Any good vidcasts for TCPMP for JAMIN and other like PPCs?

[floepie]

So, I'm pretty much a noob when it comes down to video formats, but I do know that TCPMP excels in the DivX/Xvid arena.

It seems many like the podcast/vidcast DL.TV with Patrick Norton and that Heron guy, and I'd like to tune in to it regularly with a subscription. They have feeds for the various video formats, so I downloaded their latest episode in 3 formats: 1 for the video ipod (H.264 AVC), which is MP4 part 10 I believe, 1 .mp4 file using DivX/Xvid, and 1 file with a .divx extension. I'm not too sure how the latter 2 differ as it seems both use the divx codec.

What I've found though kind of troubles me in terms of benchmarking. The AVC format at that resolution was terrible - only managed 33% or so. The .divx file was only slightly better at around 40%. But, the .mp4 (divx) file wound up with a respectable 60%.

Now, in order to hit at least the magic 100% for these files, I'm assuming that some sort conversion process must be in order - that is, resizing or resampling the videos.

Is there some tool to do this in a fairly automated way, and are there any good vidcasts that might work with the JAMIN "out of the box" w/o having to modify the files each time? BTW, I have a very speedy 150x card, so there shouldn't be a bottleneck there...

Thanks...

[GSmith]

If you give me the exact URLs of the feeds then I can try them in FeederReader and give you some guidance on playing them back. My guess at this point is that the mp4 file and .divx differ potentially in video encoding and/or audio encoding. I suspect that the .mp4 file is MPEG4 Part 2 while the "divx" format is not MPEG4. (for more explanation about this, see http://mobilesmith.blogspot.com/2006/08/mpeg4-overview.html )

Another difference might be the audio encoding. The "iPod" video must be encoded with AAC-encoded audio (that is all the iPod supports). So if you are able to hear the "iPod" video at all, then you must have the AAC decoder installed with TCPMP.

The better H.264 codec for TCPMP ("CoreAVC") are not available right now pending the resolution of licensing issues (see http://feederreader.pocketcasting.com/viewtopic.php?p=1698#1698 ). By default H.264 will play in the FFMPEG decoder available within TCPMP, but its performance is lacking. For any serious playback of H.264 on a Pocket PC, you will want to get the CoreAVC for TCPMP when it is released.

I can give you more information if you tell me the URLs of the feeds.

Greg Smith
Author, FeederReader - The Windows Mobile RSS Aggregator - news, blogs, audio, video, podcasts direct to your device
www.FeederReader.com - Download on the Road

[floepie]

Great! Well, here are the feeds for dl.tv :

The apple ipod video (AVC video/AAC audio):
http://rssnewsapps.ziffdavis.com/audioblogs/DLTVvidcast.xml

H.264 (QT video/ ? audio)
http://rssnewsapps.ziffdavis.com/audioblogs/DLTV.H.264.xml

Xvid (Divx/Xvid video/ MP3 audio)
http://rssnewsapps.ziffdavis.com/audioblogs/DLTV.xvid.xml

MPEG4 (Divx/Xvid video/ AAC audio)
http://rssnewsapps.ziffdavis.com/audioblogs/DLTV.mp4.xml


I think the only difference between the Xvid and mp4 versions is the resolution (the Xvid version is 640x480) and the mp4 version is a bit smaller. Also, the audio codec differs. I suppose the Xvid version cannot have the .mp4 extension because its audio doesn't comply with mp4 standards because it's in the mp3 format.

When you talk about the new h.264 codec (CoreAVC) to be released, is this intended for use with the "quicktime h.264" or the "AVC h.264" or both?

[GSmith]

H.264 is another name for AVC. The names derive from the different contributing organizations: I believe H.264 is from ISO organization and AVC is from the MPEG organization. As far as I know, they are identical video encoding specifications.

With that in mind, both "quicktime H.264" and "AVC H.264" would at a minimum specify the video encoding. And neither would necessarily be MPEG4-compliant because they could have different audio encodings (other than MPEG4 Part 3 also known as AAC), and they could be contained in files or streams that are not MPEG4 Part 14-compliant.

My believe is that TCPMP CoreAVC will handle both of these because they are (as far as I can tell from the name) identical.

Keep in mind that Quicktime Pro introduces some confusion about MPEG4 because one of the video encoding selections gives as alternatives either "MPEG4" or "H.264". I believe these are in fact referring to "MPEG4 Part 2" and "MPEG4 Part 10".

I could go on, but I'll wait for specific questions before carrying on a 10-page monologue.

I hope my ramblings have helped. Part of the difficulty in all of this is the confusion introduced by players, encoders, and companies. But I've ranted on this before (see the afore-mentioned "MPEG4 Overview" article: http://mobilesmith.blogspot.com/2006/08/mpeg4-overview.html )

Greg Smith
Author, FeederReader - The Windows Mobile RSS Aggregator - news, blogs, audio, video, podcasts direct to your device
www.FeederReader.com - Download on the Road

[floepie]

Yes, I read your blog post. Very imformative. With that knowledge then, as I suspected, the only reason why I had better luck with the .mp4 than the .divx was because the .divx resolution was larger, as the video codecs are identical.

[floepie]

OK, so I tried PocketDivxEncoder to resize and recompress some of the above files from dl.tv. That really did the trick. This is a very easy thing to do, but I think I'm also going to look at auto GK as well, as I think it can do batch processing.

FWIW, Pocketdivxencoder doesn't actually encode with any divx codec, but rather the ffmpeg codec by default, or if desired, the divx codec and outputs using the .avi container with mp3 for audio.