| 1 | /* |
| 2 | * Microsoft RTP/ASF support. |
| 3 | * Copyright (c) 2008 Ronald S. Bultje |
| 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 | /** |
| 23 | * @file |
| 24 | * @brief Microsoft RTP/ASF support |
| 25 | * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net> |
| 26 | */ |
| 27 | |
| 28 | #include "libavutil/base64.h" |
| 29 | #include "libavutil/avstring.h" |
| 30 | #include "libavutil/intreadwrite.h" |
| 31 | #include "rtp.h" |
| 32 | #include "rtpdec_formats.h" |
| 33 | #include "rtsp.h" |
| 34 | #include "asf.h" |
| 35 | #include "avio_internal.h" |
| 36 | #include "internal.h" |
| 37 | |
| 38 | /** |
| 39 | * From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not |
| 40 | * contain any padding. Unfortunately, the header min/max_pktsize are not |
| 41 | * updated (thus making min_pktsize invalid). Here, we "fix" these faulty |
| 42 | * min_pktsize values in the ASF file header. |
| 43 | * @return 0 on success, <0 on failure (currently -1). |
| 44 | */ |
| 45 | static int rtp_asf_fix_header(uint8_t *buf, int len) |
| 46 | { |
| 47 | uint8_t *p = buf, *end = buf + len; |
| 48 | |
| 49 | if (len < sizeof(ff_asf_guid) * 2 + 22 || |
| 50 | memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) { |
| 51 | return -1; |
| 52 | } |
| 53 | p += sizeof(ff_asf_guid) + 14; |
| 54 | do { |
| 55 | uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid)); |
| 56 | if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) { |
| 57 | if (chunksize > end - p) |
| 58 | return -1; |
| 59 | p += chunksize; |
| 60 | continue; |
| 61 | } |
| 62 | |
| 63 | /* skip most of the file header, to min_pktsize */ |
| 64 | p += 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2; |
| 65 | if (p + 8 <= end && AV_RL32(p) == AV_RL32(p + 4)) { |
| 66 | /* and set that to zero */ |
| 67 | AV_WL32(p, 0); |
| 68 | return 0; |
| 69 | } |
| 70 | break; |
| 71 | } while (end - p >= sizeof(ff_asf_guid) + 8); |
| 72 | |
| 73 | return -1; |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * The following code is basically a buffered AVIOContext, |
| 78 | * with the added benefit of returning -EAGAIN (instead of 0) |
| 79 | * on packet boundaries, such that the ASF demuxer can return |
| 80 | * safely and resume business at the next packet. |
| 81 | */ |
| 82 | static int packetizer_read(void *opaque, uint8_t *buf, int buf_size) |
| 83 | { |
| 84 | return AVERROR(EAGAIN); |
| 85 | } |
| 86 | |
| 87 | static void init_packetizer(AVIOContext *pb, uint8_t *buf, int len) |
| 88 | { |
| 89 | ffio_init_context(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL); |
| 90 | |
| 91 | /* this "fills" the buffer with its current content */ |
| 92 | pb->pos = len; |
| 93 | pb->buf_end = buf + len; |
| 94 | } |
| 95 | |
| 96 | int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p) |
| 97 | { |
| 98 | int ret = 0; |
| 99 | if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) { |
| 100 | AVIOContext pb; |
| 101 | RTSPState *rt = s->priv_data; |
| 102 | AVDictionary *opts = NULL; |
| 103 | int len = strlen(p) * 6 / 8; |
| 104 | char *buf = av_mallocz(len); |
| 105 | av_base64_decode(buf, p, len); |
| 106 | |
| 107 | if (rtp_asf_fix_header(buf, len) < 0) |
| 108 | av_log(s, AV_LOG_ERROR, |
| 109 | "Failed to fix invalid RTSP-MS/ASF min_pktsize\n"); |
| 110 | init_packetizer(&pb, buf, len); |
| 111 | if (rt->asf_ctx) { |
| 112 | avformat_close_input(&rt->asf_ctx); |
| 113 | } |
| 114 | if (!(rt->asf_ctx = avformat_alloc_context())) |
| 115 | return AVERROR(ENOMEM); |
| 116 | rt->asf_ctx->pb = &pb; |
| 117 | av_dict_set(&opts, "no_resync_search", "1", 0); |
| 118 | ret = avformat_open_input(&rt->asf_ctx, "", &ff_asf_demuxer, &opts); |
| 119 | av_dict_free(&opts); |
| 120 | if (ret < 0) |
| 121 | return ret; |
| 122 | av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0); |
| 123 | rt->asf_pb_pos = avio_tell(&pb); |
| 124 | av_free(buf); |
| 125 | rt->asf_ctx->pb = NULL; |
| 126 | } |
| 127 | return ret; |
| 128 | } |
| 129 | |
| 130 | static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index, |
| 131 | PayloadContext *asf, const char *line) |
| 132 | { |
| 133 | if (stream_index < 0) |
| 134 | return 0; |
| 135 | if (av_strstart(line, "stream:", &line)) { |
| 136 | RTSPState *rt = s->priv_data; |
| 137 | |
| 138 | s->streams[stream_index]->id = strtol(line, NULL, 10); |
| 139 | |
| 140 | if (rt->asf_ctx) { |
| 141 | int i; |
| 142 | |
| 143 | for (i = 0; i < rt->asf_ctx->nb_streams; i++) { |
| 144 | if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) { |
| 145 | *s->streams[stream_index]->codec = |
| 146 | *rt->asf_ctx->streams[i]->codec; |
| 147 | s->streams[stream_index]->need_parsing = |
| 148 | rt->asf_ctx->streams[i]->need_parsing; |
| 149 | rt->asf_ctx->streams[i]->codec->extradata_size = 0; |
| 150 | rt->asf_ctx->streams[i]->codec->extradata = NULL; |
| 151 | avpriv_set_pts_info(s->streams[stream_index], 32, 1, 1000); |
| 152 | } |
| 153 | } |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | struct PayloadContext { |
| 161 | AVIOContext *pktbuf, pb; |
| 162 | uint8_t *buf; |
| 163 | }; |
| 164 | |
| 165 | /** |
| 166 | * @return 0 when a packet was written into /p pkt, and no more data is left; |
| 167 | * 1 when a packet was written into /p pkt, and more packets might be left; |
| 168 | * <0 when not enough data was provided to return a full packet, or on error. |
| 169 | */ |
| 170 | static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf, |
| 171 | AVStream *st, AVPacket *pkt, |
| 172 | uint32_t *timestamp, |
| 173 | const uint8_t *buf, int len, uint16_t seq, |
| 174 | int flags) |
| 175 | { |
| 176 | AVIOContext *pb = &asf->pb; |
| 177 | int res, mflags, len_off; |
| 178 | RTSPState *rt = s->priv_data; |
| 179 | |
| 180 | if (!rt->asf_ctx) |
| 181 | return -1; |
| 182 | |
| 183 | if (len > 0) { |
| 184 | int off, out_len = 0; |
| 185 | |
| 186 | if (len < 4) |
| 187 | return -1; |
| 188 | |
| 189 | av_freep(&asf->buf); |
| 190 | |
| 191 | ffio_init_context(pb, (uint8_t *)buf, len, 0, NULL, NULL, NULL, NULL); |
| 192 | |
| 193 | while (avio_tell(pb) + 4 < len) { |
| 194 | int start_off = avio_tell(pb); |
| 195 | |
| 196 | mflags = avio_r8(pb); |
| 197 | if (mflags & 0x80) |
| 198 | flags |= RTP_FLAG_KEY; |
| 199 | len_off = avio_rb24(pb); |
| 200 | if (mflags & 0x20) /**< relative timestamp */ |
| 201 | avio_skip(pb, 4); |
| 202 | if (mflags & 0x10) /**< has duration */ |
| 203 | avio_skip(pb, 4); |
| 204 | if (mflags & 0x8) /**< has location ID */ |
| 205 | avio_skip(pb, 4); |
| 206 | off = avio_tell(pb); |
| 207 | |
| 208 | if (!(mflags & 0x40)) { |
| 209 | /** |
| 210 | * If 0x40 is not set, the len_off field specifies an offset |
| 211 | * of this packet's payload data in the complete (reassembled) |
| 212 | * ASF packet. This is used to spread one ASF packet over |
| 213 | * multiple RTP packets. |
| 214 | */ |
| 215 | if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) { |
| 216 | uint8_t *p; |
| 217 | avio_close_dyn_buf(asf->pktbuf, &p); |
| 218 | asf->pktbuf = NULL; |
| 219 | av_free(p); |
| 220 | } |
| 221 | if (!len_off && !asf->pktbuf && |
| 222 | (res = avio_open_dyn_buf(&asf->pktbuf)) < 0) |
| 223 | return res; |
| 224 | if (!asf->pktbuf) |
| 225 | return AVERROR(EIO); |
| 226 | |
| 227 | avio_write(asf->pktbuf, buf + off, len - off); |
| 228 | avio_skip(pb, len - off); |
| 229 | if (!(flags & RTP_FLAG_MARKER)) |
| 230 | return -1; |
| 231 | out_len = avio_close_dyn_buf(asf->pktbuf, &asf->buf); |
| 232 | asf->pktbuf = NULL; |
| 233 | } else { |
| 234 | /** |
| 235 | * If 0x40 is set, the len_off field specifies the length of |
| 236 | * the next ASF packet that can be read from this payload |
| 237 | * data alone. This is commonly the same as the payload size, |
| 238 | * but could be less in case of packet splitting (i.e. |
| 239 | * multiple ASF packets in one RTP packet). |
| 240 | */ |
| 241 | |
| 242 | int cur_len = start_off + len_off - off; |
| 243 | int prev_len = out_len; |
| 244 | out_len += cur_len; |
| 245 | if (FFMIN(cur_len, len - off) < 0) |
| 246 | return -1; |
| 247 | if ((res = av_reallocp(&asf->buf, out_len)) < 0) |
| 248 | return res; |
| 249 | memcpy(asf->buf + prev_len, buf + off, |
| 250 | FFMIN(cur_len, len - off)); |
| 251 | avio_skip(pb, cur_len); |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | init_packetizer(pb, asf->buf, out_len); |
| 256 | pb->pos += rt->asf_pb_pos; |
| 257 | pb->eof_reached = 0; |
| 258 | rt->asf_ctx->pb = pb; |
| 259 | } |
| 260 | |
| 261 | for (;;) { |
| 262 | int i; |
| 263 | |
| 264 | res = ff_read_packet(rt->asf_ctx, pkt); |
| 265 | rt->asf_pb_pos = avio_tell(pb); |
| 266 | if (res != 0) |
| 267 | break; |
| 268 | for (i = 0; i < s->nb_streams; i++) { |
| 269 | if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) { |
| 270 | pkt->stream_index = i; |
| 271 | return 1; // FIXME: return 0 if last packet |
| 272 | } |
| 273 | } |
| 274 | av_free_packet(pkt); |
| 275 | } |
| 276 | |
| 277 | return res == 1 ? -1 : res; |
| 278 | } |
| 279 | |
| 280 | static PayloadContext *asfrtp_new_context(void) |
| 281 | { |
| 282 | return av_mallocz(sizeof(PayloadContext)); |
| 283 | } |
| 284 | |
| 285 | static void asfrtp_free_context(PayloadContext *asf) |
| 286 | { |
| 287 | if (asf->pktbuf) { |
| 288 | uint8_t *p = NULL; |
| 289 | avio_close_dyn_buf(asf->pktbuf, &p); |
| 290 | asf->pktbuf = NULL; |
| 291 | av_free(p); |
| 292 | } |
| 293 | av_freep(&asf->buf); |
| 294 | av_free(asf); |
| 295 | } |
| 296 | |
| 297 | #define RTP_ASF_HANDLER(n, s, t) \ |
| 298 | RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \ |
| 299 | .enc_name = s, \ |
| 300 | .codec_type = t, \ |
| 301 | .codec_id = AV_CODEC_ID_NONE, \ |
| 302 | .parse_sdp_a_line = asfrtp_parse_sdp_line, \ |
| 303 | .alloc = asfrtp_new_context, \ |
| 304 | .free = asfrtp_free_context, \ |
| 305 | .parse_packet = asfrtp_parse_packet, \ |
| 306 | } |
| 307 | |
| 308 | RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", AVMEDIA_TYPE_VIDEO); |
| 309 | RTP_ASF_HANDLER(asf_pfa, "x-asf-pf", AVMEDIA_TYPE_AUDIO); |