ffmpegX v0.0.6g Q--> Divx to SVCD?

[thomasbbb]

I've read the manual (chpt 10...to be added!) and many messages on this board but still can't figure out how to convert an AVI file to SVCD format...

I think I've got the video. I simply chose the Quick Preset "SVCD (NTSC)" and clicked ENCODE... the video portion came out remarkably well (any suggestions for tweaking welcome), but there is NO audio... i've tried every option imaginable but to no avail.

Could someone please walk me through this... step by step... I'll be happy to submit a summary of whatever workable procedure we come up with to Wizeman for chapter 10 in his User Manual.

Information about source file:
avi file
Video: msmpeg4, 688x384, 23.98 fps, 800 kb/s
Audio: mp3, 48000 Hz, stereo, 96 kb/s

Note: If I can get the audio to show up (!), would also like to downsample to 44.1Hz.

Any help would be greatly appreciated. thanks

thom

[ZeroSix]

Run your .avi through Divx doctor to get a .mov file. Load the .mov file in ffmpeg and use the same presets and see where this gets you...

If this doesnt work, you can always extract the .mp3 file, convert it to .wav and then convert the .wav to mp2 or ac3 and mux with the resulting video only file you got from ffmpeg.

Hope this helps.

[thomasbbb]

hi ZeroSix...

thanks for your advice... I converted the .avi file to a .mov file per your suggestion, but unfortunately get the same results... no audio whatsoever. You said to try...

"always extract the .mp3 file, convert it to .wav and then convert the .wav to mp2 or ac3 and mux with the resulting video only file you got from ffmpeg."

Could you be a little more specific, ie, what program do I use for the conversion and which one for the mux (sorry, newbie).

And while I have your attention, how can I downsample the audio from 48k Hz to 44.1k Hz?

Thanks for your help.

thom

[ZeroSix]

When you play the .mov file you got from Divx Doctor in QT is there sound?

Click on EDIT in QT and select EXTRACT TRACKS and choose the audio track.

Then export this to a .wav file and name it audio.wav and place it on your desktop, not to worry about its sampling rate or anything.

Then open your terminal and type the following:

mp2enc -o ~/desktop/audio.mp2 -V < ~/desktop/audio.wav

This is provided that you have mp2enc installed. If you do not we will have to go another route.

Then open ffmpegX and click on TOOLS and click the button that says VIDEO. This will prompt you to open a file. and select your .mpg file that was generated [the one without audio] and uncheck every box except DEMUX. click on GO.

This will give you an elementary stream [.m2v probably]

Open that .m2v file under the same TOOLS section of ffmpegX as VIDEO and open your resulting .mp2 file under audio and select MUX AS SVCD.

Hope this helps.

Of course, you could always use Ross's program Missing Mpeg Tools to encode your .wav file as .MP2. It does a great job and is free. http://homepage.mac.com/rnc

back to phantasy star online... have a good one!!!

[thomasbbb]

hi ZeroSix...

well, I'm half way there... I have the audio.mp2 file... unbelievably, I trashed the mpg file so will have to process .avi file again in ffmegX... it's 700mb, and with my computer (G4 450), it takes about 12 HOURS to complete!! so it's going to take me awhile to let you know the results.

BTW, you asked about sound on divx doctored .avi file, yes, audio was there in QT.

While I have your attention, I also DLed several mpeg2 files that have 48k Hz audio stream... how do I change audio to 44.1k Hz? can't use QT because it doesn't see separate tracks to extract.

thanks for all your help... i wish the whole avi->svcd process could be done at once in ffmegX.. all these passes take soooo long!

regards

thom

[thomasbbb]

hi ZeroSix...

well, here's my final report.

To recap, I wanted to convert a divx file to svcd. The file was:

Video: msmpeg4, 688x384, 23.98 fps, 800 kb/s
Audio: mp3, 48000 Hz, stereo, 96 kb/s

For the video:
- Video codec set to MPEG2 [MPG] (mpeg2enc)
- Bitrate Calculator set to length of movie, one CD, and 80min mode-2
- Autosize set to SVCD NTSC, which auto-set the video size to 480x480
- Framerate set to NTSC FILM note: if set to NTSC (29.97), the video and audio were always out of sync

For Audio:
Nothing! I unchecked Encode Audio, ffmpegx still processed the audio and wonderfully downsampled it to 44.1 Hz

For Options:
- bicubic scaling...on
- Altivec...on
- QT encode...on
- VOB Letterbox...on note: this needs to be checked for the video to retain proper aspect ratio... I don't no why, but if it's unchecked, the image is stretched.
- Profile set to XSVCD
For Tools: turned everything off

And miraculously, it worked!

Thanks for all your help. It inspired me to keep going.

[rorschach]

Hi Thomasbbb,

I followed your AvI to SVCD specs as exactly as I could; and after 3 attempts, with 2 of them resulting in excellent video quality (but i turned off the VOB Letterbox button as the video dimensions were 448x336, 48khz, 25fps;47 minutes) I am pleased at having the ability to make a SVCD however, in all attempts the audio is off-synched! In the 2nd attempt, the video is (as best as I can describe it) "squishy, streaky multi-colored video." (??) But that was File B, not File A which were the 2 other attempts.

In the first attempt I accidentally had Set 3:2 on and Standard SVCD but that resulted in excellent video too.

How to get the audio properly synched? In previous attempts at plain VCD I was able to get what appeared to be a proper MPEG at 320x240/25fps but naturally, burning to CD-RW doesn't play on the DVD Player...

Next, I'm going to attempt an Encode Audio option just to see if that makes a difference, but I thought I should check in here first.

This is a great board. Especially the Mac division! I wish the webmasters could add a Mac Tutorials section so ThomasBBB's procedural can be added...

Be Seein' You...

[thomasbbb]

hmmm...

I remember having sync problems too, and found that setting the framerate to same as the original source did the trick... so, for example, you mentioned your video is 25 fps.. under video tab, go to framerate and set it to "PAL (25)"...

and again, I always turn "encode audio" off under the audio tab...

hope this helps... let me know.

thom

[rorschach]

I've succeeded in synching the soundtrack! I've succeeded in burning the SVCD to disk and playing it on my DVD!

...BUT! (moan!) because the fps was set at 25fps, although it looks and sounds fine on the PC, the DVD *recognizes* the fps and it plays with a herky-jerky movement. That means, by my analysis, that the DVD realizes the program is LESS THAN the required 29.97fps to make it play smoothly.

Question: How do I get an SVCD encoding up to 29.97fps from an AVI source that plays on 25fps and still keep the soundtrack synched?

Thanks!

[thomasbbb]

that's odd...

I hate to mention this possbility because it's not going to solve anything, but i think it could be your DVD player... they all have their idiosyncracies, for example, my Sony player doesn't like 48k Hz audio (in SVCD format)... it will play the audio just a wee bit lower than it should, noticeable especially with dialogue, so when I encounter such files i have to downsample it to 44.1k hz (SVCD compliant) before burning.

Anyway, I have many many SVCDs converted from avi files, they're 25fps (and sometimes 23.97fps) and all play smoothly on my Sony... I know this doesn't solve your problem, just wanted to offer a possible explanation..

good luck.

thom

[Wizeman]

Lots of good info in this thread, will make use of it in an updated manual.

Just a note on the jerky movement of NTSC source -> PAL target - I've tried for years (!) but have been unable to get smooth motion. Leave it at NTSC, and it will be smooth.

Idiosyncracies abound on DVD players; thank God there is such a good forum here on dvdrhelp.com for finding out more about your particular one. For instance, my new Pioneer DV-350 (thank God it plays the "wrongly burned" SVCDs I have so many of, i.e. .bin burned as Disc Image in Toast) *can* play the xDVDs I've made (that is multiple SVCD MPEG2s on a DVDr disc - highly unorthodox but very very nice) *but* demands the audio to be 48khz rather than the usual 44.1... If the audio is 44.1, it still plays - but the sound is too fast and high-pitched, while the video "skips" frames to catch up! Looks hilarious

Oh, and about unchecking boxes like "Encode video/audio" - it's not enough. If you want to bypass the encoding step for video/audio, you need to also choose "Passthrough" in the pulldown menu for codec.

/Wizeman

[thomasbbb]

hi Wizeman...

when you say "Leave it at NTSC, and it will be smooth.", I am confused by what you mean. I actually got the idea of setting the framerate to the same as source (avi) from you ffmpegX guide.

Under the Video tab, i set Autosize to "SVCD NTSC", but for Framerate only three choices are provided: NTSC(29.97), NTSC FILM (23.976), PAL (25)... now, to obtain the final mpeg2 with a framerate of 25 fps (same as source), are you saying choose NTSC(29.97) and then change the numeric value to 25? does that work? I was under the impression that these choices could not be changed...

regards,

thom

[rorschach]

I'm very disappointed. In a procedure using Quicktime Pro (AVI to MOV) and Toast, a video file with an original 25 fps can be successfully translated and synched to a 29.97 MPEG that is VCD compliant.

Why can't FFMPEGX create a 29.97 (SVCD) MPEG from an 25fps AVI? If we adjust the video frame rate, can't we also adjust the audio frame rate to synch as well?

I will check the burned CD with a friend's DVD and see if he has a similar "herky-jerky" playback.

In alternate, I will now attempt straight VCDs from the AVIs I have and will use Thomas' SVCD specs as an analog unless someone has different settings for that as well.