There are already several places in the codebase that match desc->name
against "xyz", and many downstream clients replicate this behavior.
I have no idea why this is not just a flag.
Motivated by my desire to add yet another check for XYZ to the codebase,
and I'd rather not keep copy/pasting a string comparison hack.
ISO C++ forbids compound-literals. It's not available with MSVC.
This is a known issue from 10 years ago, and that's why there is a
av_get_time_base_q().
Since we have no plan to remove AV_TIME_BASE_Q, just make it
available in C++.
There are multiple choices:
1. Use C++11 syntax: AVRational{1, AV_TIME_BASE}
Users may still use C++98 to write new code. So no.
2. Use av_get_time_base_q().
It's for this purpose. But it's not compile time constants as
AV_TIME_BASE_Q in C.
So I choose av_make_q() as Anton's suggestion.
https://libav-devel.libav.narkive.com/ZQCWfTun/patch-0-2-fix-avutil-h-usage-from-c
Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
av_image_copy() accepts const uint8_t* const * as source;
lots of user have uint8_t* const * and therefore either
cast (the majority) or copy the array of pointers.
This commit changes this by adding a static inline wrapper
for av_image_copy() that casts between the two types
so that we do not need to add casts everywhere else.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Also constify AVAudioFifo* in the peek functions
besides constifying intermediate pointers (void**->void * const *).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This is done immediately without waiting for the next major bump
just as in 9546b3a1cb and
4eaaa38d3d.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
These are in-place transforms, required for DCT-I and DST-I.
Templated as the mod2 variant requires minor modifications, and is
required specifically for DCT-I/DST-I.
C++ doesn't support designated initializers until C++20. We have
a bunch of pre-defined channel layouts, the gains to make them
usable in C++ exceed the losses.
Bump minor version so C++ project can check before use these defines.
Also initialize .opaque field explicitly to reduce warning in C++.
Signed-off-by: James Almer <jamrial@gmail.com>
av_channel_name(), av_channel_description() and
av_channel_layout_describe() are supposed to return the size
of the needed buffer to allow the user to check for truncation;
the documentation ("If the returned value is bigger than buf_size,
then the string was truncated.") confirms that size does not
mean strlen.
Yet the AVBPrint API, i.e. AVBPrint.len, does not account for
the terminating '\0'. Therefore the returned length is off by one.
Furthermore, also check for whether the returned value actually
fits in an int (which is the return value of these functions).
Reviewed-by: Nicolas George <george@nsup.org>
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The AVBPrint API guarantees that the string buffer is always
zero-terminated; in order to honour this guarantee, there
obviously must be a string buffer at all and it must have
a size >= 1. Therefore av_bprint_init_for_buffer() treats
passing a NULL buffer or size == 0 as invalid data that
leads to undefined behaviour, namely NPD in case NULL is provided
or a write to a buffer of size 0 in case size == 0.
But it would be easy to support this, namely by using the internal
buffer with AV_BPRINT_SIZE_COUNT_ONLY in case size == 0.
There is a reason to allow this: Several functions like
av_channel_(description|name) are actually wrappers
around corresponding AVBPrint functions. They accept user
provided buffers and are supposed to return the required
size of the buffer, which would allow the user to call
it once to get the required buffer size and call it once
more after having allocated the buffer.
If av_bprint_init_for_buffer() treats size == 0 as invalid,
all these users would need to check for this themselves
and basically add the same codeblock that this patch
adds to av_bprint_init_for_buffer().
This change is in line with e.g. snprintf() which also allows
the pointer to be NULL in case size is zero.
This fixes Coverity issues #1503074, #1503076 and #1503082;
all of these issues are about providing NULL to the channel-layout
functions that are wrappers around AVBPrint versions.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Uses the existing code for av_get_random_seed() to return a buffer with
cryptographically secure random data, or an error if none could be generated.
Signed-off-by: James Almer <jamrial@gmail.com>
nvenc declares support for these formats, but if hwcontext_cuda doesn't
do that as well, then it's not possible to hwupload them for use in a
possible cuda pipeline before encoding.
0th order modified bessel function of the first kind are used in multiple
places, lets avoid having 3+ different implementations
I picked this one as its accurate and quite fast, it can be replaced if
a better one is found
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The hack was added to enable exporting of vulkan images to DRM.
On Intel hardware, specifically for DRM images, all planes must be
allocated next to each other, due to hardware limitation, so the hack
used a single large allocation and suballocated all planes from it.
By natively supporting multiplane images, the driver is what decides
the layout, so exporting just works.
It's a hack because it conflicted heavily with image allocation, and
with the whole ecosystem in general, before multiplane images were
supported, which just made it redundant.
This is also the commit which broke the hwcontext hardest and prompted
the entire rewrite in the first place.
Not only this is information that relies on the concept of a sequence of
frames, which is completely out of place as a field in AVFrame, but there are
no known or intended uses of this field.
Signed-off-by: James Almer <jamrial@gmail.com>
The function now accepts an existing buffer to avoid unnecessary allocations,
as well as only reporting the needed amount of bytes if you pass a NULL pointer
as input for data.
For this, both parameters become input and output, as well as making data
optional. This is backwards compatible, and as such not breaking any existing
use of the function in external code (if there's any).
Signed-off-by: James Almer <jamrial@gmail.com>
These fields are supposed to store information about the packet the
frame was decoded from, specifically the byte offset it was stored at
and its size.
However,
- the fields are highly ad-hoc - there is no strong reason why
specifically those (and not any other) packet properties should have a
dedicated field in AVFrame; unlike e.g. the timestamps, there is no
fundamental link between coded packet offset/size and decoded frames
- they only make sense for frames produced by decoding demuxed packets,
and even then it is not always the case that the encoded data was
stored in the file as a contiguous sequence of bytes (in order for pos
to be well-defined)
- pkt_pos was added without much explanation, apparently to allow
passthrough of this information through lavfi in order to handle byte
seeking in ffplay. That is now implemented using arbitrary user data
passthrough in AVFrame.opaque_ref.
- several filters use pkt_pos as a variable available to user-supplied
expressions, but there seems to be no established motivation for using them.
- pkt_size was added for use in ffprobe, but that too is now handled
without using this field. Additonally, the values of this field
produced by libavcodec are flawed, as described in the previous
ffprobe conversion commit.
In summary - these fields are ill-defined and insufficiently motivated,
so deprecate them.
Their usefulness is questionable, very few decoders set them, and their type
should have been int64_t. A replacement field can be added later if a valid use
case is found.
Signed-off-by: Marton Balint <cus@passwd.hu>
This is a more explicit iteration API rather than using the "magic"
av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX) which is not really
trivial to grasp what it does when casually reading through code.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
