We were already accepting AvFrame for swscale inputs, but for the output
a different SwConverterTarget trait was being used.
The old interface had a few issues:
- The use of memory mapping traits, putting a dependency on crosvm/base
- Insufficient metadata, not being able to represent custom padding on
the stride or non-contiguous plane layouts
- Inconsistency between input and output types
In this patch, we:
1. Introduce a AvFrame-based API to replace the old SwConverter API.
2. Add a TryAsAvFrameExt extension trait inside devices/ to convert
virtio handles to AvFrames.
(This is placed inside devices to avoid ffmpeg depending on base.)
3. Add a new wrapper type, MemoryMappingAvBufferSource, that wraps a
MemoryMappingArena and implements AvBufferSource for it. This was
technically not sound, but it's a low-risk attack vector that we
implicitly allowed before. The patch doesn't change the behavior; it
just makes this assumption more explicit.
BUG=b:239897269
TEST=cargo test --features "video-decoder,ffmpeg" -p devices -p ffmpeg
Change-Id: Id15e19b7d2452d1bc722a65f941c2c9150876205
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/3889245
Commit-Queue: Tatsuyuki Ishi <ishitatsuyuki@google.com>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
The virtio video decoder device is currently only available under very
drastic conditions: a build linked against libvda (a ChromeOS-only
library that needs the cros chroot to be built and linked against), and
a ChromeOS-flavored Chrome instance running alongside crosvm, so the
browser can provide the video decoding service through Mojo.
This makes the decoder device very difficult to develop on for
non-Chromies, and also for Chromies actually since they will always need
a DUT to test it on.
This patch introduces an alternative decoder backend based on
ffmpeg's libraries that performs decoding on the host's CPU. It supports both
guest pages and virtio objects as target, and can be considered a
reliable and predictable way to test the decoder in any environment.
We introduce our own ffmpeg bindings after a quick state of the art
revealed that the existing ones were all unsuitable, either for
technical or licensing reasons. Doing so is also not a big effort and
does not add any new external crate dependency to crosvm.
BUG=b:169295147
TEST=cargo test --features "video-decoder,ffmpeg" -p devices ffmpeg
TEST=v4l2r's simple_decoder example decodes test-25fps.h264 properly with the
following command:
./simple_decoder test-25fps.h264 /dev/video0 --input_format h264 --save test-25fps.nv12
TEST=ARCVM Android youtube plays videos correctly when the ffmpeg
backend is used.
Change-Id: Ic9c586193f7939f2a3fe59d009c3666585a8bbc7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3026355
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Alexandre Courbot <acourbot@chromium.org>
Reviewed-by: Keiichi Watanabe <keiichiw@chromium.org>
