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     enum RTMPPacketType type;
  79
  80     if (url_read(h, &hdr, 1) != 1)
  81         return AVERROR(EIO);
  82     channel_id = hdr & 0x3F;
  83
  84     if (channel_id < 2) { //special case for channel number >= 64
  85         buf[1] = 0;
  86         if (url_read_complete(h, buf, channel_id + 1) != channel_id + 1)
  87             return AVERROR(EIO);
  88         channel_id = AV_RL16(buf) + 64;
  89     }
  90     data_size = prev_pkt[channel_id].data_size;
  91     type      = prev_pkt[channel_id].type;
  92     extra     = prev_pkt[channel_id].extra;
  93
  94     hdr >>= 6;
  95     if (hdr == RTMP_PS_ONEBYTE) {
  96         timestamp = prev_pkt[channel_id].timestamp;
  97     } else {
  98         if (url_read_complete(h, buf, 3) != 3)
  99             return AVERROR(EIO);
 100         timestamp = AV_RB24(buf);
 101         if (hdr != RTMP_PS_FOURBYTES) {
 102             if (url_read_complete(h, buf, 3) != 3)
 103                 return AVERROR(EIO);
 104             data_size = AV_RB24(buf);
 105             if (url_read_complete(h, &type, 1) != 1)
 106                 return AVERROR(EIO);
 107             if (hdr == RTMP_PS_TWELVEBYTES) {
 108                 if (url_read_complete(h, buf, 4) != 4)
 109                     return AVERROR(EIO);
 110                 extra = AV_RL32(buf);
 111             }
 112         }
 113     }
 114     if (ff_rtmp_packet_create(p, channel_id, type, timestamp, data_size))
 115         return -1;
 116     p->extra = extra;
 117     // save history
 118     prev_pkt[channel_id].channel_id = channel_id;
 119     prev_pkt[channel_id].type       = type;
 120     prev_pkt[channel_id].data_size  = data_size;
 121     prev_pkt[channel_id].timestamp  = timestamp;
 122     prev_pkt[channel_id].extra      = extra;
 123     while (data_size > 0) {
 124         int toread = FFMIN(data_size, chunk_size);
 125         if (url_read_complete(h, p->data + offset, toread) != toread) {
 126             ff_rtmp_packet_destroy(p);
 127             return AVERROR(EIO);
 128         }
 129         data_size -= chunk_size;
 130         offset    += chunk_size;
 131         if (data_size > 0) {
 132             url_read_complete(h, &t, 1); //marker
 133             if (t != (0xC0 + channel_id))
 134                 return -1;
 135         }
 136     }
 137     return 0;
 138 }
 139
 140 int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
 141                          int chunk_size, RTMPPacket *prev_pkt)
 142 {
 143     uint8_t pkt_hdr[16], *p = pkt_hdr;
 144     int mode = RTMP_PS_TWELVEBYTES;
 145     int off = 0;
 146
 147     //TODO: header compression
 148     bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
 149     if (mode != RTMP_PS_ONEBYTE) {
 150         bytestream_put_be24(&p, pkt->timestamp);
 151         if (mode != RTMP_PS_FOURBYTES) {
 152             bytestream_put_be24(&p, pkt->data_size);
 153             bytestream_put_byte(&p, pkt->type);
 154             if (mode == RTMP_PS_TWELVEBYTES)
 155                 bytestream_put_le32(&p, pkt->extra);
 156         }
 157     }
 158     url_write(h, pkt_hdr, p-pkt_hdr);
 159     while (off < pkt->data_size) {
 160         int towrite = FFMIN(chunk_size, pkt->data_size - off);
 161         url_write(h, pkt->data + off, towrite);
 162         off += towrite;
 163         if (off < pkt->data_size) {
 164             uint8_t marker = 0xC0 | pkt->channel_id;
 165             url_write(h, &marker, 1);
 166         }
 167     }
 168     return 0;
 169 }
 170
 171 int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
 172                           int timestamp, int size)
 173 {
 174     pkt->data = av_malloc(size);
 175     if (!pkt->data)
 176         return AVERROR(ENOMEM);
 177     pkt->data_size  = size;
 178     pkt->channel_id = channel_id;
 179     pkt->type       = type;
 180     pkt->timestamp  = timestamp;
 181     pkt->extra      = 0;
 182
 183     return 0;
 184 }
 185
 186 void ff_rtmp_packet_destroy(RTMPPacket *pkt)
 187 {
 188     if (!pkt)
 189         return;
 190     av_freep(&pkt->data);
 191     pkt->data_size = 0;
 192 }
 193
 194 int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
 195 {
 196     const uint8_t *base = data;
 197
 198     if (data >= data_end)
 199         return -1;
 200     switch (*data++) {
 201     case AMF_DATA_TYPE_NUMBER:      return 9;
 202     case AMF_DATA_TYPE_BOOL:        return 2;
 203     case AMF_DATA_TYPE_STRING:      return 3 + AV_RB16(data);
 204     case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
 205     case AMF_DATA_TYPE_NULL:        return 1;
 206     case AMF_DATA_TYPE_ARRAY:
 207         data += 4;
 208     case AMF_DATA_TYPE_OBJECT:
 209         for (;;) {
 210             int size = bytestream_get_be16(&data);
 211             int t;
 212             if (!size) {
 213                 data++;
 214                 break;
 215             }
 216             if (data + size >= data_end || data + size < data)
 217                 return -1;
 218             data += size;
 219             t = ff_amf_tag_size(data, data_end);
 220             if (t < 0 || data + t >= data_end)
 221                 return -1;
 222             data += t;
 223         }
 224         return data - base;
 225     case AMF_DATA_TYPE_OBJECT_END:  return 1;
 226     default:                        return -1;
 227     }
 228 }
 229
 230 int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
 231                            const uint8_t *name, uint8_t *dst, int dst_size)
 232 {
 233     int namelen = strlen(name);
 234     int len;
 235
 236     if (data_end - data < 3)
 237         return -1;
 238     if (*data++ != AMF_DATA_TYPE_OBJECT)
 239         return -1;
 240     for (;;) {
 241         int size = bytestream_get_be16(&data);
 242         if (!size)
 243             break;
 244         if (data + size >= data_end || data + size < data)
 245             return -1;
 246         data += size;
 247         if (size == namelen && !memcmp(data-size, name, namelen)) {
 248             switch (*data++) {
 249             case AMF_DATA_TYPE_NUMBER:
 250                 snprintf(dst, dst_size, "%g", av_int2dbl(AV_RB64(data)));
 251                 break;
 252             case AMF_DATA_TYPE_BOOL:
 253                 snprintf(dst, dst_size, "%s", *data ? "true" : "false");
 254                 break;
 255             case AMF_DATA_TYPE_STRING:
 256                 len = bytestream_get_be16(&data);
 257                 av_strlcpy(dst, data, FFMIN(len+1, dst_size));
 258                 break;
 259             default:
 260                 return -1;
 261             }
 262             return 0;
 263         }
 264         len = ff_amf_tag_size(data, data_end);
 265         if (len < 0 || data + len >= data_end || data + len < data)
 266             return -1;
 267         data += len;
 268     }
 269     return -1;
 270 }