avcodec/avcodec: Add FFHWAccel, hide internals of AVHWAccel

This commit is the AVHWAccel analogue of commit
20f972701806be20a77f808db332d9489343bb78: It moves the private fields
of AVHWAccel to a new struct FFHWAccel extending AVHWAccel
in an internal header (namely hwaccel_internal.h).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 150 insertions, 0 deletions

diff --git a/libavcodec/hwaccel_internal.h b/libavcodec/hwaccel_internal.h
index 6e6f5c7cf9..edfe283150 100644
--- a/libavcodec/hwaccel_internal.h
+++ b/libavcodec/hwaccel_internal.h
@@ -23,7 +23,157 @@
 #ifndef AVCODEC_HWACCEL_INTERNAL_H
 #define AVCODEC_HWACCEL_INTERNAL_H
 
+#include <stdint.h>
+
+#include "avcodec.h"
+
 #define HWACCEL_CAP_ASYNC_SAFE      (1 << 0)
 #define HWACCEL_CAP_THREAD_SAFE     (1 << 1)
 
+typedef struct FFHWAccel {
+    /**
+     * The public AVHWAccel. See avcodec.h for it.
+     */
+    AVHWAccel p;
+
+    /**
+     * Allocate a custom buffer
+     */
+    int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
+
+    /**
+     * Called at the beginning of each frame or field picture.
+     *
+     * Meaningful frame information (codec specific) is guaranteed to
+     * be parsed at this point. This function is mandatory.
+     *
+     * Note that buf can be NULL along with buf_size set to 0.
+     * Otherwise, this means the whole frame is available at this point.
+     *
+     * @param avctx the codec context
+     * @param buf the frame data buffer base
+     * @param buf_size the size of the frame in bytes
+     * @return zero if successful, a negative value otherwise
+     */
+    int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
+
+    /**
+     * Callback for parameter data (SPS/PPS/VPS etc).
+     *
+     * Useful for hardware decoders which keep persistent state about the
+     * video parameters, and need to receive any changes to update that state.
+     *
+     * @param avctx the codec context
+     * @param type the nal unit type
+     * @param buf the nal unit data buffer
+     * @param buf_size the size of the nal unit in bytes
+     * @return zero if successful, a negative value otherwise
+     */
+    int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
+
+    /**
+     * Callback for each slice.
+     *
+     * Meaningful slice information (codec specific) is guaranteed to
+     * be parsed at this point. This function is mandatory.
+     *
+     * @param avctx the codec context
+     * @param buf the slice data buffer base
+     * @param buf_size the size of the slice in bytes
+     * @return zero if successful, a negative value otherwise
+     */
+    int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
+
+    /**
+     * Called at the end of each frame or field picture.
+     *
+     * The whole picture is parsed at this point and can now be sent
+     * to the hardware accelerator. This function is mandatory.
+     *
+     * @param avctx the codec context
+     * @return zero if successful, a negative value otherwise
+     */
+    int (*end_frame)(AVCodecContext *avctx);
+
+    /**
+     * Size of per-frame hardware accelerator private data.
+     *
+     * Private data is allocated with av_mallocz() before
+     * AVCodecContext.get_buffer() and deallocated after
+     * AVCodecContext.release_buffer().
+     */
+    int frame_priv_data_size;
+
+    /**
+     * Size of the private data to allocate in
+     * AVCodecInternal.hwaccel_priv_data.
+     */
+    int priv_data_size;
+
+    /**
+     * Internal hwaccel capabilities.
+     */
+    int caps_internal;
+
+    /**
+     * Initialize the hwaccel private data.
+     *
+     * This will be called from ff_get_format(), after hwaccel and
+     * hwaccel_context are set and the hwaccel private data in AVCodecInternal
+     * is allocated.
+     */
+    int (*init)(AVCodecContext *avctx);
+
+    /**
+     * Uninitialize the hwaccel private data.
+     *
+     * This will be called from get_format() or avcodec_close(), after hwaccel
+     * and hwaccel_context are already uninitialized.
+     */
+    int (*uninit)(AVCodecContext *avctx);
+
+    /**
+     * Fill the given hw_frames context with current codec parameters. Called
+     * from get_format. Refer to avcodec_get_hw_frames_parameters() for
+     * details.
+     *
+     * This CAN be called before AVHWAccel.init is called, and you must assume
+     * that avctx->hwaccel_priv_data is invalid.
+     */
+    int (*frame_params)(AVCodecContext *avctx, AVBufferRef *hw_frames_ctx);
+
+    /**
+     * Copy necessary context variables from a previous thread context to the current one.
+     * For thread-safe hwaccels only.
+     */
+    int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
+
+    /**
+     * Callback to free the hwaccel-specific frame data.
+     *
+     * @param hwctx a pointer to an AVHWDeviceContext.
+     * @param data the per-frame hardware accelerator private data to be freed.
+     */
+    void (*free_frame_priv)(void *hwctx, uint8_t *data);
+
+    /**
+     * Callback to flush the hwaccel state.
+     */
+    void (*flush)(AVCodecContext *avctx);
+} FFHWAccel;
+
+static inline const FFHWAccel *ffhwaccel(const AVHWAccel *codec)
+{
+    return (const FFHWAccel*)codec;
+}
+
+#define FF_HW_CALL(avctx, function, ...) \
+        (ffhwaccel((avctx)->hwaccel)->function((avctx), __VA_ARGS__))
+
+#define FF_HW_SIMPLE_CALL(avctx, function) \
+        (ffhwaccel((avctx)->hwaccel)->function(avctx))
+
+#define FF_HW_HAS_CB(avctx, function) \
+        ((avctx)->hwaccel && ffhwaccel((avctx)->hwaccel)->function)
+
 #endif /* AVCODEC_HWACCEL_INTERNAL */