Commit c2f3eec4 authored by Ronald S. Bultje's avatar Ronald S. Bultje
Browse files

Implement RTSP-MS/ASF packet parsing - this completes RTSP-MS support. See

discussion in "[PATCH] RTSP-MS 14/15: ASF packet parsing" thread on mailinglist.

Originally committed as revision 19516 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent e9a832e5
......@@ -28,6 +28,7 @@ version <next>:
- DivX (XSUB) subtitle encoder
- nonfree libamr support for AMR-NB/WB decoding/encoding removed
- Experimental AAC encoder
- RTP depacketization of ASF and RTSP from WMS servers
......
......@@ -27,11 +27,73 @@
#include <libavutil/base64.h>
#include <libavutil/avstring.h>
#include <libavutil/intreadwrite.h>
#include "rtp.h"
#include "rtp_asf.h"
#include "rtsp.h"
#include "asf.h"
/**
* From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not
* contain any padding. Unfortunately, the header min/max_pktsize are not
* updated (thus making min_pktsize invalid). Here, we "fix" these faulty
* min_pktsize values in the ASF file header.
* @return 0 on success, <0 on failure (currently -1).
*/
static int
rtp_asf_fix_header(uint8_t *buf, int len)
{
uint8_t *p = buf, *end = buf + len;
if (len < sizeof(ff_asf_guid) * 2 + 22 ||
memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
return -1;
}
p += sizeof(ff_asf_guid) + 14;
do {
uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
if (chunksize > end - p)
return -1;
p += chunksize;
continue;
}
/* skip most of the file header, to min_pktsize */
p += 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
if (p + 8 <= end && AV_RL32(p) == AV_RL32(p + 4)) {
/* and set that to zero */
AV_WL32(p, 0);
return 0;
}
break;
} while (end - p >= sizeof(ff_asf_guid) + 8);
return -1;
}
/**
* The following code is basically a buffered ByteIOContext,
* with the added benefit of returning -EAGAIN (instead of 0)
* on packet boundaries, such that the ASF demuxer can return
* safely and resume business at the next packet.
*/
static int
packetizer_read(void *opaque, uint8_t *buf, int buf_size)
{
return AVERROR(EAGAIN);
}
static void
init_packetizer(ByteIOContext *pb, uint8_t *buf, int len)
{
init_put_byte(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);
/* this "fills" the buffer with its current content */
pb->pos = len;
pb->buf_end = buf + len;
}
void ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
{
if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
......@@ -41,12 +103,16 @@ void ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
char *buf = av_mallocz(len);
av_base64_decode(buf, p, len);
init_put_byte(&pb, buf, len, 0, NULL, NULL, NULL, NULL);
if (rtp_asf_fix_header(buf, len) < 0)
av_log(s, AV_LOG_ERROR,
"Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
init_packetizer(&pb, buf, len);
if (rt->asf_ctx) {
av_close_input_stream(rt->asf_ctx);
rt->asf_ctx = NULL;
}
av_open_input_stream(&rt->asf_ctx, &pb, "", &asf_demuxer, NULL);
rt->asf_pb_pos = url_ftell(&pb);
av_free(buf);
rt->asf_ctx->pb = NULL;
}
......@@ -79,12 +145,142 @@ asfrtp_parse_sdp_line (AVFormatContext *s, int stream_index,
return 0;
}
struct PayloadContext {
ByteIOContext *pktbuf, pb;
char *buf;
};
/**
* @return 0 when a packet was written into /p pkt, and no more data is left;
* 1 when a packet was written into /p pkt, and more packets might be left;
* <0 when not enough data was provided to return a full packet, or on error.
*/
static int
asfrtp_parse_packet (AVFormatContext *s, PayloadContext *asf, AVStream *st,
AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, int flags)
{
ByteIOContext *pb = &asf->pb;
int res, mflags, len_off;
RTSPState *rt = s->priv_data;
if (!rt->asf_ctx)
return -1;
if (len > 0) {
int off, out_len;
if (len < 4)
return -1;
init_put_byte(pb, buf, len, 0, NULL, NULL, NULL, NULL);
mflags = get_byte(pb);
if (mflags & 0x80)
flags |= RTP_FLAG_KEY;
len_off = get_be24(pb);
if (mflags & 0x20) /**< relative timestamp */
url_fskip(pb, 4);
if (mflags & 0x10) /**< has duration */
url_fskip(pb, 4);
if (mflags & 0x8) /**< has location ID */
url_fskip(pb, 4);
off = url_ftell(pb);
av_freep(&asf->buf);
if (!(mflags & 0x40)) {
/**
* If 0x40 is not set, the len_off field specifies an offset of this
* packet's payload data in the complete (reassembled) ASF packet.
* This is used to spread one ASF packet over multiple RTP packets.
*/
if (asf->pktbuf && len_off != url_ftell(asf->pktbuf)) {
uint8_t *p;
url_close_dyn_buf(asf->pktbuf, &p);
asf->pktbuf = NULL;
av_free(p);
}
if (!len_off && !asf->pktbuf &&
!(res = url_open_dyn_packet_buf(&asf->pktbuf, rt->asf_ctx->packet_size)))
return res;
if (!asf->pktbuf)
return AVERROR(EIO);
put_buffer(asf->pktbuf, buf + off, len - off);
if (!(flags & RTP_FLAG_MARKER))
return -1;
out_len = url_close_dyn_buf(asf->pktbuf, &asf->buf);
asf->pktbuf = NULL;
} else {
/**
* If 0x40 is set, the len_off field specifies the length of the
* next ASF packet that can be read from this payload data alone.
* This is commonly the same as the payload size, but could be
* less in case of packet splitting (i.e. multiple ASF packets in
* one RTP packet).
*/
if (len_off != len) {
av_log_missing_feature(s,
"RTSP-MS packet splitting", 1);
return -1;
}
asf->buf = av_malloc(len - off);
out_len = len - off;
memcpy(asf->buf, buf + off, len - off);
}
init_packetizer(pb, asf->buf, out_len);
pb->pos += rt->asf_pb_pos;
pb->eof_reached = 0;
rt->asf_ctx->pb = pb;
}
for (;;) {
int i;
res = av_read_packet(rt->asf_ctx, pkt);
rt->asf_pb_pos = url_ftell(pb);
if (res != 0)
break;
for (i = 0; i < s->nb_streams; i++) {
if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
pkt->stream_index = i;
return 1; // FIXME: return 0 if last packet
}
}
av_free_packet(pkt);
}
return res == 1 ? -1 : res;
}
static PayloadContext *
asfrtp_new_context (void)
{
return av_mallocz(sizeof(PayloadContext));
}
static void
asfrtp_free_context (PayloadContext *asf)
{
if (asf->pktbuf) {
uint8_t *p = NULL;
url_close_dyn_buf(asf->pktbuf, &p);
asf->pktbuf = NULL;
av_free(p);
}
av_freep(&asf->buf);
av_free(asf);
}
#define RTP_ASF_HANDLER(n, s, t) \
RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
s, \
t, \
CODEC_ID_NONE, \
asfrtp_parse_sdp_line, \
asfrtp_new_context, \
asfrtp_free_context, \
asfrtp_parse_packet, \
};
RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", CODEC_TYPE_VIDEO);
......
......@@ -249,6 +249,10 @@ typedef struct RTSPState {
//@{
/** ASF demuxer context for the embedded ASF stream from WMS servers */
AVFormatContext *asf_ctx;
/** cache for position of the asf demuxer, since we load a new
* data packet in the bytecontext for each incoming RTSP packet. */
uint64_t asf_pb_pos;
//@}
} RTSPState;
......
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