Split it into sections that describe in detail
* the components of the transcoding pipeline
* the main features it handles, in order of complexity
* streamcopy
* transcoding
* filtering
Replace the current confusing/misleading diagrams with new ones that
actually reflect the program components and data flow between them.
893f3fde4c made libavcodec link to libshaderc/libglslang, though
no codecs depend on it at this immediate moment.
This was merged largely as a coordination effort to synchronize three
different developers' repositories to allow them to send patches without
overlapping functionality in between.
This line can be removed once the first component to depend on spirv_compiler
lands, but leaving it in is fine too.
We started defauling to nasm 8 years ago.
We are still compatible with yasm 0.8.0, released in 2009. **15 years ago**.
The time has more than come to remove support for it.
Maintaining compatibility started cutting into writing new code long ago.
We still can't have 2-argument instructions, preprocessor booleans, and all
AVX2 code must still be wrapped in ifdefs. Newly added code often breaks this.
This is the same as with libavfilter.
We will need SPIR-V compilation for at least three different things,
like the VC-2 encoder and decoder, AV1 film grain synthesis for
hardware with no support for it, and possibly other codecs.
The code is not currently used by libavutil, its just where our
common Vulkan code is.
Since SPIR-V compilation will be needed by lavc, move it, rather
than having lavc including lavfi.
With multilayer001.heic:
Before:
[hevc @ ...] Scalability type 2 not supported
[hevc @ ...] Ignoring unsupported VPS extension
[hevc @ ...] The following bit-depths are currently specified: 8, 9, 10 and 12 bits, chroma_format_idc is 0, depth is 0
After:
[hevc @ ...] Scalability type 2 not supported
[hevc @ ...] Ignoring unsupported VPS extension
[hevc @ ...] SPS 1 references an unsupported VPS extension. Ignoring
Signed-off-by: James Almer <jamrial@gmail.com>
This silences a lot of compile warnings (around 160 instances at least), when
compiling with Clang.
These warnings look like this:
libavformat/http.c:176:133: warning: implicit conversion from 'long long' to 'double' changes value from 9223372036854775807 to 9223372036854775808 [-Wimplicit-const-int-float-conversion]
176 | { "end_offset", "try to limit the request to bytes preceding this offset", OFFSET(end_off), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT64_MAX, D },
| ~ ^~~~~~~~~
Signed-off-by: Martin Storsjö <martin@martin.st>
This file is never included explicitly anywhere else, it's only
included implicitly by passing -Pconfig.asm on the command line.
Signed-off-by: Martin Storsjö <martin@martin.st>
Due to the nature of multithreading, using a "ready check" mechanism may introduce a deadlock. For example:
Suppose all tasks have been submitted to the executor, and the last thread checks the entire list and finds
no ready tasks. It then goes to sleep, waiting for a new task. However, for some multithreading-related reason,
a task becomes ready after the check. Since no other thread is aware of this and no new tasks are being added to
the executor, a deadlock occurs.
In VVC, this function is unnecessary because we use a scoreboard. All tasks submitted to the executor are ready tasks.
We still need several refactors to improve the current VVC decoder's performance,
which will frequently break the API/ABI. To mitigate this, we've copied the executor from
avutil to avcodec. Once the API/ABI is stable, we will move this class back to avutil
Anton Khirnov
Lynne via ffmpeg-devel
James Almer
Lynne
IndecisiveTurtle
Gyan Doshi
Martin Storsjö
Nuo Mi
Marvin Scholz