FFmpeg/libavcodec/decode.h
Andreas Rheinhardt 20f9727018 avcodec/codec_internal: Add FFCodec, hide internal part of AVCodec
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.

This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-03-21 01:33:09 +01:00

98 lines
3.3 KiB
C

/*
* generic decoding-related code
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_DECODE_H
#define AVCODEC_DECODE_H
#include "libavutil/buffer.h"
#include "libavutil/frame.h"
#include "libavutil/hwcontext.h"
#include "avcodec.h"
/**
* This struct stores per-frame lavc-internal data and is attached to it via
* private_ref.
*/
typedef struct FrameDecodeData {
/**
* The callback to perform some delayed processing on the frame right
* before it is returned to the caller.
*
* @note This code is called at some unspecified point after the frame is
* returned from the decoder's decode/receive_frame call. Therefore it cannot rely
* on AVCodecContext being in any specific state, so it does not get to
* access AVCodecContext directly at all. All the state it needs must be
* stored in the post_process_opaque object.
*/
int (*post_process)(void *logctx, AVFrame *frame);
void *post_process_opaque;
void (*post_process_opaque_free)(void *opaque);
/**
* Per-frame private data for hwaccels.
*/
void *hwaccel_priv;
void (*hwaccel_priv_free)(void *priv);
} FrameDecodeData;
/**
* Called by decoders to get the next packet for decoding.
*
* @param pkt An empty packet to be filled with data.
* @return 0 if a new reference has been successfully written to pkt
* AVERROR(EAGAIN) if no data is currently available
* AVERROR_EOF if and end of stream has been reached, so no more data
* will be available
*/
int ff_decode_get_packet(AVCodecContext *avctx, AVPacket *pkt);
/**
* Set various frame properties from the codec context / packet data.
*/
int ff_decode_frame_props(AVCodecContext *avctx, AVFrame *frame);
/**
* Make sure avctx.hw_frames_ctx is set. If it's not set, the function will
* try to allocate it from hw_device_ctx. If that is not possible, an error
* message is printed, and an error code is returned.
*/
int ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,
enum AVHWDeviceType dev_type);
int ff_attach_decode_data(AVFrame *frame);
/**
* Check whether the side-data of src contains a palette of
* size AVPALETTE_SIZE; if so, copy it to dst and return 1;
* else return 0.
* Also emit an error message upon encountering a palette
* with invalid size.
*/
int ff_copy_palette(void *dst, const AVPacket *src, void *logctx);
/**
* Perform decoder initialization and validation.
* Called when opening the decoder, before the FFCodec.init() call.
*/
int ff_decode_preinit(AVCodecContext *avctx);
#endif /* AVCODEC_DECODE_H */