flv.h

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/**********************************************************************************************/
/* The MIT License                                                                            */
/*                                                                                            */
/* Copyright 2016-2017 Twitch Interactive, Inc. or its affiliates. All Rights Reserved.       */
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/* of this software and associated documentation files (the "Software"), to deal              */
/* in the Software without restriction, including without limitation the rights               */
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#ifndef LIBCAPTION_FLV_H
#define LIBCAPTION_FLV_H

#include "mpeg.h"
#include <inttypes.h>
#include <stddef.h>
#include <stdio.h>
#define FLV_HEADER_SIZE 13
#define FLV_FOOTER_SIZE 4
#define FLV_TAG_HEADER_SIZE 11
#define FLV_TAG_FOOTER_SIZE 4
typedef struct {
    uint8_t* data;
    size_t aloc;
} flvtag_t;

void flvtag_init(flvtag_t* tag);
void flvtag_free(flvtag_t* tag);
void flvtag_swap(flvtag_t* tag1, flvtag_t* tag2);
typedef enum {
    flvtag_type_audio = 0x08,
    flvtag_type_video = 0x09,
    flvtag_type_scriptdata = 0x12,
} flvtag_type_t;

static inline flvtag_type_t flvtag_type(flvtag_t* tag) { return (flvtag_type_t)tag->data[0] & 0x1F; }
typedef enum {
    flvtag_soundformat_unknown = -1,
    flvtag_soundformat_linearpcmplatformendian = 0,
    flvtag_soundformat_adpcm = 1,
    flvtag_soundformat_mp3 = 2,
    flvtag_soundformat_linearpcmlittleendian = 3,
    flvtag_soundformat_nellymoser_16khzmono = 4,
    flvtag_soundformat_nellymoser_8khzmono = 5,
    flvtag_soundformat_nellymoser = 6,
    flvtag_soundformat_g711alawlogarithmicpcm = 7,
    flvtag_soundformat_g711mulawlogarithmicpcm = 8,
    flvtag_soundformat_reserved = 9,
    flvtag_soundformat_aac = 10,
    flvtag_soundformat_speex = 11,
    flvtag_soundformat_mp3_8khz = 14,
    flvtag_soundformat_devicespecificsound = 15
} flvtag_soundformat_t;

static inline flvtag_soundformat_t flvtag_soundformat(flvtag_t* tag) { return (flvtag_type_audio != flvtag_type(tag)) ? flvtag_soundformat_unknown : (flvtag_soundformat_t)(tag->data[0] >> 4) & 0x0F; }
typedef enum {
    flvtag_codecid_unknown = -1,
    flvtag_codecid_sorensonh263 = 2,
    flvtag_codecid_screenvideo = 3,
    flvtag_codecid_on2vp6 = 4,
    flvtag_codecid_on2vp6withalphachannel = 5,
    flvtag_codecid_screenvideoversion2 = 6,
    flvtag_codecid_avc = 7
} flvtag_codecid_t;

static inline flvtag_codecid_t flvtag_codecid(flvtag_t* tag) { return (flvtag_type_video != flvtag_type(tag)) ? (flvtag_codecid_unknown) : (tag->data[11] & 0x0F); }
typedef enum {
    flvtag_frametype_unknown = -1,
    flvtag_frametype_keyframe = 1,
    flvtag_frametype_interframe = 2,
    flvtag_frametype_disposableinterframe = 3,
    flvtag_frametype_generatedkeyframe = 4,
    flvtag_frametype_commandframe = 5
} flvtag_frametype_t;

static inline flvtag_frametype_t flvtag_frametype(flvtag_t* tag) { return (flvtag_type_video != flvtag_type(tag)) ? flvtag_frametype_keyframe : ((tag->data[11] >> 4) & 0x0F); }
typedef enum {
    flvtag_avcpackettype_unknown = -1,
    flvtag_avcpackettype_sequenceheader = 0,
    flvtag_avcpackettype_nalu = 1,
    flvtag_avcpackettype_endofsequence = 2
} flvtag_avcpackettype_t;

static inline flvtag_avcpackettype_t flvtag_avcpackettype(flvtag_t* tag) { return (flvtag_codecid_avc != flvtag_codecid(tag)) ? flvtag_avcpackettype_unknown : tag->data[12]; }
static inline size_t flvtag_size(flvtag_t* tag) { return (tag->data[1] << 16) | (tag->data[2] << 8) | tag->data[3]; }
static inline uint32_t flvtag_timestamp(flvtag_t* tag) { return (tag->data[7] << 24) | (tag->data[4] << 16) | (tag->data[5] << 8) | tag->data[6]; }
static inline uint32_t flvtag_dts(flvtag_t* tag) { return flvtag_timestamp(tag); }
static inline uint32_t flvtag_cts(flvtag_t* tag) { return (flvtag_avcpackettype_nalu != flvtag_avcpackettype(tag)) ? 0 : (tag->data[13] << 16) | (tag->data[14] << 8) | tag->data[15]; }
static inline uint32_t flvtag_pts(flvtag_t* tag) { return flvtag_dts(tag) + flvtag_cts(tag); }
static inline double flvtag_dts_seconds(flvtag_t* tag) { return flvtag_dts(tag) / 1000.0; }
static inline double flvtag_cts_seconds(flvtag_t* tag) { return flvtag_cts(tag) / 1000.0; }
static inline double flvtag_pts_seconds(flvtag_t* tag) { return flvtag_pts(tag) / 1000.0; }
size_t flvtag_header_size(flvtag_t* tag);
size_t flvtag_payload_size(flvtag_t* tag);
uint8_t* flvtag_payload_data(flvtag_t* tag);
FILE* flv_open_read(const char* flv);
FILE* flv_open_write(const char* flv);
FILE* flv_close(FILE* flv);
static inline const uint8_t* flvtag_raw_data(flvtag_t* tag) { return tag->data; }
static inline const size_t flvtag_raw_size(flvtag_t* tag) { return flvtag_size(tag) + FLV_TAG_HEADER_SIZE + FLV_TAG_FOOTER_SIZE; }
int flv_read_tag(FILE* flv, flvtag_t* tag);
int flv_write_tag(FILE* flv, flvtag_t* tag);
int flv_read_header(FILE* flv, int* has_audio, int* has_video);
int flv_write_header(FILE* flv, int has_audio, int has_video);
// If the tage has more that on sei message, they will be combined into one
sei_t* flv_read_sei(FILE* flv, flvtag_t* tag);
int flvtag_initavc(flvtag_t* tag, uint32_t dts, int32_t cts, flvtag_frametype_t type);
int flvtag_avcwritenal(flvtag_t* tag, uint8_t* data, size_t size);
int flvtag_addcaption_scc(flvtag_t* tag, const scc_t* scc);
int flvtag_addcaption_text(flvtag_t* tag, const utf8_char_t* text);
int flvtag_amfcaption_708(flvtag_t* tag, uint32_t timestamp, sei_message_t* msg);
// This method is expermental, and not currently available on Twitch
int flvtag_amfcaption_utf8(flvtag_t* tag, uint32_t timestamp, const utf8_char_t* text);
#endif