iPod h.264 Settings file

[rumplestiltskin]

I've attached an ffmpegX Settings file that I've been using to encode very high quality H264 videos for my iPod. The results are very close to what you would get if you use Apple's "H264 for iPod" export from QT Pro (or iMovie, etc.). File size is similar, as well.

The attached setting file is:

ffmpegx_setting-ipodh264,500kb,48k@128k,q5-30,30fps.ffx

Note that this setting is for 16:9 (320x176) so you'll have to change this if your source file is 4:3.

Just in case the file can't be found (maybe I pooched the UL process), here are the specs I used:

(from the Summary popup)
iPod h.264

(from the Video tab)
16:9 (320x176)
NTSC 29.97 fps
500kbps

(from the Audio tab)
96kb
48000Hz
Stereo
CBR
>>>Watch out; I used track 1 because I had two tracks and wanted the second. Track 0 is the first. Set this properly for your situation! <<<

(Nothing from the Filters tab)

(from the Options tab)
Contant bitrate
i4x4 analysis
Decode with Quicktime (necessary if you end up with video that's twice the speed of the audio).
QMin: 5
QMax: 30

After about 50 encodings of the same file at various settings, I believe three settings have made the important difference:

500kbps video - lower rates are fine for "iPod only" but this setting produces videos that look fine on (other than big-screen) TV's.

QMin and QMax of, respectively, 5 and 30. This adds a bit to the encoding time and also boosts the file size (about 70%).

I haven't played with the ME function settings yet but will do so to see if there is anything to be gained.

I'm using a 2.0GHz dual-CPU G5 (Spring'05 generation). Encoding using these settings takes about an hour or so for a 100 minute video. Apple's QT Pro "export" function takes about 6-8 hours. The quality is virtually the same.

By the way, you might think that I should simply use the MPEG-4 settings and make the video larger (640x360) and use a higher bitrate. To match the quality of "my" settings for H264, the mpeg4 settings will produce a file that's much larger. Specifically:

1.3GB AVI source > iPod H264 setting (standard) > 291MB
1.3GB AVI source > iPod H264 setting (mine) > 491MB
1.3GB AVI source > Apple's iPod export > 495MB
1.3GB AVI source > ffmpegX mpeg4 tweaked for = quality) > 670MB

I should also note that a QMin of 2 resulted in a file that would transfer to the iPod but would not play and, once in the iPod, could not be renamed within iTunes (and would crash the app).

This is not meant to be a "here it is; the final answer" message; rather, please consider it a starting point for experimentation on your part. How can we improve quality and still keep the file size reasonable?

[major]

Don't forget to post the PSNR value, which describes the achieved quality level.

[rumplestiltskin]

Major,

I don't see where PSNR appears when using the iPod h.264 settings.

[major]

It is printed in the process output, in a blue line such as this:
"x264 [info]: PSNR Mean Y:45.064 U:47.479 V:47.121 Avg:45.674 Global:45.325 kb/s:194.08"

The "Global" PSNR is the value to use.

[rumplestiltskin]

Apparently, the "MP4 H264" (mencoder) setting is not iPod compatible (with Qmin:5 and QMax:30 although the "Q" setting may have nothing to do with it).

Not a complaint, mind you, but just another result to report.

[major]

Yes, the MP4 H264 preset is not for the iPod, but for insane quality encodings to be viewed on the computer. Use iPod H264 preset for a low-level, baseline profile stream compliant with iPod.

[rumplestiltskin]

Funny thing - Using the preset with "my" settings seems to encode many of my video's with beautiful results. However, Citizen Kane shows some artifacts and I think it's because it's B&W. The problem areas are in expanses of monotones (the foggy night scene at the start of the film, for example). Time for more experimentation, I guess.

BTW: A few of my other vids that had not converted with a quality level I wanted -did so- after applying my tweaks (500kb, QMin5-Qmax30). I've also been using the "Decode with QuickTime" checkbox simply to avoid the possibility of that double-speed video mentioned in other threads. The app (v0.0.9uR2 as of this writing) is working great.