The VideoLAN Forums

Hi there,

about a few days ago I came across a problem in VLC which I have not been able to work myself around, and I am in dire need of help. Although having previously worked fine, about two or three days ago VLC stopped transcoding FLV files - any FLV files. The files have originated from a wide range of websites, including YouTube, obtained with Orbit Downloader, and up until now transcoding them to MP4 with VLC has worked (mostly) seamlessly, and I have not encountered this problem before. I have successfully converted maybe 60, 70 files.

Now, however, when I attempt at transcoding an FLV file to MP4 through the Transcoding Wizard (per usual), although it seems to be transcoding as normal, I get the following error message:

main: cannot add a new stream (unsupported while muxing to this format)
stream_out_transcode: cannot add this stream

Once the transcoding process is complete, when opening the resulting MP4 file in QuickTime, it either refuses to open the file because "it contains some invalid data" or it opens the file, but it only seems to have audio - there is no video screen. At times, it has also given me an error saying the MP4 file "is not a movie file", but the aforementioned two are the most common errors I get, with the 'audio-only' file being the most common result.

VLC is installed on Macbook Pro with Mac OS X 10.4.11. The problem was first encountered in VLC 0.8.6c, but I have also tested transcoding in the following versions: 0.8.6d, 0.9.0 Nov 2 nightly version, and 0.8.6b (all of which I downloaded and installed after the problem surfaced), and to no avail. When transcoding the FLV file in the nightly version, VLC said it "could not open the encoder." I did not make any changes in the VLC preferences prior to the problem surfacing. I did install a Mac OS X update on Nov 24, but with certainty I can say that transcoding FLV to MP4 still worked in VLC on Nov 26, after which it has refused to transcode properly.

I searched the forum, FAQ and other documentation but was unable find a working solution (or at least one which I could understand). I deleted or reset the VLC preferences at least three times, but nothing changed.

It is always the video that is missing from the resulting MP4 file (if it works at all). I have tested it with numerous FLV files, and none work. Although VLC does play the files properly, it no longer transcodes them. I am not an expert on VLC or computers/computer language, but if there is additional information you need, I will try to provide it, and I would be most grateful for any help! Thank you.

I tested VLC 0.8.6d with a brand new username in Mac OS X - I created a fresh username and then reinstalled VLC and then tried transcoding a FLV file - but still no results. The resulting MP4 still only seems to contain audio. Hopefully that is of some help in figuring this out.

I was also able to locate the FLV video file I was successfully able to convert to MP4 on Nov 26 even after installing the Mac OS X update on Nov 24, and, strangely enough, when re-transcoding the FLV file, the MP4 file seems alright - video, audio everything. No other FLV files will transcode properly, however. Could this mean the Mac OS X update I installed has something to do with the problem I'm experiencing (I don't seem to be able to uninstall the update to check it myself)?

Thanks for the suggestion, I'll check that out.

It's been a while since I tried using VLC on Mac OS X to convert FLV to MP4. I had to try to remember why I was doing it in the first place. I think it was to burn FLVs to DVD for some older, non-computer-using people. I never did complete that project, so I'm glad your message reminded me of it.

I had an idea that QuickTime Player should be able to work with FLVs, since I installed the Perian (http://perian.org/) component for QuickTime. I tried it and it worked. Then, using QT Player's "Save as..." feature, I saved the FLV as an Apple MOV file. I'm fairly certain the Mac DVD tools I have will let me burn that to DVD. I could probably use VLC to convert the MOV to MP4 if I needed to. (I did try to convert to MP4, but QT Player didn't like the resulting file. I might need to change some transcode settings.)

This isn't as elegant as an all-in-one VLC solution, but I think it should work with a little experimentation.

I just wasted the past two hours trying to get around this, I couldn't convert an FLV file to MP4 and tried every setting under the sun, and now I find out that this is the problem.

Is there any way to convert FLV to MP4 using Windows? At the moment I can convert the audio only.

is it working now? what's the command line to stream this in RTSP?

https://trac.videolan.org/vlc/ticket/2850 and http://www.edsupport.cc/mguhlin/share/i ... VLCflv2mov