Certain hardware decoding APIs are not guaranteed to be thread-safe, so
having the user access decoded hardware surfaces while the decoder is
running in another thread can cause failures (this is mainly known to
happen with DXVA2).
For such hwaccels, only allow the decoding thread to run while the user
is inside a lavc decode call (avcodec_send_packet/receive_frame).
Currently, the new decoding API is pretty much just a wrapper around the
old deprecated one. This is problematic, since it interferes with making
full use of the flexibility added by the new API. The old API should
also be removed at some future point.
Reorganize the code so that the new send_packet/receive_frame functions
call the actual decoding directly and change the old deprecated
avcodec_decode_* functions into wrappers around the new API.
The new internal API for decoders is now changing as well. Before this
commit, it mirrors the public API, so the decoders need to implement
send_packet() and receive_frame() callbacks. This turns out to require
awkward constructs in both the decoders and the generic code. After this
commit, the decoders only implement the receive_frame() callback and
call a new internal function, ff_decode_get_packet() to obtain input
data, in the same manner to how the bitstream filters now work.
avcodec will now always make a reference to the input packet, which means
that non-refcounted input packets will be copied. Keeping the previous
behaviour, where this copy could sometimes be avoided, would make the
code significantly more complex and fragile for only dubious gains,
since packets are typically small and everyone who cares about
performance should use refcounted packets anyway.
We cannot deprecate it until the new parser API is in place, because of
the way libavformat works. But the majority of the users can already
simply replace it with avcodec_free_context(), which will simplify the
transition once it is finally deprecated.
This function is supposed to "reset" a codec context to a clean state so
that it can be opened again. The only reason it exists is to allow using
AVStream.codec as a decoding context (after it was already
opened/used/closed by avformat_find_stream_info()). Since that behaviour
is now deprecated, there is no reason for this function to exist
anymore.
Since AVCodecContext contains a lot of complex state, copying a codec
context is not a well-defined operation. The purpose for which it is
typically used (which is well-defined) is copying the stream parameters
from one codec context to another. That is now possible with through the
AVCodecParameters API. Therefore, there is no reason for
avcodec_copy_context() to exist.
Until now, the decoding API was restricted to outputting 0 or 1 frames
per input packet. It also enforces a somewhat rigid dataflow in general.
This new API seeks to relax these restrictions by decoupling input and
output. Instead of doing a single call on each decode step, which may
consume the packet and may produce output, the new API requires the user
to send input first, and then ask for output.
For now, there are no codecs supporting this API. The API can work with
codecs using the old API, and most code added here is to make them
interoperate. The reverse is not possible, although for audio it might.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
This API is intended to allow passing around codec parameters without
using full AVCodecContext (which also contains codec options and
encoder/decoder state).
This option is only used by mpegvideoenc.
It is a very codec-specific option, so deprecate the global variant.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by mpegvideoenc.
It is a very codec-specific options, so deprecate the global variant.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This options is only used by huffyuv, ffvhuv, jpegls, mjpeg,
mpegvideoenc, png, utvideo.
It is a very codec-specific options, so deprecate the global variant.
Set proper limits to the maximum allowed values, and update utvideoenc
tests to use the new option name.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
These options are only used by alac and flac.
They are very codec-specific options, so deprecate the global variants.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by mpegvideoenc and openh264.
It is a very codec-specific option, so deprecate the global variant.
The openh264 option is dropped altogether since it is just a fallback
for -max_nal_size anyway.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by mpeg2.
It is a very codec-specific option, so deprecate the global variant.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by ffv1 and ffvhuff.
It is a very codec-specific option, so deprecate the global variant.
Improve documentation a little.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by mpegvideoenc, and xvid.
It is a very codec-specific option, so deprecate the global variant.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by mpegvideoenc, x264, xavs, and vpx.
It is a very codec-specific option, so deprecate the global variant.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by mpegvideoenc, x264, and xavs.
It is a very codec-specific option, so deprecate the global variant.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by x264 and xavs.
It is a very codec-specific option, so deprecate the global variant.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
These options are only used by mpegvideoenc and vpx.
They are very codec-specific options, so deprecate the global variants.
Add an allowed value to the private options for frame_skip_cmp which
seems to have been forgotten, but perfectly working.
The libvpx frame dropping feature uses one of such option
(frame_skip_threshold) without the other three. For this reason rename
the option to something more consistent with the other libvpx variables.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This option is only used by mpegvideoenc,
It is a very codec-specific option, so deprecate the global variant.
Set proper limits to the maximum allowed values.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
The b_frame_strategy option is only used by mpegvideoenc, qsv, x264, and
xavs, while b_sensitivity is only used by mpegvideoenc.
These are very codec-specific options, so deprecate the global variants.
Set proper limits to the maximum allowed values.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
These variables are coming from mpegvideoenc where are supposedly used
as bit counters on various frame properties. However their use is
unclear as they lack documentation, are available only from a very small
subset of encoders, and they are hardly used in the wild. Also frame_bits
in aacenc is employed in a similar way.
Remove this functionality from AVCodecContex, these variable are mostly
frame properties, and too few encoders support setting them with anything
useful.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Most option values are simply unused or ignored and in practice the
majory of codecs only need to check whether to enable rle or not.
Add appropriate codec private options which better expose the allowed
features.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Anton Khirnov
Vittorio Giovara
Diego Biurrun
Luca Barbato
Yogender Gupta
Paul B Mahol
Francois Cartegnie
Martin Storsjö
wm4