iPod TV not working with defaults

[dan_tortorici]

I have been trying to increase the quality of iPod video for TV as I see many others have. I have been using what I believe are the defaults for the iPod TV setting in ffmpegX:

ffmpeg xvid, 480x272, 878 kbps, 29.97 fps, no crop
aac, 48000 Hz, 96 kbps

Autosize is set to 16:9

Will not transfer to the iPod due to incompatible format.
Plays fine in iTunes.

Any idea why?

thx
Dan

[vcdking]

Same thing is happening to me. It was working fine untill i updated to Itunes 6.0.2 and then it stopped working. Need help quickly!!!!!

[vcdking]

I might have found a solution, still don't know why it stopped working?

Farther down on the topics list a guy said to format it as PSP, playstation portable, so i tried. It seemed to work fine now.

[dan_tortorici]

The PSP version is less resolution though:
ffmpeg xvid, 320x240, 300 kbps, 29.97 fps, no crop
aac, 24000 Hz, 32 kbps

and only seems marginally better than the iPod H.264
x264 h264, 320x176, 200 kbps, 29.97 fps, no crop
aac, 48000 Hz, 96 kbps
which works fine for me.

Here is iPod TV
ffmpeg xvid, 480x272, 878 kbps, 29.97 fps, no crop
aac, 48000 Hz, 96 kbps

[KnightED]

I've been testing the preset for the ipod TV setup and its not the video that is the problem. If you open the files up inside quicktime you will probably see the audio bitrate is above 160 which is the max bitrate for the ipod to play inside a aac file in a mp4 video.

You can use Quicktime Pro to fix these files using the passthough on the video and 160kbits on the audio limit though the .mp4 export and then they will work fine on your ipod.

i've been playing with the setting for ffmpeg's audio bitrate limiter to see which setting will always work. I'll update when i find that.

[rkelez]

Definately interested in that info and whatever the issue is hope for an update from major or something to address this issue as I plan to do a lot of encoding soon.

[KnightED]

I've found out if you set the audio bitrate to 80 kps it will average out in the 5 tests i did anyways to ~ 159.89 or 160 kbits (Number from Quicktime) and they were all playable on my ipod video.

So Please update the the ipod TV preset to reflect these.

[rkelez]

Ok so just to clarify. Setting within ffmpeg the audio bitrate to 80 ends up giving you 160? Sounds like bitrate doubles for some reason or whatever but i'll try and let you know as well.

[KnightED]

Yes setting the bitrate inside ffmpegx to 80 yields these results.

[rkelez]

Currently runnin the passthrough to see if that all works. For future use what things in the options tab would be good to use when encoding for the ipod in mpeg4? Currently doing:
High Quality
2pass
Decode with Quicktime
on right:
Q from 3-30
keyfram 20

Any suggestions to improve quality and I don't care about size increase.

[KnightED]

Well i would definitely turn off the decode with quicktime to start as quicktime does a yuv -> rgb -> yuv ( assuming from mpeg2 or mpeg4 source) conversion unless the video can only be played from quicktime.

The lower the min Q the lower the worse quality you are willing to accept so turn that up to 8 - 10.
They keyframe should be somewhere right around the fps of the video.
fps== frames per second so for example nstc dvd are 29.99 so an fps of 30 is good Pal are 25 so 25 is good.

[rkelez]

I thought the Q setting was the other way around in the farther the spread the better but whatever I can see that, so 8-10 is ideal? what about 3-5, 7-9, etc. Thanks.

As for my results on the whole audio bitrate stuff. Encoded movie using that 80kbps in audio and yes it indeed worked and will sync to the ipod through itunes. When i info the video in itunes it indeed does say the audio is 159 kbps so I guess 80kbps in audio is indeed the fix for others having that problem. Major I hope you'll put out a r3 to fix that up.

[KnightED]

Well you can set the Q lower but the lower it goes the less tolerance for variance there is. Mpeg-4 is a smart codec and uses the least possible bitrate it can get away with so having a lower Q will allow the quality to be less in some instances to lower the bitrate.

The Lower you set it the larger the file. For Best quality you can use min 2 max 4 that's usually good enough for it to find its way though but you would want to set the bitrate higher then the suggested amount for best results.

[rkelez]

I'm already doing 2500 bitrate so don't imagine i'm worried about size. I'm basically encoding some videos and bringin em over to a friends house every now and then. Otherwise got 500 gigs sitting here to play with and i usually delete the videos after i've seen em anyway.