ffmpegX MPEG-2 Blocky

[promoter]

I'm using ffmpegX & mpeg2enc to convert a QuickTime .MOV -> MPEG2. The .MOV was exported from iMovie at the highest quality setting. I used ffmpegX's MPEG-2 (NTSC) preset to create two disk images, which I burned to CD-RW using Toast Titanium's "Multitrack CD-ROM XA" feature.

The disk plays well on an Apex 1200 player (e.g., no skipping, audio glitches). But moving objects are terribly blocky & pixellated. It's not just a few artifacts around the perimeter of the object. The whole object appears shimmery, as in a TV report where someone's face is being obscured. Static objects like the background scene appear fine.

To eliminate the Apex player as the problem, I used ffmpegX to create new MPEG-2 files (instead of disk images) & played them on the Mac using VideoLAN Client 0.4.4. The blockiness persisted. I burned the MPEG-2 files to CD-RW & saw the same blockiness on the Apex. I'm a real newbie and tried futzing with the bit rate & other settings to no avail.

Can anyone offer some ideas on how to correct this? By the way, a big "thank you," Major, for making ffmpegX available. I can't imagine going through the tedium of doing a lot of conversions in mpeg2enc using the command line interface.

[major]

Is it a .DV file? if yes you should activate the "high quality enabled" flag in the movie properties > Video Track > High quality panel of Quicktime player and save.

[promoter]

Major,

Thanks for putting me on the right track. It's not a .DV file, but an iMovie .MOV export. When I checked the "High Quality" video property, QuickTime Pro 5 Player displayed almost identical fuzziness on playback of the .MOV. I think I may have exported the file at too low a quality. To create a standard SVCD, what should the iMovie .MOV export quality/settings be? Thanks again for your advice.

[promoter]

Major,

Success! After fussing w/the iMovie export settings, this is what works for me:

-Export to QuickTime, "Expert" settings:
Image Settings: Width 720, Height 480, Compression: None, Millions of Colors+, Quality: Best, Frames per Second: 29.97

-Open in QuickTime Player Pro 5.0, set the "High Quality" flag as you suggested, save the .MOV.

-Use ffmpegX 0.0.4a's SVCD Quick Preset to create the disk image pair to burn to CD using Toast Titanium.

There's a thin black band at the top/bottom of the resulting frame when played on the TV, like letterboxing but not as wide. I've successfully burned a short clip onto CD-RW, and will begin encoding an entire movie right after this post. Thanks again for all your help! The quality is head-and-shoulders better than Toast's Video CD format, and worth the extra disk changes.

[LD-50]

Promoter,

I am in a similar place as you — just curious — did you export from iMovie as DV/DVCPRO NTSC? I have dv footage and have encountered a problem similar to yours. Thanks.

[promoter]

LD-50:

I saw the blockiness when using iMovie's Export -> To (For?) iDVD command to create the source .MOV . (To Major: I think this is what you meant by a .DV file. ) When I used ffmpegX's MPEG-2 NTSC Quick Preset to create an MPEG-2, this is what I saw:

- Apex 1200: Moving objects are extremely blocky/shimmery. Stationary objects appear fine.

- VideoLAN Client: Moving objects consist of very thin moving horizontal lines. This was pronounced but not as distracting as on the Apex as the "interference pattern" was much finer. Interestingly, I could reproduce the Apex's shimmeriness exactly by selecting the "Deinterlace" command and then playing the video back. Stationary objects appear fine.

I exported a short clip using iMovie's "For iDVD" setting and opened the .MOV in QuickTime Player. It looked fine on playback. However, when I set the "High Quality" bit I saw the same fine "interference pattern" during playback that I observed in the converted MPEG-2 using VideoLAN Client. Since the interference seemed to be related to using the "For iDVD" export option to create the source .MOV, I experimented with iMovie's Export to QuickTime "Expert" settings to find something that looked reasonable when burned to an SVCD and displayed on my TV.

After addressing the initial blockiness problem, I was disappointed with the chunky overall appearance of my MPEG-2. I thought it might be caused by one of the software packages (iMovie, ffmpegX, mpeg2enc) interpolating the final resolution from a mismatched source .MOV. I got a clue from http://homepage.mac.com/RNC, where he assumes a 720 x 480 source file resolution. When I exported the source .MOV from iMovie at that resolution, the final SVCD looked much better.

Amending my previous report: When exporting from iMovie, I had to switch Compression from "None" to "Video" to create my source .MOV. Using "None," iMovie reported insufficient space to complete the export after processing about 10 minutes of video. The destination drive had >26 GB free, so I must have been creating an enormous file. There may be a better setting, but the quality using "Video" is acceptable to me.

[major]

There may be a better setting, but the quality using "Video" is acceptable to me.

If you export captured video from a camera, you could just keep the DV codec used when capturing. You will save time and keep quality.

[promoter]

If you export captured video from a camera, you could just keep the DV codec used when capturing. You will save time and keep quality.

Hi, Major,

The video was from two sources: Straight from a DV camcorder, and from an analog VHS tape through a Canopus ADVC-100. I almost always do some editing in iMovie before burning to disk. Can you suggest a better compression setting than "Video," or is that pretty good? Thanks for your help!