bps), ratio: 8000->16000 (64.0 kbit)
X11 opening display: :0.0
vo: X11 color mask:  FFFF  (R:F800 G:7E0 B:1F)
vo: X11 running at 1024x768 with depth 16 and 16 bpp (":0.0" => local display)
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
INFO: libavcodec init OK!
libavcodec: CPU flags: mmx mmxext sse
Detected video codec: [ffh263] vfm:5 (FFmpeg H263+ decoder)
==========================================================================
AO: [oss] 8000Hz 1ch Signed 16-bit (Little-Endian)
AO: Description: OSS/ioctl audio output
AO: Author: A'rpi
ao2: 8000 Hz  1 chans  Signed 16-bit (Little-Endian)
audio_setup: using '/dev/dsp' dsp device
audio_setup: sample format: Signed 16-bit (Little-Endian) (requested: Signed 16-bit (Little-Endian))
audio_setup: using 1 channels (requested: 1)
audio_setup: using 8000 Hz samplerate (requested: 8000)
audio_setup: frags: 256/256  (128 bytes/frag)  free:  32768
FPS forced to be 15.000  (ftime: 0.067)
Start playing...


MPlayer interrupted by signal 2 in module: decode_audio 
DEMUXER: freeing demuxer at 0x838cdc8  
DEMUXER: freeing sh_audio at 0x838fdf0  
DEMUXER: freeing sh_video at 0x8387730  
vo: uninit ...
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gdb: Symbol `emacs_ctlx_keymap' has different size in shared object, consider re-linking
GNU gdb 2002-04-01-cvs
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-linux"...
(gdb) r -fps 15 rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-800 
0.mov -dumpstream
Starting program: /home/michael/MPlayer/main/mplayer -fps 15 rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov -dumpstream


MPlayer CVS-020720-22:23-2.95.4 (C) 2000-2002 Arpad Gereoffy (see DOCS!)

CPU: Intel Celeron 2/Pentium III Coppermine,Geyserville (Family: 6, Stepping: 1)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 SSE

Reading /home/michael/.mplayer/codecs.conf: 38 audio & 105 video codecs
Linux RTC init error: Device or resource busy
Using usleep() timing
Font /home/michael/.mplayer/font/font.desc loaded successfully! (191 chars)
Can't open input config file /home/michael/.mplayer/input.conf : No such file or directory
Can't open input config file /usr/local/share/mplayer/input.conf : No such file or directory
Falling back on default (hardcoded) input config

Playing rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov
Connected to server: darwin.horizonlive.com
Stream not seekable!
[New Thread 1024 (LWP 5659)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1024 (LWP 5659)]
0x00000000 in ?? ()
(gdb) bt
#0  0x00000000 in ?? ()
#1  0x08151c73 in stream_fill_buffer (s=0x403dd091) at stream.c:58
#2  0x403dd0bf in __libc_start_main () from /lib/libc.so.6
(gdb) q
A debugging session is active.
Do you still want to close the debugger?(y or n) 


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