[MPlayer-users] Audio Frame Drop : Urgently needed

RuthLess Konqueror ruthlesskonqueror at yahoo.com
Mon Oct 23 01:07:45 CEST 2006


Hello ,
     I apologize for not providing the details. Here
they are as follows:

+Objective+: To evaluate multimedia performance in th
e presence of --network-- delay.

+setup+
Command used in all the cases were :
(i) ./mplayer rtsp://192.168.103.2/blade.mov
streaming_server (SS): Darwin at 192.168.103.2 with
hinted movie, blade.mov.

(ii) network setup: SS <-> Router (R) <-> Client (C)

The audio and video stream (for the client) are fixed
to stream at port 32796 32794 respectively. The router
classifies the flow based on the port numbers and
introduces delay on the corresponding UDP stream.

+ Observation +
=================
Now --without any delay-- we see that mplayer decodes
4257 video frames. 

However when the router introduces 300 ms delay to
randomly chosen 100 UDP packets in the **audio
stream** (and only audio stream, no video stream), 
we find that only 2218 frames have been decoded. 

Same experiment repeated with introduction of delay in
the video stream results in 4183 frames. 

The reason 300 ms was chosen is that during rtp
streaming the average AV variation revolves round
-*300*- ms.

Here are the data:

Original : 4257 frames
With audio delay: 2218 frames decoded
with video delay : 4183 frames decoded

My questions are as follows:

1. Why is the multimedia stream more affected i.e. why
more video frames are getting dropped, when delay is
introduced to the audio stream ?

2. I can understand that whole video frame may be
dropped due to AV-Synch issues, but in the displayed
frame it shows degraded picture quality (blockiness,
some black areas,etc.) . Why is that so ?

3. How do I capture the audio frames that are getting
dropped ?

Please find the script results below :

******************************************************************************
                        No Delay
******************************************************************************
 ./mplayer rtsp://192.168.103.2/blade.mov
MPlayer dev-SVN-r20333-4.1.0 (C) 2000-2006 MPlayer
Team
CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (Family: 15,
Model: 4, Stepping: 1)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1
SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 SSE
SSE2

Playing rtsp://192.168.103.2/blade.mov.
Resolving 192.168.103.2 for AF_INET6...
Couldn't resolve name for AF_INET6: 192.168.103.2
Connecting to server 192.168.103.2[192.168.103.2]:
554...
A single media stream only is supported atm.
rtsp_session: unsupported RTSP server. Server type is
'DSS/5.5 (Build/489.7; Platform/Linux; Release/Darwin;
)'.
STREAM_LIVE555, URL: rtsp://192.168.103.2/blade.mov
Stream not seekable!
 file format detected.
Initiated "video/MP4V-ES" RTP subsession on port 32794
Initiated "audio/MPEG4-GENERIC" RTP subsession on port
32796
demux_rtp: Guessed the video frame rate as 30
frames-per-second.
        (If this is wrong, use the "-fps <frame-rate>"
option instead.)
VIDEO:  [mp4v]  0x0  0bpp  30.000 fps    0.0 kbps (
0.0 kbyte/s)
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec
codec family
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg
MPEG-4)
==========================================================================
==========================================================================
Opening audio decoder: [faad] AAC (MPEG2/4 Advanced
Audio Coding)
FAAD: compressed input bitrate missing, assuming
128kbit/s!
AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio:
16000->176400)
Selected audio codec: [faad] afm: faad (FAAD AAC
(MPEG-2/MPEG-4 Audio) decoder)
==========================================================================
AO: [oss] 44100Hz 2ch s16le (2 bytes per sample)
Starting playback...
[mpeg4 @ 0x88224b8]header damaged
Error while decoding frame!
VDec: vo config request - 352 x 288 (preferred
colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.22:1 - prescaling to correct movie
aspect.
VO: [xv] 352x288 => 352x288 Planar YV12
New_Face failed. Maybe the font path is wrong. 2 ??%
??% ??,?% 0 0
Please supply the text font file
(~/.mplayer/subfont.ttf).
subtitle font: load_sub_face failed.
A: 141.5 V: 141.8 A-V: -0.365 ct:  0.000 4257/4257 ??%
??% ??,?% 4242 0

******************************************************************************
                        Audio Stream Delayed
******************************************************************************
./mplayer rtsp://192.168.103.2/blade.mov
MPlayer dev-SVN-r20333-4.1.0 (C) 2000-2006 MPlayer
Team
CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (Family: 15,
Model: 4, Stepping: 1)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1
SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 SSE
SSE2

Playing rtsp://192.168.103.2/blade.mov.
Resolving 192.168.103.2 for AF_INET6...
Couldn't resolve name for AF_INET6: 192.168.103.2
Connecting to server 192.168.103.2[192.168.103.2]:
554...
A single media stream only is supported atm.
rtsp_session: unsupported RTSP server. Server type is
'DSS/5.5 (Build/489.7; Platform/Linux; Release/Darwin;
)'.STREAM_LIVE555, URL: rtsp://192.168.103.2/blade.mov
Stream not seekable!
 file format detected.
Initiated "video/MP4V-ES" RTP subsession on port 32794
Initiated "audio/MPEG4-GENERIC" RTP subsession on port
32796
demux_rtp: Guessed the video frame rate as 30
frames-per-second.
        (If this is wrong, use the "-fps <frame-rate>"
option instead.)
VIDEO:  [mp4v]  0x0  0bpp  30.000 fps    0.0 kbps (
0.0 kbyte/s)
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec
codec family
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg
MPEG-4)
==========================================================================
==========================================================================
Opening audio decoder: [faad] AAC (MPEG2/4 Advanced
Audio Coding)
FAAD: compressed input bitrate missing, assuming
128kbit/s!
AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio:
16000->176400)
Selected audio codec: [faad] afm: faad (FAAD AAC
(MPEG-2/MPEG-4 Audio) decoder)
==========================================================================
AO: [oss] 44100Hz 2ch s16le (2 bytes per sample)
Starting playback...
[mpeg4 @ 0x88224b8]header damaged
Error while decoding frame!
VDec: vo config request - 352 x 288 (preferred
colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.22:1 - prescaling to correct movie
aspect.
VO: [xv] 352x288 => 352x288 Planar YV12
New_Face failed. Maybe the font path is wrong. 2 ??%
??% ??,?% 0 0
Please supply the text font file
(~/.mplayer/subfont.ttf).
subtitle font: load_sub_face failed.
A:   7.6 V:   7.1 A-V:  0.483 ct:  0.000 216/216 ??%
??% ??,?% 201 0

          
************************************************
           **** Your system is too SLOW to play this! 
****
          
************************************************

Possible reasons, problems, workarounds:
- Most common: broken/buggy _audio_ driver
  - Try -ao sdl or use the OSS emulation of ALSA.
  - Experiment with different values for -autosync, 30
is a good start.
- Slow video output
  - Try a different -vo driver (-vo help for a list)
or try -framedrop!
- Slow CPU
  - Don't try to play a big DVD/DivX on a slow CPU!
Try some of the lavdopts,
    e.g. -vfm ffmpeg -lavdopts
lowres=1:fast:skiploopfilter=all.
- Broken file
  - Try various combinations of -nobps -ni -forceidx
-mc 0.
- Slow media (NFS/SMB mounts, DVD, VCD etc)
  - Try -cache 8192.
- Are you using -cache to play a non-interleaved AVI
file?
  - Try -nocache.
Read DOCS/HTML/en/video.html for tuning/speedup tips.
If none of this helps you, read
DOCS/HTML/en/bugreports.html.

A: 120.7 V: 119.9 A-V:  0.766 ct:  0.000 2218/2218 ??%
??% ??,?% 2203 0

******************************************************************************
                        Video Stream Delayed
******************************************************************************

./mplayer rtsp://192.168.103.2/blade.mov
MPlayer dev-SVN-r20333-4.1.0 (C) 2000-2006 MPlayer
Team
CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (Family: 15,
Model: 4, Stepping: 1)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1
SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 SSE
SSE2

Playing rtsp://192.168.103.2/blade.mov.
Resolving 192.168.103.2 for AF_INET6...
Couldn't resolve name for AF_INET6: 192.168.103.2
Connecting to server 192.168.103.2[192.168.103.2]:
554...
A single media stream only is supported atm.
rtsp_session: unsupported RTSP server. Server type is
'DSS/5.5 (Build/489.7; Platform/Linux; Release/Darwin;
)'.
STREAM_LIVE555, URL: rtsp://192.168.103.2/blade.mov
Stream not seekable!
 file format detected.
Initiated "video/MP4V-ES" RTP subsession on port 32794
Initiated "audio/MPEG4-GENERIC" RTP subsession on port
32796
demux_rtp: Guessed the video frame rate as 30
frames-per-second.
        (If this is wrong, use the "-fps <frame-rate>"
option instead.)
VIDEO:  [mp4v]  0x0  0bpp  30.000 fps    0.0 kbps (
0.0 kbyte/s)
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec
codec family
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg
MPEG-4)
==========================================================================
==========================================================================
Opening audio decoder: [faad] AAC (MPEG2/4 Advanced
Audio Coding)
FAAD: compressed input bitrate missing, assuming
128kbit/s!
AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio:
16000->176400)
Selected audio codec: [faad] afm: faad (FAAD AAC
(MPEG-2/MPEG-4 Audio) decoder)
==========================================================================
AO: [oss] 44100Hz 2ch s16le (2 bytes per sample)
Starting playback...
[mpeg4 @ 0x88224b8]header damaged
Error while decoding frame!
VDec: vo config request - 352 x 288 (preferred
colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.22:1 - prescaling to correct movie
aspect.
VO: [xv] 352x288 => 352x288 Planar YV12
New_Face failed. Maybe the font path is wrong. 2 ??%
??% ??,?% 0 0
Please supply the text font file
(~/.mplayer/subfont.ttf).
subtitle font: load_sub_face failed.
A: 141.5 V: 141.8 A-V: -0.360 ct:  0.000 4183/4183 ??%
??% ??,?% 4168 0
***********************************************************************


--- The Wanderer <inverseparadox at comcast.net> wrote:

> RuthLess Konqueror wrote:
> 
> > Hi , I have setup 3 pcs a Darwin Streaming Server
> , a click router
> > and the third one as the mplayer client.  I use
> rtsp streaming and
> > hence we have two rtp streams : the audio stream
> and the video rtp
> > stream.
> > 
> > Now when I introduce delay specifically to the rtp
> audio stream, what
> > I observe is a huge degradation of the audio
> quality.
> 
> <snip>
> 
> Please provide the exact command lines used. This is
> a universal rule,
> applying to all valid problem reports. In almost all
> cases, the full
> (non-snipped) text output of MPlayer is also
> desirable.
> 
> -- 
>        The Wanderer
> 
> Warning: Simply because I argue an issue does not
> mean I agree with any
> side of it.
> 
> Secrecy is the beginning of tyranny.
> _______________________________________________
> MPlayer-users mailing list
> MPlayer-users at mplayerhq.hu
>
http://lists.mplayerhq.hu/mailman/listinfo/mplayer-users
> 


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