Use optional sTER chunk defining side-by-side stereo pair
within "Extensions to the PNG 1.2 Specification", version 1.3.0.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The commit 932ff70 introducing this header mentions it should be public.
Reviewed-by: Ronald S. Bultje <rsbultje@gmail.com>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
HWAccels with frame threads are fundamentally flawed in avcodecs current
design, and there are several known problems ranging from image corruption
to driver crashes.
These problems come down to two design problems in the interaction of
threads and HWAccel decoding:
(1)
While avcodec prevents parallel decoding and as such simultaneous access
to the hardware accelerator from the decoding threads, it cannot account
for the user code and its access to the hardware surfaces and the hardware
itself.
This can result in image corruption or even driver crashes if the
user code locks image surfaces while they are being used by the decoder
threads as reference frames.
The current HWAccel API does not offer any way to ensure exclusive access
to the hardware or the surfaces if frame threading is used.
(2)
Initialization of the HWAccel with frame threads is non-trivial, and many
decoders had and still have issues that cause excess calls to the
get_format callback.
This will potentially cause duplicate HWAccel initialization, which in
extreme cases can even lead to driver crashes if the HWAccel is
re-initialized while the user code is actively accessing the hardware
surfaces associated with it, or lead to image corruption due to lost
reference frames.
While both of these issues are solvable, fixing (1) would at least require
a huge API redesign which would move a lot of complexity into the user
code.
The only reason the combination of frame threads and HWAccel was
considered useful is to allow a seamless fallback to multi-threaded
software decoding if the HWAccel is not available, however the issues
outlined above far outweigh this.
The proper solution for a fallback is to re-open the AVCodecContext with
threading enabled if the HWAccel failed, which is a practice commonly used
by various user applications using avcodec today already.
Reviewed-by: Gwenole Beauchesne <gb.devel@gmail.com>
Reviewed-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Hendrik Leppkes <h.leppkes@gmail.com>
When the encoder is fed with less frames than its delay, the picture list
looks like { NULL, NULL, ..., frame, frame, frame }. When flushing the
encoder (input frame == NULL), we need to ensure the picture list is
shifted enough so that we do not return an empty packet, which would
mean the encoder has finished, while it has not encoded any frame.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This fixes extra semicolons that clang 3.7 on GNU/Linux warns about.
These were trigggered when built under -Wpedantic, which essentially
checks for strict ISO compliance in numerous ways.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
These casts are unnecessary, and may safely be removed.
Found by enabling -Wpedantic on clang 3.7.
Tested with FATE.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
This structure served as a bridge between data pointers and frames,
but it suffers from several limitations:
- it is not refcounted and data must be copied to every time
- it cannot be expanded without ABI break due to being used on the stack
- its functions are just wrappers to imgutils which add a layer of
unneeded indirection, and maintenance burden
- it allows hacks like embedding uncompressed data in packets
- its use is often confusing to our users
AVFrame provides a much better API, and, if a full blown frame is not
needed, it is just as simple and more straightfoward to use data and
linesize arrays directly.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Register mmaldec as mpeg2 decoder. Supporting mpeg2 in mmaldec is just a
matter of setting the correct MMAL_ENCODING on the input port. To ease the
addition of further supported mmal codecs a macro is introduced to generate
the decoder and decoder class structs.
Signed-off-by: Julian Scheel <julian@jusst.de>
Signed-off-by: wm4 <nfxjfg@googlemail.com>
This function is only used within other inline asm functions, hence the
HAVE_MMX_INLINE guard. Per recent discussions, we should not worry about
the performance of inline asm-only builds.
It is only used inside libavcodec.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
avpriv_ac3_parse_header was removed in commit 3dfb643.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
There is no avpriv_atomic_get, instead avpriv_atomic_int_get is to be used for
integers. This fixes building mmaldec.
Signed-off-by: Julian Scheel <julian@jusst.de>
Reviewed-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Use the new fields directly instead of the ones from AVPicture.
This removes a layer of indirection which serves no pratical purpose
whatsoever, and will help in removing AVPicture structure completely
later.
Every subtitle encoder/decoder seamlessly points to the new arrays,
so it is possible to deprecate AVSubtitleRect.pict.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Kirill Gavrilov
Andreas Cadhalpun
Hendrik Leppkes
Timothy Gu
Kieran Kunhya
Michael Niedermayer
Luca Barbato
Clément Bœsch
Paul B Mahol
Tom Butterworth
Vittorio Giovara
Alexis Ballier
Ganesh Ajjanagadde
Ronald S. Bultje
Marton Balint
Carl Eugen Hoyos
Arttu Ylä-Outinen
Julian Scheel
James Almer