libavformat/rtmppkt.c

   1 /*
   2  * RTMP input format
   3  * Copyright (c) 2009 Kostya Shishkov
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavcodec/bytestream.h"
  23 #include "libavutil/avstring.h"
  24 #include "avformat.h"
  25
  26 #include "rtmppkt.h"
  27 #include "flv.h"
  28
  29 void ff_amf_write_bool(uint8_t **dst, int val)
  30 {
  31     bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
  32     bytestream_put_byte(dst, val);
  33 }
  34
  35 void ff_amf_write_number(uint8_t **dst, double val)
  36 {
  37     bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
  38     bytestream_put_be64(dst, av_dbl2int(val));
  39 }
  40
  41 void ff_amf_write_string(uint8_t **dst, const char *str)
  42 {
  43     bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
  44     bytestream_put_be16(dst, strlen(str));
  45     bytestream_put_buffer(dst, str, strlen(str));
  46 }
  47
  48 void ff_amf_write_null(uint8_t **dst)
  49 {
  50     bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
  51 }
  52
  53 void ff_amf_write_object_start(uint8_t **dst)
  54 {
  55     bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
  56 }
  57
  58 void ff_amf_write_field_name(uint8_t **dst, const char *str)
  59 {
  60     bytestream_put_be16(dst, strlen(str));
  61     bytestream_put_buffer(dst, str, strlen(str));
  62 }
  63
  64 void ff_amf_write_object_end(uint8_t **dst)
  65 {
  66     /* first two bytes are field name length = 0,
  67      * AMF object should end with it and end marker
  68      */
  69     bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
  70 }
  71
  72 int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
  73                         int chunk_size, RTMPPacket *prev_pkt)
  74 {
  75     uint8_t hdr, t, buf[16];
  76     int channel_id, timestamp, data_size, offset = 0;
  77     uint32_t extra = 0;
  78     uint8_t type;
  79
  80     if (url_read(h, &hdr, 1) != 1)
  81         return AVERROR(EIO);
  82     channel_id = hdr & 0x3F;
  83
  84     data_size = prev_pkt[channel_id].data_size;
  85     type      = prev_pkt[channel_id].type;
  86     extra     = prev_pkt[channel_id].extra;
  87
  88     hdr >>= 6;
  89     if (hdr == RTMP_PS_ONEBYTE) {
  90         //todo
  91         return -1;
  92     } else {
  93         if (url_read_complete(h, buf, 3) != 3)
  94             return AVERROR(EIO);
  95         timestamp = AV_RB24(buf);
  96         if (hdr != RTMP_PS_FOURBYTES) {
  97             if (url_read_complete(h, buf, 3) != 3)
  98                 return AVERROR(EIO);
  99             data_size = AV_RB24(buf);
 100             if (url_read_complete(h, &type, 1) != 1)
 101                 return AVERROR(EIO);
 102             if (hdr == RTMP_PS_TWELVEBYTES) {
 103                 if (url_read_complete(h, buf, 4) != 4)
 104                     return AVERROR(EIO);
 105                 extra = AV_RL32(buf);
 106             }
 107         }
 108     }
 109     if (ff_rtmp_packet_create(p, channel_id, type, timestamp, data_size))
 110         return -1;
 111     p->extra = extra;
 112     // save history
 113     prev_pkt[channel_id].channel_id = channel_id;
 114     prev_pkt[channel_id].type       = type;
 115     prev_pkt[channel_id].data_size  = data_size;
 116     prev_pkt[channel_id].timestamp  = timestamp;
 117     prev_pkt[channel_id].extra      = extra;
 118     while (data_size > 0) {
 119         int toread = FFMIN(data_size, chunk_size);
 120         if (url_read_complete(h, p->data + offset, toread) != toread) {
 121             ff_rtmp_packet_destroy(p);
 122             return AVERROR(EIO);
 123         }
 124         data_size -= chunk_size;
 125         offset    += chunk_size;
 126         if (data_size > 0) {
 127             url_read_complete(h, &t, 1); //marker
 128             if (t != (0xC0 + channel_id))
 129                 return -1;
 130         }
 131     }
 132     return 0;
 133 }
 134
 135 int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
 136                          int chunk_size, RTMPPacket *prev_pkt)
 137 {
 138     uint8_t pkt_hdr[16], *p = pkt_hdr;
 139     int mode = RTMP_PS_TWELVEBYTES;
 140     int off = 0;
 141
 142     //TODO: header compression
 143     bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
 144     if (mode != RTMP_PS_ONEBYTE) {
 145         bytestream_put_be24(&p, pkt->timestamp);
 146         if (mode != RTMP_PS_FOURBYTES) {
 147             bytestream_put_be24(&p, pkt->data_size);
 148             bytestream_put_byte(&p, pkt->type);
 149             if (mode == RTMP_PS_TWELVEBYTES)
 150                 bytestream_put_le32(&p, pkt->extra);
 151         }
 152     }
 153     url_write(h, pkt_hdr, p-pkt_hdr);
 154     while (off < pkt->data_size) {
 155         int towrite = FFMIN(chunk_size, pkt->data_size - off);
 156         url_write(h, pkt->data + off, towrite);
 157         off += towrite;
 158         if (off < pkt->data_size) {
 159             uint8_t marker = 0xC0 | pkt->channel_id;
 160             url_write(h, &marker, 1);
 161         }
 162     }
 163     return 0;
 164 }
 165
 166 int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
 167                           int timestamp, int size)
 168 {
 169     pkt->data = av_malloc(size);
 170     if (!pkt->data)
 171         return AVERROR(ENOMEM);
 172     pkt->data_size  = size;
 173     pkt->channel_id = channel_id;
 174     pkt->type       = type;
 175     pkt->timestamp  = timestamp;
 176     pkt->extra      = 0;
 177
 178     return 0;
 179 }
 180
 181 void ff_rtmp_packet_destroy(RTMPPacket *pkt)
 182 {
 183     if (!pkt)
 184         return;
 185     av_freep(&pkt->data);
 186     pkt->data_size = 0;
 187 }
 188
 189 int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
 190 {
 191     const uint8_t *base = data;
 192
 193     if (data >= data_end)
 194         return -1;
 195     switch (*data++) {
 196     case AMF_DATA_TYPE_NUMBER:      return 9;
 197     case AMF_DATA_TYPE_BOOL:        return 2;
 198     case AMF_DATA_TYPE_STRING:      return 3 + AV_RB16(data);
 199     case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
 200     case AMF_DATA_TYPE_NULL:        return 1;
 201     case AMF_DATA_TYPE_ARRAY:
 202         data += 4;
 203     case AMF_DATA_TYPE_OBJECT:
 204         for (;;) {
 205             int size = bytestream_get_be16(&data);
 206             int t;
 207             if (!size) {
 208                 data++;
 209                 break;
 210             }
 211             if (data + size >= data_end || data + size < data)
 212                 return -1;
 213             data += size;
 214             t = ff_amf_tag_size(data, data_end);
 215             if (t < 0 || data + t >= data_end)
 216                 return -1;
 217             data += t;
 218         }
 219         return data - base;
 220     case AMF_DATA_TYPE_OBJECT_END:  return 1;
 221     default:                        return -1;
 222     }
 223 }
 224
 225 int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
 226                            const uint8_t *name, uint8_t *dst, int dst_size)
 227 {
 228     int namelen = strlen(name);
 229     int len;
 230
 231     if (data_end - data < 3)
 232         return -1;
 233     if (*data++ != AMF_DATA_TYPE_OBJECT)
 234         return -1;
 235     for (;;) {
 236         int size = bytestream_get_be16(&data);
 237         if (!size)
 238             break;
 239         if (data + size >= data_end || data + size < data)
 240             return -1;
 241         data += size;
 242         if (size == namelen && !memcmp(data-size, name, namelen)) {
 243             switch (*data++) {
 244             case AMF_DATA_TYPE_NUMBER:
 245                 snprintf(dst, dst_size, "%g", av_int2dbl(AV_RB64(data)));
 246                 break;
 247             case AMF_DATA_TYPE_BOOL:
 248                 snprintf(dst, dst_size, "%s", *data ? "true" : "false");
 249                 break;
 250             case AMF_DATA_TYPE_STRING:
 251                 len = bytestream_get_be16(&data);
 252                 av_strlcpy(dst, data, FFMIN(len+1, dst_size));
 253                 break;
 254             default:
 255                 return -1;
 256             }
 257             return 0;
 258         }
 259         len = ff_amf_tag_size(data, data_end);
 260         if (len < 0 || data + len >= data_end || data + len < data)
 261             return -1;
 262         data += len;
 263     }
 264     return -1;
 265 }