Issues with latest update (2.1.2)

This message was edited 4 times. Last update was at 04/15/2010 00:04:58

Due to recent changes in AppStore approval policy and new requirement for applications that stream video we had to reimplement the way live conversion works. The biggest benefit is that we have variable quality control in place which greatly improves streaming over 3G. There are however some drawbacks:

Seeking doesn't work with firmware 3.0:
It was not possible to make seeking during streaming with the older firmware. If there is enough demand we can add functionality to seek before streaming starts (only on 3.0 though). If you are unable to update to 3.1 please reply to this thread and let us know why.

Seeking (with firmware 3.1) lacks proper visual feedback and feels glitchy:
This is an issue with the iPhone Media Player component. We have reported it to Apple. Hopefully they'll fix it in future firmware updates.

Seeking doesn't work at all (with firmware 3.1):
We have had very few reports of this. If this is your case, please post the live conversion log here. It could be a bug in the new conversion pipeline (or new ffmpeg build). We'll do our best to resolve it.

Playback using TV out can't be resumed from last position:
Given that iPhone SDK lacks documented API for TV out and we aren't able to use undocumented API any more we had to find alternative approach. Unfortunately this approach doesn't allow us to implement this feature.

Playback using TV out stops when iPhone gets locked:
This should be fixed in next Air Video update (already submitted to Apple for review).

The video quality is really bad on local WiFi:
If your iPhone WiFi IP address is not standard local network address Air Video Server might think it is streaming over internet, so it starts with the lowest enabled bandwidth. The iPhone media player should after a while request faster stream (resulting in improved quality). If this is your case please tell us what IP address has your iPhone assigned. We'll try to fix this in next server update. Read the following paragraph for a workaround.
EDIT: Should be fixed in 2.2.5-beta1.

Issues with automatic quality control:
Sometimes iPhone Media Player makes poor choice about the bandwidth that the network can handle. However you can chose the allowed bandwidths in Air Video conversion settings (Go to Conversion Settings -> Global Conversion Settings in the iPhone App). You can even disable all bandwidths except one that fits your network requirements preventing the media player from adjusting the quality on it's own.

If you encounter any problem with the update, please share as much information as possible. No detail is insignificant. Live Conversion log can usually be very helpful.

I find it very sad that the posibility to oneself set resolution och quality is gone from the client!
For many users this feature might be to advanced, but when running it on a older slow server or streaming on 3g ... id like to myself beeing able to find the best res/quality crossover .
Now, one is forced to setting the bandwidth only to adjust this.

PLEASE include a advanced tab in the iphone client where to old setting, res. and quality feature can be foun
Otherwise , thanks for a truly great application!!

Best regards,
TooT

Hi,

you can set the max resolution in global conversion settings. The quality however worked the other way around. The biggest problem was that with same quality different movies scenes could result in very varying bitrate which made it quite difficult to watch videos over 3G.

Why is deblocking turned off in the ffmpeg string?

-flags -loop

I find that losing this causes a huge decrease in perceptible quality.

This message was edited 1 time. Last update was at 01/30/2010 16:47:09

TylerL wrote:Why is deblocking turned off in the ffmpeg string?

-flags -loop

I find that losing this causes a huge decrease in perceptible quality.

Well, with some high resolution h264 videos the decoder can't parallelize decoding properly with deblocking enabled. Can I ask you what codec is your video encoded using? I've noticed this being an issue with MPEG2 videos, so -loop should be disabled for those.

I've so far tried H.264, MPEG-4, and MPEG-1 source files, all of which the iPhone encode is done with in-loop deblocking for the stream disabled.

TylerL wrote:I've so far tried H.264, MPEG-4, and MPEG-1 source files, all of which the iPhone encode is done with in-loop deblocking for the stream disabled.

Are the artifacts visible with the H264 videos? Can you make a screenshot of a video frame?

Settings: 384k and 512k streaming options enabled

Here's an MPEG-4 source (~640x480):

Here's an H.264 source (1280x720):

Most-easily noticed after a scene change. The first sample shows telltale artifacts from a lack of in-loop deblocking on playback, while the last two images are more like hell clips, with the individual macroblocks very pronounced.

I haven't done much with the new multithreaded H.264 decoding in ffmpeg, but I don't think the in-loop deblock option (for the encoded file) would affect the disabling of deblocking for decoding the original stream (which is definitely a good idea in most cases).

Okay, in next server update the loop filter will be enabled.

Awesome

Thank you!

TylerL wrote:Why is deblocking turned off in the ffmpeg string?

-flags -loop

I find that losing this causes a huge decrease in perceptible quality.

Very good point.
The x264 guide here is quite helpful in this respect.

Loop filter should be enabled in 2.2.5-beta1

So much better. Thanks!

Just remember that receiving tons of obscure and distracting feature requests is a sign that you're doing something right :p

This reply is actually in relation to the most recent update (2.2.4). During the installation of the update there is an error which prevents the version from updating properly. This is turn means I can't use Air Video at all on my iPhone because it tells me my server is out of date. The error message states "Error opening file for writing C:\Program Files\AirVideoServer\AirVideoServer.exe". Please fix this as I can't use the app I have purchased and i'm getting frustrated!

You need to stop the Air Video Server that you are currently running before installing the update. Also if you install the latest beta the installer will check if the server is still running.

http://www.inmethod.com/forum/posts/list/557.page