A generic format for multiple mobile phones

[Clown shoes]

Hi all, I have been asked by a client to produce a small film that can be placed on many random mobile phones. This is going to be done as a drop in type scenario where people will come to a booth at a conference and have the film placed on their phone there and then (this is already sounding like a nightmare!!!) The film will be of part of the conference that they are attending so it will need to be encoded there, removing the opportunity to encode different versions in advance. I am currently thinking of using Canopus Procoder 2 to do the encode. It uses QT to produce an MP4 that is 176 x 144, 15fps, 192kbps. The audio is AAC-LC, mono, 16kbps, 8,000khz. My question is: Is 192kbps the maximum bitrate I can get away with before some phones have issues with playback? Or inversely is 192kbps too high? What I need is a file format that is going to play back on as many phones as is possible. Does any one know if there are phones that may have problems with this format in general? Finaly does anyone know of an easy way of transfering data to multiple types of phones easily? (sorry this is an idiotic question and I already know the answer is NO, but I guess I am just clutching at straws here. The client has thrown me a real curve ball here and typically cannot appreciate the complications in what he is asking!)

Many many thanks in advance to anyone who can help here, any suggestions will be greatfuly welcomed.

ClownShoes :thanks:

[smok3]

well, as a data trasfer, my v3 can do at least:
1-get data through email (not very friendly)
2-get data directly from web page, ala somepage.com/yourfile.mp4 (good one)
3-bluetooth
4-ir?

so make at least one (2) and multiple (3) 'servers' that can do bluetooth, you can use phones, laptops, ect.

as of the format, not sure, but do make multiple versions.

[SenorKaffee]

You will need to provide IR and Bluetooth access. You should also provide a station with a multi-card reader, with my 6230i it would be easiest to just copy the file on the MMC.

Web access would be slow (no local network) and many employees will have this service blocked. Everything working with cables will be much faster, but you just can´t buy hundreds of cables

For maximum compatibility you could stick to MPEG-4 Visual Simple Profile @ Level 1. 64 kbps, QCIF @ 15fps. Some mobiles can also only decode AMR audio.

[Randi]

and others can decode aac but their processors are too slow to REALLY handle it, so you end up with asynchronous playback (the early Samsung 3G phone for example

[Hyper Shinchan]

For maximum compatibility you could stick to MPEG-4 Visual Simple Profile @ Level 1. 64 kbps, QCIF @ 15fps. Some mobiles can also only decode AMR audio.
3GPP specs says MPEG-4 Visual Simple Profile @ Level 0. Anyway I don't think that it's really a problem to use bitrate as high as 128 kbps. Anyway for the maximum compatibility you would use H.263. I suggest to use FFMPEG with 2-pass encoding at 128 kbps. And of course if the audio is speech it's better to use AMR-NB (btw imo AAC is useless at 8 khz, but it's only my opinion).

[check]

I'm guessing you've thought of this, but have you suggested to the client you produce two or three different movie versions to cover all bases? Otherwise you'll be stuck with lower quality footage for compatibility.
Also don't forget the real total bitrate of your encode there is 192+16.
Finally, I've done some low bitrate encoding of tv shows and so on before (anywhere from 20-150kbits for the video), and I'd suggest you put more bitrate to the audio. Of course, it depends how they will listen to it but total newbies can spot terrible audio better than terrible video in my experience.

[Zero1]

The most common type of video I have seen on mobile phones is MPEG-4 SP, 176x144 @ 11.988fps (half film) or 15.000fps with AAC Audio (cannot tell offhand, but likely to be mono LC-AAC). That would certainly catch a majority. To be certain everyone can play it though, I think you may have to encode 2 or 3 versions as suggested.

As for bitrate, I would aim to keep the total bitrate under 160kbps. I would probably use 24kbps 16KHz AAC as a starting point for experimentation.

As for making the video available to people, whenever I have used bluetooth, I have found it slow (like 14kbps, but it's probably faster than that). Bluetooth is probably the most popular method, IR would also be good to support, and as for the direct download, this might be good if you have a Wireless B/G device, as some phones has Wireless LAN/Wifi (my Nokia N91 does). The MMC suggestion was also sound, but make sure you get a multi card reader since they come in all shapes and sizes. My friend's Nokia 6600 uses a full size MMC, but my old Nokia 6260 uses a RSMMC (Reduced Size) which has lower voltages IIRC. That's the Symbian OS phones, my other friend has a Sony Ericsson S700i which uses Sony Magicgate.

The N91 (314MHz CPU), and upcoming N92/93 support H.264 Baseline@L2 which translates to 60fps @ 176x144, 20fps @ 320x240 or 15fps @ 352x240. I pulled those values from Annex A, but chances are the hardware is capable of more than that, but these are the minimum supported requirements, which I don't think is too shabby for a mobile phone. In theory, full native resolution at 208x176 would support 42fps. Nice, I can see myself doing a lot of encoding in the future.

Edit
You might find this very interesting http://forum.nokia.com/main/resources/technologies/audiovideo/
Note that they refer to something called MPEG-4 VSP, it's just Nokia mangling abbreviations (it's simply MPEG-4 SP or MPEG-4 Visual, Simple Profile).

Seeing as these phones support MPEG-4 SP and H.264, I wonder if ASP support is there (I know my old 6260 could deal with it, but the CPU was too weak to view at a decent framerate)