Panasonic Camera Streaming MJPEG Video with G.726 Audio

[rlhart]

I have a Panasonic BL-131A Network Camera. It is capable of streaming MJPEG video OR streaming JPEG video with G.726 audio.

I am running Win XP SP2 with VLC 8.6c and a free Sharp G.726 Codec Installed.

VLC will play the MJPEG video only stream (Open Network Stream). Mozzilla Firefox will also play this stream.
http://hartnet.servebeer.com/nphMotionJpeg?Resolution=320x240&Quality=Standard
username: vlc_user
password: vlc_pw

VLC will NOT play the MJPEG video with G.726 audio stream. VLC receives the stream but does nothing with it. Mozzilla Firefox plays the video stream, but wants to save the audio/g726 stream to a file, ignoring the sharp G.726 codec.
http://hartnet.servebeer.com/nphVideo?Mode=0&Resolution=320x240&Quality=Standard
username: vlc_user
password: vlc_pw

Does anyone know if there is some way to get the Panasonic BL-131a Network Camera streaming MJPEG video with G.726 audio working with VLC? Hope some one can figure this out.

The latest Panasonic Camera Inteface Spec is avalable at:
http://panasonic.co.jp/pcc/products/en/netwkcam/download/us/document/Camera_CGI_Interface_v3.13.pdf
I have internet port 80 translated to local port 50000 for the camera. There is also an MPEG4 video with G.726 audio stream available from the camera.


Thanks,

[VLC_help]

VLC can't use external codecs, so my guess is that VLC doesn't either detect the audio or it doesn't support it. You can check this by pressing Ctril+i during playback and check advanced information tab and chech what is says about audio.

[rlhart]

Appears you are correct about VLC not supporting external codecs, but from my research the VLC release notes indicate all the functionality required to decode my Panasonic camera MJPEG video with G.726 audio stream, was supposed to be available back in VLC 8.0. and it is at 8.6c. Looks like some one broke something along the way or just never got it right.

Again I hope someone can take a look at this and figure it out. Thanks,


Changes between 0.7.2 and 0.8.0:
-----------------------------------------------------
Demuxers:
* Support for MJPEG webcams (i.e. AXIS cams)

Codecs:
* G.726 audio support

[funman]

give a try to 0.8.0 release, http://www.videolan.org/mirror.php?mirr ... -win32.exe

[rlhart]

I tied VLC 0.8.0 and it did not ask for User name & PW so I assume it pre-dates Http authentication implementation in VLC. The camera cannot run without a login account.


Any other suggestion?

Thanks,

[rchen]

With the panasonic BL 131-A network camera, I tried the following vlc command
http/mpga://cam_ip/nphVideo?Mode=0&Resolution=320x240

This gave me the following errors

main debug: looking for demux2 module: 45 candidates
mjpeg debug: Multipart MIME detected, using separator: myboundary
mjpeg warning: Content-type: audio/g726, image/jpeg is expected
mjpeg debug: discard MIME header: Content-length: 1000 ffmpeg debug: detected format: mp3
ffmpeg error: av_find_stream_info failed
ps error: cannot peek
vobsub debug: could not read vobsub IDX file
main error: no suitable demux module for `http/://cam_ip/nphVideo?Mode=0&Resolution=320x240'
main debug: removing module "access_http"
main debug: thread times: real 1m54.156250s, kernel 0m0.125000s, user 0m0.296875s
main debug: thread 4380 joined (input/input.c:412)

I therefore tried forcing the demux to mpga to force the audio decoder to start using the mpeg_audio decoder using the following command
http/mpga://cam_ip/nphVideo?Mode=0&Resolution=320x240

However I get the following error
mpeg_audio debug: emulated startcode
mpeg_audio debug: emulated startcode (no startcode on following frame)
mpeg_audio debug: emulated startcode
mpeg_audio debug: emulated startcode
mpeg_audio debug: emulated startcode

What does the "mpeg_audio_debug: emulated startcode" error messsage indicate ?
Can I force the adpcm audio decoder using the vlc command line ?
Or there other decoders I can force to try to decode the g.276 audio from the panasonic cam ?
If I take wireshark captures of the audio from the camera will that help in diagnosing the issue with the g.726 feed ?
How can I compile in / add in external audio codecs in vlc ?
Thanks,
R Chen

[VLC_help]

Adding additional codecs to VLC might be a little tricky (without compiling it isn't possible and creating a filter from scratch is hard). It seems that FFmpeg supports G.726 but I am not sure why this supported hasn't been added to VLC or why is it disabled or broken.

[rlhart]

I originally started this thread and have a small update.

The audio G.726 codec in VLC does work with the Panasonic BLC-131a Camera for playing buffered MPEG-4 videos so this is not the problem.

If you setup the camera to buffer a video and then trigger the camera it buffers a video file that can be retrieved and played with VLC (ie. Task2_File1_Rec.asf) using the following command line format in VLC.
http://192.168.0.104:50000/./nphReplayA ... o=2&File=1
This only plays a video file, but shows the G.726 codec in VLC does work.

The fact that VLC can play a .asf file streamed to it but not an actual video stream with the same encoding is a mystery.
Perhaps I just don't know the correct port and setup to the camera?

This connects but no g726 audio or MJPEG video and no VLC error reported.
http://192.168.0.104:50000/nphVideo?Mod ... y=Standard

Don't really know how to set this up for MPEG-4. Manual says the stream must be setup first using rtsp: to port :554?
[url]rtp://192.168.0.104:33000/nphMpeg4/g726-320x240/audio;seq=27433;rtptime=10049[/url][

[rchen]

Response for rlhart
The mpeg4 video from the BL-131a cam (without sound) can be directly played using http://cam_ip/rtpOverHttp?Url=nphMpeg4/nil-320x240
The mjpeg video from the BL-131a cam (without sound) can be directly played using http://cam_ip/nphMotionJpeg?Resolution=320x240

I am unable to play mpeg4 video stream or see that the G726 codec is loaded using your suggested command http://cam_ip/./nphReplayAsf?Type=2&TaskNo=2&File=1
I get the http service unavilable error message. Is there a config that you have to turn on at the BL-131 ?
access_http error: error: HTTP/1.0 503 Service Unavailable

Question for big-cone Huna / VLC Help:
I am assuming that the selection of the codecs done using the FourCCs. I do see the FOURCCs of g726 in the ffmpeg codec src code. However this is only compiled if the libavcodec build is greater than 4706 (#if LIBAVCODEC_BUILD >= 4706) When will this be true ?
Also I was thinking of adding a "G", "7", "2", "6" to the 4ccs in modules/codec/ffmpeg/ffmpeg.c. Will this help force load the G726 audio ?

Thanks,
rchen

[rchen]

An update on why buffered asf works and a few questions

The BL 131a camera has the ability to store video in an asf format.
The asf file contains GUIDs that identify the audio and video content.
Vlc is sets the top level demux as asf
Based on the GUIDs vlc determines the audio content and video content and appropriately uses the adpcm/g726 and mpeg4 codec

A live BL 131a camera stream is a multipart encoded mime stream.
The Content type for audio is Content-type: audio/g726
Since the stream is an http stream, vlc sets the access to http.
Vlc enumerates all the exisiting demuxers to find the appropriate top level demux for this format and ends up picking mjpeg demuxer

However mjpeg looks at the mime content and expects an image as opposed to Content-type: audio/g726

Questions I have are:
1) Is mjpeg the right top level demux for a multipart mime stream ?
2) How does mjpeg end up picking the correct audio and video codecs ?
3) Can ffmpeg handle adpcm audio in an mp3 container ? (Since I believe that this is the content that is being received).

I am learing things as I go along my investigations. Any pointers to guide me in the correct direction ?

Thanks,
rchen

[rchen]

Another update on the live stream via BL 131a.

If I am looking at the code correctly:
Turns out that mjpeg is indeed an incorrect demux for mime encoded audio streams
It also turns out that none of the other demuxs have support for extracting a mime encoded audio stream

It also seems that to resolve this issue a new demux module would have to be written that parses through mime encoded streams, and enables the correct adpcm codec.

Can somebody plz tell me if this is true ?

Thanks,
rchen

[Jean-Baptiste Kempf]

This is weird but might be true. Did you try ffplay on them ?

[rchen]

Having the audio in an asf container works.
ffplay is however unable to play http streams that require authentication.

Thanks,
rchen

[Jean-Baptiste Kempf]

I know, but if ffplay can read the dumped streamed, so should vlc.

[rchen]

The dumped stream can be read using the asf container by VLC. The live mime encoded stream cannot be read since there are no appropriate demuxers.

Thanks,
rchen

[wftl]

It has been a while, but has anyone come up with an answer for this one? I opened another post that covers essentially the same ground, but have heard nothing.

viewtopic.php?f=13&t=46896&p=148745&hil ... ra#p148745

There is obviously audio coming from this but I can't seem to play it with VLC (I don't really want to resort to Internet Explorer since I can't do anything with the stream).

Thanks for any replies.

[hackeron]

Anyone?

[VLC_help]

If you tried with nightlies and it doesn't work then there isn't really anything you can do (well you can code the support by yourself ).
http://nightlies.videolan.org/

[hackeron]

If you tried with nightlies and it doesn't work then there isn't really anything you can do (well you can code the support by yourself ).
http://nightlies.videolan.org/

Here is an example captured from the camera stream http://hackeron.dyndns.org/asd.ts -- this stream should include audio but vlc doesn't show it and yes I'm using latest nightlies

[VLC_help]

Mediainfo also only identifies video from that file. tsMuxer doesn't identify that file at all.

[hackeron]

http://hackeron.dyndns.org/asd.ts is available again if anyone is interested in working on this problem. Latest VLC still won't play the G.726 audio embedded in the file

[Jean-Baptiste Kempf]

Borken file.

[wuyou013]

The dumped stream can be read using the asf container by VLC. The live mime encoded stream cannot be read since there are no appropriate demuxers.

Thanks

[Chudilo]

Thanks for the info so far.
I got vlc to display the video, rather easily.
Just FYI if anyone needs a quick way to bookmark the stream (as saving the playlist doesn't work) you can create a text file with the full URL in it.
I gave it an "mrl" extension and then told windows to open MRL files with VLC.

Does anyone think that contacting Panasonic to perhaps contribute to VLC code is worthwile?

[hubschrauber]

I collected a bit of information on this topic but I'm still not convinced I have anything that will work reliably. I'm posting here just in case this gets someone a step closer.

1. The Panasonic BL-C131A has a permission setting in the "Level 3" section for a "General User" that is inconspicuously named "Listen." If that is checked, the audio stream is delivered to the client in the rtsp connection stream. If not, the camera just doesn't deliver the multipart mime audio content at all.

2. The ActiveX component in IE connects to the audio using an http 1.0 "get" request with the url path nphAudio (discovered that using WireShark) I tried streaming that directly to a browser (by putting http://cameraip:cameraport/nphAudio in the address bar), directly to VLC as an audio-only stream, and as the secondary stream on an rtsp stream connection in VLC. None of that worked, but it is clear that the camera responds with audio data to a request on that URL path. The response to the ActiveX connection in IE (captured by WireShark/WinPcap) was:

• HTTP/1.0 200 OK
  Content-type: multipart/x-mixed-replace;boundary=--myboundary
  --myboundary
  Content-type: audio/g726
  ...binary data...

3. Even the latest release (2010.01.22) of the openRTSP command line utility from the Live555 Streaming Media package, which I think VLC uses to handle rtsp streams, will capture the audio stream but it displays the following message:

• Warning: We don't implement a QuickTime Audio Media Data Type for the "G726-32" track, so we'll insert a dummy "????" Media Data Atom instead. A separate, codec-specific editing pass will be needed before this track can be played.

This is just my speculation, but if VLC is consuming that, maybe it has trouble guessing the codec to play the audio stream.

4. VLC displays the following messages repeatedly in the Error Log when the audio is playing:

• [0x442fbdc] avcodec decoder error: more than 5 seconds of late video -> dropping frame (computer too slow?)
  QPainter::begin: Paint device returned engine == 0, type: 1

I'm not sure what those messages mean but if the machine on which I was running VLC is too slow, I suspect there aren't many around that would be fast enough.

I'd like to know if there is a reliable way (VLC or otherwise) to capture both audio and video from the Panasonic IP camera so if these bits of info get you closer, please post what else you sort out.