trying to convert AVI to DVD. mplex error. Cannot find .mpa file?

[anarchyx34]

I'm trying to use ffmpegx to convert an AVI file to DVD format. The reason I need to use ffmpegx is because this AVI has image type subtitles. It seems to be doing the subtitles ok, but I got an error halfway through the encoding process, likely when it finished with the video and went to do the audio.

**ERROR: [mplex] Unable to open file /Users/Joey/Movies/L.Change.The.World[2008]DvDrip.AC3-Stress/L.Change.The.World[2008]DvDrip.AC3-Stress.avi.ff.mpa for reading.

What I'm confused about is that it didn't seem to create an mpa file to begin with, so why would it have a problem opening it?

[tomlee59]

That's sort of the problem -- it can't open it because it can't find it. It can't find it because it isn't creating it. But it needs to.

Can you post more info, particularly about the nature of the source file? If the audio codec isn't supported, or has some other odd characteristics, then the audio conversion will fail.

[anarchyx34]

I will when I get home. The audio does play when I hit the preview button in the filters menu. Thanks for the help.

[Case]

As your source file has AC3 audio, you might want to use the Passthrough option to keep the audio as-is, when making the DVD. MPEG audio (.mpa) would be a needless conversion.

[anarchyx34]

Ok, the source is AC3 format. If I use the passthrough option will it solve the problem? I'm going to try.

More specificaly

ac3, 48000 Hz, 5:1, 384 kb/s

Is it supposed to create the .mpa file right in the beginning of the encoding process? Because i do get a folder with audiodump.wav and stream.yuv in it.

[tomlee59]

The .wav and .yuv files are the temporary intermediate formats ffmpegx uses for audio and video, respectively, prior to conversion into the final formats. Ffmpegx does video conversion first, and then audio, followed by multiplexing and authoring. The temp files are automatically deleted after ffmpegx is finished with its business, but if an error causes premature termination, they can be left undeleted.

Passthrough is often the best option if the source audio is already in a compliant format, which ac3 most certainly is for DVD. Avoiding a transcode preserves quality, and saves time.

[anarchyx34]

I tried it with passthrough. Same problem. I would use a different encoder, but mpeg2enc is the only one that will work with this type of subtitle. grrrr... this is frustrating! Is there any way I could have it encode the audio with the video, then I can just have Toast re-encode it again into DVD format?

[Case]

I just tested the DVD mpeg2enc preset with Decode with mplayer, and apparently the Passthrough isn't respected; the audio is encoded as MPEG layer II (.mpa) anyway.

I encoded the AVI and it created a fine VIDEO_TS folder, without complaining about being unable to read the .mpa file. I don't know why it would error out on your system. The audiodump.wav is converted with the mp2enc audio encoder inside ffmpegX. The process did however consume loads of memory with a 13.2 MB log file, but that shouldn't be a problem on your 2 GB RAM system. I don't suppose you ran out of disk space either?

[Case]

If you still have the .mpv video file, you could mux that with an .ac3 audio file (extracted from the AVI).