Fwd: Re: output format

[MacFH - C E Macfarlane - News]

Tch!  Both Fred and then myself forgot to reply to all ...


-------- Forwarded Message --------
Subject: Re: output format
Date: Tue, 28 Mar 2023 01:13:58 +0100
From: MacFH - C E Macfarlane - News <news at macfh.co.uk>
To: fred.d <fred.d at timelords.org.uk>

On 27/03/2023 18:54, fred.d wrote:
> 
> On 27/03/2023 18:22, MacFH - C E Macfarlane - News wrote:
>>
>> On 27/03/2023 17:56, fred.d wrote:
>>>
>>> Recently started using gip to download sounds and audio files.
>>>
>>> Unfortunately I've got my prefs set to force output to mpeg .TS. 
>>> Result is my downloaded audio is being converted to .ts files unless 
>>> I override the command line with --raw when downloading audio :-(
>>
>> What command-line option are you using to set this?
> 
> options config file:  mpegts 1

Equivalent to ...

--mpeg-ts     Ensure raw audio and video files are re-muxed into MPEG-TS 
file regardless of stream format. Overrides --raw.

>>> Does anyone know a way to configure gip Video output format 
>>> separately from Audio output format? I've had a quick look at all the 
>>> options I have docs on but I can't see anything obvious.
>>
>> Difficult to say without knowing how you set the preference in the 
>> first place.

I think you have two options.  The following examples use "Bells On 
Sunday" (radio) and weather forecasts (TV) as being conveniently short 
programmes with correspondingly small download sizes to test with. Also, 
make sure you read the notes below before trying anything out:

1.  Leave the option --mpeg-ts as is, but add an additional 
post-download option for audio files using --command-radio to convert 
the download to m4a (or any other audio format of your choice).  The 
downside of this is that it may sometimes mean converting audio files 
twice, depending on the format of the original download.

Example:

--command-radio "ffmpeg -i '<filename>' -c:a copy '<fileprefix>.m4a' && 
del '<filename>" --type radio --pid m001jkbm --raw -g

2.  Remove that option altogether and use the --raw option instead, and 
give different --command-radio and --command-tv options to get the two 
different types into the respective end formats required.  This should 
ensure that each type only gets converted once.

Examples:

--command-radio "ffmpeg -i '<filename>' -c:a copy '<fileprefix>.m4a' && 
del '<filename>" --type radio --pid m001jkbm --raw -g

--command-tv "ffmpeg -i '<filename>' -c:a copy -c:v copy 
'<fileprefix>.mp4' & del '<filename>" --type tv --tv-quality sd --pid 
m001kjpf --raw -g

IMPORTANT!  Notes:

Firstly, note that unless you want to keep the originally downloaded 
file as well as the converted file, you have to include a command to 
delete it, the double ampersand means that the del command only happens 
if the ffmpeg command didn't produce an error code when making the 
conversion.  The command is for a Windows set up, you'd use rm instead 
of DEL on a Linux system.

Secondly, the above FFMPEG commands are greatly simplified from the 
original commands that GiP would have fed to FFMPEG without the 
--mpeg-ts or --raw options being specified, which may be why the video 
one above corresponding to 2 below gave an avalanche of 'Invalid DTS' 
messages that don't occur when you let GiP do the job.  As the weather 
video played back alright, I didn't bother to investigate that further.

1) ffmpeg -loglevel fatal -stats -y -i "<path>\Bells On Sunday - 
Cathedral Church Of St Mary The Virgin With St Paul In Blackburn 
Lancashire.hls.ts" "-c:v" copy "-c:a" copy "-bsf:a" aac_adtstoasc 
-movflags faststart "<path>\Bells On Sunday - Cathedral Church Of St 
Mary The Virgin With St Paul In Blackburn Lancashire.partial.m4a"

2) ffmpeg -loglevel fatal -stats -y -i "<path>\Weather For The Week 
Ahead - 2023-03-27.hls.ts" "-c:v" copy "-c:a" copy "-bsf:a" 
aac_adtstoasc -movflags faststart "<path>\Weather For The Week Ahead - 
2023-03-27.partial.mp4"

Thirdly, the available substitution parameters to use in the filenames 
are here, but not all will have values in all circumstances, for example 
<rawaudio> was empty when I tried it

https://github.com/get-iplayer/get_iplayer/wiki/subparams

Lastly, I know that once upon another life in some obscure case I tried 
to use a post-download command before, but struggled with it for hours, 
and now can't remember whether actually I ever even got it to work!  A 
significant part of the problem was that, as above, you need to put some 
parameters in quotes, for example filenames with spaces, but they tend 
to get stripped off by GetIPlayer when it feeds the quoted parameters to 
the external command.  I remember a lot of faffing around with single 
quotes inside double, and vice versa, trying to get it to work, but 
above examples do work on my system!