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We have been using VLC to play streaming MPEG-4 for years. With the release of 2.0.1 it no longer can decode the frames as indicated in the messages.

The MPEG-4 is in an RTP packet. Neither RTSP or SAP, which are both supported will work.

Can you share us the messages? And maybe a sample URL?

I can't share a URL because this is multicasting from a hardware streaming MPEG-4 encoder. Here is a list of the messages when the stream is started. Never had a problem with any previous version.

main debug: adding item `rtsp://192.168.5.132' (URL deleted )
qt4 debug: Adding a new MRL to recent ones: rtsp://192.168.5.132
main debug: rebuilding array of current - root Playlist
main debug: rebuild done - 1 items, index -1
main debug: processing request item:(URL deleted ), node: null, skip: 0
main debug: resyncing on(URL deleted )
main debug:(URL deleted ) is at 0
main debug: starting playback of the new playlist item
main debug: creating new input thread
main debug: Creating an input for (URL deleted )
main debug: no fetch required for (null) (art currently (null))
main debug: using timeshift granularity of 50 MiB, in path 'C:\Users\John\AppData\Local\Temp'
main debug: (URL deleted )gives access `rtsp' demux `' path `192.168.5.132'
main debug: creating demux: access='rtsp' demux='' location='192.168.5.132' file='\\192.168.5.132'
main debug: looking for access_demux module: 1 candidate
live555 debug: version 2011.12.23
live555 debug: RTP subsession 'video/MP4V-ES'
main debug: selecting program id=0
live555 debug: setup start: 0.000000 stop:0.000000
live555 debug: play start: 0.000000 stop:0.000000
main debug: using access_demux module "live555"
main debug: TIMER module_need() : 33.768 ms - Total 33.768 ms / 1 intvls (Avg 33.768 ms)
main debug: looking for decoder module: 31 candidates
qt4 debug: IM: Setting an input
avcodec debug: libavcodec initialized (interface 0x360a64)
avcodec debug: trying to use direct rendering
avcodec debug: allowing 4 thread(s) for decoding
avcodec debug: ffmpeg codec (MPEG-4 Video) started
avcodec debug: using frame thread mode with 4 threads
main debug: using decoder module "avcodec"
main debug: TIMER module_need() : 19.221 ms - Total 19.221 ms / 1 intvls (Avg 19.221 ms)
main debug: looking for meta reader module: 2 candidates
lua debug: Trying Lua scripts in C:\Users\John\AppData\Roaming\vlc\lua\meta\reader
lua debug: Trying Lua scripts in C:\Program Files (x86)\VideoLAN\VLC\lua\meta\reader
lua debug: Trying Lua playlist script C:\Program Files (x86)\VideoLAN\VLC\lua\meta\reader\filename.luac
main debug: no meta reader module matching "any" could be loaded
main debug: TIMER module_need() : 2.654 ms - Total 2.654 ms / 1 intvls (Avg 2.654 ms)
main debug: `rtsp://192.168.5.132' successfully opened
main debug: Buffering 0%
main debug: Buffering 3%
main debug: Buffering 6%
main debug: Buffering 10%
avcodec warning: cannot decode one frame (8475 bytes)
main debug: Buffering 13%
avcodec warning: cannot decode one frame (9048 bytes)
main debug: Buffering 16%
avcodec warning: cannot decode one frame (8718 bytes)
avcodec warning: cannot decode one frame (8301 bytes)
main debug: Buffering 20%
main debug: Buffering 23%
.
.
.
avcodec warning: cannot decode one frame (8833 bytes)
main debug: incoming request - stopping current input
main debug: dying input
main debug: control: stopping input
main debug: dying input
avcodec warning: cannot decode one frame (8720 bytes)
main debug: removing module "avcodec"
avcodec debug: ffmpeg codec (MPEG-4 Video) stopped
main debug: killing decoder fourcc `mp4v', 0 PES in FIFO
main debug: removing module "live555"
main debug: Program doesn't contain anymore ES
main debug: dead input
qt4 debug: IM: Deleting the input

Does it work any better if you limit FFmpeg threads to 1?
http://wiki.videolan.org/WindowsFAQ-2.0 ... r_laggy.29

I will give that a try. I need to investigate more. On a different version of our streaming encoder it works. I am now suspecting that it has something to do with the SDP data. Will report back when I know more.

John A

Setting the FFMPEG thread count to 1 solved this issue for me.

Known issue.

Is there an automatic way to install VLC with the FFmpeg thread count setting set to 1? I'm asking because otherwise we do have to handle a lot of customer requests telling us that VLC can't play our mp4v/mp4a RTP stream when they only need to change this setting.

Yes, deploy the vlcrc with the right tag. Or help us (finance) a fix for this issue.