ffmpeg/libavformat/sapdec.c
Andreas Rheinhardt 790f793844 avutil/common: Don't auto-include mem.h
There are lots of files that don't need it: The number of object
files that actually need it went down from 2011 to 884 here.

Keep it for external users in order to not cause breakages.

Also improve the other headers a bit while just at it.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-03-31 00:08:43 +01:00

247 lines
7.2 KiB
C

/*
* Session Announcement Protocol (RFC 2974) demuxer
* Copyright (c) 2010 Martin Storsjo
*
* 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 "avformat.h"
#include "demux.h"
#include "libavutil/avstring.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mem.h"
#include "network.h"
#include "os_support.h"
#include "internal.h"
#include "avio_internal.h"
#include "url.h"
#include "rtpdec.h"
#if HAVE_POLL_H
#include <poll.h>
#endif
struct SAPState {
URLContext *ann_fd;
AVFormatContext *sdp_ctx;
FFIOContext sdp_pb;
uint16_t hash;
char *sdp;
int eof;
};
static int sap_probe(const AVProbeData *p)
{
if (av_strstart(p->filename, "sap:", NULL))
return AVPROBE_SCORE_MAX;
return 0;
}
static int sap_read_close(AVFormatContext *s)
{
struct SAPState *sap = s->priv_data;
if (sap->sdp_ctx)
avformat_close_input(&sap->sdp_ctx);
ffurl_closep(&sap->ann_fd);
av_freep(&sap->sdp);
ff_network_close();
return 0;
}
static int sap_read_header(AVFormatContext *s)
{
struct SAPState *sap = s->priv_data;
char host[1024], path[1024], url[1024];
uint8_t recvbuf[RTP_MAX_PACKET_LENGTH];
const AVInputFormat *infmt;
int port;
int ret, i;
if (!ff_network_init())
return AVERROR(EIO);
av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port,
path, sizeof(path), s->url);
if (port < 0)
port = 9875;
if (!host[0]) {
/* Listen for announcements on sap.mcast.net if no host was specified */
av_strlcpy(host, "224.2.127.254", sizeof(host));
}
ff_url_join(url, sizeof(url), "udp", NULL, host, port, "?localport=%d",
port);
ret = ffurl_open_whitelist(&sap->ann_fd, url, AVIO_FLAG_READ,
&s->interrupt_callback, NULL,
s->protocol_whitelist, s->protocol_blacklist, NULL);
if (ret)
goto fail;
while (1) {
int addr_type, auth_len;
int pos;
ret = ffurl_read(sap->ann_fd, recvbuf, sizeof(recvbuf) - 1);
if (ret == AVERROR(EAGAIN))
continue;
if (ret < 0)
goto fail;
recvbuf[ret] = '\0'; /* Null terminate for easier parsing */
if (ret < 8) {
av_log(s, AV_LOG_WARNING, "Received too short packet\n");
continue;
}
if ((recvbuf[0] & 0xe0) != 0x20) {
av_log(s, AV_LOG_WARNING, "Unsupported SAP version packet "
"received\n");
continue;
}
if (recvbuf[0] & 0x04) {
av_log(s, AV_LOG_WARNING, "Received stream deletion "
"announcement\n");
continue;
}
addr_type = recvbuf[0] & 0x10;
auth_len = recvbuf[1];
sap->hash = AV_RB16(&recvbuf[2]);
pos = 4;
if (addr_type)
pos += 16; /* IPv6 */
else
pos += 4; /* IPv4 */
pos += auth_len * 4;
if (pos + 4 >= ret) {
av_log(s, AV_LOG_WARNING, "Received too short packet\n");
continue;
}
#define MIME "application/sdp"
if (strcmp(&recvbuf[pos], MIME) == 0) {
pos += strlen(MIME) + 1;
} else if (strncmp(&recvbuf[pos], "v=0\r\n", 5) == 0) {
// Direct SDP without a mime type
} else {
av_log(s, AV_LOG_WARNING, "Unsupported mime type %s\n",
&recvbuf[pos]);
continue;
}
sap->sdp = av_strdup(&recvbuf[pos]);
if (!sap->sdp) {
ret = AVERROR(ENOMEM);
goto fail;
}
break;
}
av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", sap->sdp);
ffio_init_read_context(&sap->sdp_pb, sap->sdp, strlen(sap->sdp));
infmt = av_find_input_format("sdp");
if (!infmt)
goto fail;
sap->sdp_ctx = avformat_alloc_context();
if (!sap->sdp_ctx) {
ret = AVERROR(ENOMEM);
goto fail;
}
sap->sdp_ctx->max_delay = s->max_delay;
sap->sdp_ctx->pb = &sap->sdp_pb.pub;
sap->sdp_ctx->interrupt_callback = s->interrupt_callback;
if ((ret = ff_copy_whiteblacklists(sap->sdp_ctx, s)) < 0)
goto fail;
ret = avformat_open_input(&sap->sdp_ctx, "temp.sdp", infmt, NULL);
if (ret < 0)
goto fail;
if (sap->sdp_ctx->ctx_flags & AVFMTCTX_NOHEADER)
s->ctx_flags |= AVFMTCTX_NOHEADER;
for (i = 0; i < sap->sdp_ctx->nb_streams; i++) {
AVStream *st = avformat_new_stream(s, NULL);
if (!st) {
ret = AVERROR(ENOMEM);
goto fail;
}
st->id = i;
avcodec_parameters_copy(st->codecpar, sap->sdp_ctx->streams[i]->codecpar);
st->time_base = sap->sdp_ctx->streams[i]->time_base;
}
return 0;
fail:
sap_read_close(s);
return ret;
}
static int sap_fetch_packet(AVFormatContext *s, AVPacket *pkt)
{
struct SAPState *sap = s->priv_data;
int fd = ffurl_get_file_handle(sap->ann_fd);
int n, ret;
struct pollfd p = {fd, POLLIN, 0};
uint8_t recvbuf[RTP_MAX_PACKET_LENGTH];
if (sap->eof)
return AVERROR_EOF;
while (1) {
n = poll(&p, 1, 0);
if (n <= 0 || !(p.revents & POLLIN))
break;
ret = ffurl_read(sap->ann_fd, recvbuf, sizeof(recvbuf));
if (ret >= 8) {
uint16_t hash = AV_RB16(&recvbuf[2]);
/* Should ideally check the source IP address, too */
if (recvbuf[0] & 0x04 && hash == sap->hash) {
/* Stream deletion */
sap->eof = 1;
return AVERROR_EOF;
}
}
}
ret = av_read_frame(sap->sdp_ctx, pkt);
if (ret < 0)
return ret;
if (s->ctx_flags & AVFMTCTX_NOHEADER) {
while (sap->sdp_ctx->nb_streams > s->nb_streams) {
int i = s->nb_streams;
AVStream *st = avformat_new_stream(s, NULL);
if (!st) {
return AVERROR(ENOMEM);
}
st->id = i;
avcodec_parameters_copy(st->codecpar, sap->sdp_ctx->streams[i]->codecpar);
st->time_base = sap->sdp_ctx->streams[i]->time_base;
}
}
return ret;
}
const FFInputFormat ff_sap_demuxer = {
.p.name = "sap",
.p.long_name = NULL_IF_CONFIG_SMALL("SAP input"),
.p.flags = AVFMT_NOFILE,
.priv_data_size = sizeof(struct SAPState),
.read_probe = sap_probe,
.read_header = sap_read_header,
.read_packet = sap_fetch_packet,
.read_close = sap_read_close,
};