RTMPDump - No audio

[Quazar]

Hi,

I have not used RTMPDump for a while and decided to give it another go. Last time, everything worked flawlessly (using RTMPDumpHelper). But now, for some reason, it stopped downloading audio and I do not know why.

The error message I get is "WARNING: ignoring too small audio packet: size 0" but when I check the packets in WireShark they are certainly not empty. The site I'm trying to record from is MFC and I do not quite understand the parameters RTMPDump uses to solve this myself.

The command looks a little something like this:

rtmpdump -r "rtmp://video461.myfreecams.com:1935/NxServer" 
-a "NxServer" 
-f "WIN 16,0,0,305" 
-W "http://www.myfreecams.com/mfc2/flash/MfcVideo150223.swf" 
-p "http://www.myfreecams.com/mfc2/static/player.html?broadcaster_id=0&cache_id=1427783278&target=main" 
-C N:93524796.000000 
-C S: 
-C N:106485247.000000 
-C S:DOWNLOAD 
-C N:6485247.000000 
-y "mp4:mfc_106485247.f4v" 
-o "2015-04-02_01-05-08_mp4_mfc_106485247.flv"

Can anyone see a flaw? I'd be willing not to use RTMPDumpHelper but I do not quite understand how to determine the required parameters without it (especially the additional conndata).

Thanks in advance.

[rambus8]

(sorry for my bad english)
I use rtmpdumphelper for capture MFC streaming and works perfect.
I receive the same message (WARNING: ignoring too small audio packet: size 0) but the audio works fine.

maybe your problem is that you are using a video player (like VLC) that dont have the libspexx codec. If this is the problem....you can use a player with libspexx codec built in (like media player classic) or you can convert the audio from libspexx to mp3 with ffmpeg (thai is what I usually do).

[Quazar]

Thank you very much. You were right, the audio is recorded properly (unless the stream has been muted manually).

For future googlers: This is the command I use for converting the files.

ffmpeg -i INPUT_PATH -c:v libx264 -crf 23 -c:a libvo_aacenc -g:a 100 OUTPUT_PATH

[slim10]

Originally Posted by Quazar

Thank you very much. You were right, the audio is recorded properly (unless the stream has been muted manually).

For future googlers: This is the command I use for converting the files.

ffmpeg -i INPUT_PATH -c:v libx264 -crf 23 -c:a libvo_aacenc -g:a 100 OUTPUT_PATH

Why are you re-encoding the video? Re-encoding video takes a long time and you will lose some video quality. I would replace "-c:v libx264 -crf 23" with "-c:v copy."

What is the "-g:a 100" option? I don't see "-g:a" in FFmpeg's help or html documents.

[Quazar]

I misspelled, its "q:a" not "g:a" and afaik sets the "desired audio quality". I'm used to using H.264 as video codec, so its kind of a habit. I've not noticed any subjective difference in quality thus far.