VIDEO -- modes=flashhigh / flashstd and default_modename.mp4

[Andy Bircumshaw]

On 16/1/2011, at 6:19pm, M2 wrote:
> ...
> have just tried --multimode to record b00rrd81 (Human Planet - E1) to see the quality difference
> and noticed that flashhigh (335MB) and flashstd (202MB) are same screen resolution 640 x 360 / Audio but different in size.

Yes, that sounds about right.

The video can be recorded at the same resolution but different bitrates. The higher bitrate gives more information about the picture and therefore higher quality.

The lower quality is most obvious in larger areas of flat colours, if you look at the backgrounds of scenes in which there is not too much movement - dark skies, snowfields and white (or light) walls.

See, for example, figures 2 & 5in the "examples" section of: http://en.wikipedia.org/wiki/Dither#Examples
If you look at the area of white underneath the cat's chin, then this is the kind of thing you see a lot on iPlayer downloads. It won't be as exaggerated as that, but it's very often present (even in most flashhigh shows, I think).

Looking for these artefacts is the best way to spoil your TV viewing experience. Until recently I couldn't see the difference between DVD and blu-ray, but I see flaws everywhere now - even in blu-rays.

If you watch the two recordings side by side, I'm sure you'll see the difference.

> So far I have managed to colate this info about video files:
> --modes=flashhd - H.264    1280 x 720 1704 kbps     AAC+ 240 kbps xx00 kbps
> --modes=flashvhigh - H.264    832 x 468    1404 kbps     AAC+ 96 kbps 1500 kbps
> --modes=flashhigh - H.264    640 x 360    704 kbps         AAC+  96 kbps 800 kbps
> --modes=flashstd - H.264    640 x 360    704 kbps         AAC+  96 kbps 800 kbps
> --modes=flashlow - H.264    400 x 224

It wouldn't surprise me if this table (scroll down) is out of date:
http://beebhack.wikia.com/wiki/IPlayer_TV

If I'm reading that right you agree with it on everything except the bitrate of HD mode. I could well believe that the BBC reduced the bitrate of HD mode since August 2009, considering how ISPs have bitched and whined in the past about how much data iPlayer uses, how many people have HD TVs these days and how most of them probably can't see the difference.

> As well as is there any way that when I do not use --multimode at the end of the file I have for flashhigh
> Human_Planet_-_1._Oceans_-_Into_the_Blue_b00rrd81_default_flashhigh.mp4
> 
> insted of just
> 
> Human_Planet_-_1._Oceans_-_Into_the_Blue_b00rrd81_default.mp4


If I'm reading you right, I think this is what you're looking for:

$ get_iplayer --longhelp | grep -i prefix
 --file-prefix <format>           The filename prefix (excluding dir and extension) using formatting fields. e.g. '<name>-<episode>-<pid>'
$ 

I found that with `get_iplayer --longhelp | grep -i name` and looking through the results. grepping the output of --longhelp is always my first resort when I need usage help.

aB.