[mythtv] LAME is mandatory?

[Colin Guthrie]

Hi,

I realised I'd cocked up a bit when I read this reply but I'll justify
my self with lame excuses (geddit??) later... :p

Stuart Morgan wrote:
> On Saturday 01 March 2008 13:42:01 Colin Guthrie wrote:
>> Can I ask if anyone has any thoughts on this? We will not be able to
>> ship MythTV in Mandriva due to patent issues relating to MP3 encoding
>> support. (it will still be possible to ship it in or PLF repositories
>> with MP3 encoding enabled). I'd imagine other distros will have similar
>> problems.
> 
> The argument is, and always has been that mythtv includes ffmpeg which has 
> similar issues. On what grounds does a distro permit ffmpeg but not lame?

Well we ship ffmpeg with in such a state that the contentious parts are
not compiled for the default distribution but third party versions
(based on the same spec file actually) are available relatively easily.
It's not an officially sanctioned channel, but it keeps things all neat
and tidy.

Essentially the PLF build has the following additional options:
        --enable-libmp3lame \
        --enable-libfaad \
        --enable-libfaac \
        --enable-libx264 \
        --enable-libxvid \
        --enable-libamr_nb --enable-libamr_wb



>> Do any devs think this is actually an important issue? If so I will
>> update the patch, but I'm not going to bother doing this is it's not
>> going to get upstream.
> 
> I think it is, but my opinion may not count for much. I certainly don't have 
> the time to review and help integrate the patch.
> 
>> I'll just have to ship MythTV 0.20 in Mandriva
>> which would be a real shame for our MythTV lovers.
> 
> 0.20 has the same dependency.

Lame Excuse 1: Yes, I realise this! I've been a bit backlogged with
tasks of late and the "update myth packages" has been chucked to the
bottom of the pile. I did the first part a while back and removed a
patch which allowed compilation without lame when looking to see if I
needed to rediff it as I saw the option --enable-libmp3lame in
configure. I just assumed from this that lame was now optional and that
the patch was no longer needed. One less rediff. Yay!

Fast forward a few weeks and I've totally forgotten the above events and
start again, with the invalid assumption that lame has "become"
mandatory somewhere between 0.20 and 0.21... stupid me!

I've rediffed the patch and will post it on the ticket shortly. It
should be enough to make Myth work (albeit without MP3 encoding or
decoding support in NuppelVideoDecoder - the original patch was able to
use MAD to decode rather than lame but as NVP now uses libavcodec rather
than lame calls directly, squeezing this back in now is a harder task
which I'm not really up to right now).

I guess the ultimate solution would be for ffmpeg to integrate MAD
decoding and LAME encoding/decoding and make each optional. Perhaps it
does have multiple MP3 decoders that I don't know about (not spent too
much time learning) and it only really uses LAME for encoding anyway.


I guess a larger problem of whether there are other ffmpeg related
codecs included by default that I should patch out of the way (or make
configurable). I did noticed a faad related runtime loading option, but
seeing as the lame one was basically a lie I should investigate this
further!

Cheers for the input.

Col

-- 

+------------------------+
|     Colin Guthrie      |
+------------------------+
| myth(at)colin.guthr.ie |
| http://colin.guthr.ie/ |
+------------------------+