This extends the syntax for specifying input streams in -map and complex
filtergraph labels, to allow selecting a view by view ID, index, or
position. The corresponding decoder is then set up to decode the
appropriate view and send frames for that view to the correct
filtergraph input(s).
Having macros initialize local variables seems strange to me, and there
are no more current users of these macros. (The one that was commented
out was incorrect anyway, since the macro has changed in the meantime)
This approach has the major advantage that only parsing can fail (due to
a malformed specifier or memory allocation failure). Since parsing is
done generically, while matching is per-option, this will allow to
remove substantial amounts of error checking code in following commits.
The new code also explicitly allows stream specifiers to be followed by
additional characters, which should allow cleaner handling of optional
maps, i.e. -map <stream_specifier>?, which is currently implemented in a
hacky way that breaks when the stream specifier itself contains the '?'
character (this can happen when matching metadata). It will also allow
further extending the syntax, which will be useful in following commits.
This introduces some minor behaviour changes:
* Matching metadata tags now requires the ':' character in keys or
values to be escaped. Previously it could not be present in keys, and
would be used verbatim in values. The change is required in order to
know where the value terminates.
* Multiple stream types in a single specifier are now rejected - such a
specifier makes no sense.
* Non-existent stream group ID or index is now ignored with a warning
rather than causing a failure. This is consistent with program
handling and is required to make matching fail-free.
This has multiple advantages:
* The macro has multiple parameters that often have similar or identical
values, yet very different meanings (one is the name of the
OptionsContext member where the parsed options are stored, the other
the name of the variable into which the result is written); this
change makes each of these explicit.
* The macro returns on failure, which may cause leaks - this was the
reason for adding MATCH_PER_STREAM_OPT_CLEAN(), also ost_add()
currently leaks encoder_opts. The new function returns failure to its
caller, which decides how to deal with it. While that adds a lot of
error checks/forwards for now, those will be reduced in following
commits.
* new code is type- and const- correct
Invocations of MATCH_PER_STREAM_OPT() with other types will be converted
in following commits.
Share the code between encoding and decoding. Instead of checking every
stream's options dictionary (which is also used for other purposes),
track all used options in a dedicated dictionary.
It is only used by ffprobe (once) and ffplay (twice);
inlining it avoids including it unnecessarily into ffmpeg.
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Currently it requires every single OPT_SPEC option to be accompanied by
an array of alternate names for this option. The vast majority of
options have no alternate names, resulting in a large numbers of
unnecessary single-element arrays that merely contain the option name.
Extend the option parsing API to allow marking options as having
alternate names, or as being the canonical name for some existing
alternatives. Use this new information to avoid the need for
abovementioned unnecessary single-element arrays.
This is designed to improve and unify error handling for
allocation failures for the many (often small) allocations that we have
in the fftools. These typically either don't return an error message
or an error message that is not really helpful to the user
and can be replaced by a generic error message without loss of
information.
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
If 'opts' could not be allocated, exiting the program to avoid crash when release it.
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Yu Yang <yuyang14@kuaishou.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Currently, adding a (separately allocated) element to a list of pointers
works by first reallocating the array of pointers and (on success)
incrementing its size and only then allocating the new element.
If the latter allocation fails, the size is inconsistent, i.e.
array[nb_array_elems - 1] is NULL. Our cleanup code crashes in such
scenarios.
Fix this by adding an auxiliary function that atomically allocates
and adds a new element to a list of pointers.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
These were intended to pass options to auto-inserted avresample
resampling filters. Yet FFmpeg uses swresample for this purpose
(with its own AVDictionary swr_opts similar to resample_opts).
Therefore said options were not forwarded any more since commit
911417f0b34e611bf084319c5b5a4e4e630da940; moreover since commit
420cedd497 avresample options are
not even recognized and ignored any more. Yet there are still
remnants of all of this. This commit gets rid of them.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The obstacle to do so was in filter_codec_opts: It uses searches
the AVCodec for options via the AV_OPT_SEARCH_FAKE_OBJ method, which
requires using a void * that points to a pointer to a const AVClass.
When using const AVCodec *, one can not simply use a pointer that points
to the AVCodec's pointer to its AVClass, as said pointer is const, too.
This is fixed by using a temporary pointer to the AVClass.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
The option tables of the various fftools (in particular ffprobe) are
arrays of OptionDef; said type contains a union of a pointer to void and
a function pointer of type int (*)(void *, const char *, const char *)
as well as a size_t. Some entries (namely the common entry for writing a
report as well as several more of ffprobe's entries) used the pointer to
void to store a pointer to functions of type int (*)(const char *) or
type int (*)(const char *, const char *); nevertheless, when the functions
are actually called in write_option (in cmdutils.c), it is done via a
pointer of the first type.
There are two things wrong here:
1. Pointer to void can be converted to any pointer to incomplete or
object type and back; but they are nevertheless not completely generic
pointers: There is no provision in the C standard that guarantees their
convertibility with function pointers. C90 lacks a generic function
pointer, C99 made every function pointer a generic function pointer and
still disallows the convertibility with void *.
2. The signature of the called function differs from the signature
of the pointed-to type. This is undefined behaviour in C99 (given that
C90 lacks a way to convert function pointers at all, it doesn't say
anything about such a situation). It only works because none of the
functions this patch is about make any use of their parameters at all.
Therefore this commit changes the type of the relevant functions
to match the type used for the call and uses the union's function
pointer to store it. This is legal even in C90.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Anton Khirnov
Niklas Haas
Marton Balint
Andreas Rheinhardt
James Almer
Yu Yang
Thilo Borgmann
Andreas Rheinhardt