ok so you have your brand new memory stick and your have a long flight across the pond and you want to maximise the amount of video you can store.
this section is about getting the most out of your space, maybe at the cost of a little bit of quality. Saying that though, AVC is such a powerful codec that you can drop the filesize down nicely without it hindering your viewing pleasure. Its perfectly possible to fit five 90 minute movies onto a 1gb memory stick. Yep I did say five, thats around 8 hours of movies, maybe even more if you want to drop the bitrate a little more.
As you may know, file size is purely dependant on bit rate and duration. Normally dropping the bit rate will cause excessive blocks and other artefacts that would hinder your viewing of the video. AVC is without doubt the best codec at lower bit rates and its inbuilt de-blocking filter can only help if your considering going for smaller file size at a small expense of quality. Also, think about using automated 3 pass. Its normally suggested that more than one pass is only really good for hitting a desired file size, but its been suggested to me on doom9 that it also may help for low bit rate material. I have nothing to prove this, but it cant hurt, unless your time is limited of course.
So, lets get onto the details. First thing, dont be afraid to experiment with the bit rate. As the single biggest factor in file size, its the area to focus on. Try and few test encodes at 200, then maybe drop the rate down to 185. If your happy enough, ie. it doesnt impare your enjoyment of the video, then your okay. Remember the point is to balance file size with quality, we arent going for DVD reproduction here.
The next thing to look at is the inbuilt deblock
filter. this basically smooths over the blocks you would normally get
with a low bit rate. The higher the number, the greater the smoothing
at the expense of detail. Normally you would want to keep as much detail
as possible, but in our case, the removing of obvious blocking might be
preferable. In the example below I have setting of +3 and +3, this is
very strong and probably is the highest you should go. If you use
negative numbers, this will have the reverse affect and is only a good
idea if you have plenty of bit rate. See in the example below I have set
my bit rate to 175, use automated 3 pass and have the deblock at 3,3.
Its also a good idea to use the slower PSP
profile, there is little point dropping the bit rate and then not taking
advantage of the full encoding options. Of course this will take longer
to encode, but if your doing this for a long plane journey, start your
encoding well in advance.
Thats pretty much it for the video, the best advice is to experiment. Of
course slower movement video like soap operas will probably end up
looking a heck of a lot better at a lower bit rate than faster moving
action movies and of course sports. So try things out and see whats
acceptable to. Personally, I find 185 bit rate and 3,3 deblocking to be
fine for movies such as Go or converting TV shows like little britain
etc.
The other option is audio, if your watching a soap
opera, you could consider converting the audio to mono. I know this
sounds crazy, but if you convert to mono, you can halve the size of your
audio. Normally I wouldnt advise this, but if maximising space is your
aim, then you could consider it. Now megui handles the free nero audio
converter, its very simple to convert to mono.
A 64kb mono file with be roughly the same quality as a stereo 128kb
file, for argument sake. Of course experiment with whatever bit rate is
low enough without causing impairment of the viewing experience. Anyway,
enough of that guff! get muxing....