Commit c5388c07 authored by Luca Abeni's avatar Luca Abeni
Browse files

Introduce an SDP generator

Originally committed as revision 9806 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent 0eb7d780
......@@ -6,7 +6,7 @@ include ../config.mak
CFLAGS+=-I$(SRC_PATH)/libavcodec
OBJS= utils.o cutils.o os_support.o allformats.o
OBJS= utils.o cutils.o os_support.o allformats.o sdp.o
HEADERS = avformat.h avio.h rtp.h rtsp.h rtspcodes.h
......
......@@ -833,6 +833,21 @@ int av_get_frame_filename(char *buf, int buf_size,
*/
int av_filename_number_test(const char *filename);
/**
* Generate an SDP for an RTP session.
*
* @param ac array of AVFormatContexts describing the RTP streams. If the
* array is composed by only one context, such context can contain
* multiple AVStreams (one AVStream per RTP stream). Otherwise,
* all the contexts in the array (an AVCodecContext per RTP stream)
* must contain only one AVStream
* @param n_streams number of AVCodecContexts contained in ac
* @return a pointer to the SDP (an array of chars which is allocated by
* avf_sdp_create(), and must be freed by the caller), or NULL in
* case of failure.
*/
char *avf_sdp_create(AVFormatContext *ac[], int n_streams);
#ifdef HAVE_AV_CONFIG_H
#include "os_support.h"
......
/*
* 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;
}
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