video: rewrite filtering glue code

Get rid of the old vf.c code. Replace it with a generic filtering
framework, which can potentially handle more than just --vf. At least
reimplementing --af with this code is planned.

This changes some --vf semantics (including runtime behavior and the
"vf" command). The most important ones are listed in interface-changes.

vf_convert.c is renamed to f_swscale.c. It is now an internal filter
that can not be inserted by the user manually.

f_lavfi.c is a refactor of player/lavfi.c. The latter will be removed
once --lavfi-complex is reimplemented on top of f_lavfi.c. (which is
conceptually easy, but a big mess due to the data flow changes).

The existing filters are all changed heavily. The data flow of the new
filter framework is different. Especially EOF handling changes - EOF is
now a "frame" rather than a state, and must be passed through exactly
once.

Another major thing is that all filters must support dynamic format
changes. The filter reconfig() function goes away. (This sounds complex,
but since all filters need to handle EOF draining anyway, they can use
the same code, and it removes the mess with reconfig() having to predict
the output format, which completely breaks with libavfilter anyway.)

In addition, there is no automatic format negotiation or conversion.
libavfilter's primitive and insufficient API simply doesn't allow us to
do this in a reasonable way. Instead, filters can use f_autoconvert as
sub-filter, and tell it which formats they support. This filter will in
turn add actual conversion filters, such as f_swscale, to perform
necessary format changes.

vf_vapoursynth.c uses the same basic principle of operation as before,
but with worryingly different details in data flow. Still appears to
work.

The hardware deint filters (vf_vavpp.c, vf_d3d11vpp.c, vf_vdpaupp.c) are
heavily changed. Fortunately, they all used refqueue.c, which is for
sharing the data flow logic (especially for managing future/past
surfaces and such). It turns out it can be used to factor out most of
the data flow. Some of these filters accepted software input. Instead of
having ad-hoc upload code in each filter, surface upload is now
delegated to f_autoconvert, which can use f_hwupload to perform this.

Exporting VO capabilities is still a big mess (mp_stream_info stuff).

The D3D11 code drops the redundant image formats, and all code uses the
hw_subfmt (sw_format in FFmpeg) instead. Although that too seems to be a
big mess for now.

f_async_queue is unused.

1 files changed, 59 insertions, 0 deletions

diff --git a/filters/f_output_chain.h b/filters/f_output_chain.h
new file mode 100644
index 0000000000..64667ed1bd
--- /dev/null
+++ b/filters/f_output_chain.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#include "options/m_option.h"
+#include "video/mp_image.h"
+
+#include "filter.h"
+
+enum mp_output_chain_type {
+    MP_OUTPUT_CHAIN_VIDEO = 1,      // --vf
+};
+
+// A classic single-media filter chain, which reflects --vf and --af.
+// It manages the user-specified filter chain, and VO/AO output conversions.
+// Also handles some automatic filtering (auto rotation and such).
+struct mp_output_chain {
+    // This filter will have 1 input (from decoder) and 1 output (to VO/AO).
+    struct mp_filter *f;
+
+    bool got_input_eof;
+    bool got_output_eof;
+
+    // The filter chain output could not be converted to any format the output
+    // supports.
+    bool failed_output_conversion;
+
+    // Set if any formats in the chain changed. The user can reset the flag.
+    // For implementing change notifications out input/output_params.
+    bool reconfig_happened;
+
+    // --- for type==MP_OUTPUT_CHAIN_VIDEO
+    struct mp_image_params input_params;
+    struct mp_image_params output_params;
+    double container_fps;
+};
+
+// (free by freeing mp_output_chain.f)
+struct mp_output_chain *mp_output_chain_create(struct mp_filter *parent,
+                                               enum mp_output_chain_type type);
+
+// Set the VO, which will be used to determine basic capabilities like format
+// and rotation support, and to init hardware filtering things.
+// For type==MP_OUTPUT_CHAIN_VIDEO only.
+struct vo;
+void mp_output_chain_set_vo(struct mp_output_chain *p, struct vo *vo);
+
+// Send a command to the filter with the target label.
+bool mp_output_chain_command(struct mp_output_chain *p, const char *target,
+                             struct mp_filter_command *cmd);
+
+// Perform a seek reset _and_ reset all filter failure states, so that future
+// filtering continues normally.
+void mp_output_chain_reset_harder(struct mp_output_chain *p);
+
+// Try to exchange the filter list. If creation of any filter fails, roll
+// back the changes, and return false.
+struct m_obj_settings;
+bool mp_output_chain_update_filters(struct mp_output_chain *p,
+                                    struct m_obj_settings *list);
+