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         int len = strlen(p) * 6 / 8;
00103         char *buf = av_mallocz(len);
00104         av_base64_decode(buf, p, len);
00105 
00106         if (rtp_asf_fix_header(buf, len) < 0)
00107             av_log(s, AV_LOG_ERROR,
00108                    "Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
00109         init_packetizer(&pb, buf, len);
00110         if (rt->asf_ctx) {
00111             avformat_close_input(&rt->asf_ctx);
00112         }
00113         if (!(rt->asf_ctx = avformat_alloc_context()))
00114             return AVERROR(ENOMEM);
00115         rt->asf_ctx->pb      = &pb;
00116         ret = avformat_open_input(&rt->asf_ctx, "", &ff_asf_demuxer, NULL);
00117         if (ret < 0)
00118             return ret;
00119         av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0);
00120         rt->asf_pb_pos = avio_tell(&pb);
00121         av_free(buf);
00122         rt->asf_ctx->pb = NULL;
00123     }
00124     return ret;
00125 }
00126 
00127 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
00128                                  PayloadContext *asf, const char *line)
00129 {
00130     if (av_strstart(line, "stream:", &line)) {
00131         RTSPState *rt = s->priv_data;
00132 
00133         s->streams[stream_index]->id = strtol(line, NULL, 10);
00134 
00135         if (rt->asf_ctx) {
00136             int i;
00137 
00138             for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
00139                 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
00140                     *s->streams[stream_index]->codec =
00141                         *rt->asf_ctx->streams[i]->codec;
00142                     rt->asf_ctx->streams[i]->codec->extradata_size = 0;
00143                     rt->asf_ctx->streams[i]->codec->extradata = NULL;
00144                     avpriv_set_pts_info(s->streams[stream_index], 32, 1, 1000);
00145                 }
00146            }
00147         }
00148     }
00149 
00150     return 0;
00151 }
00152 
00153 struct PayloadContext {
00154     AVIOContext *pktbuf, pb;
00155     uint8_t *buf;
00156 };
00157 
00163 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
00164                                AVStream *st, AVPacket *pkt,
00165                                uint32_t *timestamp,
00166                                const uint8_t *buf, int len, int flags)
00167 {
00168     AVIOContext *pb = &asf->pb;
00169     int res, mflags, len_off;
00170     RTSPState *rt = s->priv_data;
00171 
00172     if (!rt->asf_ctx)
00173         return -1;
00174 
00175     if (len > 0) {
00176         int off, out_len = 0;
00177 
00178         if (len < 4)
00179             return -1;
00180 
00181         av_freep(&asf->buf);
00182 
00183         ffio_init_context(pb, buf, len, 0, NULL, NULL, NULL, NULL);
00184 
00185         while (avio_tell(pb) + 4 < len) {
00186             int start_off = avio_tell(pb);
00187 
00188             mflags = avio_r8(pb);
00189             if (mflags & 0x80)
00190                 flags |= RTP_FLAG_KEY;
00191             len_off = avio_rb24(pb);
00192             if (mflags & 0x20)   
00193                 avio_skip(pb, 4);
00194             if (mflags & 0x10)   
00195                 avio_skip(pb, 4);
00196             if (mflags & 0x8)    
00197                 avio_skip(pb, 4);
00198             off = avio_tell(pb);
00199 
00200             if (!(mflags & 0x40)) {
00207                 if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) {
00208                     uint8_t *p;
00209                     avio_close_dyn_buf(asf->pktbuf, &p);
00210                     asf->pktbuf = NULL;
00211                     av_free(p);
00212                 }
00213                 if (!len_off && !asf->pktbuf &&
00214                     (res = avio_open_dyn_buf(&asf->pktbuf)) < 0)
00215                     return res;
00216                 if (!asf->pktbuf)
00217                     return AVERROR(EIO);
00218 
00219                 avio_write(asf->pktbuf, buf + off, len - off);
00220                 avio_skip(pb, len - off);
00221                 if (!(flags & RTP_FLAG_MARKER))
00222                     return -1;
00223                 out_len     = avio_close_dyn_buf(asf->pktbuf, &asf->buf);
00224                 asf->pktbuf = NULL;
00225             } else {
00234                 int cur_len = start_off + len_off - off;
00235                 int prev_len = out_len;
00236                 void *newmem;
00237                 out_len += cur_len;
00238                 if (FFMIN(cur_len, len - off) < 0)
00239                     return -1;
00240                 newmem = av_realloc(asf->buf, out_len);
00241                 if (!newmem)
00242                     return -1;
00243                 asf->buf = newmem;
00244                 memcpy(asf->buf + prev_len, buf + off,
00245                        FFMIN(cur_len, len - off));
00246                 avio_skip(pb, cur_len);
00247             }
00248         }
00249 
00250         init_packetizer(pb, asf->buf, out_len);
00251         pb->pos += rt->asf_pb_pos;
00252         pb->eof_reached = 0;
00253         rt->asf_ctx->pb = pb;
00254     }
00255 
00256     for (;;) {
00257         int i;
00258 
00259         res = av_read_packet(rt->asf_ctx, pkt);
00260         rt->asf_pb_pos = avio_tell(pb);
00261         if (res != 0)
00262             break;
00263         for (i = 0; i < s->nb_streams; i++) {
00264             if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
00265                 pkt->stream_index = i;
00266                 return 1; // FIXME: return 0 if last packet
00267             }
00268         }
00269         av_free_packet(pkt);
00270     }
00271 
00272     return res == 1 ? -1 : res;
00273 }
00274 
00275 static PayloadContext *asfrtp_new_context(void)
00276 {
00277     return av_mallocz(sizeof(PayloadContext));
00278 }
00279 
00280 static void asfrtp_free_context(PayloadContext *asf)
00281 {
00282     if (asf->pktbuf) {
00283         uint8_t *p = NULL;
00284         avio_close_dyn_buf(asf->pktbuf, &p);
00285         asf->pktbuf = NULL;
00286         av_free(p);
00287     }
00288     av_freep(&asf->buf);
00289     av_free(asf);
00290 }
00291 
00292 #define RTP_ASF_HANDLER(n, s, t) \
00293 RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
00294     .enc_name         = s, \
00295     .codec_type       = t, \
00296     .codec_id         = CODEC_ID_NONE, \
00297     .parse_sdp_a_line = asfrtp_parse_sdp_line, \
00298     .alloc            = asfrtp_new_context, \
00299     .free             = asfrtp_free_context, \
00300     .parse_packet     = asfrtp_parse_packet,   \
00301 }
00302 
00303 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf",  AVMEDIA_TYPE_VIDEO);
00304 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf",  AVMEDIA_TYPE_AUDIO);