Requests For Features

[Vangelis forthnet]

Hi...

On Sat Sep 26 17:07:13 BST 2015, Budgie wrote:

> with long complex titles with meaningless reference numbers

 These are the default filenames GFV generates, based on the
RTMPDUMP playpaths (i.e. stream identifiers) used on the
ITV V-O-D RTMP server; a recent example would be:

1-8697-0044-001_Downton-Abbey-Episode-1_PC011800_16X9.flv

While the first "serial number" does seem meaningless
to us (it probably does mean something to ITV stuff),
the rest of the filename is descriptive enough;
"PC01" refers to stream type (... for PCs!),
while 1800 refers to nominal overall file bitrate
(currently the highest they offer: video BR ~ 1700kbps,
audio BR ~ 96kbps); 16X9 is self evident
(896x504p for PC011800).

If you choose to use GFV's --filename (-f) switch
in the download command (e.g. -f  "Downton-Abbey-S06E01.flv";
MUST include file extension), then the
downloaded FLV file will have a more "meaningful" filename...

> which make them difficult to type without error

Why would you need to type manually long filenames?
On win32 I choose "Rename" from the right-click context menu
and then save the filename to clipboard - from there
it's usually pasted onto a text editor, where I compose/edit
any command to be pasted onto the Command Prompt Window...

> This seems to work OK but if you can suggest improvements please do.

I do not find myself often in need of batch remuxing FLV files -
Usually I do them one-at-a-time, using a simple windows batch file;
if anyone cares, here it is:

FLVtoMP4remux.bat =>
---------------------------------------------------------
@echo off

Title Losslessly Remux FLV to MP4
echo *** Remux AV streams to MP4 container ***

FOR %%F in (*.flv) DO ffmpeg -i "%%F" -c copy -bsf:a aac_adtstoasc -f mp4 
"%%~nF.mp4"

rundll32 user32.dll,MessageBeep MB_ICONWARNING

echo MP4 FILE CREATED SUCCESSFULLY...
echo.
echo WARNING: WILL THEN DELETE ORIGINAL FLV FILE!
echo [If you don't want this, close (X) the Command Prompt Window]
PAUSE

DEL "*.flv"

echo REMUX TO MP4 CONTAINER COMPLETED SUCCESSFULLY :-)

PAUSE
:END
---------------------------------------------------------

> The mp4 files are all about 3 MiB smaller (in 1.0 GiB). Why is that?

Fear not! This is a lossless remux, so no loss of quality
(either video/audio) is involved.
If you care to see the output from the ffmpeg remux,
in the end it states something along these lines:

video:704889kB audio:47404kB subtitle:0kB other streams:0kB global 
headers:0kB
muxing overhead: 0.362477%

"muxing overhead" is the extra file size (disk space) needed for the
media file to be created in the chosen media container (this is put
very grossly, I'm sure others can rephrase this more accurately...).

"muxing overhead" = (Overall media file size) - (combined sizes of all RAW 
media streams contained inside)

The MP4 container has less overhead (is more compact)
than the initial FLV one, hence the small reduction in file size;
as a rule of thumb, when the exact same raw streams are at hand,

muxing overhead: .TS > .FLV > .MP4 ~= .MKV

The difference between MP4 & MKV is less pronounced...

> When running the script I get the following comments for each file 
> converted:
>
> [mp4 @ 0x22d38e0] Codec for stream 0 does not use global headers but
> container format requires global headers
> [mp4 @ 0x22d38e0] Codec for stream 1 does not use global headers but
> container format requires global headers
>
> This omission does not appear fatal but what is going on?

Please read my June 20th list post:

http://lists.infradead.org/pipermail/get_iplayer/2015-June/007859.html

Both are benign warnings, issued by FFmpeg branch 2.7+,
that do not translate to any end file deficiency...

-----------------------------------------------------------------
A personal comment to the thread title ( Requests For Features):

Up until this time, I am still hoping that some Perl wizard
out-there will undertake the task of integrating ITV support
to GiP (much like the case in GiA) - the itv.pm plugin
that is used in GiA for indexing ITV offerings

https://raw.githubusercontent.com/GetiPlayerAutomator/get-iplayer-automator/master/plugins/itv.plugin

does still work in GiP, if put inside
".get_iplayer/plugins" folder;
get_iplayer --type=itv -f --force
lists all the available ITV progs...

Then for the actual downloading,
some perl code could be borrowed from GFV -
only a few additional perl modules (to the ones
already shipped with GiP on Win) are needed for that;
rtmpdump & ffmpeg are already there,
so we could end up with nice MP4s natively
(even tagged ones, if ITV metadata is used...).
It's a shame that one has to install Perl separately,
then install GFV perl script and then place rtmpdump (& ffmpeg)
in the same folder, to have a working setup (on Windows)
(I don't want to add them to PATH...).
 Most sadly, dinkypumpkin is planning to put
an end (?) to my (and, no doubt, others') wishful thinking:
https://github.com/get-iplayer/get_iplayer/issues/142
https://github.com/get-iplayer/get_iplayer/issues/199

C'est la vie!
-----------------------------------------------------------------

Kind regards to all,
Vangelis.