m2v and aiff into ffmpegX - no sound encoded?

[Smithers]

I use MPEG Streamclip to import and edit from an unencrypted DVD and then wish to use ffmpegX to compress.

The most obvious and lossless way to do this appears to be to use "Demux to m2v and aiff" (or, indeed, AC3) in Streamclip and import those files to ffmpegX.

The m2v file imports no problem into ffmpegX and I then use "Add Audio" to select the audio file but the resulting avi file ends up with no sound. I have tried this with the mencoder and ffmpeg (with "decode with Quicktime" selected) options with the same result.

The only combination I have found to work reliably is to use the "Convert to MPEG with MP2" option in Streamclip which ffmpeg deals with perfectly. (sometimes, If I use just "Convert to MPEG," ffmpegX sees the video and audio files but, again, the resulting avi has no sound.)

So, two questions really:

A. Am I doing something incredibly stupid with regard to importing the m2v and aiff files into ffmpegX?

B. Even if I'm not, does "Convert to MPEG," (in MPEGStreamclip) create a file that (as near as dammit) is the same quality as the original m2v file from the DVD?

Thanks in advance.

[major]

aiff files are not supported in ffmpegX, you should use WAV or mp2, mp3, ac3, etc. I don't know how Streamclip is engineered but I suppose it demuxes and remuxes the video stream as it is.

[Smithers]

Many thanks for the prompt reply, major.

I've done some experimenting with partial success:

Demuxed to separate m2v and ac3 files from MPEGStreamclip.
Dragged and dropped m2v file to "From" window in Summary tab.
Clicked "Add Audio" under Audio tab and directed the path to the ac3 file.

- Using "Divx Mencoder" preset, the file went through the encoding process but failed to open in Quicktime player, with the error "Couldn't open the file... because there is an error in the program."

- Using "Divx ffmpeg" preset WITH "Decode with Quicktime" selected, the file encoded and opened OK in Quicktime Player with picture, but no sound. (I do have an ac3 codec installed in Quicktime)

- Using "Divx ffmpeg" preset WITHOUT "Decode with Quicktime" selected, the file encoded and then played in Quicktime Player (sound and vision) without problem.

[major]

I will test these differences. However, I'm curious about why you demux into elementary streams instead of saving as VOB ("Save" in streamclip), and encoding from VOB.

[Smithers]

major - I think the word here may be "Eureka!"

I was unaware that using "Save" in Streamclip would create a single vob file. If it preserves any edits (which I'm assuming it will) then that is, of course, the way to go.

The reason I was trying to use demuxed files is because I had contacted the author of MPEGStreamclip and asked him what he thought was the best way to transfer to ffmpegX and that is what he suggested. Maybe he didn't realise that ffmpegX could import vob files.

If in doing so, I have identified a small problem with ffmpegX, I hope it has helped - hopefully I haven't thrown you any Red Herrings!

Once again, thank you very much for your time and help.

[Smithers]

Just a quick update after further experimentation with MPEGStreamclip:

If you just Trim from either or both ends, using "Save" will generate an edited single vob file. If you use Cut to remove a section anywhere between the start and finish, using "Save" will "convert" to a single MPEG file.

So I guess this brings me full circle to asking whether there is any significant difference of picture quality in that MPEG file over the original m2v/vob file?

If there is, I would obviously like to be able to use m2v/ac3 import in ffmpegX although, as I've already mentioned, I have managed this with the ffmpeg preset but not mencoder.

[major]

I don't know how Streamclip deals about the creation of such MPG file, perhaps you should ask the author on that point. Concerning the other points I will let you know after my tests.

[Smithers]

Concerning the other points I will let you know after my tests.

Hi Major,

Have you managed to do any tests yet?

I've been following the other thread "mencoder not recognising ac3 audio of a transport stream?" with interest as well.

Cheers

[major]

Unfortunately not still, but I hope to find time to do them soon.