From c5388c07841280e0c8b6828b56c538d784aa0f1a Mon Sep 17 00:00:00 2001 From: Luca Abeni Date: Thu, 26 Jul 2007 22:34:26 +0000 Subject: Introduce an SDP generator Originally committed as revision 9806 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/sdp.c | 217 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 217 insertions(+) create mode 100644 libavformat/sdp.c (limited to 'libavformat/sdp.c') diff --git a/libavformat/sdp.c b/libavformat/sdp.c new file mode 100644 index 0000000000..8cedcd151a --- /dev/null +++ b/libavformat/sdp.c @@ -0,0 +1,217 @@ +/* + * copyright (c) 2007 Luca Abeni + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "avstring.h" +#include "avformat.h" + +#define MAX_EXTRADATA_SIZE ((INT_MAX - 10) / 2) + +struct sdp_session_level { + int sdp_version; /**< protocol version (currently 0) */ + int id; /**< session id */ + int version; /**< session version */ + int start_time; /**< session start time (NTP time, in seconds), + or 0 in case of permanent session */ + int end_time; /**< session end time (NTP time, in seconds), + or 0 if the session is not bounded */ + int ttl; /**< TTL, in case of multicast stream */ + const char *user; /**< username of the session's creator */ + const char *src_addr; /**< IP address of the machine from which the session was created */ + const char *dst_addr; /**< destination IP address (can be multicast) */ + const char *name; /**< session name (can be an empty string) */ +}; + +static void dest_write(char *buff, int size, const char *dest_addr, int ttl) +{ + if (dest_addr) { + if (ttl > 0) { + av_strlcatf(buff, size, "c=IN IP4 %s/%d\r\n", dest_addr, ttl); + } else { + av_strlcatf(buff, size, "c=IN IP4 %s\r\n", dest_addr); + } + } +} + +static void sdp_write_header(char *buff, int size, struct sdp_session_level *s) +{ + av_strlcatf(buff, size, "v=%d\r\n" + "o=- %d %d IN IPV4 %s\r\n" + "t=%d %d\r\n" + "s=%s\r\n" + "a=tool:libavformat\r\n", + s->sdp_version, + s->id, s->version, s->src_addr, + s->start_time, s->end_time, + s->name[0] ? s->name : "No Name"); + dest_write(buff, size, s->dst_addr, s->ttl); +} + +static int get_address(char *dest_addr, int size, int *ttl, const char *url) +{ + int port; + const char *p; + + url_split(NULL, 0, NULL, 0, dest_addr, size, &port, NULL, 0, url); + + *ttl = 0; + p = strchr(url, '?'); + if (p) { + char buff[64]; + int is_multicast = find_info_tag(buff, sizeof(buff), "multicast", p); + + if (is_multicast) { + if (find_info_tag(buff, sizeof(buff), "ttl", p)) { + *ttl = strtol(buff, NULL, 10); + } else { + *ttl = 5; + } + } + } + + return port; +} + +static void digit_to_char(char *dst, uint8_t src) +{ + if (src < 10) { + *dst = '0' + src; + } else { + *dst = 'A' + src - 10; + } +} + +static char *data_to_hex(char *buff, const uint8_t *src, int s) +{ + int i; + + for(i = 0; i < s; i++) { + digit_to_char(buff + 2 * i, src[i] >> 4); + digit_to_char(buff + 2 * i + 1, src[i] & 0xF); + } + + return buff; +} + +static char *sdp_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type) +{ + char *config = NULL; + + switch (c->codec_id) { + case CODEC_ID_MPEG4: + if (c->flags & CODEC_FLAG_GLOBAL_HEADER) { + if (c->extradata_size > MAX_EXTRADATA_SIZE) { + av_log(NULL, AV_LOG_ERROR, "Too many extra data!\n"); + + return NULL; + } + config = av_malloc(10 + c->extradata_size * 2); + if (config == NULL) { + av_log(NULL, AV_LOG_ERROR, "Cannot allocate memory for the config info\n"); + return NULL; + } + memcpy(config, "; config=", 9); + data_to_hex(config + 9, c->extradata, c->extradata_size); + config[9 + c->extradata_size * 2] = 0; + } + av_strlcatf(buff, size, "a=rtpmap:%d MP4V-ES/90000\r\n" + "a=fmtp:%d profile-level-id=1%s\r\n", + payload_type, + payload_type, config ? config : ""); + break; + default: + /* Nothing special to do, here... */ + break; + } + + av_free(config); + + return buff; +} + +static void sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl) +{ + const char *type; + int payload_type; + + payload_type = rtp_get_payload_type(c); + if (payload_type < 0) { + payload_type = 96; /* FIXME: how to assign a private pt? rtp.c is broken too */ + } + + switch (c->codec_type) { + case CODEC_TYPE_VIDEO : type = "video" ; break; + case CODEC_TYPE_AUDIO : type = "audio" ; break; + case CODEC_TYPE_SUBTITLE: type = "text" ; break; + default : type = "application"; break; + } + + av_strlcatf(buff, size, "m=%s %d RTP/AVP %d\r\n", type, port, payload_type); + dest_write(buff, size, dest_addr, ttl); + + sdp_media_attributes(buff, size, c, payload_type); +} + +#define SDP_BUFFER_SIZE 2048 +char *avf_sdp_create(AVFormatContext *ac[], int n_files) +{ + char *buff; + struct sdp_session_level s; + int i, j, port, ttl; + char dst[32]; + + buff = av_mallocz(SDP_BUFFER_SIZE); + if (buff == NULL) { + return NULL; + } + + memset(&s, 0, sizeof(struct sdp_session_level)); + s.user = "-"; + s.src_addr = "127.0.0.1"; /* FIXME: Properly set this */ + s.name = ac[0]->title; + + port = 0; + ttl = 0; + if (n_files == 1) { + port = get_address(dst, sizeof(dst), &ttl, ac[0]->filename); + if (port > 0) { + s.dst_addr = dst; + s.ttl = ttl; + } + } + sdp_write_header(buff, SDP_BUFFER_SIZE, &s); + + dst[0] = 0; + for (i = 0; i < n_files; i++) { + if (n_files != 1) { + port = get_address(dst, sizeof(dst), &ttl, ac[i]->filename); + } + for (j = 0; j < ac[i]->nb_streams; j++) { + sdp_write_media(buff, SDP_BUFFER_SIZE, + ac[i]->streams[j]->codec, dst[0] ? dst : NULL, + (port > 0) ? port + j * 2 : 0, ttl); + if (port <= 0) { + av_strlcatf(buff, SDP_BUFFER_SIZE, + "a=control:streamid=%d\r\n", i + j); + } + } + } + + return buff; +} -- cgit v1.2.3