Re: [OE-core] [PATCH] [RFC] ffmpeg: make LICENSE_FLAGS fine-grained

["Yann Dirson" <yann.dirson@blade-group.com>]

Hi Alex,

Le mar. 23 mars 2021 à 17:42, Alexander Kanavin
<alex.kanavin@gmail.com> a écrit :
>
> Is it possible to further split the NONCOMMERCIAL_PACKAGECONFIGS into ones that are enabled and disabled, and use the former in PACKAGECONFIG itself?

You mean something like this ?

# PACKAGECONFIG features that do not pull codecs
NONCOMMERCIAL_DEFAULT_PACKAGECONFIGS = " \
 avdevice avfilter avformat swresample swscale postproc avresample \
 alsa bzlib drm gpl lzma pic pthreads shared zlib \
 ${@bb.utils.contains('AVAILTUNES', 'mips32r2', 'mips32r2', '', d)} \
 ${@bb.utils.contains('DISTRO_FEATURES', 'x11', 'xv xcb', '', d)} \
"
NONCOMMERCIAL_NONDEFAULT_PACKAGECONFIGS = " \
 altivec bzlib gsm jack openssl sdl2 \
"

PACKAGECONFIG ??= "avcodec theora \
                   ${NONCOMMERCIAL_DEFAULT_PACKAGECONFIGS}"

I admit I'm not completely sure about every feature's status.

I tend to think that if ffmpeg relies on a lib providing an
implementation, and there
are patent-related risks, it should that lib setting a LICENSE_FLAG.
Eg. x264 and others
already sets the "commercial" flag, so I'm tempted to not add a
duplicate flag in
ffmpeg (in the same spirit as my patches against gst-libav and mpv).
Would it be
good enough ?

>
>
> Alex
>
> On Tue, 23 Mar 2021 at 17:38, Yann Dirson <yann.dirson@blade-group.com> wrote:
>>
>> From: Yann Dirson <yann@blade-group.com>
>>
>> The rationale here is that if the user can only whitelist "commercial"
>> to use any part of ffmpeg, even it the list of features is carefully
>> reviewed when switching the whitelisting on, there was nothing to
>> guard from inadvertently activating a new feature that would not have
>> been reviewed.
>>
>> This patch adds one LICENSE_FLAGS value for each feature, except for
>> those that bring no codec, trying to be on the same level of legal
>> safety - but then I may miss something.
>>
>> I tried to leave out of the safe NONCOMMERCIAL_PACKAGECONFIGS list
>> anything that brings a codec, notably libavcodec.  I also did not look
>> at non-default features yet.
>>
>> There may still be a problem if any feature in ffmpeg gets activated
>> by default upstream and not registed as a PACKAGECONFIG feature.  At
>> least any of those that depend on another lib would not be enabled,
>> that could be seen as a sufficient safeguard.
>> ---
>>  meta/recipes-multimedia/ffmpeg/ffmpeg_4.3.2.bb | 12 +++++++++++-
>>  1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/meta/recipes-multimedia/ffmpeg/ffmpeg_4.3.2.bb b/meta/recipes-multimedia/ffmpeg/ffmpeg_4.3.2.bb
>> index 08be38ca50..3a36c95151 100644
>> --- a/meta/recipes-multimedia/ffmpeg/ffmpeg_4.3.2.bb
>> +++ b/meta/recipes-multimedia/ffmpeg/ffmpeg_4.3.2.bb
>> @@ -16,7 +16,17 @@ LICENSE_libavutil = "${@bb.utils.contains('PACKAGECONFIG', 'gpl', 'GPLv2+', 'LGP
>>  LICENSE_libpostproc = "GPLv2+"
>>  LICENSE_libswresample = "${@bb.utils.contains('PACKAGECONFIG', 'gpl', 'GPLv2+', 'LGPLv2.1+', d)}"
>>  LICENSE_libswscale = "${@bb.utils.contains('PACKAGECONFIG', 'gpl', 'GPLv2+', 'LGPLv2.1+', d)}"
>> -LICENSE_FLAGS = "commercial"
>> +
>> +# PACKAGECONFIG features that do not pull codecs
>> +NONCOMMERCIAL_PACKAGECONFIGS = " \
>> + alsa bzlib drm gpl lzma zlib xcb xv \
>> + avdevice avfilter avformat swresample swscale postproc avresample \
>> +"
>> +# An ffmpeg feature not in NONCOMMERCIAL_PACKAGECONFIGS should be explicitly whitelisted.
>> +# See https://ffmpeg.org/legal.html
>> +LICENSE_FLAGS = "${@' '.join('commercial_' + cfg \
>> +                             for cfg in '${PACKAGECONFIG}'.split() \
>> +                             if cfg not in '${NONCOMMERCIAL_PACKAGECONFIGS}'.split())}"
>>
>>  LIC_FILES_CHKSUM = "file://COPYING.GPLv2;md5=b234ee4d69f5fce4486a80fdaf4a4263 \
>>                      file://COPYING.GPLv3;md5=d32239bcb673463ab874e80d47fae504 \
>> --
>> 2.30.2
>>
>>
>> 
>>


-- 
Yann Dirson <yann@blade-group.com>
Blade / Shadow -- http://shadow.tech