VSO Software Forum

Hi,

years ago i used convertX2DVD and was very satisfied with it. At the moment i'm searching for a tool which converts videos into playable iPod files. So i've downloaded your converter besides an other one (movavi). And here's the problem:

Your video-converter changes automatically the framerate from 25fps to 30fps when using the iPod-profile.

Can you tell me, where to manually set the fps, so that the created video will have the same framerate like the original one?

It is possible to set the fps on custom-profile, but as the custom-profile has no possibility to tell the converter which format-profile to use, it's worthless for iPod-files, cause the iPod only seems to accept "Baseline" but your tool then automatically creates a video @ "High"-format-profile. With the movavi-converter i'm able to set the fps as well as the profile, but the encoding-result regarding the video-picture is far away from your's.

So please be so kind to tell me what to do.
Many thanks in advance

Your video-converter changes automatically the framerate from 25fps to 30fps when using the iPod-profile.

iPod uses 30FPS - so that is correct. Why do you want to use 25FPS with iPod?

Cause i want to connect my iPod with a treadmill and both, the display of the treadmill and the video have 50 respectively 25 fps. So if the iPod won't change the framerate itself to 30fps, i'd rather have the video in 25fps to get a smooth playback.

I'm just starting to find out all possibilities, but as far as i know, for a smooth video-playpack the video-fps has to fit to the display - or is the iPod not able to play back the video in it's original framerate on an external device?

Hello Slevin,

If you want the smoothest playback, you would use the highest video settings available for the medium you're using, including the highest fps it supports, which in your case is 30 fps.

Are you saying the treadmill you use has an A/V in where you can watch your videos on it from your iPod?

Thanks for reading,
Neil M

Hello Copnm,

a high framerate doesn't result in a smooth playback. The source-video has an original framerate, and everything else depends on that framerate.

There are three points which have to match perfectly:
1. the framerate of the video
2. the device playing the video
3. the device displaying the video

Let's assume the video has 25fps, so for a perfect playback the device has to play the video with 25fps and the screen must be able to set the refresh-rate to 25, 50, 75, 100.

If just one of the hw-devices isn't able to handle the original framerate it's not possible to get a smooth playback. In best case it jitters, in worst case it stutters.

So if the source-video is 25fps, you can't encode it to 30fps without smoothness-loss (by creating extra-frames) OR audio-frequent-raise (when you just speedup).

Of course a high framerate is best, but ONLY if the source has a high fps and all devices are able to handle it. You can't get a smoother playback than the original-video-framerate serves.

The treadmill has an extra-slot for iPod-devices, i can't say how the signal is injected or if it's able to check and adjust the framerate from the iPod. The standard-framerate of the treadmill-screen is 50fps.

Hello Slevin,

Slevin wrote:...a high framerate doesn't result in a smooth playback. The source-video has an original framerate, and everything else depends on that framerate.

Yes, a high fps DOES result in smoother playback. The only way it wouldn't is if you are duplicating frames to increase fps, which is basically excess.

Slevin wrote:...There are three points which have to match perfectly:
1. the framerate of the video
2. the device playing the video
3. the device displaying the video

It does not have to match exactly, just needs to be within the parameters that the medium supports.

Slevin wrote:...Let's assume the video has 25fps, so for a perfect playback the device has to play the video with 25fps and the screen must be able to set the refresh-rate to 25, 50, 75, 100.

The only thing you really need to know about the relationship between fps and screen refresh rate is that your fps should not exceed the screen's refresh rate or you will have tearing.

Slevin wrote:...If just one of the hw-devices isn't able to handle the original framerate it's not possible to get a smooth playback. In best case it jitters, in worst case it stutters.

There should be no "jitters" or "stutters" if you work within the parameters.

Slevin wrote:...So if the source-video is 25fps, you can't encode it to 30fps without smoothness-loss (by creating extra-frames) OR audio-frequent-raise (when you just speedup).

If the source is 25 fps, you CAN increase it to 30 fps. All that happens is 5 extra frames are added/duplicated, nothing else. Audio should not be affected, and if it does, then that's an internal conflict within the program.

Slevin wrote:...Of course a high framerate is best, but ONLY if the source has a high fps and all devices are able to handle it. You can't get a smoother playback than the original-video-framerate serves.

A high fps is always best, but if you're going to be duplicating frames, then you don't need to as long as that fps is supported by your medium. Smoothness is perceived by the viewer. So if you think the original fps is good, then leave it.

Slevin wrote:...The treadmill has an extra-slot for iPod-devices, i can't say how the signal is injected or if it's able to check and adjust the framerate from the iPod. The standard-framerate of the treadmill-screen is 50fps.

Are you saying the treadmill's screen has a 50 HZ refresh rate?

Thanks for reading,
Neil M

Yes, the treadmill-screen has a 50hz refreshrate.

I've been working with videos for many many years and there is nothing to discuss about the NEED of compatibility between video-framerate, player and screen-refreshrate. There is absolutely NO parameters you could be within than the one i've explained in my post above: all 3 points have to fit one-to-one.

Creating extra-frames CAUSES jitter (except you double ALL frames) - if you really don't think so, please learn the basics of video-editing. I know, many people even don't recognise a pulldown as long as nobody will show them - but once you're looking at, you'll see all the crap...

Further, and there i wanna turn back to my primary question, a video played with 30fps on a screen with a refreshrate @ 50hz WILL CAUSE STUTTER. So to see if the iPod is able to play AND output 25fps my question was:

How can i set the framerate at iPod-profile OR how can i set the format to "Baseline"-h264 at custom-profile?

How can i set the framerate at iPod-profile OR how can i set the format to "Baseline"-h264 at custom-profile?

Technically; iPod has lcd pixel display. It does not really care about FPS. You should be able to convert to 25FPS video as long as you keep video screen size in iPod limits. Internal display is 320x240 pixels but it can output 640x480 to TV. Both these resolutions are NTSC and NTSC FPS on TV is 29.97FPS.

You might be able to convert to 640x480 and use 25FPS, but that is non-standard and there is no quarantee that it works. If treadmill has also lcd display then it most likely will play that file.
Treadmill seems to be PAL if it has 25 or 50FPS, and most PAL systems can play NTSC files without any modifications - they just slow down a little due more frames every second. (ie; total playing time increases, 5 seconds of PAL plays 125 frames but 5 seconds of NTSC has 150 frames so it takes 6 seconds to play 5 seconds of NTSC original in PAL)
Of course it is possible that treadmill can recognize NTSC and drops frames accordingly to keep playing speed - that makes stuttering.

• iPod video specifications from Apple’s website:
  H.264 video: up to 768 Kbps, 320 x 240, 30 frames per sec., Baseline Profile up to Level 1.3 with AAC-LC up to 160 Kbps, 48 Khz, stereo audio in .m4v, .mp4 and .mov file formats
  MPEG-4 video: up to 2.5 mbps, 480 x 480, 30 frames per sec., Simple Profile with AAC-LC up to 160 Kbps, 48 Khz, stereo audio in .m4v, .mp4 and .mov file formats
  iPhone video specifications from Apple's website:
  H.264 video: up to 1.5 Mbps, 640 by 480 pixels, 30 frames per second, Low-Complexity version of the H.264 Baseline Profile with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats
  H.264 video: up to 2.5 Mbps, 640 by 480 pixels, 30 frames per second, Baseline Profile up to Level 3.0 with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats
  MPEG-4 video: up to 2.5 Mbps, 640 by 480 pixels, 30 frames per second, Simple Profile with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats

I know a lot less than what JJ is providing, but I noticed if the video codec h.264 is selected in the custom profile editor there is the option to set the profile to 'baseline', maybe a solution would be to make this setting available when mp4 video codec is selected also?

Have you tried in the custom profile editor in the 1st step, to "get profile from sample file..." and convert to a profile made from that sample? does that work?

Hi Claire, can you tell me where to set the option "Baseline"?

When i create a new custom-profile i can select:
- profile-name: whatever
- container: MP4 Video
- video-codec: H.264
- resolution: user-defined x*y
- video aspect ratio: no access
- video framerate: 25 (or same as source)
- and bitrate: 15000

But unfortunately i can't find the menu-item where to change the format. Also i've searched at "advanced edit", without success. Many thanks in advance.

Creating a profile from sample file unfortunately doesn't regard the format, so although the sample-file has "Baseline" the new profile-from-sample-file will create "High@L4.1".

if you select mp4 container and video codec H.264 check H264 options (see screenshot)
this is in beta version 1.4.0.8

So i'll download the beta...
Thanks Claire, that's all i've wanted^^.

Greets and have a nice weekend