PeerStreamer

/*

 * RTMP input format

 * Copyright (c) 2009 Kostya Shishkov

 *

 * 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

 */

#include "libavcodec/bytestream.h"

#include "libavutil/avstring.h"

#include "avformat.h"

#include "rtmppkt.h"

#include "flv.h"

void ff_amf_write_bool(uint8_t **dst, int val)

{

    bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);

    bytestream_put_byte(dst, val);

}

void ff_amf_write_number(uint8_t **dst, double val)

{

    bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);

    bytestream_put_be64(dst, av_dbl2int(val));

}

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

{

    bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);

    bytestream_put_be16(dst, strlen(str));

    bytestream_put_buffer(dst, str, strlen(str));

}

void ff_amf_write_null(uint8_t **dst)

{

    bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);

}

void ff_amf_write_object_start(uint8_t **dst)

{

    bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);

}

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

{

    bytestream_put_be16(dst, strlen(str));

    bytestream_put_buffer(dst, str, strlen(str));

}

void ff_amf_write_object_end(uint8_t **dst)

{

    /* first two bytes are field name length = 0,

     * AMF object should end with it and end marker

     */

    bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);

}

int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,

                        int chunk_size, RTMPPacket *prev_pkt)

{

    uint8_t hdr, t, buf[16];

    int channel_id, timestamp, data_size, offset = 0;

    uint32_t extra = 0;

    enum RTMPPacketType type;

    if (url_read(h, &hdr, 1) != 1)

        return AVERROR(EIO);

    channel_id = hdr & 0x3F;

    if (channel_id < 2) { //special case for channel number >= 64

        buf[1] = 0;

        if (url_read_complete(h, buf, channel_id + 1) != channel_id + 1)

            return AVERROR(EIO);

        channel_id = AV_RL16(buf) + 64;

    }

    data_size = prev_pkt[channel_id].data_size;

    type      = prev_pkt[channel_id].type;

    extra     = prev_pkt[channel_id].extra;

    hdr >>= 6;

    if (hdr == RTMP_PS_ONEBYTE) {

        timestamp = prev_pkt[channel_id].timestamp;

    } else {

        if (url_read_complete(h, buf, 3) != 3)

            return AVERROR(EIO);

        timestamp = AV_RB24(buf);

        if (hdr != RTMP_PS_FOURBYTES) {

            if (url_read_complete(h, buf, 3) != 3)

                return AVERROR(EIO);

            data_size = AV_RB24(buf);

            if (url_read_complete(h, buf, 1) != 1)

                return AVERROR(EIO);

            type = buf[0];

            if (hdr == RTMP_PS_TWELVEBYTES) {

                if (url_read_complete(h, buf, 4) != 4)

                    return AVERROR(EIO);

                extra = AV_RL32(buf);

            }

        }

        if (timestamp == 0xFFFFFF) {

            if (url_read_complete(h, buf, 4) != 4)

                return AVERROR(EIO);

            timestamp = AV_RB32(buf);

        }

    }

    if (ff_rtmp_packet_create(p, channel_id, type, timestamp, data_size))

        return -1;

    p->extra = extra;

    // save history

    prev_pkt[channel_id].channel_id = channel_id;

    prev_pkt[channel_id].type       = type;

    prev_pkt[channel_id].data_size  = data_size;

    prev_pkt[channel_id].timestamp  = timestamp;

    prev_pkt[channel_id].extra      = extra;

    while (data_size > 0) {

        int toread = FFMIN(data_size, chunk_size);

        if (url_read_complete(h, p->data + offset, toread) != toread) {

            ff_rtmp_packet_destroy(p);

            return AVERROR(EIO);

        }

        data_size -= chunk_size;

        offset    += chunk_size;

        if (data_size > 0) {

            url_read_complete(h, &t, 1); //marker

            if (t != (0xC0 + channel_id))

                return -1;

        }

    }

    return 0;

}

int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,

                         int chunk_size, RTMPPacket *prev_pkt)

{

    uint8_t pkt_hdr[16], *p = pkt_hdr;

    int mode = RTMP_PS_TWELVEBYTES;

    int off = 0;

    //TODO: header compression

    bytestream_put_byte(&p, pkt->channel_id | (mode << 6));

    if (mode != RTMP_PS_ONEBYTE) {

        bytestream_put_be24(&p, pkt->timestamp >= 0xFFFFFF ? 0xFFFFFF : pkt->timestamp);

        if (mode != RTMP_PS_FOURBYTES) {

            bytestream_put_be24(&p, pkt->data_size);

            bytestream_put_byte(&p, pkt->type);

            if (mode == RTMP_PS_TWELVEBYTES)

                bytestream_put_le32(&p, pkt->extra);

        }

        if (pkt->timestamp >= 0xFFFFFF)

            bytestream_put_be32(&p, pkt->timestamp);

    }

    url_write(h, pkt_hdr, p-pkt_hdr);

    while (off < pkt->data_size) {

        int towrite = FFMIN(chunk_size, pkt->data_size - off);

        url_write(h, pkt->data + off, towrite);

        off += towrite;

        if (off < pkt->data_size) {

            uint8_t marker = 0xC0 | pkt->channel_id;

            url_write(h, &marker, 1);

        }

    }

    return 0;

}

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

                          int timestamp, int size)

{

    pkt->data = av_malloc(size);

    if (!pkt->data)

        return AVERROR(ENOMEM);

    pkt->data_size  = size;

    pkt->channel_id = channel_id;

    pkt->type       = type;

    pkt->timestamp  = timestamp;

    pkt->extra      = 0;

    return 0;

}

void ff_rtmp_packet_destroy(RTMPPacket *pkt)

{

    if (!pkt)

        return;

    av_freep(&pkt->data);

    pkt->data_size = 0;

}

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

{

    const uint8_t *base = data;

    if (data >= data_end)

        return -1;

    switch (*data++) {

    case AMF_DATA_TYPE_NUMBER:      return 9;

    case AMF_DATA_TYPE_BOOL:        return 2;

    case AMF_DATA_TYPE_STRING:      return 3 + AV_RB16(data);

    case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);

    case AMF_DATA_TYPE_NULL:        return 1;

    case AMF_DATA_TYPE_ARRAY:

        data += 4;

    case AMF_DATA_TYPE_OBJECT:

        for (;;) {

            int size = bytestream_get_be16(&data);

            int t;

            if (!size) {

                data++;

                break;

            }

            if (data + size >= data_end || data + size < data)

                return -1;

            data += size;

            t = ff_amf_tag_size(data, data_end);

            if (t < 0 || data + t >= data_end)

                return -1;

            data += t;

        }

        return data - base;

    case AMF_DATA_TYPE_OBJECT_END:  return 1;

    default:                        return -1;

    }

}

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)

{

    int namelen = strlen(name);

    int len;

    while (*data != AMF_DATA_TYPE_OBJECT && data < data_end) {

        len = ff_amf_tag_size(data, data_end);

        if (len < 0)

            len = data_end - data;

        data += len;

    }

    if (data_end - data < 3)

        return -1;

    data++;

    for (;;) {

        int size = bytestream_get_be16(&data);

        if (!size)

            break;

        if (data + size >= data_end || data + size < data)

            return -1;

        data += size;

        if (size == namelen && !memcmp(data-size, name, namelen)) {

            switch (*data++) {

            case AMF_DATA_TYPE_NUMBER:

                snprintf(dst, dst_size, "%g", av_int2dbl(AV_RB64(data)));

                break;

            case AMF_DATA_TYPE_BOOL:

                snprintf(dst, dst_size, "%s", *data ? "true" : "false");

                break;

            case AMF_DATA_TYPE_STRING:

                len = bytestream_get_be16(&data);

                av_strlcpy(dst, data, FFMIN(len+1, dst_size));

                break;

            default:

                return -1;

            }

            return 0;

        }

        len = ff_amf_tag_size(data, data_end);

        if (len < 0 || data + len >= data_end || data + len < data)

            return -1;

        data += len;

    }

    return -1;

}