| Message ID | 20211226171650.372-1-dcnieho@gmail.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [FFmpeg-devel,RFC] avdevice: lock to minor version of avformat | expand |
| Context | Check | Description |
|---|---|---|
| andriy/make_x86 | fail | Make failed |
| andriy/make_ppc | fail | Make failed |
FWIW, the macro #define AV_MAKE_MAJOR_MINOR_FUNC_NAME(name,major,minor) AV_GLUE(av,name)AV_GLUE(_version_,major)AV_GLUE(_,minor) doesn't compile on patchwork (https://patchwork.ffmpeg.org/check/49062/), but worked fine for me on MSVC. Is MSVC non-compliant somehow? Suggestions appreciated, I'm no star in C macros. In any case, this is a discussion starter, so let it not compiling not hold us back from that. Cheers, Dee On Sun, Dec 26, 2021 at 6:17 PM Diederick Niehorster <dcnieho@gmail.com> wrote: > > As per discussion on the list ( > https://ffmpeg.org/pipermail/ffmpeg-devel/2021-June/281513.html, see > especially https://ffmpeg.org/pipermail/ffmpeg-devel/2021-June/281586.html), > to resolve the the unholy ABI-relationship between libavdevice and > libavformat and allow easier working on the part of the avdevice API > that lives in avformat, lock avdevice to a specific major and minor > version of avformat. > > Signed-off-by: Diederick Niehorster <dcnieho@gmail.com> > --- > libavdevice/avdevice.c | 10 ++++++++++ > libavdevice/version.h | 10 ++++++++++ > libavformat/utils.c | 5 +++++ > libavformat/version.h | 11 +++++++++++ > libavutil/macros.h | 2 ++ > 5 files changed, 38 insertions(+) > > diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c > index 8f460c7564..b608ec532f 100644 > --- a/libavdevice/avdevice.c > +++ b/libavdevice/avdevice.c > @@ -38,6 +38,16 @@ unsigned avdevice_version(void) > return LIBAVDEVICE_VERSION_INT; > } > > +unsigned avdevice_version_same_minor() > +{ > + // check version of loaded lavf has same major and minor version as > + // this library was compiled against > + if ((avformat_version_same_minor()) & ~0xFF != (LIBAVFORMAT_VERSION_INT & ~0xFF)) > + abort(); > + > + return avformat_version(); > +} > + > const char * avdevice_configuration(void) > { > return FFMPEG_CONFIGURATION; > diff --git a/libavdevice/version.h b/libavdevice/version.h > index 41f568d6b0..4c511a7f53 100644 > --- a/libavdevice/version.h > +++ b/libavdevice/version.h > @@ -26,6 +26,7 @@ > */ > > #include "libavutil/version.h" > +#include "libavutil/macros.h" > > #define LIBAVDEVICE_VERSION_MAJOR 59 > #define LIBAVDEVICE_VERSION_MINOR 1 > @@ -48,4 +49,13 @@ > */ > #define FF_API_DEVICE_CAPABILITIES (LIBAVDEVICE_VERSION_MAJOR < 60) > > +/** > + * avdevice_version_same_minor() expands to a function with > + * the same minor and major version it was compiled against > + * encoded in it. Enables linking locking to the minor version > + * of other libraries they were compiled against. > + */ > +#define avdevice_version_same_minor AV_MAKE_MAJOR_MINOR_FUNC_NAME(device,LIBAVFORMAT_VERSION_MAJOR,LIBAVFORMAT_VERSION_MINOR) > +unsigned avdevice_version_same_minor(); > + > #endif /* AVDEVICE_VERSION_H */ > diff --git a/libavformat/utils.c b/libavformat/utils.c > index 332ba534d2..607a777c3f 100644 > --- a/libavformat/utils.c > +++ b/libavformat/utils.c > @@ -63,6 +63,11 @@ unsigned avformat_version(void) > return LIBAVFORMAT_VERSION_INT; > } > > +unsigned avformat_version_same_minor() > +{ > + return avformat_version(); > +} > + > const char *avformat_configuration(void) > { > return FFMPEG_CONFIGURATION; > diff --git a/libavformat/version.h b/libavformat/version.h > index 379a68cc7c..2423800687 100644 > --- a/libavformat/version.h > +++ b/libavformat/version.h > @@ -28,6 +28,7 @@ > */ > > #include "libavutil/version.h" > +#include "libavutil/macros.h" > > // Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium) > // Also please add any ticket numbers that you believe might be affected here > @@ -63,4 +64,14 @@ > > > #define FF_API_R_FRAME_RATE 1 > + > +/** > + * avformat_version_same_minor() expands to a function with > + * the same minor and major version it was compiled against > + * encoded in it. Enables linking locking to the minor version > + * of other libraries they were compiled against. > + */ > +#define avformat_version_same_minor AV_MAKE_MAJOR_MINOR_FUNC_NAME(format,LIBAVFORMAT_VERSION_MAJOR,LIBAVFORMAT_VERSION_MINOR) > +unsigned avformat_version_same_minor(); > + > #endif /* AVFORMAT_VERSION_H */ > diff --git a/libavutil/macros.h b/libavutil/macros.h > index 2a7567c3ea..dda1bf6452 100644 > --- a/libavutil/macros.h > +++ b/libavutil/macros.h > @@ -73,6 +73,8 @@ > * @} > */ > > +#define AV_MAKE_MAJOR_MINOR_FUNC_NAME(name,major,minor) AV_GLUE(av,name)AV_GLUE(_version_,major)AV_GLUE(_,minor) > + > #define AV_PRAGMA(s) _Pragma(#s) > > #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1)) > -- > 2.28.0.windows.1 >
Diederick C. Niehorster: > FWIW, the macro > #define AV_MAKE_MAJOR_MINOR_FUNC_NAME(name,major,minor) > AV_GLUE(av,name)AV_GLUE(_version_,major)AV_GLUE(_,minor) > doesn't compile on patchwork > (https://patchwork.ffmpeg.org/check/49062/), but worked fine for me on > MSVC. Is MSVC non-compliant somehow? Suggestions appreciated, I'm no > star in C macros. > AV_GLUE(av,name)AV_GLUE(_version_,major)AV_GLUE(_,minor) will yield three preprocessor tokens after macro expansion, one for each AV_GLUE. There will be no whitespace between them and yet they are different preprocessor tokens. After the preprocessor has been run, these preprocessor tokens are directly converted into tokens; there is no "rescan" that joins preprocessor tokens that are not separated by whitespace (and therefore appear to you to be a single token). And therefore the result is incompliant. It seems like MSVC does such a rescan, but the specs allow a compiler to omit it (and GCC apparently does so). > In any case, this is a discussion starter, so let it not compiling not > hold us back from that. > > Cheers, > Dee > > On Sun, Dec 26, 2021 at 6:17 PM Diederick Niehorster <dcnieho@gmail.com> wrote: >> >> As per discussion on the list ( >> https://ffmpeg.org/pipermail/ffmpeg-devel/2021-June/281513.html, see >> especially https://ffmpeg.org/pipermail/ffmpeg-devel/2021-June/281586.html), >> to resolve the the unholy ABI-relationship between libavdevice and >> libavformat and allow easier working on the part of the avdevice API >> that lives in avformat, lock avdevice to a specific major and minor >> version of avformat. >> >> Signed-off-by: Diederick Niehorster <dcnieho@gmail.com> >> --- >> libavdevice/avdevice.c | 10 ++++++++++ >> libavdevice/version.h | 10 ++++++++++ >> libavformat/utils.c | 5 +++++ >> libavformat/version.h | 11 +++++++++++ >> libavutil/macros.h | 2 ++ >> 5 files changed, 38 insertions(+) >> >> diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c >> index 8f460c7564..b608ec532f 100644 >> --- a/libavdevice/avdevice.c >> +++ b/libavdevice/avdevice.c >> @@ -38,6 +38,16 @@ unsigned avdevice_version(void) >> return LIBAVDEVICE_VERSION_INT; >> } >> >> +unsigned avdevice_version_same_minor() >> +{ >> + // check version of loaded lavf has same major and minor version as >> + // this library was compiled against >> + if ((avformat_version_same_minor()) & ~0xFF != (LIBAVFORMAT_VERSION_INT & ~0xFF)) >> + abort(); >> + >> + return avformat_version(); >> +} >> + >> const char * avdevice_configuration(void) >> { >> return FFMPEG_CONFIGURATION; >> diff --git a/libavdevice/version.h b/libavdevice/version.h >> index 41f568d6b0..4c511a7f53 100644 >> --- a/libavdevice/version.h >> +++ b/libavdevice/version.h >> @@ -26,6 +26,7 @@ >> */ >> >> #include "libavutil/version.h" >> +#include "libavutil/macros.h" >> >> #define LIBAVDEVICE_VERSION_MAJOR 59 >> #define LIBAVDEVICE_VERSION_MINOR 1 >> @@ -48,4 +49,13 @@ >> */ >> #define FF_API_DEVICE_CAPABILITIES (LIBAVDEVICE_VERSION_MAJOR < 60) >> >> +/** >> + * avdevice_version_same_minor() expands to a function with >> + * the same minor and major version it was compiled against >> + * encoded in it. Enables linking locking to the minor version >> + * of other libraries they were compiled against. >> + */ >> +#define avdevice_version_same_minor AV_MAKE_MAJOR_MINOR_FUNC_NAME(device,LIBAVFORMAT_VERSION_MAJOR,LIBAVFORMAT_VERSION_MINOR) >> +unsigned avdevice_version_same_minor(); >> + >> #endif /* AVDEVICE_VERSION_H */ >> diff --git a/libavformat/utils.c b/libavformat/utils.c >> index 332ba534d2..607a777c3f 100644 >> --- a/libavformat/utils.c >> +++ b/libavformat/utils.c >> @@ -63,6 +63,11 @@ unsigned avformat_version(void) >> return LIBAVFORMAT_VERSION_INT; >> } >> >> +unsigned avformat_version_same_minor() >> +{ >> + return avformat_version(); >> +} >> + >> const char *avformat_configuration(void) >> { >> return FFMPEG_CONFIGURATION; >> diff --git a/libavformat/version.h b/libavformat/version.h >> index 379a68cc7c..2423800687 100644 >> --- a/libavformat/version.h >> +++ b/libavformat/version.h >> @@ -28,6 +28,7 @@ >> */ >> >> #include "libavutil/version.h" >> +#include "libavutil/macros.h" >> >> // Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium) >> // Also please add any ticket numbers that you believe might be affected here >> @@ -63,4 +64,14 @@ >> >> >> #define FF_API_R_FRAME_RATE 1 >> + >> +/** >> + * avformat_version_same_minor() expands to a function with >> + * the same minor and major version it was compiled against >> + * encoded in it. Enables linking locking to the minor version >> + * of other libraries they were compiled against. >> + */ >> +#define avformat_version_same_minor AV_MAKE_MAJOR_MINOR_FUNC_NAME(format,LIBAVFORMAT_VERSION_MAJOR,LIBAVFORMAT_VERSION_MINOR) >> +unsigned avformat_version_same_minor(); >> + >> #endif /* AVFORMAT_VERSION_H */ >> diff --git a/libavutil/macros.h b/libavutil/macros.h >> index 2a7567c3ea..dda1bf6452 100644 >> --- a/libavutil/macros.h >> +++ b/libavutil/macros.h >> @@ -73,6 +73,8 @@ >> * @} >> */ >> >> +#define AV_MAKE_MAJOR_MINOR_FUNC_NAME(name,major,minor) AV_GLUE(av,name)AV_GLUE(_version_,major)AV_GLUE(_,minor) >> + >> #define AV_PRAGMA(s) _Pragma(#s) >> >> #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1)) >> -- >> 2.28.0.windows.1 >>
diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c index 8f460c7564..b608ec532f 100644 --- a/libavdevice/avdevice.c +++ b/libavdevice/avdevice.c @@ -38,6 +38,16 @@ unsigned avdevice_version(void) return LIBAVDEVICE_VERSION_INT; } +unsigned avdevice_version_same_minor() +{ + // check version of loaded lavf has same major and minor version as + // this library was compiled against + if ((avformat_version_same_minor()) & ~0xFF != (LIBAVFORMAT_VERSION_INT & ~0xFF)) + abort(); + + return avformat_version(); +} + const char * avdevice_configuration(void) { return FFMPEG_CONFIGURATION; diff --git a/libavdevice/version.h b/libavdevice/version.h index 41f568d6b0..4c511a7f53 100644 --- a/libavdevice/version.h +++ b/libavdevice/version.h @@ -26,6 +26,7 @@ */ #include "libavutil/version.h" +#include "libavutil/macros.h" #define LIBAVDEVICE_VERSION_MAJOR 59 #define LIBAVDEVICE_VERSION_MINOR 1 @@ -48,4 +49,13 @@ */ #define FF_API_DEVICE_CAPABILITIES (LIBAVDEVICE_VERSION_MAJOR < 60) +/** + * avdevice_version_same_minor() expands to a function with + * the same minor and major version it was compiled against + * encoded in it. Enables linking locking to the minor version + * of other libraries they were compiled against. + */ +#define avdevice_version_same_minor AV_MAKE_MAJOR_MINOR_FUNC_NAME(device,LIBAVFORMAT_VERSION_MAJOR,LIBAVFORMAT_VERSION_MINOR) +unsigned avdevice_version_same_minor(); + #endif /* AVDEVICE_VERSION_H */ diff --git a/libavformat/utils.c b/libavformat/utils.c index 332ba534d2..607a777c3f 100644 --- a/libavformat/utils.c +++ b/libavformat/utils.c @@ -63,6 +63,11 @@ unsigned avformat_version(void) return LIBAVFORMAT_VERSION_INT; } +unsigned avformat_version_same_minor() +{ + return avformat_version(); +} + const char *avformat_configuration(void) { return FFMPEG_CONFIGURATION; diff --git a/libavformat/version.h b/libavformat/version.h index 379a68cc7c..2423800687 100644 --- a/libavformat/version.h +++ b/libavformat/version.h @@ -28,6 +28,7 @@ */ #include "libavutil/version.h" +#include "libavutil/macros.h" // Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium) // Also please add any ticket numbers that you believe might be affected here @@ -63,4 +64,14 @@ #define FF_API_R_FRAME_RATE 1 + +/** + * avformat_version_same_minor() expands to a function with + * the same minor and major version it was compiled against + * encoded in it. Enables linking locking to the minor version + * of other libraries they were compiled against. + */ +#define avformat_version_same_minor AV_MAKE_MAJOR_MINOR_FUNC_NAME(format,LIBAVFORMAT_VERSION_MAJOR,LIBAVFORMAT_VERSION_MINOR) +unsigned avformat_version_same_minor(); + #endif /* AVFORMAT_VERSION_H */ diff --git a/libavutil/macros.h b/libavutil/macros.h index 2a7567c3ea..dda1bf6452 100644 --- a/libavutil/macros.h +++ b/libavutil/macros.h @@ -73,6 +73,8 @@ * @} */ +#define AV_MAKE_MAJOR_MINOR_FUNC_NAME(name,major,minor) AV_GLUE(av,name)AV_GLUE(_version_,major)AV_GLUE(_,minor) + #define AV_PRAGMA(s) _Pragma(#s) #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
As per discussion on the list ( https://ffmpeg.org/pipermail/ffmpeg-devel/2021-June/281513.html, see especially https://ffmpeg.org/pipermail/ffmpeg-devel/2021-June/281586.html), to resolve the the unholy ABI-relationship between libavdevice and libavformat and allow easier working on the part of the avdevice API that lives in avformat, lock avdevice to a specific major and minor version of avformat. Signed-off-by: Diederick Niehorster <dcnieho@gmail.com> --- libavdevice/avdevice.c | 10 ++++++++++ libavdevice/version.h | 10 ++++++++++ libavformat/utils.c | 5 +++++ libavformat/version.h | 11 +++++++++++ libavutil/macros.h | 2 ++ 5 files changed, 38 insertions(+)