PeerStreamer

/*

 * RTMP packet utilities

 * Copyright (c) 2009 Kostya Shishkov

 *

 * This file is part of Libav.

 *

 * Libav 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.

 *

 * Libav 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 Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#ifndef AVFORMAT_RTMPPKT_H

#define AVFORMAT_RTMPPKT_H

#include "avformat.h"

/** maximum possible number of different RTMP channels */

#define RTMP_CHANNELS 65599

/**

 * channels used to for RTMP packets with different purposes (i.e. data, network

 * control, remote procedure calls, etc.)

 */

enum RTMPChannel {

    RTMP_NETWORK_CHANNEL = 2,   ///< channel for network-related messages (bandwidth report, ping, etc)

    RTMP_SYSTEM_CHANNEL,        ///< channel for sending server control messages

    RTMP_SOURCE_CHANNEL,        ///< channel for sending a/v to server

    RTMP_VIDEO_CHANNEL = 8,     ///< channel for video data

    RTMP_AUDIO_CHANNEL,         ///< channel for audio data

};

/**

 * known RTMP packet types

 */

typedef enum RTMPPacketType {

    RTMP_PT_CHUNK_SIZE   =  1,  ///< chunk size change

    RTMP_PT_BYTES_READ   =  3,  ///< number of bytes read

    RTMP_PT_PING,               ///< ping

    RTMP_PT_SERVER_BW,          ///< server bandwidth

    RTMP_PT_CLIENT_BW,          ///< client bandwidth

    RTMP_PT_AUDIO        =  8,  ///< audio packet

    RTMP_PT_VIDEO,              ///< video packet

    RTMP_PT_FLEX_STREAM  = 15,  ///< Flex shared stream

    RTMP_PT_FLEX_OBJECT,        ///< Flex shared object

    RTMP_PT_FLEX_MESSAGE,       ///< Flex shared message

    RTMP_PT_NOTIFY,             ///< some notification

    RTMP_PT_SHARED_OBJ,         ///< shared object

    RTMP_PT_INVOKE,             ///< invoke some stream action

    RTMP_PT_METADATA     = 22,  ///< FLV metadata

} RTMPPacketType;

/**

 * possible RTMP packet header sizes

 */

enum RTMPPacketSize {

    RTMP_PS_TWELVEBYTES = 0, ///< packet has 12-byte header

    RTMP_PS_EIGHTBYTES,      ///< packet has 8-byte header

    RTMP_PS_FOURBYTES,       ///< packet has 4-byte header

    RTMP_PS_ONEBYTE          ///< packet is really a next chunk of a packet

};

/**

 * structure for holding RTMP packets

 */

typedef struct RTMPPacket {

    int            channel_id; ///< RTMP channel ID (nothing to do with audio/video channels though)

    RTMPPacketType type;       ///< packet payload type

    uint32_t       timestamp;  ///< packet full timestamp

    uint32_t       ts_delta;   ///< timestamp increment to the previous one in milliseconds (latter only for media packets)

    uint32_t       extra;      ///< probably an additional channel ID used during streaming data

    uint8_t        *data;      ///< packet payload

    int            data_size;  ///< packet payload size

} RTMPPacket;

/**

 * Create new RTMP packet with given attributes.

 *

 * @param pkt        packet

 * @param channel_id packet channel ID

 * @param type       packet type

 * @param timestamp  packet timestamp

 * @param size       packet size

 * @return zero on success, negative value otherwise

 */

int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,

                          int timestamp, int size);

/**

 * Free RTMP packet.

 *

 * @param pkt packet

 */

void ff_rtmp_packet_destroy(RTMPPacket *pkt);

/**

 * Read RTMP packet sent by the server.

 *

 * @param h          reader context

 * @param p          packet

 * @param chunk_size current chunk size

 * @param prev_pkt   previously read packet headers for all channels

 *                   (may be needed for restoring incomplete packet header)

 * @return number of bytes read on success, negative value otherwise

 */

int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,

                        int chunk_size, RTMPPacket *prev_pkt);

/**

 * Send RTMP packet to the server.

 *

 * @param h          reader context

 * @param p          packet to send

 * @param chunk_size current chunk size

 * @param prev_pkt   previously sent packet headers for all channels

 *                   (may be used for packet header compressing)

 * @return number of bytes written on success, negative value otherwise

 */

int ff_rtmp_packet_write(URLContext *h, RTMPPacket *p,

                         int chunk_size, RTMPPacket *prev_pkt);

/**

 * Print information and contents of RTMP packet.

 *

 * @param ctx        output context

 * @param p          packet to dump

 */

void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p);

/**

 * @defgroup amffuncs functions used to work with AMF format (which is also used in .flv)

 * @see amf_* funcs in libavformat/flvdec.c

 * @{

 */

/**

 * Calculate number of bytes taken by first AMF entry in data.

 *

 * @param data input data

 * @param data_end input buffer end

 * @return number of bytes used by first AMF entry

 */

int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end);

/**

 * Retrieve value of given AMF object field in string form.

 *

 * @param data     AMF object data

 * @param data_end input buffer end

 * @param name     name of field to retrieve

 * @param dst      buffer for storing result

 * @param dst_size output buffer size

 * @return 0 if search and retrieval succeeded, negative value otherwise

 */

int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,

                           const uint8_t *name, uint8_t *dst, int dst_size);

/**

 * Write boolean value in AMF format to buffer.

 *

 * @param dst pointer to the input buffer (will be modified)

 * @param val value to write

 */

void ff_amf_write_bool(uint8_t **dst, int val);

/**

 * Write number in AMF format to buffer.

 *

 * @param dst pointer to the input buffer (will be modified)

 * @param num value to write

 */

void ff_amf_write_number(uint8_t **dst, double num);

/**

 * Write string in AMF format to buffer.

 *

 * @param dst pointer to the input buffer (will be modified)

 * @param str string to write

 */

void ff_amf_write_string(uint8_t **dst, const char *str);

/**

 * Write AMF NULL value to buffer.

 *

 * @param dst pointer to the input buffer (will be modified)

 */

void ff_amf_write_null(uint8_t **dst);

/**

 * Write marker for AMF object to buffer.

 *

 * @param dst pointer to the input buffer (will be modified)

 */

void ff_amf_write_object_start(uint8_t **dst);

/**

 * Write string used as field name in AMF object to buffer.

 *

 * @param dst pointer to the input buffer (will be modified)

 * @param str string to write

 */

void ff_amf_write_field_name(uint8_t **dst, const char *str);

/**

 * Write marker for end of AMF object to buffer.

 *

 * @param dst pointer to the input buffer (will be modified)

 */

void ff_amf_write_object_end(uint8_t **dst);

/** @} */ // AMF funcs

#endif /* AVFORMAT_RTMPPKT_H */