FFmpeg: libavformat/rtpdec_asf.c Source File

00001 /*
00002  * Microsoft RTP/ASF support.
00003  * Copyright (c) 2008 Ronald S. Bultje
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 #include "libavutil/base64.h"
00029 #include "libavutil/avstring.h"
00030 #include "libavutil/intreadwrite.h"
00031 #include "rtp.h"
00032 #include "rtpdec_formats.h"
00033 #include "rtsp.h"
00034 #include "asf.h"
00035 #include "avio_internal.h"
00036 #include "internal.h"
00037 
00045 static int rtp_asf_fix_header(uint8_t *buf, int len)
00046 {
00047     uint8_t *p = buf, *end = buf + len;
00048 
00049     if (len < sizeof(ff_asf_guid) * 2 + 22 ||
00050         memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
00051         return -1;
00052     }
00053     p += sizeof(ff_asf_guid) + 14;
00054     do {
00055         uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
00056         if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
00057             if (chunksize > end - p)
00058                 return -1;
00059             p += chunksize;
00060             continue;
00061         }
00062 
00063         /* skip most of the file header, to min_pktsize */
00064         p += 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
00065         if (p + 8 <= end && AV_RL32(p) == AV_RL32(p + 4)) {
00066             /* and set that to zero */
00067             AV_WL32(p, 0);
00068             return 0;
00069         }
00070         break;
00071     } while (end - p >= sizeof(ff_asf_guid) + 8);
00072 
00073     return -1;
00074 }
00075 
00082 static int packetizer_read(void *opaque, uint8_t *buf, int buf_size)
00083 {
00084     return AVERROR(EAGAIN);
00085 }
00086 
00087 static void init_packetizer(AVIOContext *pb, uint8_t *buf, int len)
00088 {
00089     ffio_init_context(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);
00090 
00091     /* this "fills" the buffer with its current content */
00092     pb->pos     = len;
00093     pb->buf_end = buf + len;
00094 }
00095 
00096 int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
00097 {
00098     int ret = 0;
00099     if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
00100         AVIOContext pb;
00101         RTSPState *rt = s->priv_data;
00102         AVDictionary *opts = NULL;
00103         int len = strlen(p) * 6 / 8;
00104         char *buf = av_mallocz(len);
00105         av_base64_decode(buf, p, len);
00106 
00107         if (rtp_asf_fix_header(buf, len) < 0)
00108             av_log(s, AV_LOG_ERROR,
00109                    "Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
00110         init_packetizer(&pb, buf, len);
00111         if (rt->asf_ctx) {
00112             avformat_close_input(&rt->asf_ctx);
00113         }
00114         if (!(rt->asf_ctx = avformat_alloc_context()))
00115             return AVERROR(ENOMEM);
00116         rt->asf_ctx->pb      = &pb;
00117         av_dict_set(&opts, "no_resync_search", "1", 0);
00118         ret = avformat_open_input(&rt->asf_ctx, "", &ff_asf_demuxer, &opts);
00119         av_dict_free(&opts);
00120         if (ret < 0)
00121             return ret;
00122         av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0);
00123         rt->asf_pb_pos = avio_tell(&pb);
00124         av_free(buf);
00125         rt->asf_ctx->pb = NULL;
00126     }
00127     return ret;
00128 }
00129 
00130 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
00131                                  PayloadContext *asf, const char *line)
00132 {
00133     if (stream_index < 0)
00134         return 0;
00135     if (av_strstart(line, "stream:", &line)) {
00136         RTSPState *rt = s->priv_data;
00137 
00138         s->streams[stream_index]->id = strtol(line, NULL, 10);
00139 
00140         if (rt->asf_ctx) {
00141             int i;
00142 
00143             for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
00144                 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
00145                     *s->streams[stream_index]->codec =
00146                         *rt->asf_ctx->streams[i]->codec;
00147                     rt->asf_ctx->streams[i]->codec->extradata_size = 0;
00148                     rt->asf_ctx->streams[i]->codec->extradata = NULL;
00149                     avpriv_set_pts_info(s->streams[stream_index], 32, 1, 1000);
00150                 }
00151            }
00152         }
00153     }
00154 
00155     return 0;
00156 }
00157 
00158 struct PayloadContext {
00159     AVIOContext *pktbuf, pb;
00160     uint8_t *buf;
00161 };
00162 
00168 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
00169                                AVStream *st, AVPacket *pkt,
00170                                uint32_t *timestamp,
00171                                const uint8_t *buf, int len, int flags)
00172 {
00173     AVIOContext *pb = &asf->pb;
00174     int res, mflags, len_off;
00175     RTSPState *rt = s->priv_data;
00176 
00177     if (!rt->asf_ctx)
00178         return -1;
00179 
00180     if (len > 0) {
00181         int off, out_len = 0;
00182 
00183         if (len < 4)
00184             return -1;
00185 
00186         av_freep(&asf->buf);
00187 
00188         ffio_init_context(pb, buf, len, 0, NULL, NULL, NULL, NULL);
00189 
00190         while (avio_tell(pb) + 4 < len) {
00191             int start_off = avio_tell(pb);
00192 
00193             mflags = avio_r8(pb);
00194             if (mflags & 0x80)
00195                 flags |= RTP_FLAG_KEY;
00196             len_off = avio_rb24(pb);
00197             if (mflags & 0x20)   
00198                 avio_skip(pb, 4);
00199             if (mflags & 0x10)   
00200                 avio_skip(pb, 4);
00201             if (mflags & 0x8)    
00202                 avio_skip(pb, 4);
00203             off = avio_tell(pb);
00204 
00205             if (!(mflags & 0x40)) {
00212                 if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) {
00213                     uint8_t *p;
00214                     avio_close_dyn_buf(asf->pktbuf, &p);
00215                     asf->pktbuf = NULL;
00216                     av_free(p);
00217                 }
00218                 if (!len_off && !asf->pktbuf &&
00219                     (res = avio_open_dyn_buf(&asf->pktbuf)) < 0)
00220                     return res;
00221                 if (!asf->pktbuf)
00222                     return AVERROR(EIO);
00223 
00224                 avio_write(asf->pktbuf, buf + off, len - off);
00225                 avio_skip(pb, len - off);
00226                 if (!(flags & RTP_FLAG_MARKER))
00227                     return -1;
00228                 out_len     = avio_close_dyn_buf(asf->pktbuf, &asf->buf);
00229                 asf->pktbuf = NULL;
00230             } else {
00239                 int cur_len = start_off + len_off - off;
00240                 int prev_len = out_len;
00241                 void *newmem;
00242                 out_len += cur_len;
00243                 if (FFMIN(cur_len, len - off) < 0)
00244                     return -1;
00245                 newmem = av_realloc(asf->buf, out_len);
00246                 if (!newmem)
00247                     return -1;
00248                 asf->buf = newmem;
00249                 memcpy(asf->buf + prev_len, buf + off,
00250                        FFMIN(cur_len, len - off));
00251                 avio_skip(pb, cur_len);
00252             }
00253         }
00254 
00255         init_packetizer(pb, asf->buf, out_len);
00256         pb->pos += rt->asf_pb_pos;
00257         pb->eof_reached = 0;
00258         rt->asf_ctx->pb = pb;
00259     }
00260 
00261     for (;;) {
00262         int i;
00263 
00264         res = ff_read_packet(rt->asf_ctx, pkt);
00265         rt->asf_pb_pos = avio_tell(pb);
00266         if (res != 0)
00267             break;
00268         for (i = 0; i < s->nb_streams; i++) {
00269             if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
00270                 pkt->stream_index = i;
00271                 return 1; // FIXME: return 0 if last packet
00272             }
00273         }
00274         av_free_packet(pkt);
00275     }
00276 
00277     return res == 1 ? -1 : res;
00278 }
00279 
00280 static PayloadContext *asfrtp_new_context(void)
00281 {
00282     return av_mallocz(sizeof(PayloadContext));
00283 }
00284 
00285 static void asfrtp_free_context(PayloadContext *asf)
00286 {
00287     if (asf->pktbuf) {
00288         uint8_t *p = NULL;
00289         avio_close_dyn_buf(asf->pktbuf, &p);
00290         asf->pktbuf = NULL;
00291         av_free(p);
00292     }
00293     av_freep(&asf->buf);
00294     av_free(asf);
00295 }
00296 
00297 #define RTP_ASF_HANDLER(n, s, t) \
00298 RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
00299     .enc_name         = s, \
00300     .codec_type       = t, \
00301     .codec_id         = AV_CODEC_ID_NONE, \
00302     .parse_sdp_a_line = asfrtp_parse_sdp_line, \
00303     .alloc            = asfrtp_new_context, \
00304     .free             = asfrtp_free_context, \
00305     .parse_packet     = asfrtp_parse_packet,   \
00306 }
00307 
00308 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf",  AVMEDIA_TYPE_VIDEO);
00309 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf",  AVMEDIA_TYPE_AUDIO);