@@ -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;