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FFmpeg/libavcodec/cbs_sei.h
Jan Ekström f4bebc0c34 avcodec/cbs_{h2645,sei}: add support for Ambient Viewing Environment SEI
Defined by H.274, this SEI message is utilized by iPhones to save
the nominal ambient viewing environment for the display of recorded
HDR content.
2023-01-13 20:53:02 +02:00

206 lines
6.8 KiB
C

/*
* 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_CBS_SEI_H
#define AVCODEC_CBS_SEI_H
#include <stddef.h>
#include <stdint.h>
#include "libavutil/buffer.h"
#include "cbs.h"
#include "sei.h"
typedef struct SEIRawFillerPayload {
uint32_t payload_size;
} SEIRawFillerPayload;
typedef struct SEIRawUserDataRegistered {
uint8_t itu_t_t35_country_code;
uint8_t itu_t_t35_country_code_extension_byte;
uint8_t *data;
AVBufferRef *data_ref;
size_t data_length;
} SEIRawUserDataRegistered;
typedef struct SEIRawUserDataUnregistered {
uint8_t uuid_iso_iec_11578[16];
uint8_t *data;
AVBufferRef *data_ref;
size_t data_length;
} SEIRawUserDataUnregistered;
typedef struct SEIRawMasteringDisplayColourVolume {
uint16_t display_primaries_x[3];
uint16_t display_primaries_y[3];
uint16_t white_point_x;
uint16_t white_point_y;
uint32_t max_display_mastering_luminance;
uint32_t min_display_mastering_luminance;
} SEIRawMasteringDisplayColourVolume;
typedef struct SEIRawContentLightLevelInfo {
uint16_t max_content_light_level;
uint16_t max_pic_average_light_level;
} SEIRawContentLightLevelInfo;
typedef struct SEIRawAlternativeTransferCharacteristics {
uint8_t preferred_transfer_characteristics;
} SEIRawAlternativeTransferCharacteristics;
typedef struct SEIRawAmbientViewingEnvironment {
uint32_t ambient_illuminance;
uint16_t ambient_light_x;
uint16_t ambient_light_y;
} SEIRawAmbientViewingEnvironment;
typedef struct SEIRawMessage {
uint32_t payload_type;
uint32_t payload_size;
void *payload;
AVBufferRef *payload_ref;
uint8_t *extension_data;
AVBufferRef *extension_data_ref;
size_t extension_bit_length;
} SEIRawMessage;
typedef struct SEIRawMessageList {
SEIRawMessage *messages;
int nb_messages;
int nb_messages_allocated;
} SEIRawMessageList;
typedef struct SEIMessageState {
// The type of the payload being written.
uint32_t payload_type;
// When reading, contains the size of the payload to allow finding the
// end of variable-length fields (such as user_data_payload_byte[]).
// (When writing, the size will be derived from the total number of
// bytes actually written.)
uint32_t payload_size;
// When writing, indicates that payload extension data is present so
// all extended fields must be written. May be updated by the writer
// to indicate that extended fields have been written, so the extension
// end bits must be written too.
uint8_t extension_present;
} SEIMessageState;
struct GetBitContext;
struct PutBitContext;
typedef int (*SEIMessageReadFunction)(CodedBitstreamContext *ctx,
struct GetBitContext *rw,
void *current,
SEIMessageState *sei);
typedef int (*SEIMessageWriteFunction)(CodedBitstreamContext *ctx,
struct PutBitContext *rw,
void *current,
SEIMessageState *sei);
typedef struct SEIMessageTypeDescriptor {
// Payload type for the message. (-1 in this field ends a list.)
int type;
// Valid in a prefix SEI NAL unit (always for H.264).
uint8_t prefix;
// Valid in a suffix SEI NAL unit (never for H.264).
uint8_t suffix;
// Size of the decomposed structure.
size_t size;
// Read bitstream into SEI message.
SEIMessageReadFunction read;
// Write bitstream from SEI message.
SEIMessageWriteFunction write;
} SEIMessageTypeDescriptor;
// Macro for the read/write pair. The clumsy cast is needed because the
// current pointer is typed in all of the read/write functions but has to
// be void here to fit all cases.
#define SEI_MESSAGE_RW(codec, name) \
.read = (SEIMessageReadFunction) cbs_ ## codec ## _read_ ## name, \
.write = (SEIMessageWriteFunction)cbs_ ## codec ## _write_ ## name
// End-of-list sentinel element.
#define SEI_MESSAGE_TYPE_END { .type = -1 }
/**
* Find the type descriptor for the given payload type.
*
* Returns NULL if the payload type is not known.
*/
const SEIMessageTypeDescriptor *ff_cbs_sei_find_type(CodedBitstreamContext *ctx,
int payload_type);
/**
* Allocate a new payload for the given SEI message.
*/
int ff_cbs_sei_alloc_message_payload(SEIRawMessage *message,
const SEIMessageTypeDescriptor *desc);
/**
* Allocate a new empty SEI message in a message list.
*
* The new message is in place nb_messages - 1.
*/
int ff_cbs_sei_list_add(SEIRawMessageList *list);
/**
* Free all SEI messages in a message list.
*/
void ff_cbs_sei_free_message_list(SEIRawMessageList *list);
/**
* Add an SEI message to an access unit.
*
* Will add to an existing SEI NAL unit, or create a new one for the
* message if there is no suitable existing one.
*
* Takes a new reference to payload_buf, if set. If payload_buf is
* NULL then the new message will not be reference counted.
*/
int ff_cbs_sei_add_message(CodedBitstreamContext *ctx,
CodedBitstreamFragment *au,
int prefix,
uint32_t payload_type,
void *payload_data,
AVBufferRef *payload_buf);
/**
* Iterate over messages with the given payload type in an access unit.
*
* Set message to NULL in the first call. Returns 0 while more messages
* are available, AVERROR(ENOENT) when all messages have been found.
*/
int ff_cbs_sei_find_message(CodedBitstreamContext *ctx,
CodedBitstreamFragment *au,
uint32_t payload_type,
SEIRawMessage **message);
/**
* Delete all messages with the given payload type from an access unit.
*/
void ff_cbs_sei_delete_message_type(CodedBitstreamContext *ctx,
CodedBitstreamFragment *au,
uint32_t payload_type);
#endif /* AVCODEC_CBS_SEI_H */