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libavformat/rtpdec_asf.c

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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_asf.h"
00033 #include "rtsp.h"
00034 #include "asf.h"
00035 
00043 static int rtp_asf_fix_header(uint8_t *buf, int len)
00044 {
00045     uint8_t *p = buf, *end = buf + len;
00046 
00047     if (len < sizeof(ff_asf_guid) * 2 + 22 ||
00048         memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
00049         return -1;
00050     }
00051     p += sizeof(ff_asf_guid) + 14;
00052     do {
00053         uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
00054         if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
00055             if (chunksize > end - p)
00056                 return -1;
00057             p += chunksize;
00058             continue;
00059         }
00060 
00061         /* skip most of the file header, to min_pktsize */
00062         p += 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
00063         if (p + 8 <= end && AV_RL32(p) == AV_RL32(p + 4)) {
00064             /* and set that to zero */
00065             AV_WL32(p, 0);
00066             return 0;
00067         }
00068         break;
00069     } while (end - p >= sizeof(ff_asf_guid) + 8);
00070 
00071     return -1;
00072 }
00073 
00080 static int packetizer_read(void *opaque, uint8_t *buf, int buf_size)
00081 {
00082     return AVERROR(EAGAIN);
00083 }
00084 
00085 static void init_packetizer(ByteIOContext *pb, uint8_t *buf, int len)
00086 {
00087     init_put_byte(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);
00088 
00089     /* this "fills" the buffer with its current content */
00090     pb->pos     = len;
00091     pb->buf_end = buf + len;
00092 }
00093 
00094 void ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
00095 {
00096     if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
00097         ByteIOContext pb;
00098         RTSPState *rt = s->priv_data;
00099         int len = strlen(p) * 6 / 8;
00100         char *buf = av_mallocz(len);
00101         av_base64_decode(buf, p, len);
00102 
00103         if (rtp_asf_fix_header(buf, len) < 0)
00104             av_log(s, AV_LOG_ERROR,
00105                    "Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
00106         init_packetizer(&pb, buf, len);
00107         if (rt->asf_ctx) {
00108             av_close_input_stream(rt->asf_ctx);
00109             rt->asf_ctx = NULL;
00110         }
00111         av_open_input_stream(&rt->asf_ctx, &pb, "", &asf_demuxer, NULL);
00112         rt->asf_pb_pos = url_ftell(&pb);
00113         av_free(buf);
00114         rt->asf_ctx->pb = NULL;
00115     }
00116 }
00117 
00118 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
00119                                  PayloadContext *asf, const char *line)
00120 {
00121     if (av_strstart(line, "stream:", &line)) {
00122         RTSPState *rt = s->priv_data;
00123 
00124         s->streams[stream_index]->id = strtol(line, NULL, 10);
00125 
00126         if (rt->asf_ctx) {
00127             int i;
00128 
00129             for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
00130                 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
00131                     *s->streams[stream_index]->codec =
00132                         *rt->asf_ctx->streams[i]->codec;
00133                     rt->asf_ctx->streams[i]->codec->extradata_size = 0;
00134                     rt->asf_ctx->streams[i]->codec->extradata = NULL;
00135                     av_set_pts_info(s->streams[stream_index], 32, 1, 1000);
00136                 }
00137            }
00138         }
00139     }
00140 
00141     return 0;
00142 }
00143 
00144 struct PayloadContext {
00145     ByteIOContext *pktbuf, pb;
00146     char *buf;
00147 };
00148 
00154 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
00155                                AVStream *st, AVPacket *pkt,
00156                                uint32_t *timestamp,
00157                                const uint8_t *buf, int len, int flags)
00158 {
00159     ByteIOContext *pb = &asf->pb;
00160     int res, mflags, len_off;
00161     RTSPState *rt = s->priv_data;
00162 
00163     if (!rt->asf_ctx)
00164         return -1;
00165 
00166     if (len > 0) {
00167         int off, out_len;
00168 
00169         if (len < 4)
00170             return -1;
00171 
00172         init_put_byte(pb, buf, len, 0, NULL, NULL, NULL, NULL);
00173         mflags = get_byte(pb);
00174         if (mflags & 0x80)
00175             flags |= RTP_FLAG_KEY;
00176         len_off = get_be24(pb);
00177         if (mflags & 0x20)   
00178             url_fskip(pb, 4);
00179         if (mflags & 0x10)   
00180             url_fskip(pb, 4);
00181         if (mflags & 0x8)    
00182             url_fskip(pb, 4);
00183         off = url_ftell(pb);
00184 
00185         av_freep(&asf->buf);
00186         if (!(mflags & 0x40)) {
00192             if (asf->pktbuf && len_off != url_ftell(asf->pktbuf)) {
00193                 uint8_t *p;
00194                 url_close_dyn_buf(asf->pktbuf, &p);
00195                 asf->pktbuf = NULL;
00196                 av_free(p);
00197             }
00198             if (!len_off && !asf->pktbuf &&
00199                 (res = url_open_dyn_buf(&asf->pktbuf)) < 0)
00200                 return res;
00201             if (!asf->pktbuf)
00202                 return AVERROR(EIO);
00203 
00204             put_buffer(asf->pktbuf, buf + off, len - off);
00205             if (!(flags & RTP_FLAG_MARKER))
00206                 return -1;
00207             out_len     = url_close_dyn_buf(asf->pktbuf, &asf->buf);
00208             asf->pktbuf = NULL;
00209         } else {
00217             if (len_off != len) {
00218                 av_log_missing_feature(s,
00219                     "RTSP-MS packet splitting", 1);
00220                 return -1;
00221             }
00222             asf->buf = av_malloc(len - off);
00223             out_len  = len - off;
00224             memcpy(asf->buf, buf + off, len - off);
00225         }
00226 
00227         init_packetizer(pb, asf->buf, out_len);
00228         pb->pos += rt->asf_pb_pos;
00229         pb->eof_reached = 0;
00230         rt->asf_ctx->pb = pb;
00231     }
00232 
00233     for (;;) {
00234         int i;
00235 
00236         res = av_read_packet(rt->asf_ctx, pkt);
00237         rt->asf_pb_pos = url_ftell(pb);
00238         if (res != 0)
00239             break;
00240         for (i = 0; i < s->nb_streams; i++) {
00241             if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
00242                 pkt->stream_index = i;
00243                 return 1; // FIXME: return 0 if last packet
00244             }
00245         }
00246         av_free_packet(pkt);
00247     }
00248 
00249     return res == 1 ? -1 : res;
00250 }
00251 
00252 static PayloadContext *asfrtp_new_context(void)
00253 {
00254     return av_mallocz(sizeof(PayloadContext));
00255 }
00256 
00257 static void asfrtp_free_context(PayloadContext *asf)
00258 {
00259     if (asf->pktbuf) {
00260         uint8_t *p = NULL;
00261         url_close_dyn_buf(asf->pktbuf, &p);
00262         asf->pktbuf = NULL;
00263         av_free(p);
00264     }
00265     av_freep(&asf->buf);
00266     av_free(asf);
00267 }
00268 
00269 #define RTP_ASF_HANDLER(n, s, t) \
00270 RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
00271     .enc_name         = s, \
00272     .codec_type       = t, \
00273     .codec_id         = CODEC_ID_NONE, \
00274     .parse_sdp_a_line = asfrtp_parse_sdp_line, \
00275     .open             = asfrtp_new_context, \
00276     .close            = asfrtp_free_context, \
00277     .parse_packet     = asfrtp_parse_packet,   \
00278 };
00279 
00280 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf",  AVMEDIA_TYPE_VIDEO);
00281 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf",  AVMEDIA_TYPE_AUDIO);

Generated on Fri Sep 16 2011 17:17:50 for FFmpeg by  doxygen 1.7.1