[FFmpeg-devel] [PATCH] lavc: always build dnxhddata

[James Almer]

On 7/24/2016 6:14 PM, Michael Niedermayer wrote:
> On Sun, Jul 24, 2016 at 06:04:18PM -0300, James Almer wrote:
>> On 7/24/2016 5:59 PM, Matthieu Bouron wrote:
>>> On Sun, Jul 24, 2016 at 10:53:51PM +0200, Michael Niedermayer wrote:
>>>> On Sun, Jul 24, 2016 at 10:40:58PM +0200, Michael Niedermayer wrote:
>>>>> On Sun, Jul 24, 2016 at 10:30:35PM +0200, Matthieu Bouron wrote:
>>>>>> From: Matthieu Bouron <matthieu.bouron at stupeflix.com>
>>>>>>
>>>>>> lavc/movenc rely on avpriv_dnxhd_parse_header_prefix declared by
>>>>>> dnxhddata.h since e47981dab7fb7c9499b959cb0125b7281301969a.
>>>>>>
>>>>>> Fixes a missing symbol error in lavc/movenc if the dnxhd encoder is not
>>>>>> enabled.
>>>>>> ---
>>>>>>  libavcodec/Makefile | 5 +++--
>>>>>>  1 file changed, 3 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
>>>>>> index abef19e..4fc4b09 100644
>>>>>> --- a/libavcodec/Makefile
>>>>>> +++ b/libavcodec/Makefile
>>>>>> @@ -32,6 +32,7 @@ OBJS = allcodecs.o                                                      \
>>>>>>         codec_desc.o                                                     \
>>>>>>         d3d11va.o                                                        \
>>>>>>         dirac.o                                                          \
>>>>>> +       dnxhddata.o                                                      \
>>>>>>         dv_profile.o                                                     \
>>>>>>         imgconvert.o                                                     \
>>>>>>         jni.o                                                            \
>>>>>> @@ -241,8 +242,8 @@ OBJS-$(CONFIG_DIRAC_DECODER)           += diracdec.o dirac.o diracdsp.o diractab
>>>>>>                                            dirac_arith.o mpeg12data.o dirac_dwt.o \
>>>>>>                                            dirac_vlc.o
>>>>>>  OBJS-$(CONFIG_DFA_DECODER)             += dfa.o
>>>>>> -OBJS-$(CONFIG_DNXHD_DECODER)           += dnxhddec.o dnxhddata.o
>>>>>> -OBJS-$(CONFIG_DNXHD_ENCODER)           += dnxhdenc.o dnxhddata.o
>>>>>> +OBJS-$(CONFIG_DNXHD_DECODER)           += dnxhddec.o
>>>>>> +OBJS-$(CONFIG_DNXHD_ENCODER)           += dnxhdenc.o
>>>>>
>>>>> why dont you add dnxhddata.o to the demuxer needing it ?
>>>>
>>>> patch ok, i missed that this was a dependancy between the 2 libs
>>>> thought it was within a lib
>>>
>>> Pushed. Thanks.
>>>
>>> Matthieu
>>
>> Please revert this change and instead add a 
>> "OBJS-$(CONFIG_MOV_MUXER) += dnxhddata.o" line to the libavformat
>> dependencies section.
> 
> doesnt this break the ABI of libavcodec ?

No more than it already is, assuming this can be considered a
mistake in how avpriv functions are made available.

dnxhddata.c contains like three avpriv functions, the oldest
from 2013, and the file has never been built unconditionally.
Any ffmpeg build without dnxhd de/encoder, mxf muxer or dnxhd
demuxer from the past few years hasn't built it.
There are other files, like mpeg4audio.c, that are also not
built unconditionally and also have avpriv functions.

> either avpriv_dnxhd_parse_header_prefix is part of the ABI of
> libavcodec or its not

If avpriv functions are meant to be part of the ABI and their
presence not depend on configure time options, then that's
something that will have to be changed across the codebase
in general.

Looking at this function closely now, it could have been added
to dnxhddata.h instead. No need for avpriv_ prefix and to
forcefully build an object file full of data tables that it
doesn't need.

> 
> [...]
> 
> 
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>