ffmpeg结构体一览表

不念不忘少年蓝@ 2023-01-15 15:25 123阅读 0赞

AVFormatContext

typedef struct AVFormatContext { 
        /** * A class for logging and @ref avoptions. Set by avformat_alloc_context(). * Exports (de)muxer private options if they exist. */
        const AVClass *av_class;
    
        /** * The input container format. * * Demuxing only, set by avformat_open_input(). */
        ff_const59 struct AVInputFormat *iformat;
    
        /** * The output container format. * * Muxing only, must be set by the caller before avformat_write_header(). */
        ff_const59 struct AVOutputFormat *oformat;
    
        /** * Format private data. This is an AVOptions-enabled struct * if and only if iformat/oformat.priv_class is not NULL. * * - muxing: set by avformat_write_header() * - demuxing: set by avformat_open_input() */
        void *priv_data;
    
        /** * I/O context. * * - demuxing: either set by the user before avformat_open_input() (then * the user must close it manually) or set by avformat_open_input(). * - muxing: set by the user before avformat_write_header(). The caller must * take care of closing / freeing the IO context. * * Do NOT set this field if AVFMT_NOFILE flag is set in * iformat/oformat.flags. In such a case, the (de)muxer will handle * I/O in some other way and this field will be NULL. */
        AVIOContext *pb;
    
        /* stream info */
        /** * Flags signalling stream properties. A combination of AVFMTCTX_*. * Set by libavformat. */
        int ctx_flags;
    
        /** * Number of elements in AVFormatContext.streams. * * Set by avformat_new_stream(), must not be modified by any other code. */
        unsigned int nb_streams;
        /** * A list of all streams in the file. New streams are created with * avformat_new_stream(). * * - demuxing: streams are created by libavformat in avformat_open_input(). * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also * appear in av_read_frame(). * - muxing: streams are created by the user before avformat_write_header(). * * Freed by libavformat in avformat_free_context(). */
        AVStream **streams;
    
    #if FF_API_FORMAT_FILENAME
        /** * input or output filename * * - demuxing: set by avformat_open_input() * - muxing: may be set by the caller before avformat_write_header() * * @deprecated Use url instead. */
        attribute_deprecated
        char filename[1024];
    #endif
    
        /** * input or output URL. Unlike the old filename field, this field has no * length restriction. * * - demuxing: set by avformat_open_input(), initialized to an empty * string if url parameter was NULL in avformat_open_input(). * - muxing: may be set by the caller before calling avformat_write_header() * (or avformat_init_output() if that is called first) to a string * which is freeable by av_free(). Set to an empty string if it * was NULL in avformat_init_output(). * * Freed by libavformat in avformat_free_context(). */
        char *url;
    
        /** * Position of the first frame of the component, in * AV_TIME_BASE fractional seconds. NEVER set this value directly: * It is deduced from the AVStream values. * * Demuxing only, set by libavformat. */
        int64_t start_time;
    
        /** * Duration of the stream, in AV_TIME_BASE fractional * seconds. Only set this value if you know none of the individual stream * durations and also do not set any of them. This is deduced from the * AVStream values if not set. * * Demuxing only, set by libavformat. */
        int64_t duration;
    
        /** * Total stream bitrate in bit/s, 0 if not * available. Never set it directly if the file_size and the * duration are known as FFmpeg can compute it automatically. */
        int64_t bit_rate;
    
        unsigned int packet_size;
        int max_delay;
    
        /** * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*. * Set by the user before avformat_open_input() / avformat_write_header(). */
        int flags;
    #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
    #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
    #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
    #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
    #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
    #define AVFMT_FLAG_NOPARSE 0x0020 ///< Do not use AVParsers, you also must set AVFMT_FLAG_NOFILLIN as the fillin code works on frames and no parsing -> no frames. Also seeking to frames can not work if parsing to find frame boundaries has been disabled
    #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
    #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
    #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
    #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
    /** * When muxing, try to avoid writing any random/volatile data to the output. * This includes any random IDs, real-time timestamps/dates, muxer version, etc. * * This flag is mainly intended for testing. */
    #define AVFMT_FLAG_BITEXACT 0x0400
    #if FF_API_LAVF_MP4A_LATM
    #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Deprecated, does nothing.
    #endif
    #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
    #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (this could be made default once all code is converted)
    #if FF_API_LAVF_KEEPSIDE_FLAG
    #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing.
    #endif
    #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
    #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
    #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
    
        /** * Maximum size of the data read from input for determining * the input container format. * Demuxing only, set by the caller before avformat_open_input(). */
        int64_t probesize;
    
        /** * Maximum duration (in AV_TIME_BASE units) of the data read * from input in avformat_find_stream_info(). * Demuxing only, set by the caller before avformat_find_stream_info(). * Can be set to 0 to let avformat choose using a heuristic. */
        int64_t max_analyze_duration;
    
        const uint8_t *key;
        int keylen;
    
        unsigned int nb_programs;
        AVProgram **programs;
    
        /** * Forced video codec_id. * Demuxing: Set by user. */
        enum AVCodecID video_codec_id;
    
        /** * Forced audio codec_id. * Demuxing: Set by user. */
        enum AVCodecID audio_codec_id;
    
        /** * Forced subtitle codec_id. * Demuxing: Set by user. */
        enum AVCodecID subtitle_codec_id;
    
        /** * Maximum amount of memory in bytes to use for the index of each stream. * If the index exceeds this size, entries will be discarded as * needed to maintain a smaller size. This can lead to slower or less * accurate seeking (depends on demuxer). * Demuxers for which a full in-memory index is mandatory will ignore * this. * - muxing: unused * - demuxing: set by user */
        unsigned int max_index_size;
    
        /** * Maximum amount of memory in bytes to use for buffering frames * obtained from realtime capture devices. */
        unsigned int max_picture_buffer;
    
        /** * Number of chapters in AVChapter array. * When muxing, chapters are normally written in the file header, * so nb_chapters should normally be initialized before write_header * is called. Some muxers (e.g. mov and mkv) can also write chapters * in the trailer. To write chapters in the trailer, nb_chapters * must be zero when write_header is called and non-zero when * write_trailer is called. * - muxing: set by user * - demuxing: set by libavformat */
        unsigned int nb_chapters;
        AVChapter **chapters;
    
        /** * Metadata that applies to the whole file. * * - demuxing: set by libavformat in avformat_open_input() * - muxing: may be set by the caller before avformat_write_header() * * Freed by libavformat in avformat_free_context(). */
        AVDictionary *metadata;
    
        /** * Start time of the stream in real world time, in microseconds * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the * stream was captured at this real world time. * - muxing: Set by the caller before avformat_write_header(). If set to * either 0 or AV_NOPTS_VALUE, then the current wall-time will * be used. * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that * the value may become known after some number of frames * have been received. */
        int64_t start_time_realtime;
    
        /** * The number of frames used for determining the framerate in * avformat_find_stream_info(). * Demuxing only, set by the caller before avformat_find_stream_info(). */
        int fps_probe_size;
    
        /** * Error recognition; higher values will detect more errors but may * misdetect some more or less valid parts as errors. * Demuxing only, set by the caller before avformat_open_input(). */
        int error_recognition;
    
        /** * Custom interrupt callbacks for the I/O layer. * * demuxing: set by the user before avformat_open_input(). * muxing: set by the user before avformat_write_header() * (mainly useful for AVFMT_NOFILE formats). The callback * should also be passed to avio_open2() if it's used to * open the file. */
        AVIOInterruptCB interrupt_callback;
    
        /** * Flags to enable debugging. */
        int debug;
    #define FF_FDEBUG_TS 0x0001
    
        /** * Maximum buffering duration for interleaving. * * To ensure all the streams are interleaved correctly, * av_interleaved_write_frame() will wait until it has at least one packet * for each stream before actually writing any packets to the output file. * When some streams are "sparse" (i.e. there are large gaps between * successive packets), this can result in excessive buffering. * * This field specifies the maximum difference between the timestamps of the * first and the last packet in the muxing queue, above which libavformat * will output a packet regardless of whether it has queued a packet for all * the streams. * * Muxing only, set by the caller before avformat_write_header(). */
        int64_t max_interleave_delta;
    
        /** * Allow non-standard and experimental extension * @see AVCodecContext.strict_std_compliance */
        int strict_std_compliance;
    
        /** * Flags for the user to detect events happening on the file. Flags must * be cleared by the user once the event has been handled. * A combination of AVFMT_EVENT_FLAG_*. */
        int event_flags;
    #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
    
        /** * Maximum number of packets to read while waiting for the first timestamp. * Decoding only. */
        int max_ts_probe;
    
        /** * Avoid negative timestamps during muxing. * Any value of the AVFMT_AVOID_NEG_TS_* constants. * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use) * - muxing: Set by user * - demuxing: unused */
        int avoid_negative_ts;
    #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
    #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
    #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
    
        /** * Transport stream id. * This will be moved into demuxer private options. Thus no API/ABI compatibility */
        int ts_id;
    
        /** * Audio preload in microseconds. * Note, not all formats support this and unpredictable things may happen if it is used when not supported. * - encoding: Set by user * - decoding: unused */
        int audio_preload;
    
        /** * Max chunk time in microseconds. * Note, not all formats support this and unpredictable things may happen if it is used when not supported. * - encoding: Set by user * - decoding: unused */
        int max_chunk_duration;
    
        /** * Max chunk size in bytes * Note, not all formats support this and unpredictable things may happen if it is used when not supported. * - encoding: Set by user * - decoding: unused */
        int max_chunk_size;
    
        /** * forces the use of wallclock timestamps as pts/dts of packets * This has undefined results in the presence of B frames. * - encoding: unused * - decoding: Set by user */
        int use_wallclock_as_timestamps;
    
        /** * avio flags, used to force AVIO_FLAG_DIRECT. * - encoding: unused * - decoding: Set by user */
        int avio_flags;
    
        /** * The duration field can be estimated through various ways, and this field can be used * to know how the duration was estimated. * - encoding: unused * - decoding: Read by user */
        enum AVDurationEstimationMethod duration_estimation_method;
    
        /** * Skip initial bytes when opening stream * - encoding: unused * - decoding: Set by user */
        int64_t skip_initial_bytes;
    
        /** * Correct single timestamp overflows * - encoding: unused * - decoding: Set by user */
        unsigned int correct_ts_overflow;
    
        /** * Force seeking to any (also non key) frames. * - encoding: unused * - decoding: Set by user */
        int seek2any;
    
        /** * Flush the I/O context after each packet. * - encoding: Set by user * - decoding: unused */
        int flush_packets;
    
        /** * format probing score. * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes * the format. * - encoding: unused * - decoding: set by avformat, read by user */
        int probe_score;
    
        /** * number of bytes to read maximally to identify format. * - encoding: unused * - decoding: set by user */
        int format_probesize;
    
        /** * ',' separated list of allowed decoders. * If NULL then all are allowed * - encoding: unused * - decoding: set by user */
        char *codec_whitelist;
    
        /** * ',' separated list of allowed demuxers. * If NULL then all are allowed * - encoding: unused * - decoding: set by user */
        char *format_whitelist;
    
        /** * An opaque field for libavformat internal usage. * Must not be accessed in any way by callers. */
        AVFormatInternal *internal;
    
        /** * IO repositioned flag. * This is set by avformat when the underlaying IO context read pointer * is repositioned, for example when doing byte based seeking. * Demuxers can use the flag to detect such changes. */
        int io_repositioned;
    
        /** * Forced video codec. * This allows forcing a specific decoder, even when there are multiple with * the same codec_id. * Demuxing: Set by user */
        AVCodec *video_codec;
    
        /** * Forced audio codec. * This allows forcing a specific decoder, even when there are multiple with * the same codec_id. * Demuxing: Set by user */
        AVCodec *audio_codec;
    
        /** * Forced subtitle codec. * This allows forcing a specific decoder, even when there are multiple with * the same codec_id. * Demuxing: Set by user */
        AVCodec *subtitle_codec;
    
        /** * Forced data codec. * This allows forcing a specific decoder, even when there are multiple with * the same codec_id. * Demuxing: Set by user */
        AVCodec *data_codec;
    
        /** * Number of bytes to be written as padding in a metadata header. * Demuxing: Unused. * Muxing: Set by user via av_format_set_metadata_header_padding. */
        int metadata_header_padding;
    
        /** * User data. * This is a place for some private data of the user. */
        void *opaque;
    
        /** * Callback used by devices to communicate with application. */
        av_format_control_message control_message_cb;
    
        /** * Output timestamp offset, in microseconds. * Muxing: set by user */
        int64_t output_ts_offset;
    
        /** * dump format separator. * can be ", " or "\n " or anything else * - muxing: Set by user. * - demuxing: Set by user. */
        uint8_t *dump_separator;
    
        /** * Forced Data codec_id. * Demuxing: Set by user. */
        enum AVCodecID data_codec_id;
    
    #if FF_API_OLD_OPEN_CALLBACKS
        /** * Called to open further IO contexts when needed for demuxing. * * This can be set by the user application to perform security checks on * the URLs before opening them. * The function should behave like avio_open2(), AVFormatContext is provided * as contextual information and to reach AVFormatContext.opaque. * * If NULL then some simple checks are used together with avio_open2(). * * Must not be accessed directly from outside avformat. * @See av_format_set_open_cb() * * Demuxing: Set by user. * * @deprecated Use io_open and io_close. */
        attribute_deprecated
        int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
    #endif
    
        /** * ',' separated list of allowed protocols. * - encoding: unused * - decoding: set by user */
        char *protocol_whitelist;
    
        /** * A callback for opening new IO streams. * * Whenever a muxer or a demuxer needs to open an IO stream (typically from * avformat_open_input() for demuxers, but for certain formats can happen at * other times as well), it will call this callback to obtain an IO context. * * @param s the format context * @param pb on success, the newly opened IO context should be returned here * @param url the url to open * @param flags a combination of AVIO_FLAG_* * @param options a dictionary of additional options, with the same * semantics as in avio_open2() * @return 0 on success, a negative AVERROR code on failure * * @note Certain muxers and demuxers do nesting, i.e. they open one or more * additional internal format contexts. Thus the AVFormatContext pointer * passed to this callback may be different from the one facing the caller. * It will, however, have the same 'opaque' field. */
        int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
                       int flags, AVDictionary **options);
    
        /** * A callback for closing the streams opened with AVFormatContext.io_open(). */
        void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
    
        /** * ',' separated list of disallowed protocols. * - encoding: unused * - decoding: set by user */
        char *protocol_blacklist;
    
        /** * The maximum number of streams. * - encoding: unused * - decoding: set by user */
        int max_streams;
    
        /** * Skip duration calcuation in estimate_timings_from_pts. * - encoding: unused * - decoding: set by user */
        int skip_estimate_duration_from_pts;
    
        /** * Maximum number of packets that can be probed * - encoding: unused * - decoding: set by user */
        int max_probe_packets;
    } AVFormatContext;

这里是init\_input后的堆栈数据：

Locals		
    		filename	"rtsp://172.0.8.21:9980/2/analysis"	char*
    		i	<optimized out>	
    		id3v2_extra_meta	0x0	ID3v2ExtraMeta*
    		options	@0x7ffdcd3ee2d8	AVDictionary
    		ps	@0x555556afb620	AVFormatContext
    		ret	<optimized out>	
    		//关键看这里
    		s	@0x7ffd68002c40	AVFormatContext
    			audio_codec	0x0	AVCodec*
    			audio_codec_id	AV_CODEC_ID_NONE (0)	enum AVCodecID
    			audio_preload	0	int
    			av_class	@0x7ffff0b6a0a0	AVClass
    				category	AV_CLASS_CATEGORY_MUXER (3)	AVClassCategory
    				child_class_next	0x7ffff0a7a850 <format_child_class_next>	const struct AVClass *(const struct AVClass *)*
    				child_next	0x7ffff0a7a660 <format_child_next>	void *(void *, void *)*
    				class_name	"AVFormatContext"	char*
    				get_category	0x7ffff0a7a6c0 <get_category>	AVClassCategory (void *)*
    				item_name	0x7ffff0a7a820 <format_to_name>	const char *(void *)*
    				log_level_offset_offset	0	int
    				option	@0x7ffff0b6a100	struct AVOption
    					default_val	@0x7ffff0b6a118	union { ...}
    					flags	3	int
    					help	0x0	char*
    					max	2147483647	double
    					min	-2147483648	double
    					name	"avioflags"	char*
    					offset	1292	int
    					type	AV_OPT_TYPE_FLAGS (0)	enum AVOptionType
    					unit	"avioflags"	char*
    				parent_log_context_offset	0	int
    				query_ranges	0x0	int (struct AVOptionRanges **, void *, const char *, int)*
    				version	3679076	int
    			avio_flags	0	int
    			avoid_negative_ts	-1	int
    			bit_rate	0	int64_t
    			chapters	0x0	AVChapter**
    			codec_whitelist	0x0	char*
    			control_message_cb	0	av_format_control_message
    			correct_ts_overflow	1	unsigned int
    			ctx_flags	0	int
    			data_codec	0x0	AVCodec*
    			data_codec_id	AV_CODEC_ID_NONE (0)	enum AVCodecID
    			debug	0	int
    			dump_separator	44	uint8_t
    			duration	0	int64_t
    			duration_estimation_method	AVFMT_DURATION_FROM_PTS (0)	enum AVDurationEstimationMethod
    			error_recognition	1	int
    			event_flags	0	int
    			filename	"rtsp://172.0.8.21:9980/2/analysis
    			flags	2097152	int
    			flush_packets	-1	int
    			format_probesize	1048576	int
    			format_whitelist	0x0	char*
    			fps_probe_size	-1	int
    			iformat	@0x7ffff0b8b640	struct AVInputFormat
    				codec_tag	0x0	struct AVCodecTag**
    				create_device_capabilities	0x0	int (struct AVFormatContext *, struct AVDeviceCapabilitiesQuery *)*
    				extensions	0x0	char*
    				flags	1	int
    				free_device_capabilities	0x0	int (struct AVFormatContext *, struct AVDeviceCapabilitiesQuery *)*
    				get_device_list	0x0	int (struct AVFormatContext *, struct AVDeviceInfoList *)*
    				long_name	"RTSP input"	char*
    				mime_type	0x0	char*
    				name	"rtsp"	char*
    				next	@0x7ffff0b8b7e0	struct AVInputFormat
    				priv_class	@0x7ffff0b76f60	AVClass
    					category	AV_CLASS_CATEGORY_NA (0)	AVClassCategory
    					child_class_next	0x0	const struct AVClass *(const struct AVClass *)*
    					child_next	0x0	void *(void *, void *)*
    					class_name	"RTSP demuxer"	char*
    					get_category	0x0	AVClassCategory (void *)*
    					item_name	0x7fffef180650 <av_default_item_name>	const char *(void *)*
    					log_level_offset_offset	0	int
    					option	@0x7ffff0b6df80	struct AVOption
    					parent_log_context_offset	0	int
    					query_ranges	0x0	int (struct AVOptionRanges **, void *, const char *, int)*
    					version	3679076	int
    				priv_data_size	5928	int
    				raw_codec_id	0	int
    				read_close	0x7ffff0aa9a60 <rtsp_read_close>	int (struct AVFormatContext *)*
    				read_header	0x7ffff0aab600 <rtsp_read_header>	int (struct AVFormatContext *)*
    				read_packet	0x7ffff0aaa090 <rtsp_read_packet>	int (struct AVFormatContext *, AVPacket *)*
    				read_pause	0x7ffff0aa9600 <rtsp_read_pause>	int (struct AVFormatContext *)*
    				read_play	0x7ffff0aa96b0 <rtsp_read_play>	int (struct AVFormatContext *)*
    				read_probe	0x7ffff0aa9370 <rtsp_probe>	int (const AVProbeData *)*
    				read_seek	0x7ffff0aa99e0 <rtsp_read_seek>	int (struct AVFormatContext *, int, int64_t, int)*
    				read_seek2	0x0	int (struct AVFormatContext *, int, int64_t, int64_t, int64_t, int)*
    				read_timestamp	0x0	int64_t (struct AVFormatContext *, int, int64_t *, int64_t)*
    			internal	@0x7ffd68002ac0	AVFormatInternal
    				avoid_negative_ts_use_pts	0	int
    				data_offset	0	int64_t
    				id3v2_meta	0x0	AVDictionary*
    				initialized	0	int
    				inject_global_side_data	0	int
    				missing_ts_warning	0	int
    				nb_interleaved_streams	0	int
    				offset	-9223372036854775808	int64_t
    				offset_timebase	@0x7ffd68002b10	AVRational
    					den	0	int
    					num	0	int
    				packet_buffer	0x0	struct AVPacketList*
    				packet_buffer_end	0x0	struct AVPacketList*
    				parse_queue	0x0	struct AVPacketList*
    				parse_queue_end	0x0	struct AVPacketList*
    				prefer_codec_framerate	0	int
    				raw_packet_buffer	0x0	struct AVPacketList*
    				raw_packet_buffer_end	0x0	struct AVPacketList*
    				raw_packet_buffer_remaining_size	2500000	int
    				shortest_end	-9223372036854775808	int64_t
    				streams_initialized	0	int
    			interrupt_callback	@0x7ffd68003108	AVIOInterruptCB
    				callback	0x7ffff772d1d2 <flow::FFmpegCapture::interrupt_cb(void*)>	int (void *)*
    				opaque	0x555556afb510	void*
    			io_close	0x7ffff0a7a6e0 <io_close_default>	void (struct AVFormatContext *, AVIOContext *)*
    			io_open	0x7ffff0a7a6f0 <io_open_default>	int (struct AVFormatContext *, AVIOContext **, const char *, int, AVDictionary **)*
    			io_repositioned	0	int
    			key	0x0	uint8_t*
    			keylen	0	int
    			max_analyze_duration	0	int64_t
    			max_chunk_duration	0	int
    			max_chunk_size	0	int
    			max_delay	-1	int
    			max_index_size	1048576	unsigned int
    			max_interleave_delta	10000000	int64_t
    			max_picture_buffer	3041280	unsigned int
    			max_streams	1000	int
    			max_ts_probe	50	int
    			metadata	0x0	AVDictionary*
    			metadata_header_padding	-1	int
    			nb_chapters	0	unsigned int
    			nb_programs	0	unsigned int
    			nb_streams	0	unsigned int
    			oformat	0x0	struct AVOutputFormat*
    			opaque	0x0	void*
    			open_cb	0x0	int (struct AVFormatContext *, AVIOContext **, const char *, int, const AVIOInterruptCB *, AVDictionary **)*
    			output_ts_offset	0	int64_t
    			packet_size	0	unsigned int
    			pb	0x0	AVIOContext*
    			priv_data	0x0	void*
    			probe_score	0	int
    			probesize	5000000	int64_t
    			programs	0x0	AVProgram**
    			protocol_blacklist	0x0	char*
    			protocol_whitelist	0x0	char*
    			seek2any	0	int
    			skip_estimate_duration_from_pts	0	int
    			skip_initial_bytes	0	int64_t
    			start_time	0	int64_t
    			start_time_realtime	-9223372036854775808	int64_t
    			streams	0x0	AVStream**
    			strict_std_compliance	0	int
    			subtitle_codec	0x0	AVCodec*
    			subtitle_codec_id	AV_CODEC_ID_NONE (0)	enum AVCodecID
    			ts_id	0	int
    			url	"rtsp://172.0.8.21:9980/2/analysis"	char*
    			use_wallclock_as_timestamps	0	int
    			video_codec	0x0	AVCodec*
    			video_codec_id	AV_CODEC_ID_NONE (0)	enum AVCodecID
    		tmp	@0x7ffd68001440	AVDictionary

这里是其中AVFormatContext --> priv\_data

/** * Private data for the RTSP demuxer. * * @todo Use AVIOContext instead of URLContext */
    enum RTSPServerType { 
        RTSP_SERVER_RTP,  /**< Standards-compliant RTP-server */
        RTSP_SERVER_REAL, /**< Realmedia-style server */
        RTSP_SERVER_WMS,  /**< Windows Media server */
        RTSP_SERVER_NB
    };
    
    /** * Private data for the RTSP demuxer. * * @todo Use AVIOContext instead of URLContext */
    typedef struct RTSPState { 
        const AVClass *class;             /**< Class for private options. */
        URLContext *rtsp_hd; /* RTSP TCP connection handle */
    
        /** number of items in the 'rtsp_streams' variable */
        int nb_rtsp_streams;
    
        struct RTSPStream **rtsp_streams; /**< streams in this session */
    
        /** indicator of whether we are currently receiving data from the * server. Basically this isn't more than a simple cache of the * last PLAY/PAUSE command sent to the server, to make sure we don't * send 2x the same unexpectedly or commands in the wrong state. */
        enum RTSPClientState state;
    
        /** the seek value requested when calling av_seek_frame(). This value * is subsequently used as part of the "Range" parameter when emitting * the RTSP PLAY command. If we are currently playing, this command is * called instantly. If we are currently paused, this command is called * whenever we resume playback. Either way, the value is only used once, * see rtsp_read_play() and rtsp_read_seek(). */
        int64_t seek_timestamp;
    
        int seq;                          /**< RTSP command sequence number */
    
        /** copy of RTSPMessageHeader->session_id, i.e. the server-provided session * identifier that the client should re-transmit in each RTSP command */
        char session_id[512];
    
        /** copy of RTSPMessageHeader->timeout, i.e. the time (in seconds) that * the server will go without traffic on the RTSP/TCP line before it * closes the connection. */
        int timeout;
    
        /** timestamp of the last RTSP command that we sent to the RTSP server. * This is used to calculate when to send dummy commands to keep the * connection alive, in conjunction with timeout. */
        int64_t last_cmd_time;
    
        /** the negotiated data/packet transport protocol; e.g. RTP or RDT */
        enum RTSPTransport transport;
    
        /** the negotiated network layer transport protocol; e.g. TCP or UDP * uni-/multicast */
        enum RTSPLowerTransport lower_transport;
    
        /** brand of server that we're talking to; e.g. WMS, REAL or other. * Detected based on the value of RTSPMessageHeader->server or the presence * of RTSPMessageHeader->real_challenge */
        enum RTSPServerType server_type;
    
        /** the "RealChallenge1:" field from the server */
        char real_challenge[64];
    
        /** plaintext authorization line (username:password) */
        char auth[128];
    
        /** authentication state */
        HTTPAuthState auth_state;
    
        /** The last reply of the server to a RTSP command */
        char last_reply[2048]; /* XXX: allocate ? */
    
        /** RTSPStream->transport_priv of the last stream that we read a * packet from */
        void *cur_transport_priv;
    
        /** The following are used for Real stream selection */
        //@{ 
        /** whether we need to send a "SET_PARAMETER Subscribe:" command */
        int need_subscription;
    
        /** stream setup during the last frame read. This is used to detect if * we need to subscribe or unsubscribe to any new streams. */
        enum AVDiscard *real_setup_cache;
    
        /** current stream setup. This is a temporary buffer used to compare * current setup to previous frame setup. */
        enum AVDiscard *real_setup;
    
        /** the last value of the "SET_PARAMETER Subscribe:" RTSP command. * this is used to send the same "Unsubscribe:" if stream setup changed, * before sending a new "Subscribe:" command. */
        char last_subscription[1024];
        //@}
    
        /** The following are used for RTP/ASF streams */
        //@{ 
        /** ASF demuxer context for the embedded ASF stream from WMS servers */
        AVFormatContext *asf_ctx;
    
        /** cache for position of the asf demuxer, since we load a new * data packet in the bytecontext for each incoming RTSP packet. */
        uint64_t asf_pb_pos;
        //@}
    
        /** some MS RTSP streams contain a URL in the SDP that we need to use * for all subsequent RTSP requests, rather than the input URI; in * other cases, this is a copy of AVFormatContext->filename. */
        char control_uri[1024];
    
        /** The following are used for parsing raw mpegts in udp */
        //@{ 
        struct MpegTSContext *ts;
        int recvbuf_pos;
        int recvbuf_len;
        //@}
    
        /** Additional output handle, used when input and output are done * separately, eg for HTTP tunneling. */
        URLContext *rtsp_hd_out;
    
        /** RTSP transport mode, such as plain or tunneled. */
        enum RTSPControlTransport control_transport;
    
        /* Number of RTCP BYE packets the RTSP session has received. * An EOF is propagated back if nb_byes == nb_streams. * This is reset after a seek. */
        int nb_byes;
    
        /** Reusable buffer for receiving packets */
        uint8_t* recvbuf;
    
        /** * A mask with all requested transport methods */
        int lower_transport_mask;
    
        /** * The number of returned packets */
        uint64_t packets;
    
        /** * Polling array for udp */
        struct pollfd *p;
        int max_p;
    
        /** * Whether the server supports the GET_PARAMETER method. */
        int get_parameter_supported;
    
        /** * Do not begin to play the stream immediately. */
        int initial_pause;
    
        /** * Option flags for the chained RTP muxer. */
        int rtp_muxer_flags;
    
        /** Whether the server accepts the x-Dynamic-Rate header */
        int accept_dynamic_rate;
    
        /** * Various option flags for the RTSP muxer/demuxer. */
        int rtsp_flags;
    
        /** * Mask of all requested media types */
        int media_type_mask;
    
        /** * Minimum and maximum local UDP ports. */
        int rtp_port_min, rtp_port_max;
    
        /** * Timeout to wait for incoming connections. */
        int initial_timeout;
    
        /** * timeout of socket i/o operations. */
        int stimeout;
    
        /** * Size of RTP packet reordering queue. */
        int reordering_queue_size;
    
        /** * User-Agent string */
        char *user_agent;
    
        char default_lang[4];
        int buffer_size;
        int pkt_size;
    } RTSPState;

Locals		
    		ret	<optimized out>	
    		rt	@0x7ffd640032c0	RTSPState
    			accept_dynamic_rate	0	int
    			asf_ctx	0x0	AVFormatContext*
    			asf_pb_pos	0	uint64_t
    			auth	"\000\000\000\000"... (128)	char[128]
    			auth_state	@0x7ffd640035cc	HTTPAuthState
    			buffer_size	-1	int
    			class	@0x7ffff0b76f60	AVClass
    			control_transport	RTSP_MODE_PLAIN (0)	enum RTSPControlTransport
    			control_uri	"\000\000\000"... (1024)	char[1024]
    			cur_transport_priv	0x0	void*
    			default_lang	"\000\000\000\000"	char[4]
    			get_parameter_supported	0	int
    			initial_pause	0	int
    			initial_timeout	-1	int
    			last_cmd_time	0	int64_t
    			last_reply	"\000\000\000\... (2048)	char[2048]
    			last_subscription	"\000\00"... (1024)	char[1024]
    			lower_transport	RTSP_LOWER_TRANSPORT_UDP (0)	enum RTSPLowerTransport
    			lower_transport_mask	2	int
    			max_p	0	int
    			media_type_mask	15	int
    			nb_byes	0	int
    			nb_rtsp_streams	0	int
    			need_subscription	0	int
    			p	0x0	struct pollfd*
    			packets	0	uint64_t
    			pkt_size	-1	int
    			real_challenge	"\000\000\000"	char[64]
    			real_setup	0x0	enum AVDiscard*
    			real_setup_cache	0x0	enum AVDiscard*
    			recvbuf	0x0	uint8_t*
    			recvbuf_len	0	int
    			recvbuf_pos	0	int
    			reordering_queue_size	-1	int
    			rtp_muxer_flags	0	int
    			rtp_port_max	65000	int
    			rtp_port_min	5000	int
    			rtsp_flags	0	int
    			//这两个结构体在后面网络结构中用
    			rtsp_hd	0x0	URLContext*
    			rtsp_hd_out	0x0	URLContext*
    			rtsp_streams	0x0	struct RTSPStream**
    			seek_timestamp	0	int64_t
    			seq	0	int
    			server_type	RTSP_SERVER_RTP (0)	enum RTSPServerType
    			session_id	"\"
    			state	RTSP_STATE_IDLE (0)	enum RTSPClientState
    			stimeout	0	int
    			timeout	0	int
    			transport	RTSP_TRANSPORT_RTP (0)	enum RTSPTransport
    			ts	0x0	struct MpegTSContext*
    			user_agent	"Lavf58.32.104"	char*
    		s	@0x7ffd64002c40	AVFormatContext
    			audio_codec	0x0	AVCodec*
    			audio_codec_id	AV_CODEC_ID_NONE (0)	enum AVCodecID
    			audio_preload	0	int
    			av_class	@0x7ffff0b6a0a0	AVClass
    			avio_flags	0	int
    			avoid_negative_ts	-1	int
    			bit_rate	0	int64_t
    			chapters	0x0	AVChapter**
    			codec_whitelist	0x0	char*
    			control_message_cb	0	av_format_control_message
    			correct_ts_overflow	1	unsigned int
    			ctx_flags	0	int
    			data_codec	0x0	AVCodec*
    			data_codec_id	AV_CODEC_ID_NONE (0)	enum AVCodecID
    			debug	0	int
    			dump_separator	44	uint8_t
    			duration	-9223372036854775808	int64_t
    			duration_estimation_method	AVFMT_DURATION_FROM_PTS (0)	enum AVDurationEstimationMethod
    			error_recognition	1	int
    			event_flags	0	int
    			filename	"rtsp://172.0.8.21:9980/2/analysis\
    			flags	2097152	int
    			flush_packets	-1	int
    			format_probesize	1048576	int
    			format_whitelist	0x0	char*
    			fps_probe_size	-1	int
    			iformat	@0x7ffff0b8b640	struct AVInputFormat
    			internal	@0x7ffd64002ac0	AVFormatInternal
    			interrupt_callback	@0x7ffd64003108	AVIOInterruptCB
    			io_close	0x7ffff0a7a6e0 <io_close_default>	void (struct AVFormatContext *, AVIOContext *)*
    			io_open	0x7ffff0a7a6f0 <io_open_default>	int (struct AVFormatContext *, AVIOContext **, const char *, int, AVDictionary **)*
    			io_repositioned	0	int
    			key	0x0	uint8_t*
    			keylen	0	int
    			max_analyze_duration	0	int64_t
    			max_chunk_duration	0	int
    			max_chunk_size	0	int
    			max_delay	-1	int
    			max_index_size	1048576	unsigned int
    			max_interleave_delta	10000000	int64_t
    			max_picture_buffer	3041280	unsigned int
    			max_streams	1000	int
    			max_ts_probe	50	int
    			metadata	0x0	AVDictionary*
    			metadata_header_padding	-1	int
    			nb_chapters	0	unsigned int
    			nb_programs	0	unsigned int
    			nb_streams	0	unsigned int
    			oformat	0x0	struct AVOutputFormat*
    			opaque	0x0	void*
    			open_cb	0x0	int (struct AVFormatContext *, AVIOContext **, const char *, int, const AVIOInterruptCB *, AVDictionary **)*
    			output_ts_offset	0	int64_t
    			packet_size	0	unsigned int
    			pb	0x0	AVIOContext*
    			priv_data	0x7ffd640032c0	void*
    			probe_score	100	int
    			probesize	5000000	int64_t
    			programs	0x0	AVProgram**
    			protocol_blacklist	0x0	char*
    			protocol_whitelist	0x0	char*
    			seek2any	0	int
    			skip_estimate_duration_from_pts	0	int
    			skip_initial_bytes	0	int64_t
    			start_time	-9223372036854775808	int64_t
    			start_time_realtime	-9223372036854775808	int64_t
    			streams	0x0	AVStream**
    			strict_std_compliance	0	int
    			subtitle_codec	0x0	AVCodec*
    			subtitle_codec_id	AV_CODEC_ID_NONE (0)	enum AVCodecID
    			ts_id	0	int
    			url	"rtsp://172.0.8.21:9980/2/analysis"	char*
    			use_wallclock_as_timestamps	0	int
    			video_codec	0x0	AVCodec*
    			video_codec_id	AV_CODEC_ID_NONE (0)	enum AVCodecID