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| 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 libavformat/rtpdec_asf.c |
| 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_asf.h" |
| 33 #include "rtsp.h" |
| 34 #include "asf.h" |
| 35 |
| 36 /** |
| 37 * From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not |
| 38 * contain any padding. Unfortunately, the header min/max_pktsize are not |
| 39 * updated (thus making min_pktsize invalid). Here, we "fix" these faulty |
| 40 * min_pktsize values in the ASF file header. |
| 41 * @return 0 on success, <0 on failure (currently -1). |
| 42 */ |
| 43 static int rtp_asf_fix_header(uint8_t *buf, int len) |
| 44 { |
| 45 uint8_t *p = buf, *end = buf + len; |
| 46 |
| 47 if (len < sizeof(ff_asf_guid) * 2 + 22 || |
| 48 memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) { |
| 49 return -1; |
| 50 } |
| 51 p += sizeof(ff_asf_guid) + 14; |
| 52 do { |
| 53 uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid)); |
| 54 if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) { |
| 55 if (chunksize > end - p) |
| 56 return -1; |
| 57 p += chunksize; |
| 58 continue; |
| 59 } |
| 60 |
| 61 /* skip most of the file header, to min_pktsize */ |
| 62 p += 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2; |
| 63 if (p + 8 <= end && AV_RL32(p) == AV_RL32(p + 4)) { |
| 64 /* and set that to zero */ |
| 65 AV_WL32(p, 0); |
| 66 return 0; |
| 67 } |
| 68 break; |
| 69 } while (end - p >= sizeof(ff_asf_guid) + 8); |
| 70 |
| 71 return -1; |
| 72 } |
| 73 |
| 74 /** |
| 75 * The following code is basically a buffered ByteIOContext, |
| 76 * with the added benefit of returning -EAGAIN (instead of 0) |
| 77 * on packet boundaries, such that the ASF demuxer can return |
| 78 * safely and resume business at the next packet. |
| 79 */ |
| 80 static int packetizer_read(void *opaque, uint8_t *buf, int buf_size) |
| 81 { |
| 82 return AVERROR(EAGAIN); |
| 83 } |
| 84 |
| 85 static void init_packetizer(ByteIOContext *pb, uint8_t *buf, int len) |
| 86 { |
| 87 init_put_byte(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL); |
| 88 |
| 89 /* this "fills" the buffer with its current content */ |
| 90 pb->pos = len; |
| 91 pb->buf_end = buf + len; |
| 92 } |
| 93 |
| 94 void ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p) |
| 95 { |
| 96 if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p
)) { |
| 97 ByteIOContext pb; |
| 98 RTSPState *rt = s->priv_data; |
| 99 int len = strlen(p) * 6 / 8; |
| 100 char *buf = av_mallocz(len); |
| 101 av_base64_decode(buf, p, len); |
| 102 |
| 103 if (rtp_asf_fix_header(buf, len) < 0) |
| 104 av_log(s, AV_LOG_ERROR, |
| 105 "Failed to fix invalid RTSP-MS/ASF min_pktsize\n"); |
| 106 init_packetizer(&pb, buf, len); |
| 107 if (rt->asf_ctx) { |
| 108 av_close_input_stream(rt->asf_ctx); |
| 109 rt->asf_ctx = NULL; |
| 110 } |
| 111 av_open_input_stream(&rt->asf_ctx, &pb, "", &asf_demuxer, NULL); |
| 112 rt->asf_pb_pos = url_ftell(&pb); |
| 113 av_free(buf); |
| 114 rt->asf_ctx->pb = NULL; |
| 115 } |
| 116 } |
| 117 |
| 118 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index, |
| 119 PayloadContext *asf, const char *line) |
| 120 { |
| 121 if (av_strstart(line, "stream:", &line)) { |
| 122 RTSPState *rt = s->priv_data; |
| 123 |
| 124 s->streams[stream_index]->id = strtol(line, NULL, 10); |
| 125 |
| 126 if (rt->asf_ctx) { |
| 127 int i; |
| 128 |
| 129 for (i = 0; i < rt->asf_ctx->nb_streams; i++) { |
| 130 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id)
{ |
| 131 *s->streams[stream_index]->codec = |
| 132 *rt->asf_ctx->streams[i]->codec; |
| 133 rt->asf_ctx->streams[i]->codec->extradata_size = 0; |
| 134 rt->asf_ctx->streams[i]->codec->extradata = NULL; |
| 135 av_set_pts_info(s->streams[stream_index], 32, 1, 1000); |
| 136 } |
| 137 } |
| 138 } |
| 139 } |
| 140 |
| 141 return 0; |
| 142 } |
| 143 |
| 144 struct PayloadContext { |
| 145 ByteIOContext *pktbuf, pb; |
| 146 char *buf; |
| 147 }; |
| 148 |
| 149 /** |
| 150 * @return 0 when a packet was written into /p pkt, and no more data is left; |
| 151 * 1 when a packet was written into /p pkt, and more packets might be le
ft; |
| 152 * <0 when not enough data was provided to return a full packet, or on er
ror. |
| 153 */ |
| 154 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf, |
| 155 AVStream *st, AVPacket *pkt, |
| 156 uint32_t *timestamp, |
| 157 const uint8_t *buf, int len, int flags) |
| 158 { |
| 159 ByteIOContext *pb = &asf->pb; |
| 160 int res, mflags, len_off; |
| 161 RTSPState *rt = s->priv_data; |
| 162 |
| 163 if (!rt->asf_ctx) |
| 164 return -1; |
| 165 |
| 166 if (len > 0) { |
| 167 int off, out_len; |
| 168 |
| 169 if (len < 4) |
| 170 return -1; |
| 171 |
| 172 init_put_byte(pb, buf, len, 0, NULL, NULL, NULL, NULL); |
| 173 mflags = get_byte(pb); |
| 174 if (mflags & 0x80) |
| 175 flags |= RTP_FLAG_KEY; |
| 176 len_off = get_be24(pb); |
| 177 if (mflags & 0x20) /**< relative timestamp */ |
| 178 url_fskip(pb, 4); |
| 179 if (mflags & 0x10) /**< has duration */ |
| 180 url_fskip(pb, 4); |
| 181 if (mflags & 0x8) /**< has location ID */ |
| 182 url_fskip(pb, 4); |
| 183 off = url_ftell(pb); |
| 184 |
| 185 av_freep(&asf->buf); |
| 186 if (!(mflags & 0x40)) { |
| 187 /** |
| 188 * If 0x40 is not set, the len_off field specifies an offset of this |
| 189 * packet's payload data in the complete (reassembled) ASF packet. |
| 190 * This is used to spread one ASF packet over multiple RTP packets. |
| 191 */ |
| 192 if (asf->pktbuf && len_off != url_ftell(asf->pktbuf)) { |
| 193 uint8_t *p; |
| 194 url_close_dyn_buf(asf->pktbuf, &p); |
| 195 asf->pktbuf = NULL; |
| 196 av_free(p); |
| 197 } |
| 198 if (!len_off && !asf->pktbuf && |
| 199 (res = url_open_dyn_buf(&asf->pktbuf)) < 0) |
| 200 return res; |
| 201 if (!asf->pktbuf) |
| 202 return AVERROR(EIO); |
| 203 |
| 204 put_buffer(asf->pktbuf, buf + off, len - off); |
| 205 if (!(flags & RTP_FLAG_MARKER)) |
| 206 return -1; |
| 207 out_len = url_close_dyn_buf(asf->pktbuf, &asf->buf); |
| 208 asf->pktbuf = NULL; |
| 209 } else { |
| 210 /** |
| 211 * If 0x40 is set, the len_off field specifies the length of the |
| 212 * next ASF packet that can be read from this payload data alone. |
| 213 * This is commonly the same as the payload size, but could be |
| 214 * less in case of packet splitting (i.e. multiple ASF packets in |
| 215 * one RTP packet). |
| 216 */ |
| 217 if (len_off != len) { |
| 218 av_log_missing_feature(s, |
| 219 "RTSP-MS packet splitting", 1); |
| 220 return -1; |
| 221 } |
| 222 asf->buf = av_malloc(len - off); |
| 223 out_len = len - off; |
| 224 memcpy(asf->buf, buf + off, len - off); |
| 225 } |
| 226 |
| 227 init_packetizer(pb, asf->buf, out_len); |
| 228 pb->pos += rt->asf_pb_pos; |
| 229 pb->eof_reached = 0; |
| 230 rt->asf_ctx->pb = pb; |
| 231 } |
| 232 |
| 233 for (;;) { |
| 234 int i; |
| 235 |
| 236 res = av_read_packet(rt->asf_ctx, pkt); |
| 237 rt->asf_pb_pos = url_ftell(pb); |
| 238 if (res != 0) |
| 239 break; |
| 240 for (i = 0; i < s->nb_streams; i++) { |
| 241 if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id
) { |
| 242 pkt->stream_index = i; |
| 243 return 1; // FIXME: return 0 if last packet |
| 244 } |
| 245 } |
| 246 av_free_packet(pkt); |
| 247 } |
| 248 |
| 249 return res == 1 ? -1 : res; |
| 250 } |
| 251 |
| 252 static PayloadContext *asfrtp_new_context(void) |
| 253 { |
| 254 return av_mallocz(sizeof(PayloadContext)); |
| 255 } |
| 256 |
| 257 static void asfrtp_free_context(PayloadContext *asf) |
| 258 { |
| 259 if (asf->pktbuf) { |
| 260 uint8_t *p = NULL; |
| 261 url_close_dyn_buf(asf->pktbuf, &p); |
| 262 asf->pktbuf = NULL; |
| 263 av_free(p); |
| 264 } |
| 265 av_freep(&asf->buf); |
| 266 av_free(asf); |
| 267 } |
| 268 |
| 269 #define RTP_ASF_HANDLER(n, s, t) \ |
| 270 RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \ |
| 271 .enc_name = s, \ |
| 272 .codec_type = t, \ |
| 273 .codec_id = CODEC_ID_NONE, \ |
| 274 .parse_sdp_a_line = asfrtp_parse_sdp_line, \ |
| 275 .open = asfrtp_new_context, \ |
| 276 .close = asfrtp_free_context, \ |
| 277 .parse_packet = asfrtp_parse_packet, \ |
| 278 }; |
| 279 |
| 280 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", CODEC_TYPE_VIDEO); |
| 281 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf", CODEC_TYPE_AUDIO); |
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